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Castano-Duque L, Winzeler E, Blackstock JM, Liu C, Vergopolan N, Focker M, Barnett K, Owens PR, van der Fels-Klerx HJ, Vaughan MM, Rajasekaran K. Dynamic geospatial modeling of mycotoxin contamination of corn in Illinois: unveiling critical factors and predictive insights with machine learning. Front Microbiol 2023; 14:1283127. [PMID: 38029202 PMCID: PMC10646420 DOI: 10.3389/fmicb.2023.1283127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Accepted: 09/26/2023] [Indexed: 12/01/2023] Open
Abstract
Mycotoxin contamination of corn is a pervasive problem that negatively impacts human and animal health and causes economic losses to the agricultural industry worldwide. Historical aflatoxin (AFL) and fumonisin (FUM) mycotoxin contamination data of corn, daily weather data, satellite data, dynamic geospatial soil properties, and land usage parameters were modeled to identify factors significantly contributing to the outbreaks of mycotoxin contamination of corn grown in Illinois (IL), AFL >20 ppb, and FUM >5 ppm. Two methods were used: a gradient boosting machine (GBM) and a neural network (NN). Both the GBM and NN models were dynamic at a state-county geospatial level because they used GPS coordinates of the counties linked to soil properties. GBM identified temperature and precipitation prior to sowing as significant influential factors contributing to high AFL and FUM contamination. AFL-GBM showed that a higher aflatoxin risk index (ARI) in January, March, July, and November led to higher AFL contamination in the southern regions of IL. Higher values of corn-specific normalized difference vegetation index (NDVI) in July led to lower AFL contamination in Central and Southern IL, while higher wheat-specific NDVI values in February led to higher AFL. FUM-GBM showed that temperature in July and October, precipitation in February, and NDVI values in March are positively correlated with high contamination throughout IL. Furthermore, the dynamic geospatial models showed that soil characteristics were correlated with AFL and FUM contamination. Greater calcium carbonate content in soil was negatively correlated with AFL contamination, which was noticeable in Southern IL. Greater soil moisture and available water-holding capacity throughout Southern IL were positively correlated with high FUM contamination. The higher clay percentage in the northeastern areas of IL negatively correlated with FUM contamination. NN models showed high class-specific performance for 1-year predictive validation for AFL (73%) and FUM (85%), highlighting their accuracy for annual mycotoxin prediction. Our models revealed that soil, NDVI, year-specific weekly average precipitation, and temperature were the most important factors that correlated with mycotoxin contamination. These findings serve as reliable guidelines for future modeling efforts to identify novel data inputs for the prediction of AFL and FUM outbreaks and potential farm-level management practices.
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Affiliation(s)
- Lina Castano-Duque
- Food and Feed Safety Research Unit, Southern Regional Research Center, Agriculture Research Service, United States Department of Agriculture, New Orleans, LA, United States
| | - Edwin Winzeler
- Dale Bumpers Small Farms Research Center, Agriculture Research Service, United States Department of Agriculture, Booneville, AR, United States
| | - Joshua M. Blackstock
- Dale Bumpers Small Farms Research Center, Agriculture Research Service, United States Department of Agriculture, Booneville, AR, United States
| | - Cheng Liu
- Microbiology and Agrochains Wageningen Food Safety Research, Wageningen, Netherlands
| | - Noemi Vergopolan
- Atmospheric and Ocean Science Program, Princeton University, Princeton, NJ, United States
| | - Marlous Focker
- Microbiology and Agrochains Wageningen Food Safety Research, Wageningen, Netherlands
| | - Kristin Barnett
- Agricultural Products Inspection, Illinois Department of Agriculture, Springfield, IL, United States
| | - Phillip Ray Owens
- Dale Bumpers Small Farms Research Center, Agriculture Research Service, United States Department of Agriculture, Booneville, AR, United States
| | | | - Martha M. Vaughan
- Mycotoxin Prevention and Applied Microbiology Research Unit, United States Department of Agriculture, Agricultural Research Service, National Center for Agricultural Utilization Research, Peoria, IL, United States
| | - Kanniah Rajasekaran
- Food and Feed Safety Research Unit, Southern Regional Research Center, Agriculture Research Service, United States Department of Agriculture, New Orleans, LA, United States
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Hay WT, Anderson JA, Garvin DF, McCormick SP, Busman M, Vaughan MM. Elevated CO 2 Can Worsen Fusarium Head Blight Disease Severity in Wheat but the Fhb1 QTL Provides Reliable Disease Resistance. Plants (Basel) 2023; 12:3527. [PMID: 37895995 PMCID: PMC10610529 DOI: 10.3390/plants12203527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Revised: 10/03/2023] [Accepted: 10/07/2023] [Indexed: 10/29/2023]
Abstract
Fusarium head blight (FHB) is a destructive fungal disease of wheat that causes significant economic loss due to lower yields and the contamination of grain with fungal toxins (mycotoxins), particularly deoxynivalenol (DON). FHB disease spread and mycotoxin contamination has been shown to worsen at elevated CO2, therefore, it is important to identify climate-resilient FHB resistance. This work evaluates whether wheat with the Fhb1 quantitative trait locus (QTL), the most widely deployed FHB resistance locus in wheat breeding programs, provides reliable disease resistance at elevated CO2. Near-isogenic wheat lines (NILs) derived from either a highly FHB susceptible or a more FHB resistant genetic background, with or without the Fhb1 QTL, were grown in growth chambers at ambient (400 ppm) and elevated (1000 ppm) CO2 conditions. Wheat was inoculated with Fusarium graminearum and evaluated for FHB severity. At elevated CO2, the NILs derived from more FHB-resistant wheat had increased disease spread, greater pathogen biomass and mycotoxin contamination, and lower rates of DON detoxification; this was not observed in wheat from a FHB susceptible genetic background. The Fhb1 QTL was not associated with increased disease severity in wheat grown at elevated CO2 and provided reliable disease resistance.
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Affiliation(s)
- William T. Hay
- USDA, Agricultural Research Service, National Center for Agricultural Utilization Research, Mycotoxin Prevention and Applied Microbiology Research Unit, 1815 N, University Street, Peoria, IL 61604, USA; (S.P.M.); (M.B.); (M.M.V.)
| | - James A. Anderson
- Department of Agronomy & Plant Genetics, University of Minnesota, St. Paul, MN 55108, USA; (J.A.A.); (D.F.G.)
| | - David F. Garvin
- Department of Agronomy & Plant Genetics, University of Minnesota, St. Paul, MN 55108, USA; (J.A.A.); (D.F.G.)
| | - Susan P. McCormick
- USDA, Agricultural Research Service, National Center for Agricultural Utilization Research, Mycotoxin Prevention and Applied Microbiology Research Unit, 1815 N, University Street, Peoria, IL 61604, USA; (S.P.M.); (M.B.); (M.M.V.)
| | - Mark Busman
- USDA, Agricultural Research Service, National Center for Agricultural Utilization Research, Mycotoxin Prevention and Applied Microbiology Research Unit, 1815 N, University Street, Peoria, IL 61604, USA; (S.P.M.); (M.B.); (M.M.V.)
| | - Martha M. Vaughan
- USDA, Agricultural Research Service, National Center for Agricultural Utilization Research, Mycotoxin Prevention and Applied Microbiology Research Unit, 1815 N, University Street, Peoria, IL 61604, USA; (S.P.M.); (M.B.); (M.M.V.)
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Bakker MG, Whitaker BK, McCormick SP, Ainsworth EA, Vaughan MM. Manipulating atmospheric CO 2 concentration induces shifts in wheat leaf and spike microbiomes and in Fusarium pathogen communities. Front Microbiol 2023; 14:1271219. [PMID: 37881249 PMCID: PMC10595150 DOI: 10.3389/fmicb.2023.1271219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Accepted: 09/25/2023] [Indexed: 10/27/2023] Open
Abstract
Changing atmospheric composition represents a source of uncertainty in our assessment of future disease risks, particularly in the context of mycotoxin producing fungal pathogens which are predicted to be more problematic with climate change. To address this uncertainty, we profiled microbiomes associated with wheat plants grown under ambient vs. elevated atmospheric carbon dioxide concentration [CO2] in a field setting over 2 years. We also compared the dynamics of naturally infecting versus artificially introduced Fusarium spp. We found that the well-known temporal dynamics of plant-associated microbiomes were affected by [CO2]. The abundances of many amplicon sequence variants significantly differed in response to [CO2], often in an interactive manner with date of sample collection or with tissue type. In addition, we found evidence that two strains within Fusarium - an important group of mycotoxin producing fungal pathogens of plants - responded to changes in [CO2]. The two sequence variants mapped to different phylogenetic subgroups within the genus Fusarium, and had differential [CO2] responses. This work informs our understanding of how plant-associated microbiomes and pathogens may respond to changing atmospheric compositions.
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Affiliation(s)
- Matthew G. Bakker
- Department of Microbiology, University of Manitoba, Winnipeg, MB, Canada
| | - Briana K. Whitaker
- Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, United States Department of Agriculture, Peoria, IL, United States
| | - Susan P. McCormick
- Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, United States Department of Agriculture, Peoria, IL, United States
| | - Elizabeth A. Ainsworth
- Global Change and Photosynthesis Research Unit, Agricultural Research Service, United States Department of Agriculture, Urbana, IL, United States
| | - Martha M. Vaughan
- Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, United States Department of Agriculture, Peoria, IL, United States
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Laraba I, Ward TJ, Cuperlovic-Culf M, Azimi H, Xi P, McCormick SP, Hay WT, Hao G, Vaughan MM. Insights into the Aggressiveness of the Emerging North American Population 3 (NA3) of Fusarium graminearum. Plant Dis 2023; 107:2687-2700. [PMID: 36774561 DOI: 10.1094/pdis-11-22-2698-re] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
In the United States and Canada, Fusarium graminearum (Fg) is the predominant etiological agent of Fusarium head blight (FHB), an economically devastating fungal disease of wheat and other small grains. Besides yield losses, FHB leads to grain contamination with trichothecene mycotoxins that are harmful to plant, human, and livestock health. Three genetic North American populations of Fg, differing in their predominant trichothecene chemotype (i.e., NA1/15ADON, NA2/3ADON, and NA3/NX-2), have been identified. To improve our understanding of the newly discovered population NA3 and how population-level diversity influences FHB outcomes, we inoculated heads of the moderately resistant wheat cultivar Alsen with 15 representative strains from each population and evaluated disease progression, mycotoxin accumulation, and mycotoxin production per unit Fg biomass. Additionally, we evaluated population-specific differences in induced host defense responses. The NA3 population was significantly less aggressive than the NA1 and NA2 populations but posed a similar mycotoxigenic potential. Multiomics analyses revealed patterns in mycotoxin production per unit Fg biomass, expression of Fg aggressiveness-associated genes, and host defense responses that did not always correlate with the NA3-specific severity difference. Our comparative disease assay of NA3/NX-2 and admixed NA1/NX-2 strains indicated that the reduced NA3 aggressiveness is not due solely to the NX-2 chemotype. Notably, the NA1 and NA2 populations did not show a significant advantage over NA3 in perithecia production, a fitness-related trait. Together, our data highlight that the disease outcomes were not due to mycotoxin production or host defense alone, indicating that other virulence factors and/or host defense mechanisms are likely involved.
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Affiliation(s)
- Imane Laraba
- Oak Ridge Institute for Science and Education fellow, Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, USDA, Peoria, IL 61604, U.S.A
| | - Todd J Ward
- Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, USDA, Peoria, IL 61604, U.S.A
| | | | - Hilda Azimi
- Digital Technologies Research Centre, National Research Council Canada, Ottawa, K1A 0R6, Canada
| | - Pengcheng Xi
- Digital Technologies Research Centre, National Research Council Canada, Ottawa, K1A 0R6, Canada
| | - Susan P McCormick
- Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, USDA, Peoria, IL 61604, U.S.A
| | - William T Hay
- Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, USDA, Peoria, IL 61604, U.S.A
| | - Guixia Hao
- Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, USDA, Peoria, IL 61604, U.S.A
| | - Martha M Vaughan
- Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, USDA, Peoria, IL 61604, U.S.A
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Hao G, McCormick S, Tiley H, Gutiérrez S, Yulfo-Soto G, Vaughan MM, Ward TJ. NX Trichothecenes Are Required for Fusarium graminearum Infection of Wheat. Mol Plant Microbe Interact 2023; 36:294-304. [PMID: 36653184 DOI: 10.1094/mpmi-08-22-0164-r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Fusarium graminearum causes Fusarium head blight (FHB) on wheat and barley and contaminates grains with various mycotoxins that are toxic to humans and animals. Deoxynivalenol (DON), a type B trichothecene, is an essential virulence factor that is required for F. graminearum to spread within a wheat head. Recently, novel type A trichothecenes NX-2 and NX-3 (NX) have been found in F. graminearum. NX trichothecenes lack a keto group at the C8 position. To determine if NX trichothecenes play a role similar to that of DON during F. graminearum infection, deletion mutants of TRI5, the first gene for trichothecene biosynthesis, were generated from strains PH-1, NRRL46422, and NRRL44211 (hereafter 44211) representing the 15-acetyl-DON, 3-acetyl-DON, and NX chemotypes. No trichothecene production was detected in any of the Δtri5 mutants in cultures or inoculated wheat heads. FHB symptoms were restricted to the inoculated wheat spikelets when point-inoculated with the Δtri5 mutants, confirming the necessity of NX and DON for FHB spread. Furthermore, whole-head dip inoculations revealed significant reductions in disease and fungal biomass in wheat heads inoculated with 44211Δtri5 compared with 44211. Introduction of the native 44211 TRI5 and a Trichoderma arundinaceum TRI5 ortholog in the 44211Δtri5 mutant complemented trichothecene production in vitro; however, introducing both TRI5 partially restored wild-type levels of NX in infected heads. Our results demonstrate that NX trichothecenes play an important role in Fusarium graminearum initial infection as well as FHB spread. Thus, TRI5 may serve as an ideal target to control plant infection, FHB spread, and mycotoxin production simultaneously. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
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Affiliation(s)
- Guixia Hao
- USDA, Agricultural Research Service, National Center for Agricultural Utilization Research, Mycotoxin Prevention and Applied Microbiology Research Unit. 1815 N. University, Peoria, IL 61604, U.S.A
| | - Susan McCormick
- USDA, Agricultural Research Service, National Center for Agricultural Utilization Research, Mycotoxin Prevention and Applied Microbiology Research Unit. 1815 N. University, Peoria, IL 61604, U.S.A
| | - Helene Tiley
- USDA, Agricultural Research Service, National Center for Agricultural Utilization Research, Mycotoxin Prevention and Applied Microbiology Research Unit. 1815 N. University, Peoria, IL 61604, U.S.A
| | - Santiago Gutiérrez
- Molecular Biology Department, University of Leon, Campus de Ponferrada, Avda. Astorga s/n 24400, Ponferrada, Spain
| | - Gabdiel Yulfo-Soto
- USDA, Agricultural Research Service, National Center for Agricultural Utilization Research, Mycotoxin Prevention and Applied Microbiology Research Unit. 1815 N. University, Peoria, IL 61604, U.S.A
- Oak Ridge Institute for Science and Education, USDA, Agricultural Research Service, National Center for Agricultural Utilization Research, Mycotoxin Prevention and Applied Microbiology Research Unit, Peoria, IL 61604, U.S.A
| | - Martha M Vaughan
- USDA, Agricultural Research Service, National Center for Agricultural Utilization Research, Mycotoxin Prevention and Applied Microbiology Research Unit. 1815 N. University, Peoria, IL 61604, U.S.A
| | - Todd J Ward
- USDA, Agricultural Research Service, National Center for Agricultural Utilization Research, Mycotoxin Prevention and Applied Microbiology Research Unit. 1815 N. University, Peoria, IL 61604, U.S.A
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Proctor RH, Hao G, Kim HS, Whitaker BK, Laraba I, Vaughan MM, McCormick SP. A Novel Trichothecene Toxin Phenotype Associated with Horizontal Gene Transfer and a Change in Gene Function in Fusarium. Toxins (Basel) 2022; 15:12. [PMID: 36668832 PMCID: PMC9864338 DOI: 10.3390/toxins15010012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 12/10/2022] [Accepted: 12/22/2022] [Indexed: 12/28/2022] Open
Abstract
Fusarium trichothecenes are among the mycotoxins of most concern to food and feed safety. Production of these mycotoxins and presence of the trichothecene biosynthetic gene (TRI) cluster have been confirmed in only two multispecies lineages of Fusarium: the Fusarium incarnatum-equiseti (Incarnatum) and F. sambucinum (Sambucinum) species complexes. Here, we identified and characterized a TRI cluster in a species that has not been formally described and is represented by Fusarium sp. NRRL 66739. This fungus is reported to be a member of a third Fusarium lineage: the F. buharicum species complex. Cultures of NRRL 66739 accumulated only two trichothecenes, 7-hydroxyisotrichodermin and 7-hydroxyisotrichodermol. Although these are not novel trichothecenes, the production profile of NRRL 66739 is novel, because in previous reports 7-hydroxyisotrichodermin and 7-hydroxyisotrichodermol were components of mixtures of 6-8 trichothecenes produced by several Fusarium species in Sambucinum. Heterologous expression analysis indicated that the TRI13 gene in NRRL 66739 confers trichothecene 7-hydroxylation. This contrasts the trichothecene 4-hydroxylation function of TRI13 in other Fusarium species. Phylogenetic analyses suggest that NRRL 66739 acquired the TRI cluster via horizontal gene transfer from a close relative of Incarnatum and Sambucinum. These findings provide insights into evolutionary processes that have shaped the distribution of trichothecene production among Fusarium species and the structural diversity of the toxins.
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Affiliation(s)
- Robert H. Proctor
- Mycotoxin Prevention and Applied Microbiology, National Center for Agricultural Utilization Research, Agricultural Research Service, US Department of Agriculture, 1815 N University St., Peoria, IL 61604, USA
| | - Guixia Hao
- Mycotoxin Prevention and Applied Microbiology, National Center for Agricultural Utilization Research, Agricultural Research Service, US Department of Agriculture, 1815 N University St., Peoria, IL 61604, USA
| | - Hye-Seon Kim
- Mycotoxin Prevention and Applied Microbiology, National Center for Agricultural Utilization Research, Agricultural Research Service, US Department of Agriculture, 1815 N University St., Peoria, IL 61604, USA
| | - Briana K. Whitaker
- Mycotoxin Prevention and Applied Microbiology, National Center for Agricultural Utilization Research, Agricultural Research Service, US Department of Agriculture, 1815 N University St., Peoria, IL 61604, USA
| | - Imane Laraba
- Oak Ridge Institute for Science and Education, Mycotoxin Prevention and Applied Microbiology, National Center for Agricultural Utilization Research, Agricultural Research Service, US Department of Agriculture, Peoria, IL 61604, USA
| | - Martha M. Vaughan
- Mycotoxin Prevention and Applied Microbiology, National Center for Agricultural Utilization Research, Agricultural Research Service, US Department of Agriculture, 1815 N University St., Peoria, IL 61604, USA
| | - Susan P. McCormick
- Mycotoxin Prevention and Applied Microbiology, National Center for Agricultural Utilization Research, Agricultural Research Service, US Department of Agriculture, 1815 N University St., Peoria, IL 61604, USA
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Majumdar R, Rajasekaran K, Vaughan MM, Ozias-Akins P. Editorial: Host plant resistance mechanisms against fungal pathogens. Front Plant Sci 2022; 13:1103046. [PMID: 36570920 PMCID: PMC9773977 DOI: 10.3389/fpls.2022.1103046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2022] [Accepted: 12/01/2022] [Indexed: 06/17/2023]
Affiliation(s)
- Rajtilak Majumdar
- Northwest Irrigation and Soils Research, United States Department of Agriculture-Agricultural Research Service, Kimberly, ID, United States
| | - Kanniah Rajasekaran
- Food and Feed Safety Research Unit, Southern Regional Research Center, United States Department of Agriculture-Agricultural Research Service, New Orleans, LA, United States
| | - Martha M. Vaughan
- Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, United States Department of Agriculture-Agricultural Research Service, Peoria, IL, United States
| | - Peggy Ozias-Akins
- Genetic and Genomics and Department of Horticulture, Institute of Plant Breeding, University of Georgia, Tifton, GA, United States
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Hay WT, Anderson JA, Garvin DF, McCormick SP, Vaughan MM. Fhb1 disease resistance QTL does not exacerbate wheat grain protein loss at elevated CO 2. Front Plant Sci 2022; 13:1034406. [PMID: 36518513 PMCID: PMC9742602 DOI: 10.3389/fpls.2022.1034406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Accepted: 11/11/2022] [Indexed: 06/17/2023]
Abstract
Fusarium head blight, a devastating cereal crop disease, can cause significant yield losses and contaminate grain with hazardous fungal toxins. Concerningly, recent evidence indicates that substantial grain protein content loss is likely to occur in wheat that is moderately resistant to head blight when it is grown at elevated CO2. Although wheat breeders in North America utilize a number of resistance sources and genes to reduce pathogen damage, the Fhb1 gene is widely deployed. To determine whether Fhb1 is associated with the protein content loss at elevated CO2, twelve near-isogenic spring wheat lines from either a susceptible or moderately susceptible genetic background, and with, or without the Fhb1 QTL, were grown at ambient and elevated CO2 conditions. The near-isogenic lines were evaluated for differences in physiology, productivity, and grain protein content. Our results showed that the Fhb1 QTL did not have any significant effect on plant growth, development, yield, or grain protein content at ambient or elevated CO2. Therefore, other factors in the moderately susceptible wheat genetic background are likely responsible for the more severe grain protein loss at elevated CO2.
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Affiliation(s)
- William T. Hay
- Mycotoxin Prevention and Applied Microbiology Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, USDA, Peoria, IL, United States
| | - James A. Anderson
- Department of Agronomy & Plant Genetics, University of Minnesota, St. Paul, MN, United States
| | - David F. Garvin
- Department of Agronomy & Plant Genetics, University of Minnesota, St. Paul, MN, United States
| | - Susan P. McCormick
- Mycotoxin Prevention and Applied Microbiology Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, USDA, Peoria, IL, United States
| | - Martha M. Vaughan
- Mycotoxin Prevention and Applied Microbiology Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, USDA, Peoria, IL, United States
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Montoya-Martínez AC, O'Donnell K, Busman M, Vaughan MM, McCormick SP, Santillán-Mendoza R, Pineda-Vaca D, Clapes-Garduño L, Fernández-Pavía SP, Ploetz RC, Benítez-Malvido J, Montero-Castro JC, Rodríguez-Alvarado G. Weeds Harbor Fusarium Species that Cause Malformation Disease of Economically Important Trees in Western Mexico. Plant Dis 2022; 106:612-622. [PMID: 34569826 DOI: 10.1094/pdis-06-21-1339-re] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Mango malformation disease (MMD) caused by Fusarium spp. is an important limiting factor in most production areas worldwide. Fusarium mexicanum and F. pseudocircinatum have been reported as causing MMD in Mexico. These two pathogens also cause a similar disease in Swietenia macrophylla (big-leaf mahogany malformation disease) in central western Mexico, and F. pseudocircinatum was recently reported as causing malformation disease in Tabebuia rosea (rosy trumpet) in the same region. These studies suggest that additional plant species, including weeds, might be hosts of these pathogens. The role that weed hosts might have in the disease cycle is unknown. The objectives of this work were to recover Fusarium isolates from understory vegetation in mango orchards with MMD, identify the Fusarium isolates through DNA sequence data, and determine whether F. mexicanum is capable of inducing disease in the weedy legume Senna uniflora (oneleaf senna). Additional objectives in this work were to compare Fusarium isolates recovered from weeds and mango trees in the same orchards by characterizing their phylogenetic relationships, assessing in vitro production of mycotoxins, and identifying their mating type idiomorph. A total of 59 Fusarium isolates from five species complexes were recovered from apical and lateral buds from four weed species. Two of the species within the F. fujikuroi species complex are known to cause MMD in Mexico. Trichothecene production was detected in five isolates, including F. sulawense and F. irregulare in the F. incarnatum-equiseti species complex and F. boothii in the F. sambucinum species complex. Both mating types were present among mango and weed isolates. This is the first report of herbaceous hosts harboring Fusarium species that cause mango malformation in Mexico. The information provided should prove valuable for further study of the epidemiological role of weeds in MMD and help manage the disease.
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Affiliation(s)
- Amelia C Montoya-Martínez
- Laboratorio de Patología Vegetal, IIAF, Universidad Michoacana de San Nicolás de Hidalgo, Tarímbaro, Michoacán 58880, México
| | - Kerry O'Donnell
- Mycotoxin Prevention and Applied Microbiology Research Unit, USDA-ARS, National Center for Agricultural Utilization Research, Peoria, IL 61604, U.S.A
| | - Mark Busman
- Mycotoxin Prevention and Applied Microbiology Research Unit, USDA-ARS, National Center for Agricultural Utilization Research, Peoria, IL 61604, U.S.A
| | - Martha M Vaughan
- Mycotoxin Prevention and Applied Microbiology Research Unit, USDA-ARS, National Center for Agricultural Utilization Research, Peoria, IL 61604, U.S.A
| | - Susan P McCormick
- Mycotoxin Prevention and Applied Microbiology Research Unit, USDA-ARS, National Center for Agricultural Utilization Research, Peoria, IL 61604, U.S.A
| | - Ricardo Santillán-Mendoza
- Laboratorio de Patología Vegetal, IIAF, Universidad Michoacana de San Nicolás de Hidalgo, Tarímbaro, Michoacán 58880, México
- Campo Experimental Ixtacuaco, CIRGOC, Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias, Tlapacoyan, Veracruz, México
| | - Daniela Pineda-Vaca
- Laboratorio de Patología Vegetal, IIAF, Universidad Michoacana de San Nicolás de Hidalgo, Tarímbaro, Michoacán 58880, México
| | - Lyana Clapes-Garduño
- Laboratorio de Patología Vegetal, IIAF, Universidad Michoacana de San Nicolás de Hidalgo, Tarímbaro, Michoacán 58880, México
| | - Sylvia P Fernández-Pavía
- Laboratorio de Patología Vegetal, IIAF, Universidad Michoacana de San Nicolás de Hidalgo, Tarímbaro, Michoacán 58880, México
| | - Randy C Ploetz
- Department of Plant Pathology, Tropical Research and Education Center, University of Florida, Homestead, FL 33031-3314, U.S.A
| | - Julieta Benítez-Malvido
- Instituto de Investigaciones en Ecosistemas y Sustentabilidad, Universidad Nacional Autónoma de México, Morelia, Michoacán 58190, México
| | | | - Gerardo Rodríguez-Alvarado
- Laboratorio de Patología Vegetal, IIAF, Universidad Michoacana de San Nicolás de Hidalgo, Tarímbaro, Michoacán 58880, México
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Hay WT, McCormick SP, Vaughan MM. Effects of Atmospheric CO2 and Temperature on Wheat and Corn Susceptibility to Fusarium graminearum and Deoxynivalenol Contamination. Plants 2021; 10:plants10122582. [PMID: 34961056 PMCID: PMC8709488 DOI: 10.3390/plants10122582] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/07/2021] [Revised: 11/20/2021] [Accepted: 11/22/2021] [Indexed: 11/16/2022]
Abstract
This work details the impact of atmospheric CO2 and temperature conditions on two strains of Fusarium graminearum, their disease damage, pathogen growth, mycotoxin accumulation, and production per unit fungal biomass in wheat and corn. An elevated atmospheric CO2 concentration, 1000 ppm CO2, significantly increased the accumulation of deoxynivalenol in infected plants. Furthermore, growth in cool growing conditions, 20 °C/18 °C, day and night, respectively, resulted in the highest amounts of pathogen biomass and toxin accumulation in both inoculated wheat and corn. Warm temperatures, 25 °C/23 °C, day and night, respectively, suppressed pathogen growth and toxin accumulation, with reductions as great as 99% in corn. In wheat, despite reduced pathogen biomass and toxin accumulation at warm temperatures, the fungal pathogen was more aggressive with greater disease damage and toxin production per unit biomass. Disease outcomes were also pathogen strain specific, with complex interactions between host, strain, and growth conditions. However, we found that atmospheric CO2 and temperature had essentially no significant interactions, except for greatly increased deoxynivalenol accumulation in corn at cool temperatures and elevated CO2. Plants were most susceptible to disease damage at warm and cold temperatures for wheat and corn, respectively. This work helps elucidate the complex interaction between the abiotic stresses and biotic susceptibility of wheat and corn to Fusarium graminearum infection to better understand the potential impact global climate change poses to future food security.
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Hao G, McCormick S, Vaughan MM. Effects of Double-Stranded RNAs Targeting Fusarium graminearum TRI6 on Fusarium Head Blight and Mycotoxins. Phytopathology 2021; 111:2080-2087. [PMID: 33823648 DOI: 10.1094/phyto-10-20-0468-r] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Fusarium graminearum is the causal agent of Fusarium head blight (FHB), which reduces crop yield and contaminates grains with poisonous trichothecene mycotoxins, including deoxynivalenol (DON). DON functions as an important virulence factor that promotes FHB spread in wheat; therefore, reducing DON production will decrease yield losses to FHB and increase food safety. Recent progress in the topical application of double-stranded RNA (dsRNA) to reduce F. graminearum infection has provided encouraging results. In this study, we designed and synthesized dsRNA targeting the transcription factor TRI6 (TRI6-dsRNA), which is a key regulator of DON biosynthesis. The expression of F. graminearum TRI6 was significantly lower in detached wheat heads treated with TRI6-dsRNA solution compared with the controls. Furthermore, TRI6-dsRNA treatments reduced disease and DON accumulation in inoculated detached wheat heads. Therefore, topical applications of TRI6-dsRNA on wheat heads of intact plants were assessed for their ability to reduce FHB and DON under growth chamber and greenhouse conditions. When wheat heads were treated with TRI6-dsRNA solution in growth chamber conditions, TRI6-dsRNA treatments failed to prevent FHB spread. However, when wheat heads were treated with TRI6-dsRNA solution under greenhouse conditions, FHB and DON were significantly reduced, and infection was restricted to the inoculated floret. In addition, addition of TRI6-dsRNA to toxin induction liquid media had no effect on F. graminearum 15-ADON production. Our study demonstrates that the efficacy of dsRNA applications is strongly dependent on application methods and environmental conditions.
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Affiliation(s)
- Guixia Hao
- U.S. Department of Agriculture-Agricultural Research Service, National Center for Agricultural Utilization Research, Mycotoxin Prevention and Applied Microbiology Research Unit, Peoria, IL 61604
| | - Susan McCormick
- U.S. Department of Agriculture-Agricultural Research Service, National Center for Agricultural Utilization Research, Mycotoxin Prevention and Applied Microbiology Research Unit, Peoria, IL 61604
| | - Martha M Vaughan
- U.S. Department of Agriculture-Agricultural Research Service, National Center for Agricultural Utilization Research, Mycotoxin Prevention and Applied Microbiology Research Unit, Peoria, IL 61604
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Montoya-Martínez AC, O'Donnell K, Busman M, Vaughan MM, McCormick SP, Santillán-Mendoza R, Pineda-Vaca D, Fernández-Pavía SP, Ploetz RC, Benítez-Malvido J, Montero-Castro JC, Rodríguez-Alvarado G. Malformation Disease in Tabebuia rosea (Rosy Trumpet) Caused by Fusarium pseudocircinatum in Mexico. Plant Dis 2021; 105:2822-2829. [PMID: 33904328 DOI: 10.1094/pdis-09-20-1942-re] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Tabebuia rosea (rosy trumpet) is an economically important neotropical tree in Mexico that is highly valued for the quality of its wood, which is used for furniture, crafts, and packing, and for its use as an ornamental and shade tree in parks and gardens. During surveys conducted in the lower Balsas River Basin region in the states of Guerrero and Michoacán, symptoms of floral malformation were detected in T. rosea trees. The main objectives of this study were to describe this new disease, to determine its causal agent, and to identify it using DNA sequence data. A second set of objectives was to analyze the phylogenetic relationship of the causal agent to Fusarium spp. associated with Swietenia macrophylla trees with malformation surveyed in the same region and to compare mycotoxin production and the mating type idiomorphs of fusaria recovered from T. rosea and S. macrophylla. Tabebuia rosea showed malformed inflorescences with multiple tightly curled shoots and shortened internodes. A total of 31 Fusarium isolates recovered from symptomatic T. rosea (n = 20) and S. macrophylla (n = 11) trees were identified by molecular analysis as Fusarium pseudocircinatum. Pathogenicity tests showed that isolates of F. pseudocircinatum recovered from T. rosea induced malformation in inoculated T. rosea seedlings. Eighteen F. pseudocircinatum isolates were tested for their ability to produce mycotoxins and other secondary metabolites. Moniliformin, fusaric acid, bikaverin, beauvericin, aurofusarin. and 8-O-methylbostrycoidin were produced by at least one strain of the 18 isolates tested. A multiplex PCR assay for mating type idiomorph revealed that 22 F. pseudocircinatum isolates were MAT1-1 and that 9 were MAT1-2. Here, we report a new disease of T. rosea in Mexico caused by F. pseudocircinatum.
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Affiliation(s)
- Amelia C Montoya-Martínez
- Laboratorio de Patología Vegetal, Instituto de Investigaciones Agropecuarias y Forestales (IIAF), Universidad Michoacana de San Nicolás de Hidalgo, Morelia-Zinapécuaro, Michoacán 58880, México
| | - Kerry O'Donnell
- Mycotoxin Prevention and Applied Microbiology Research Unit, U.S. Department of Agriculture Agricultural Research Service, National Center for Agricultural Utilization Research, Peoria 61604, U.S.A
| | - Mark Busman
- Mycotoxin Prevention and Applied Microbiology Research Unit, U.S. Department of Agriculture Agricultural Research Service, National Center for Agricultural Utilization Research, Peoria 61604, U.S.A
| | - Martha M Vaughan
- Mycotoxin Prevention and Applied Microbiology Research Unit, U.S. Department of Agriculture Agricultural Research Service, National Center for Agricultural Utilization Research, Peoria 61604, U.S.A
| | - Susan P McCormick
- Mycotoxin Prevention and Applied Microbiology Research Unit, U.S. Department of Agriculture Agricultural Research Service, National Center for Agricultural Utilization Research, Peoria 61604, U.S.A
| | - Ricardo Santillán-Mendoza
- Laboratorio de Patología Vegetal, Instituto de Investigaciones Agropecuarias y Forestales (IIAF), Universidad Michoacana de San Nicolás de Hidalgo, Morelia-Zinapécuaro, Michoacán 58880, México
- Campo Experimental Ixtacuaco, Centro de Investigación Regional Golfo Centro (CIRGOC), Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias, Tlapacoyan, Veracruz 93600, México
| | - Daniela Pineda-Vaca
- Laboratorio de Patología Vegetal, Instituto de Investigaciones Agropecuarias y Forestales (IIAF), Universidad Michoacana de San Nicolás de Hidalgo, Morelia-Zinapécuaro, Michoacán 58880, México
| | - Sylvia P Fernández-Pavía
- Laboratorio de Patología Vegetal, Instituto de Investigaciones Agropecuarias y Forestales (IIAF), Universidad Michoacana de San Nicolás de Hidalgo, Morelia-Zinapécuaro, Michoacán 58880, México
| | - Randy C Ploetz
- Department of Plant Pathology, Tropical Research and Education Center, University of Florida, Homestead 33031-3314, U.S.A
| | - Julieta Benítez-Malvido
- Instituto de Investigaciones en Ecosistemas y Sustentabilidad, Universidad Nacional Autónoma de México, Antigua Carretera a Pátzcuaro No. 8701, Ex Hacienda de San José de la Huerta, Morelia, Michoacán 58190, México
| | - Juan C Montero-Castro
- Facultad de Biología, Universidad Michoacana de San Nicolás de Hidalgo (UMSNH), Ciudad Universitaria, Morelia, Michoacán 58060, México
| | - Gerardo Rodríguez-Alvarado
- Laboratorio de Patología Vegetal, Instituto de Investigaciones Agropecuarias y Forestales (IIAF), Universidad Michoacana de San Nicolás de Hidalgo, Morelia-Zinapécuaro, Michoacán 58880, México
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13
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Geiser DM, Al-Hatmi AMS, Aoki T, Arie T, Balmas V, Barnes I, Bergstrom GC, Bhattacharyya MK, Blomquist CL, Bowden RL, Brankovics B, Brown DW, Burgess LW, Bushley K, Busman M, Cano-Lira JF, Carrillo JD, Chang HX, Chen CY, Chen W, Chilvers M, Chulze S, Coleman JJ, Cuomo CA, de Beer ZW, de Hoog GS, Del Castillo-Múnera J, Del Ponte EM, Diéguez-Uribeondo J, Di Pietro A, Edel-Hermann V, Elmer WH, Epstein L, Eskalen A, Esposto MC, Everts KL, Fernández-Pavía SP, da Silva GF, Foroud NA, Fourie G, Frandsen RJN, Freeman S, Freitag M, Frenkel O, Fuller KK, Gagkaeva T, Gardiner DM, Glenn AE, Gold SE, Gordon TR, Gregory NF, Gryzenhout M, Guarro J, Gugino BK, Gutierrez S, Hammond-Kosack KE, Harris LJ, Homa M, Hong CF, Hornok L, Huang JW, Ilkit M, Jacobs A, Jacobs K, Jiang C, Jiménez-Gasco MDM, Kang S, Kasson MT, Kazan K, Kennell JC, Kim HS, Kistler HC, Kuldau GA, Kulik T, Kurzai O, Laraba I, Laurence MH, Lee T, Lee YW, Lee YH, Leslie JF, Liew ECY, Lofton LW, Logrieco AF, López-Berges MS, Luque AG, Lysøe E, Ma LJ, Marra RE, Martin FN, May SR, McCormick SP, McGee C, Meis JF, Migheli Q, Mohamed Nor NMI, Monod M, Moretti A, Mostert D, Mulè G, Munaut F, Munkvold GP, Nicholson P, Nucci M, O'Donnell K, Pasquali M, Pfenning LH, Prigitano A, Proctor RH, Ranque S, Rehner SA, Rep M, Rodríguez-Alvarado G, Rose LJ, Roth MG, Ruiz-Roldán C, Saleh AA, Salleh B, Sang H, Scandiani MM, Scauflaire J, Schmale DG, Short DPG, Šišić A, Smith JA, Smyth CW, Son H, Spahr E, Stajich JE, Steenkamp E, Steinberg C, Subramaniam R, Suga H, Summerell BA, Susca A, Swett CL, Toomajian C, Torres-Cruz TJ, Tortorano AM, Urban M, Vaillancourt LJ, Vallad GE, van der Lee TAJ, Vanderpool D, van Diepeningen AD, Vaughan MM, Venter E, Vermeulen M, Verweij PE, Viljoen A, Waalwijk C, Wallace EC, Walther G, Wang J, Ward TJ, Wickes BL, Wiederhold NP, Wingfield MJ, Wood AKM, Xu JR, Yang XB, Yli-Mattila T, Yun SH, Zakaria L, Zhang H, Zhang N, Zhang SX, Zhang X. Phylogenomic Analysis of a 55.1-kb 19-Gene Dataset Resolves a Monophyletic Fusarium that Includes the Fusarium solani Species Complex. Phytopathology 2021; 111:1064-1079. [PMID: 33200960 DOI: 10.1094/phyto-08-20-0330-le] [Citation(s) in RCA: 83] [Impact Index Per Article: 27.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Scientific communication is facilitated by a data-driven, scientifically sound taxonomy that considers the end-user's needs and established successful practice. In 2013, the Fusarium community voiced near unanimous support for a concept of Fusarium that represented a clade comprising all agriculturally and clinically important Fusarium species, including the F. solani species complex (FSSC). Subsequently, this concept was challenged in 2015 by one research group who proposed dividing the genus Fusarium into seven genera, including the FSSC described as members of the genus Neocosmospora, with subsequent justification in 2018 based on claims that the 2013 concept of Fusarium is polyphyletic. Here, we test this claim and provide a phylogeny based on exonic nucleotide sequences of 19 orthologous protein-coding genes that strongly support the monophyly of Fusarium including the FSSC. We reassert the practical and scientific argument in support of a genus Fusarium that includes the FSSC and several other basal lineages, consistent with the longstanding use of this name among plant pathologists, medical mycologists, quarantine officials, regulatory agencies, students, and researchers with a stake in its taxonomy. In recognition of this monophyly, 40 species described as genus Neocosmospora were recombined in genus Fusarium, and nine others were renamed Fusarium. Here the global Fusarium community voices strong support for the inclusion of the FSSC in Fusarium, as it remains the best scientific, nomenclatural, and practical taxonomic option available.
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Affiliation(s)
- David M Geiser
- Department of Plant Pathology and Environmental Microbiology, Pennsylvania State University, University Park, PA 16802, U.S.A
| | | | - Takayuki Aoki
- Genetic Resources Center, National Agriculture and Food Research Organization, Tsukuba, Japan
| | - Tsutomu Arie
- Tokyo University of Agriculture and Technology, Fuchu, Japan
| | - Virgilio Balmas
- Dipartimento di Agraria, Università degli Studi di Sassari, Sassari, Italy
| | - Irene Barnes
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa
| | - Gary C Bergstrom
- Plant Pathology and Plant-Microbe Biology Section, Cornell University, Ithaca, NY 14853, U.S.A
| | | | - Cheryl L Blomquist
- Plant Pest Diagnostics Branch, California Department of Food and Agriculture, Sacramento, CA 95832, U.S.A
| | - Robert L Bowden
- Hard Winter Wheat Genetics Research Unit, U.S. Department of Agriculture Agricultural Research Service (USDA-ARS), Manhattan, KS 66506, U.S.A
| | - Balázs Brankovics
- Wageningen Plant Research, Wageningen University and Research, Wageningen, The Netherlands
| | - Daren W Brown
- Mycotoxin Prevention and Applied Microbiology Research Unit, USDA-ARS, Peoria, IL 61604, U.S.A
| | - Lester W Burgess
- Sydney Institute of Agriculture, Faculty of Science, University of Sydney, Sydney, Australia
| | - Kathryn Bushley
- Department of Plant and Microbial Biology, University of Minnesota, St. Paul, MN 55108, U.S.A
| | - Mark Busman
- Mycotoxin Prevention and Applied Microbiology Research Unit, USDA-ARS, Peoria, IL 61604, U.S.A
| | - José F Cano-Lira
- Mycology Unit and IISPV, Universitat Rovira i Virgili Medical School, Reus, Spain
| | - Joseph D Carrillo
- Gulf Coast Research and Education Center, University of Florida, Wimauma, FL 33598, U.S.A
| | - Hao-Xun Chang
- Department of Plant Pathology and Microbiology, National Taiwan University, Taipei, Taiwan
| | - Chi-Yu Chen
- Department of Plant Pathology, National Chung Hsing University, Taichung, Taiwan
| | - Wanquan Chen
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agriculture Sciences, Beijing, People's Republic of China
| | - Martin Chilvers
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI 48824, U.S.A
| | - Sofia Chulze
- Research Institute on Mycology and Mycotoxicology, National Scientific and Technical Research Council, National University of Rio Cuarto, Rio Cuarto, Córdoba, Argentina
| | - Jeffrey J Coleman
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL 36849, U.S.A
| | | | - Z Wilhelm de Beer
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa
| | - G Sybren de Hoog
- Department of Medical Mycology and Infectious Diseases, Center of Expertise in Mycology, Radboud University Medical Center, Canisius Wilhelmina Hospital, Nijmegen, The Netherlands
| | | | - Emerson M Del Ponte
- Departamento de Fitopatologia, Universidade Federal de Viçosa, Viçosa, Brazil
| | | | - Antonio Di Pietro
- Departamento de Genética, Campus de Excelencia Internacional Agroalimentario, Universidad de Córdoba, Córdoba, Spain
| | | | - Wade H Elmer
- Department of Plant Pathology and Ecology, Connecticut Agricultural Experiment Station, New Haven, CT 06504, U.S.A
| | - Lynn Epstein
- Department of Plant Pathology, University of California, Davis, CA 95616, U.S.A
| | - Akif Eskalen
- Department of Plant Pathology, University of California, Davis, CA 95616, U.S.A
| | | | - Kathryne L Everts
- Wye Research and Education Center, University of Maryland, Queenstown, MD 21658, U.S.A
| | - Sylvia P Fernández-Pavía
- Laboratorio de Patología Vegetal, Instituto de Investigaciones Agropecuarias y Forestales, Universidad Michoacana de San Nicolás de Hidalgo, Tarímbaro, Michoacán 58880, México
| | | | - Nora A Foroud
- Lethbridge Research and Development Centre, Agriculture and Agri-Food Canada, Lethbridge, Alberta T1J 4B1, Canada
| | - Gerda Fourie
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa
| | - Rasmus J N Frandsen
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Lyngby, Denmark
| | - Stanley Freeman
- Department of Plant Pathology and Weed Research, Agricultural Research Organization, Volcani Center, Rishon LeZion, Israel
| | - Michael Freitag
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, OR 97331, U.S.A
| | - Omer Frenkel
- Department of Plant Pathology and Weed Research, Agricultural Research Organization, Volcani Center, Rishon LeZion, Israel
| | - Kevin K Fuller
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, U.S.A
| | - Tatiana Gagkaeva
- Laboratory of Mycology and Phytopathology, All-Russian Institute of Plant Protection, St. Petersburg-Pushkin, Russia
| | | | - Anthony E Glenn
- Toxicology and Mycotoxin Research Unit, USDA-ARS, Athens, GA 30605, U.S.A
| | - Scott E Gold
- Toxicology and Mycotoxin Research Unit, USDA-ARS, Athens, GA 30605, U.S.A
| | - Thomas R Gordon
- Department of Plant Pathology, University of California, Davis, CA 95616, U.S.A
| | - Nancy F Gregory
- Department of Plant and Soil Sciences, University of Delaware, DE 19716, U.S.A
| | - Marieka Gryzenhout
- Department of Genetics, University of the Free State, Bloemfontein, South Africa
| | - Josep Guarro
- Unitat de Microbiologia, Departament de Ciències Mèdiques Bàsiques, Universitat Rovira i Virgili, Reus, Spain
| | - Beth K Gugino
- Department of Plant Pathology and Environmental Microbiology, Pennsylvania State University, University Park, PA 16802, U.S.A
| | | | - Kim E Hammond-Kosack
- Department of Biointeractions and Crop Protection, Rothamsted Research, Harpenden, United Kingdom
| | - Linda J Harris
- Ottawa Research and Development Centre, Agriculture and Agri-Food Canada, Ottawa, Ontario K1A 0C6, Canada
| | - Mónika Homa
- MTA-SZTE Fungal Pathogenicity Mechanisms Research Group, Hungarian Academy of Sciences, University of Szeged, Szeged, Hungary
| | - Cheng-Fang Hong
- Department of Plant Pathology, National Chung Hsing University, Taichung, Taiwan
| | - László Hornok
- Institute of Plant Protection, Szent István University, Gödöllő, Hungary
| | - Jenn-Wen Huang
- Department of Plant Pathology, National Chung Hsing University, Taichung, Taiwan
| | - Macit Ilkit
- Division of Mycology, Faculty of Medicine, University of Çukurova, Sarıçam, Adana, Turkey
| | - Adriaana Jacobs
- Biosystematics Unit, Plant Health and Protection, Agricultural Research Council, Pretoria, South Africa
| | - Karin Jacobs
- Department of Microbiology, Stellenbosch University, Matieland, South Africa
| | - Cong Jiang
- College of Plant Protection, Northwest Agriculture and Forestry University, Xianyang, People's Republic of China
| | - María Del Mar Jiménez-Gasco
- Department of Plant Pathology and Environmental Microbiology, Pennsylvania State University, University Park, PA 16802, U.S.A
| | - Seogchan Kang
- Department of Plant Pathology and Environmental Microbiology, Pennsylvania State University, University Park, PA 16802, U.S.A
| | - Matthew T Kasson
- Division of Plant and Soil Sciences, West Virginia University, Morgantown, WV 26506, U.S.A
| | - Kemal Kazan
- CSIRO Agriculture and Food, St. Lucia, Australia
| | - John C Kennell
- Biology Department, St. Louis University, St. Louis, MO 63101, U.S.A
| | - Hye-Seon Kim
- Mycotoxin Prevention and Applied Microbiology Research Unit, USDA-ARS, Peoria, IL 61604, U.S.A
| | - H Corby Kistler
- USDA-ARS Cereal Disease Laboratory, University of Minnesota, St. Paul, MN 55108, U.S.A
| | - Gretchen A Kuldau
- Department of Plant Pathology and Environmental Microbiology, Pennsylvania State University, University Park, PA 16802, U.S.A
| | - Tomasz Kulik
- Department of Botany and Nature Protection, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland
| | - Oliver Kurzai
- German National Reference Center for Invasive Fungal Infections NRZMyk, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knoell Institute, Jena, Germany
| | - Imane Laraba
- Mycotoxin Prevention and Applied Microbiology Research Unit, USDA-ARS, Peoria, IL 61604, U.S.A
| | - Matthew H Laurence
- Australian Institute of Botanical Science, Royal Botanic Garden and Domain Trust, Sydney, Australia
| | - Theresa Lee
- Microbial Safety Team, National Institute of Agricultural Sciences, Rural Development Administration, Wanju, Republic of Korea
| | - Yin-Won Lee
- Department of Agricultural Biotechnology, Seoul National University, Seoul, Republic of Korea
| | - Yong-Hwan Lee
- Department of Agricultural Biotechnology, Seoul National University, Seoul, Republic of Korea
| | - John F Leslie
- Department of Plant Pathology, Kansas State University, Manhattan, KS 66506, U.S.A
| | - Edward C Y Liew
- Australian Institute of Botanical Science, Royal Botanic Garden and Domain Trust, Sydney, Australia
| | - Lily W Lofton
- Toxicology and Mycotoxin Research Unit, USDA-ARS, Athens, GA 30605, U.S.A
| | - Antonio F Logrieco
- Institute of Sciences of Food Production, Research National Council, Bari, Italy
| | - Manuel S López-Berges
- Departamento de Genética, Campus de Excelencia Internacional Agroalimentario, Universidad de Córdoba, Córdoba, Spain
| | - Alicia G Luque
- Facultad de Ciencias Bioquímicas y Farmacéuticas, Centro de Referencia de Micología, Universidad Nacional de Rosario, Rosario, Argentina
| | - Erik Lysøe
- Division of Biotechnology and Plant Health, Norwegian Institute of Bioeconomy Research, Høgskoleveien, Ås, Norway
| | - Li-Jun Ma
- Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, MA 01003, U.S.A
| | - Robert E Marra
- Department of Plant Pathology and Ecology, Connecticut Agricultural Experiment Station, New Haven, CT 06504, U.S.A
| | - Frank N Martin
- Crop Improvement and Protection Research Unit, ARS-USDA, Salinas, CA 93905, U.S.A
| | - Sara R May
- Department of Plant Pathology and Environmental Microbiology, Pennsylvania State University, University Park, PA 16802, U.S.A
| | - Susan P McCormick
- Mycotoxin Prevention and Applied Microbiology Research Unit, USDA-ARS, Peoria, IL 61604, U.S.A
| | - Chyanna McGee
- Department of Plant Pathology and Environmental Microbiology, Pennsylvania State University, University Park, PA 16802, U.S.A
| | - Jacques F Meis
- Department of Medical Mycology and Infectious Diseases, Center of Expertise in Mycology, Radboud University Medical Center, Canisius Wilhelmina Hospital, Nijmegen, The Netherlands
| | - Quirico Migheli
- Dipartimento di Agraria and Nucleo Ricerca Desertificazione, Università degli Studi di Sassari, Sassari, Italy
| | - N M I Mohamed Nor
- School of Biological Sciences, Universiti Sains Malaysia, Penang, Malaysia
| | - Michel Monod
- Laboratoire de Mycologie, Service de Dermatologie, Centre Hospitalier Universitaire Vaudois, 1011 Lausanne, Switzerland
| | - Antonio Moretti
- Institute of Sciences of Food Production, Research National Council, Bari, Italy
| | - Diane Mostert
- Department of Plant Pathology, Stellenbosch University, Matieland, South Africa
| | - Giuseppina Mulè
- Institute of Sciences of Food Production, Research National Council, Bari, Italy
| | | | - Gary P Munkvold
- Department of Plant Pathology and Microbiology, Iowa State University, Ames, IA 50011, U.S.A
| | - Paul Nicholson
- Department of Crop Genetics, John Innes Centre, Norwich Research Park, Norwich, United Kingdom
| | - Marcio Nucci
- Hospital Universitário, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Kerry O'Donnell
- Mycotoxin Prevention and Applied Microbiology Research Unit, USDA-ARS, Peoria, IL 61604, U.S.A
| | - Matias Pasquali
- Department of Food, Environmental and Nutritional Sciences, University of Milano, Milan, Italy
| | - Ludwig H Pfenning
- Departamento de Fitopatologia, Universidade Federal de Lavras, Lavras, Minas Gerais State, Brazil
| | - Anna Prigitano
- Department of Biomedical Sciences for Health, University of Milano, Milan, Italy
| | - Robert H Proctor
- Mycotoxin Prevention and Applied Microbiology Research Unit, USDA-ARS, Peoria, IL 61604, U.S.A
| | - Stéphane Ranque
- Institut Hospitalier Universitaire Méditerranée Infection, Aix Marseille University, Marseille, France
| | - Stephen A Rehner
- Mycology and Nematology Genetic Diversity and Biology Laboratory, USDA-ARS, Beltsville, MD 20705, U.S.A
| | - Martijn Rep
- Swammerdam Institute for Life Science, University of Amsterdam, Amsterdam, The Netherlands
| | - Gerardo Rodríguez-Alvarado
- Laboratorio de Patología Vegetal, Instituto de Investigaciones Agropecuarias y Forestales, Universidad Michoacana de San Nicolás de Hidalgo, Tarímbaro, Michoacán 58880, México
| | - Lindy Joy Rose
- Department of Plant Pathology, Stellenbosch University, Matieland, South Africa
| | - Mitchell G Roth
- Department of Plant Pathology, University of Wisconsin, Madison, WI 53706, U.S.A
| | - Carmen Ruiz-Roldán
- Departamento de Genética, Campus de Excelencia Internacional Agroalimentario, Universidad de Córdoba, Córdoba, Spain
| | - Amgad A Saleh
- Department of Plant Protection, College of Food and Agriculture Sciences, King Saud University, Riyadh 11451, Saudi Arabia
| | - Baharuddin Salleh
- School of Biological Sciences, Universiti Sains Malaysia, Penang, Malaysia
| | - Hyunkyu Sang
- Department of Integrative Food, Bioscience and Biotechnology, Chonnam National University, Gwangju, Republic of Korea
| | - María Mercedes Scandiani
- Facultad de Ciencias Bioquímicas y Farmacéuticas, Centro de Referencia de Micología, Universidad Nacional de Rosario, Rosario, Argentina
| | - Jonathan Scauflaire
- Centre de Recherche et de Formation Agronomie, Haute Ecole Louvain en Hainaut, Montignies-sur-Sambre, Belgium
| | - David G Schmale
- School of Plant and Environmental Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, U.S.A
| | | | - Adnan Šišić
- Department of Ecological Plant Protection, University of Kassel, Witzenhausen, Germany
| | - Jason A Smith
- School of Forest Resources and Conservation, University of Florida, Gainesville, FL 32611, U.S.A
| | - Christopher W Smyth
- Department of Biological Sciences, Binghamton University, State University of New York, Binghamton, NY 13902, U.S.A
| | - Hokyoung Son
- Department of Agricultural Biotechnology, Seoul National University, Seoul, Republic of Korea
| | - Ellie Spahr
- Division of Plant and Soil Sciences, West Virginia University, Morgantown, WV 26506, U.S.A
| | - Jason E Stajich
- Department of Microbiology and Plant Pathology, University of California, Riverside, CA 92521, U.S.A
| | - Emma Steenkamp
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa
| | - Christian Steinberg
- Agroécologie, AgroSup Dijon, INRAE, University of Bourgogne Franche-Comté, Dijon, France
| | - Rajagopal Subramaniam
- Ottawa Research and Development Centre, Agriculture and Agri-Food Canada, Ottawa, Ontario K1A 0C6, Canada
| | - Haruhisa Suga
- Life Science Research Center, Gifu University, Gifu, Japan
| | - Brett A Summerell
- Australian Institute of Botanical Science, Royal Botanic Garden and Domain Trust, Sydney, Australia
| | - Antonella Susca
- Institute of Sciences of Food Production, Research National Council, Bari, Italy
| | - Cassandra L Swett
- Department of Plant Pathology, University of California, Davis, CA 95616, U.S.A
| | | | - Terry J Torres-Cruz
- Department of Plant Pathology and Environmental Microbiology, Pennsylvania State University, University Park, PA 16802, U.S.A
| | - Anna M Tortorano
- Department of Biomedical Sciences for Health, University of Milano, Milan, Italy
| | - Martin Urban
- Department of Biointeractions and Crop Protection, Rothamsted Research, Harpenden, United Kingdom
| | - Lisa J Vaillancourt
- Department of Plant Pathology, University of Kentucky, Lexington, KY 40546, U.S.A
| | - Gary E Vallad
- Gulf Coast Research and Education Center, University of Florida, Wimauma, FL 33598, U.S.A
| | - Theo A J van der Lee
- Wageningen Plant Research, Wageningen University and Research, Wageningen, The Netherlands
| | - Dan Vanderpool
- Department of Biology, Indiana University, Bloomington, IN 47405, U.S.A
| | - Anne D van Diepeningen
- Wageningen Plant Research, Wageningen University and Research, Wageningen, The Netherlands
| | - Martha M Vaughan
- Mycotoxin Prevention and Applied Microbiology Research Unit, USDA-ARS, Peoria, IL 61604, U.S.A
| | - Eduard Venter
- Department of Botany and Plant Biotechnology, University of Johannesburg, Auckland Park, South Africa
| | - Marcele Vermeulen
- Department of Microbial Biochemical and Food Biotechnology, University of the Free State, Bloemfontein, South Africa
| | - Paul E Verweij
- Department of Medical Mycology and Infectious Diseases, Center of Expertise in Mycology, Radboud University Medical Center, Canisius Wilhelmina Hospital, Nijmegen, The Netherlands
| | - Altus Viljoen
- Department of Plant Pathology, Stellenbosch University, Matieland, South Africa
| | - Cees Waalwijk
- Wageningen Plant Research, Wageningen University and Research, Wageningen, The Netherlands
| | - Emma C Wallace
- Department of Plant Pathology and Environmental Microbiology, Pennsylvania State University, University Park, PA 16802, U.S.A
| | - Grit Walther
- German National Reference Center for Invasive Fungal Infections NRZMyk, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knoell Institute, Jena, Germany
| | - Jie Wang
- DOE Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94702
| | - Todd J Ward
- Mycotoxin Prevention and Applied Microbiology Research Unit, USDA-ARS, Peoria, IL 61604, U.S.A
| | - Brian L Wickes
- Department of Microbiology, Immunology and Molecular Genetics, University of Texas Health Science Center, San Antonio, TX 78229, U.S.A
| | - Nathan P Wiederhold
- Department of Pathology, University of Texas Health Science Center, San Antonio, TX 78229, U.S.A
| | - Michael J Wingfield
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa
| | - Ana K M Wood
- Department of Biointeractions and Crop Protection, Rothamsted Research, Harpenden, United Kingdom
| | - Jin-Rong Xu
- Department of Pathology, University of Texas Health Science Center, San Antonio, TX 78229, U.S.A
| | - Xiao-Bing Yang
- Department of Crop Genetics, John Innes Centre, Norwich Research Park, Norwich, United Kingdom
| | | | - Sung-Hwan Yun
- Department of Medical Biotechnology, Soonchunhyang University, Asan, Republic of Korea
| | - Latiffah Zakaria
- School of Biological Sciences, Universiti Sains Malaysia, Penang, Malaysia
| | - Hao Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agriculture Sciences, Beijing, People's Republic of China
| | - Ning Zhang
- Department of Plant Biology, Rutgers University, New Brunswick, NJ 08901, U.S.A
| | - Sean X Zhang
- Department of Pathology, Johns Hopkins University, Baltimore, MD 21287, U.S.A
| | - Xue Zhang
- College of Plant Protection, Northwest Agriculture and Forestry University, Xianyang, People's Republic of China
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14
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Laraba I, McCormick SP, Vaughan MM, Geiser DM, O'Donnell K. Correction: Phylogenetic diversity, trichothecene potential, and pathogenicity within Fusarium sambucinum species complex. PLoS One 2021; 16:e0250812. [PMID: 33886679 PMCID: PMC8061947 DOI: 10.1371/journal.pone.0250812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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15
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Taylor L, Gutierrez S, McCormick SP, Bakker MG, Proctor RH, Teresi J, Kurtzman B, Hao G, Vaughan MM. Use of the volatile trichodiene to reduce Fusarium head blight and trichothecene contamination in wheat. Microb Biotechnol 2021; 15:513-527. [PMID: 33528888 PMCID: PMC8867995 DOI: 10.1111/1751-7915.13742] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 11/30/2020] [Accepted: 12/12/2020] [Indexed: 12/11/2022] Open
Abstract
Fusarium graminearum is the primary cause of Fusarium head blight (FHB), one of the most economically important diseases of wheat worldwide. FHB reduces yield and contaminates grain with the trichothecene mycotoxin deoxynivalenol (DON), which poses a risk to plant, human and animal health. The first committed step in trichothecene biosynthesis is formation of trichodiene (TD). The volatile nature of TD suggests that it could be a useful intra or interspecies signalling molecule, but little is known about the potential signalling role of TD during F. graminearum‐wheat interactions. Previous work using a transgenic Trichoderma harzianum strain engineered to emit TD (Th + TRI5) indicated that TD can function as a signal that can modulate pathogen virulence and host plant resistance. Herein, we demonstrate that Th + TRI5 has enhanced biocontrol activity against F. graminearum and reduced DON contamination by 66% and 70% in a moderately resistant and a susceptible cultivar, respectively. While Th + TRI5 volatiles significantly influenced the expression of the pathogenesis‐related 1 (PR1) gene, the effect was dependent on cultivar. Th + TRI5 volatiles strongly reduced DON production in F. graminearum plate cultures and downregulated the expression of TRI genes. Finally, we confirm that TD fumigation reduced DON accumulation in a detached wheat head assay.
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Affiliation(s)
- Laurie Taylor
- Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, United States Department of Agriculture, Agricultural Research Service, 1815 N University St, Peoria, IL, 61604, USA
| | - Santiago Gutierrez
- Molecular Biology Department, University of Leon, Campus de Ponferrada, Avda. Astorga s/n 24400, Ponferrada, Spain
| | - Susan P McCormick
- Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, United States Department of Agriculture, Agricultural Research Service, 1815 N University St, Peoria, IL, 61604, USA
| | - Matthew G Bakker
- Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, United States Department of Agriculture, Agricultural Research Service, 1815 N University St, Peoria, IL, 61604, USA
| | - Robert H Proctor
- Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, United States Department of Agriculture, Agricultural Research Service, 1815 N University St, Peoria, IL, 61604, USA
| | - Jennifer Teresi
- Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, United States Department of Agriculture, Agricultural Research Service, 1815 N University St, Peoria, IL, 61604, USA
| | - Ben Kurtzman
- Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, United States Department of Agriculture, Agricultural Research Service, 1815 N University St, Peoria, IL, 61604, USA
| | - Guixia Hao
- Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, United States Department of Agriculture, Agricultural Research Service, 1815 N University St, Peoria, IL, 61604, USA
| | - Martha M Vaughan
- Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, United States Department of Agriculture, Agricultural Research Service, 1815 N University St, Peoria, IL, 61604, USA
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16
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Laraba I, McCormick SP, Vaughan MM, Geiser DM, O’Donnell K. Phylogenetic diversity, trichothecene potential, and pathogenicity within Fusarium sambucinum species complex. PLoS One 2021; 16:e0245037. [PMID: 33434214 PMCID: PMC7802971 DOI: 10.1371/journal.pone.0245037] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Accepted: 12/21/2020] [Indexed: 01/01/2023] Open
Abstract
The Fusarium sambucinum species complex (FSAMSC) is one of the most taxonomically challenging groups of fusaria, comprising prominent mycotoxigenic plant pathogens and other species with various lifestyles. Among toxins produced by members of the FSAMSC, trichothecenes pose the most significant threat to public health. Herein a global collection of 171 strains, originating from diverse hosts or substrates, were selected to represent FSAMSC diversity. This strain collection was used to assess their species diversity, evaluate their potential to produce trichothecenes, and cause disease on wheat. Maximum likelihood and Bayesian analyses of a combined 3-gene dataset used to infer evolutionary relationships revealed that the 171 strains originally received as 48 species represent 74 genealogically exclusive phylogenetically distinct species distributed among six strongly supported clades: Brachygibbosum, Graminearum, Longipes, Novel, Sambucinum, and Sporotrichioides. Most of the strains produced trichothecenes in vitro but varied in type, indicating that the six clades correspond to type A, type B, or both types of trichothecene-producing lineages. Furthermore, five strains representing two putative novel species within the Sambucinum Clade produced two newly discovered type A trichothecenes, 15-keto NX-2 and 15-keto NX-3. Strains of the two putatively novel species together with members of the Graminearum Clade were aggressive toward wheat when tested for pathogenicity on heads of the susceptible cultivar Apogee. In planta, the Graminearum Clade strains produced nivalenol or deoxynivalenol and the aggressive Sambucinum Clade strains synthesized NX-3 and 15-keto NX-3. Other strains within the Brachygibbosum, Longipes, Novel, Sambucinum, and Sporotrichioides Clades were nonpathogenic or could infect the inoculated floret without spreading within the head. Moreover, most of these strains did not produce any toxin in the inoculated spikelets. These data highlight aggressiveness toward wheat appears to be influenced by the type of toxin produced and that it is not limited to members of the Graminearum Clade.
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Affiliation(s)
- Imane Laraba
- USDA, Agricultural Research Service, National Center for Agricultural Utilization Research, Mycotoxin Prevention and Applied Microbiology Research Unit. 1815 N. University, Peoria, IL, United States of America
| | - Susan P. McCormick
- USDA, Agricultural Research Service, National Center for Agricultural Utilization Research, Mycotoxin Prevention and Applied Microbiology Research Unit. 1815 N. University, Peoria, IL, United States of America
| | - Martha M. Vaughan
- USDA, Agricultural Research Service, National Center for Agricultural Utilization Research, Mycotoxin Prevention and Applied Microbiology Research Unit. 1815 N. University, Peoria, IL, United States of America
| | - David M. Geiser
- Department of Plant Pathology and Environmental Microbiology, Pennsylvania State University, University Park, Pennsylvania, PA, United States of America
| | - Kerry O’Donnell
- USDA, Agricultural Research Service, National Center for Agricultural Utilization Research, Mycotoxin Prevention and Applied Microbiology Research Unit. 1815 N. University, Peoria, IL, United States of America
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17
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Hao G, McCormick S, Usgaard T, Tiley H, Vaughan MM. Characterization of Three Fusarium graminearum Effectors and Their Roles During Fusarium Head Blight. Front Plant Sci 2020; 11:579553. [PMID: 33329641 PMCID: PMC7734257 DOI: 10.3389/fpls.2020.579553] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 11/06/2020] [Indexed: 05/29/2023]
Abstract
Fusarium graminearum causes Fusarium head blight (FHB) on wheat, barley, and other grains. During infection, F. graminearum produces deoxynivalenol (DON), which contaminates grain and functions as a virulence factor to promote FHB spread throughout the wheat head. F. graminearum secretes hundreds of putative effectors, which can interfere with plant immunity to promote disease development. However, the function of most of these putative effectors remains unknown. In this study, we investigated the expression profiles of 23 F. graminearum effector-coding genes during the early stage of wheat head infection. Gene expression analyses revealed that three effectors, FGSG_01831, FGSG_03599, and FGSG_12160, respectively, were highly induced in both a FHB susceptible and a moderately resistant variety. We generated deletion mutants for these effector genes and performed FHB virulence assays on wheat head using point and dip inoculations to evaluate FHB spread and initial infection. No statistically significant difference in FHB spread was observed in the deletion mutants. However, deletion mutants Δ01831 displayed a significant reduction in initial infection, and thus resulted in less DON contamination. To investigate the potential mechanisms involved, these three effectors were transiently expressed in Nicotiana benthamiana leaves. N. benthamiana leaves expressing these individual effectors had significantly reduced production of reactive oxygen species induced by chitin, but not by flg22. Furthermore, FGSG_01831 and FGSG_03599 markedly suppressed Bax-induced cell death when co-expressed with Bax in N. benthamiana leaves. Our study provides new insights into the functions of these effectors and suggests they play collective or redundant roles that likely ensure the successful plant infection.
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18
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Ding Y, Weckwerth PR, Poretsky E, Murphy KM, Sims J, Saldivar E, Christensen SA, Char SN, Yang B, Tong AD, Shen Z, Kremling KA, Buckler ES, Kono T, Nelson DR, Bohlmann J, Bakker MG, Vaughan MM, Khalil AS, Betsiashvili M, Dressano K, Köllner TG, Briggs SP, Zerbe P, Schmelz EA, Huffaker A. Genetic elucidation of interconnected antibiotic pathways mediating maize innate immunity. Nat Plants 2020; 6:1375-1388. [PMID: 33106639 DOI: 10.1038/s41477-020-00787-9] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Accepted: 09/11/2020] [Indexed: 05/24/2023]
Abstract
Specialized metabolites constitute key layers of immunity that underlie disease resistance in crops; however, challenges in resolving pathways limit our understanding of the functions and applications of these metabolites. In maize (Zea mays), the inducible accumulation of acidic terpenoids is increasingly considered to be a defence mechanism that contributes to disease resistance. Here, to understand maize antibiotic biosynthesis, we integrated association mapping, pan-genome multi-omic correlations, enzyme structure-function studies and targeted mutagenesis. We define ten genes in three zealexin (Zx) gene clusters that encode four sesquiterpene synthases and six cytochrome P450 proteins that collectively drive the production of diverse antibiotic cocktails. Quadruple mutants in which the ability to produce zealexins (ZXs) is blocked exhibit a broad-spectrum loss of disease resistance. Genetic redundancies ensuring pathway resiliency to single null mutations are combined with enzyme substrate promiscuity, creating a biosynthetic hourglass pathway that uses diverse substrates and in vivo combinatorial chemistry to yield complex antibiotic blends. The elucidated genetic basis of biochemical phenotypes that underlie disease resistance demonstrates a predominant maize defence pathway and informs innovative strategies for transferring chemical immunity between crops.
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Affiliation(s)
- Yezhang Ding
- Section of Cell and Developmental Biology, University of California at San Diego, La Jolla, CA, USA
| | - Philipp R Weckwerth
- Section of Cell and Developmental Biology, University of California at San Diego, La Jolla, CA, USA
| | - Elly Poretsky
- Section of Cell and Developmental Biology, University of California at San Diego, La Jolla, CA, USA
| | - Katherine M Murphy
- Department of Plant Biology, University of California Davis, Davis, CA, USA
| | - James Sims
- ETH Zurich, Institute of Agricultural Sciences, Zurich, Switzerland
| | - Evan Saldivar
- Section of Cell and Developmental Biology, University of California at San Diego, La Jolla, CA, USA
| | - Shawn A Christensen
- Chemistry Research Unit, Center for Medical, Agricultural and Veterinary Entomology, Department of Agriculture, Agricultural Research Service, Gainesville, FL, USA
| | - Si Nian Char
- Division of Plant Sciences, Bond Life Sciences Center, University of Missouri, Columbia, MO, USA
| | - Bing Yang
- Division of Plant Sciences, Bond Life Sciences Center, University of Missouri, Columbia, MO, USA
- Donald Danforth Plant Science Center, St Louis, MO, USA
| | - Anh-Dao Tong
- Section of Cell and Developmental Biology, University of California at San Diego, La Jolla, CA, USA
| | - Zhouxin Shen
- Section of Cell and Developmental Biology, University of California at San Diego, La Jolla, CA, USA
| | - Karl A Kremling
- Department of Plant Breeding and Genetics, Cornell University, Ithaca, NY, USA
| | - Edward S Buckler
- Department of Plant Breeding and Genetics, Cornell University, Ithaca, NY, USA
- Robert W. Holley Center for Agriculture and Health, Ithaca, US Department of Agriculture, Agricultural Research Service, New York, NY, USA
| | - Tom Kono
- Minnesota Supercomputing Institute, University of Minnesota, Minneapolis, MN, USA
| | - David R Nelson
- University of Tennessee Health Science Center, Memphis, TN, USA
| | - Jörg Bohlmann
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada
| | - Matthew G Bakker
- National Center for Agricultural Utilization Research, US Department of Agriculture, Agricultural Research Service, Peoria, IL, USA
- Department of Microbiology, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Martha M Vaughan
- National Center for Agricultural Utilization Research, US Department of Agriculture, Agricultural Research Service, Peoria, IL, USA
| | - Ahmed S Khalil
- Section of Cell and Developmental Biology, University of California at San Diego, La Jolla, CA, USA
| | - Mariam Betsiashvili
- Section of Cell and Developmental Biology, University of California at San Diego, La Jolla, CA, USA
| | - Keini Dressano
- Section of Cell and Developmental Biology, University of California at San Diego, La Jolla, CA, USA
| | | | - Steven P Briggs
- Section of Cell and Developmental Biology, University of California at San Diego, La Jolla, CA, USA
| | - Philipp Zerbe
- Department of Plant Biology, University of California Davis, Davis, CA, USA
| | - Eric A Schmelz
- Section of Cell and Developmental Biology, University of California at San Diego, La Jolla, CA, USA
| | - Alisa Huffaker
- Section of Cell and Developmental Biology, University of California at San Diego, La Jolla, CA, USA.
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19
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Laraba I, McCormick SP, Vaughan MM, Proctor RH, Busman M, Appell M, O'Donnell K, Felker FC, Catherine Aime M, Wurdack KJ. Pseudoflowers produced by Fusarium xyrophilum on yellow-eyed grass (Xyris spp.) in Guyana: A novel floral mimicry system? Fungal Genet Biol 2020; 144:103466. [PMID: 32956810 DOI: 10.1016/j.fgb.2020.103466] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 09/10/2020] [Accepted: 09/11/2020] [Indexed: 12/18/2022]
Abstract
Pseudoflower formation is arguably the rarest outcome of a plant-fungus interaction. Here we report on a novel putative floral mimicry system in which the pseudoflowers are composed entirely of fungal tissues in contrast to modified leaves documented in previous mimicry systems. Pseudoflowers on two perennial Xyris species (yellow-eyed grass, X. setigera and X. surinamensis) collected from savannas in Guyana were produced by Fusarium xyrophilum, a novel Fusarium species. These pseudoflowers mimic Xyris flowers in gross morphology and are ultraviolet reflective. Axenic cultures of F. xyrophilum produced two pigments that had fluorescence emission maxima in light ranges that trichromatic insects are sensitive to and volatiles known to attract insect pollinators. One of the volatiles emitted by F. xyrophilum cultures (i.e., 2-ethylhexanol) was also detected in the head space of X. laxifolia var. iridifolia flowers, a perennial species native to the New World. Results of microscopic and PCR analyses, combined with examination of gross morphology of the pseudoflowers, provide evidence that the fungus had established a systemic infection in both Xyris species, sterilized them and formed fungal pseudoflowers containing both mating type idiomorphs. Fusarium xyrophilum cultures also produced the auxin indole-3-acetic acid (IAA) and the cytokinin isopentenyl adenosine (iPR). Field observations revealed that pseudoflowers and Xyris flowers were both visited by bees. Together, the results suggest that F. xyrophilum pseudoflowers are a novel floral mimicry system that attracts insect pollinators, via visual and olfactory cues, into vectoring its conidia, which might facilitate outcrossing of this putatively heterothallic fungus and infection of previously uninfected plants.
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Affiliation(s)
- Imane Laraba
- Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, US Department of Agriculture, Peoria, IL 61604-3999, USA.
| | - Susan P McCormick
- Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, US Department of Agriculture, Peoria, IL 61604-3999, USA
| | - Martha M Vaughan
- Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, US Department of Agriculture, Peoria, IL 61604-3999, USA
| | - Robert H Proctor
- Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, US Department of Agriculture, Peoria, IL 61604-3999, USA
| | - Mark Busman
- Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, US Department of Agriculture, Peoria, IL 61604-3999, USA
| | - Michael Appell
- Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, US Department of Agriculture, Peoria, IL 61604-3999, USA
| | - Kerry O'Donnell
- Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, US Department of Agriculture, Peoria, IL 61604-3999, USA
| | - Frederick C Felker
- Functional Food Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, US Department of Agriculture, Peoria, IL 61604-3999, USA
| | - M Catherine Aime
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907-2054, USA
| | - Kenneth J Wurdack
- Department of Botany, National Museum of Natural History, Smithsonian Institution, Washington, DC 20013-2012, USA
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20
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Hay WT, McCormick SP, Hojilla-Evangelista MP, Bowman MJ, Dunn RO, Teresi JM, Berhow MA, Vaughan MM. Changes in Wheat Nutritional Content at Elevated [CO 2] Alter Fusarium graminearum Growth and Mycotoxin Production on Grain. J Agric Food Chem 2020; 68:6297-6307. [PMID: 32407107 DOI: 10.1021/acs.jafc.0c01308] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Rising atmospheric [CO2] has been shown to impact plant primary metabolism and the severity of Fusarium head blight (FHB) in wheat. In this study, we evaluated how changes in grain nutritional content due to growth at elevated [CO2] affected Fusarium graminearum growth and mycotoxin production. Susceptible (Norm) and moderately resistant (Alsen) hard spring wheat grains that had been grown at ambient (400 ppm) or elevated [CO2] (800 ppm) were independently inoculated with two F. graminearum fungal strains, which produce the trichothecene mycotoxin, deoxynivalenol. Under higher [CO2], FHB-susceptible and moderately resistant wheat had disproportionate losses in protein and mineral contents, with Alsen being more severely impacted. Furthermore, the F. graminearum strain 9F1 had increased mycotoxin biosynthesis in response to the loss of wheat nutritional content in Alsen. Our results demonstrate that future [CO2] conditions may provide a strain-specific pathogenic advantage on hosts, with greater losses in nutritional content.
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Affiliation(s)
- William T Hay
- Mycotoxin Prevention and Applied Microbiology Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, USDA, 1815 North, University Street, Peoria, Illinois 61604, United States
| | - Susan P McCormick
- Mycotoxin Prevention and Applied Microbiology Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, USDA, 1815 North, University Street, Peoria, Illinois 61604, United States
| | - Milagros P Hojilla-Evangelista
- Plant Polymer Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, USDA, Peoria, Illinois 61604, United States
| | - Michael J Bowman
- Bioenergy Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, USDA, Peoria, Illinois 61604, United States
| | - Robert O Dunn
- Bio-oils Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, USDA, Peoria, Illinois 61604, United States
| | - Jennifer M Teresi
- Mycotoxin Prevention and Applied Microbiology Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, USDA, 1815 North, University Street, Peoria, Illinois 61604, United States
| | - Mark A Berhow
- Functional Foods Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, USDA, Peoria, Illinois 61604, United States
| | - Martha M Vaughan
- Mycotoxin Prevention and Applied Microbiology Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, USDA, 1815 North, University Street, Peoria, Illinois 61604, United States
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21
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Vaughan MM, Ward TJ, McCormick SP, Orwig N, Hay WT, Proctor R, Palmquist D. Intrapopulation Antagonism Can Reduce the Growth and Aggressiveness of the Wheat Head Blight Pathogen Fusarium graminearum. Phytopathology 2020; 110:916-926. [PMID: 32125942 DOI: 10.1094/phyto-09-19-0341-r] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Fusarium graminearum is a causal agent of Fusarium head blight (FHB), a disease that reduces yield and quality of cereal crops and contaminates grain with mycotoxins that pose health risks to humans and livestock. Interpopulation antagonistic interactions between isolates that produce different trichothecene mycotoxins can reduce FHB in wheat, but it is not known if interactions between isolates with a shared population identity that produce the same trichothecenes have a similar effect. Using isolates from the predominant F. graminearum populations in North America (NA1 and NA2), we examined intrapopulation interactions by comparing growth, disease progression, and toxin production of individual isolates with multi-isolate mixes. In vitro, mycelial growth was significantly greater when most NA1 and NA2 isolates were cultured individually versus when cultured as a mixture of isolates from the same population. In susceptible wheat Norm, FHB generally progressed faster in heads inoculated with an individual isolate versus a multi-isolate mixture, but the antagonistic effect of intrapopulation interactions was more pronounced for NA1 than NA2 isolates. By contrast, in moderately resistant wheat Alsen, mixtures of isolates from either population caused obvious reductions in FHB development. Mycotoxin contamination was not consistently affected by intrapopulation interactions and varied depending on the interacting isolates from either population. Our results indicate that antagonistic intrapopulation interactions can influence FHB in controlled environmental conditions. Understanding if the regional composition of pathogen populations similarly influences FHB in the field could improve disease forecasting and management practices.
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Affiliation(s)
- Martha M Vaughan
- U.S. Department of Agriculture, Agricultural Research Services, National Center of Agricultural Utilization Research, Mycotoxin Prevention and Applied Microbiology Unit, Peoria, IL 61604
| | - Todd J Ward
- U.S. Department of Agriculture, Agricultural Research Services, National Center of Agricultural Utilization Research, Mycotoxin Prevention and Applied Microbiology Unit, Peoria, IL 61604
| | - Susan P McCormick
- U.S. Department of Agriculture, Agricultural Research Services, National Center of Agricultural Utilization Research, Mycotoxin Prevention and Applied Microbiology Unit, Peoria, IL 61604
| | - Nathane Orwig
- U.S. Department of Agriculture, Agricultural Research Services, National Center of Agricultural Utilization Research, Mycotoxin Prevention and Applied Microbiology Unit, Peoria, IL 61604
| | - William T Hay
- U.S. Department of Agriculture, Agricultural Research Services, National Center of Agricultural Utilization Research, Mycotoxin Prevention and Applied Microbiology Unit, Peoria, IL 61604
| | - Robert Proctor
- U.S. Department of Agriculture, Agricultural Research Services, National Center of Agricultural Utilization Research, Mycotoxin Prevention and Applied Microbiology Unit, Peoria, IL 61604
| | - Debra Palmquist
- U.S. Department of Agriculture, Agricultural Research Services, National Center of Agricultural Utilization Research, Mycotoxin Prevention and Applied Microbiology Unit, Peoria, IL 61604
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Wipfler R, McCormick SP, Proctor R, Teresi J, Hao G, Ward T, Alexander N, Vaughan MM. Synergistic Phytotoxic Effects of Culmorin and Trichothecene Mycotoxins. Toxins (Basel) 2019; 11:E555. [PMID: 31547160 PMCID: PMC6833022 DOI: 10.3390/toxins11100555] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 09/07/2019] [Accepted: 09/16/2019] [Indexed: 02/07/2023] Open
Abstract
Species of the fungus Fusarium cause Fusarium head blight (FHB) of cereal crops and contaminate grain with sesquiterpenoid mycotoxins, including culmorin (CUL) and trichothecenes. While the phytotoxicity of trichothecenes, such as deoxynivalenol (DON), and their role in virulence are well characterized, less is known about the phytotoxicity of CUL and its role in the development of FHB. Herein, we evaluated the phytotoxic effects of purified CUL and CUL-trichothecene mixtures using Chlamydomonas reinhardtii growth and Triticum aestivum (wheat) root elongation assays. By itself, CUL did not affect growth in either system. However, mixtures of CUL with DON, 3-acetyldeoxynivalenol, 15-acetyldeoxynivalenol, or NX-3, but not with nivalenol, inhibited growth in a synergistic manner. Synergistic phytotoxic effects of CUL and DON were also observed on multiple plant varieties and species. The severity of wheat FHB caused by 15 isolates of Fusarium graminearum was negatively correlated with the CUL/DON ratio, but positively correlated with the sum of both CUL and DON. Additionally, during the first week of infection, CUL biosynthetic genes were more highly expressed than the TRI5 trichothecene biosynthetic gene. Furthermore, genomic analysis of Fusarium species revealed that CUL and trichothecene biosynthetic genes consistently co-occur among species closely related to F. graminearum.
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Affiliation(s)
- Rebecca Wipfler
- United States Department of Agriculture, Agricultural Research Services, National Center of Agricultural Utilization Research, Peoria, IL 61604, USA.
| | - Susan P McCormick
- United States Department of Agriculture, Agricultural Research Services, National Center of Agricultural Utilization Research, Peoria, IL 61604, USA.
| | - Robert Proctor
- United States Department of Agriculture, Agricultural Research Services, National Center of Agricultural Utilization Research, Peoria, IL 61604, USA.
| | - Jennifer Teresi
- United States Department of Agriculture, Agricultural Research Services, National Center of Agricultural Utilization Research, Peoria, IL 61604, USA.
| | - Guixia Hao
- United States Department of Agriculture, Agricultural Research Services, National Center of Agricultural Utilization Research, Peoria, IL 61604, USA.
| | - Todd Ward
- United States Department of Agriculture, Agricultural Research Services, National Center of Agricultural Utilization Research, Peoria, IL 61604, USA.
| | - Nancy Alexander
- United States Department of Agriculture, Agricultural Research Services, National Center of Agricultural Utilization Research, Peoria, IL 61604, USA.
| | - Martha M Vaughan
- United States Department of Agriculture, Agricultural Research Services, National Center of Agricultural Utilization Research, Peoria, IL 61604, USA.
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Hao G, McCormick S, Vaughan MM, Naumann TA, Kim HS, Proctor R, Kelly A, Ward TJ. Fusarium graminearum arabinanase (Arb93B) Enhances Wheat Head Blight Susceptibility by Suppressing Plant Immunity. Mol Plant Microbe Interact 2019; 32:888-898. [PMID: 30759350 DOI: 10.1094/mpmi-06-18-0170-r] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Fusarium head blight (FHB) of wheat and barley caused by the fungus Fusarium graminearum reduces crop yield and contaminates grain with mycotoxins. In this study, we investigated two exo-1,5-α-L-arabinanases (Arb93A and Arb93B) secreted by F. graminearum and their effect on wheat head blight development. Arabinan is an important component of plant cell walls but it was not known whether these arabinanases play a role in FHB. Both ARB93A and ARB93B were induced during the early stages of infection. arb93A mutants did not exhibit a detectable change in ability to cause FHB, whereas arb93B mutants caused lower levels of FHB symptoms and deoxynivalenol contamination compared with the wild type. Furthermore, virulence and deoxynivalenol contamination were restored to wild-type levels in ARB93B complemented mutants. Fusion proteins of green fluorescent protein (GFP) with the predicted chloroplast peptide or the mature protein of Arb93B were not observed in the chloroplast. Reactive oxygen species (ROS) production was reduced in the infiltrated zones of Nicotiana benthamiana leaves expressing ARB93B-GFP. Coexpression of ARB93B-GFP and Bax in N. benthamiana leaves significantly suppressed Bax-programmed cell death. Our results indicate that Arb93B enhances plant disease susceptibility by suppressing ROS-associated plant defense responses.
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Affiliation(s)
- Guixia Hao
- Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, United States Department of Agriculture-Agricultural Research Service, Peoria, IL, U.S.A
| | - Susan McCormick
- Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, United States Department of Agriculture-Agricultural Research Service, Peoria, IL, U.S.A
| | - Martha M Vaughan
- Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, United States Department of Agriculture-Agricultural Research Service, Peoria, IL, U.S.A
| | - Todd A Naumann
- Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, United States Department of Agriculture-Agricultural Research Service, Peoria, IL, U.S.A
| | - Hye-Seon Kim
- Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, United States Department of Agriculture-Agricultural Research Service, Peoria, IL, U.S.A
| | - Robert Proctor
- Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, United States Department of Agriculture-Agricultural Research Service, Peoria, IL, U.S.A
| | - Amy Kelly
- Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, United States Department of Agriculture-Agricultural Research Service, Peoria, IL, U.S.A
| | - Todd J Ward
- Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, United States Department of Agriculture-Agricultural Research Service, Peoria, IL, U.S.A
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Cuperlovic-Culf M, Vaughan MM, Vermillion K, Surendra A, Teresi J, McCormick SP. Effects of Atmospheric CO 2 Level on the Metabolic Response of Resistant and Susceptible Wheat to Fusarium graminearum Infection. Mol Plant Microbe Interact 2019; 32:379-391. [PMID: 30256178 DOI: 10.1094/mpmi-06-18-0161-r] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Rising atmospheric CO2 concentrations and associated climate changes are thought to have contributed to the steady increase of Fusarium head blight (FHB) on wheat. However, our understanding of precisely how elevated CO2 influences the defense response of wheat against Fusarium graminearum remains limited. In this study, we evaluated the metabolic profiles of susceptible (Norm) and moderately resistant (Alsen) spring wheat in response to whole-head inoculation with two deoxynivalenol (DON)-producing F. graminearum isolates (DON+), isolates 9F1 and Gz3639, and a DON-deficient (DON-) isolate (Gzt40) at ambient (400 ppm) and elevated (800 ppm) CO2 concentrations. The effects of elevated CO2 were dependent on both the Fusarium strain and the wheat variety, but metabolic differences in the host can explain the observed changes in F. graminearum biomass and DON accumulation. The complexity of abiotic and biotic stress interactions makes it difficult to determine if the observed metabolic changes in wheat are a result of CO2-induced changes in the host, the pathogen, or a combination of both. However, the effects of elevated CO2 were not dependent on DON production. Finally, we identified several metabolic biomarkers for wheat that can reliably predict FHB resistance or susceptibility, even as atmospheric CO2 levels rise.
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Affiliation(s)
| | - Martha M Vaughan
- 2 Mycotoxin Prevention and Applied Microbiology Research Unit, NCAUR, USDA-ARS, Peoria, IL, U.S.A
| | - Karl Vermillion
- 2 Mycotoxin Prevention and Applied Microbiology Research Unit, NCAUR, USDA-ARS, Peoria, IL, U.S.A
| | - Anu Surendra
- 1 National Research Council Canada, Ottawa, Canada; and
| | - Jennifer Teresi
- 2 Mycotoxin Prevention and Applied Microbiology Research Unit, NCAUR, USDA-ARS, Peoria, IL, U.S.A
| | - Susan P McCormick
- 2 Mycotoxin Prevention and Applied Microbiology Research Unit, NCAUR, USDA-ARS, Peoria, IL, U.S.A
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Hao G, Naumann TA, Vaughan MM, McCormick S, Usgaard T, Kelly A, Ward TJ. Characterization of a Fusarium graminearum Salicylate Hydroxylase. Front Microbiol 2019; 9:3219. [PMID: 30671040 PMCID: PMC6331432 DOI: 10.3389/fmicb.2018.03219] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Accepted: 12/11/2018] [Indexed: 11/13/2022] Open
Abstract
Salicylic acid (SA) plays an important role in regulating plant defense responses against pathogens. However, pathogens have evolved ways to manipulate plant SA-mediated defense signaling. Fusarium graminearum causes Fusarium head blight (FHB) and reduces crop yields and quality by producing various mycotoxins. In this study, we aimed to identify the salicylate hydroxylase in F. graminearum and determine its role in wheat head blight development. We initially identified a gene in F. graminearum strain NRRL 46422 that encodes a putative salicylate hydroxylase (designated FgShyC). However, the FgShyC deletion mutant showed a similar ability to degrade SA as wild-type strain 46422; nor did overexpression of FgShyC in E. coli convert SA to catechol. The results indicate that FgShyC is not involved in SA degradation. Further genome sequence analyses resulted in the identification of eight salicylate hydroxylase candidates. Upon addition of 1 mM SA, FGSG_03657 (designated FgShy1), was induced approximately 400-fold. Heterologous expression of FgShy1 in E. coli converted SA to catechol, confirming that FgShy1 is a salicylate hydroxylase. Deletion mutants of FgShy1 were greatly impaired but not completely blocked in SA degradation. Expression analyses of infected tissue showed that FgShy1 was induced during infection, but virulence assays revealed that deletion of FgShy1 alone was not sufficient to affect FHB severity. Although the Fgshy1 deletion mutant did not reduce pathogenicity, we cannot rule out that additional salicylate hydroxylases are present in F. graminearum and characterization of these enzymes will be necessary to fully understand the role of SA-degradation in FHB pathogenesis.
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Affiliation(s)
- Guixia Hao
- Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, United States Department of Agriculture – Agricultural Research Service, Peoria, IL, United States
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Block AK, Vaughan MM, Schmelz EA, Christensen SA. Biosynthesis and function of terpenoid defense compounds in maize (Zea mays). Planta 2019; 249:21-30. [PMID: 30187155 DOI: 10.1007/s00425-018-2999-2] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Accepted: 08/30/2018] [Indexed: 05/19/2023]
Abstract
Maize produces an array of herbivore-induced terpene volatiles that attract parasitoids to infested plants and a suite of pathogen-induced non-volatile terpenoids with antimicrobial activity to defend against pests. Plants rely on complex blends of constitutive and dynamically produced specialized metabolites to mediate beneficial ecological interactions and protect against biotic attack. One such class of metabolites are terpenoids, a large and structurally diverse class of molecules shown to play significant defensive and developmental roles in numerous plant species. Despite this, terpenoids have only recently been recognized as significant contributors to pest resistance in maize (Zea mays), a globally important agricultural crop. The current review details recent advances in our understanding of biochemical structures, pathways and functional roles of maize terpenoids. Dependent upon the lines examined, maize can harbor more than 30 terpene synthases, underlying the inherent diversity of maize terpene defense systems. Part of this defensive arsenal is the inducible production of volatile bouquets that include monoterpenes, homoterpenes and sesquiterpenes, which often function in indirect defense by enabling the attraction of parasitoids and predators. More recently discovered are a subset of sesquiterpene and diterpene hydrocarbon olefins modified by cytochrome P450s to produce non-volatile end-products such kauralexins, zealexins, dolabralexins and β-costic acid. These non-volatile terpenoid phytoalexins often provide effective defense against both microbial and insect pests via direct antimicrobial and anti-feedant activity. The diversity and promiscuity of maize terpene synthases, coupled with a variety of secondary modifications, results in elaborate defensive layers whose identities, regulation and precise functions are continuing to be elucidated.
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Affiliation(s)
- Anna K Block
- Center for Medical, Agricultural and Veterinary Entomology, U.S. Department of Agriculture-Agricultural Research Service, 1700 SW 23rd Drive, Gainesville, FL, 32608, USA.
| | - Martha M Vaughan
- National Center for Agricultural Utilization Research, U.S. Department of Agriculture-Agricultural Research Service, 1815 N. University Street, Peoria, IL, 61604, USA
| | - Eric A Schmelz
- Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA, 92093, USA
| | - Shawn A Christensen
- Center for Medical, Agricultural and Veterinary Entomology, U.S. Department of Agriculture-Agricultural Research Service, 1700 SW 23rd Drive, Gainesville, FL, 32608, USA
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Jacobs-Venter A, Laraba I, Geiser DM, Busman M, Vaughan MM, Proctor RH, McCormick SP, O'Donnell K. Molecular systematics of two sister clades, the Fusarium concolor and F. babinda species complexes, and the discovery of a novel microcycle macroconidium-producing species from South Africa. Mycologia 2018; 110:1189-1204. [PMID: 30522417 DOI: 10.1080/00275514.2018.1526619] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Multilocus DNA sequence data were used to investigate species identity and diversity in two sister clades, the Fusarium concolor (FCOSC) and F. babinda species complexes. Of the 109 isolates analyzed, only 4 were received correctly identified to species and these included 1/46 F. concolor, 1/31 F. babinda, and 2/3 F. anguioides. The majority of the F. concolor and F. babinda isolates were received as F. polyphialidicum, which is a heterotypic synonym of the former species. Previously documented from South America, Africa, Europe, and Australia, our data show that F. concolor is also present in North America. The present study expands the known distribution of F. babinda in Australia to Asia, Europe, and North America. The molecular phylogenetic results support the recognition of a novel Fusarium species within the FCOSC, which is described and illustrated here as F. austroafricanum, sp. nov. It was isolated as an endophyte of kikuyu grass associated with a putative mycotoxicosis of cattle and from plant debris in soil in South Africa. Fusarium austroafricanum is most similar morphologically to F. concolor and F. babinda but differs from the latter two species in producing (i) much longer macroconidia in which the apical cell is blunt to slightly papillate and the basal cell is only slightly notched and (ii) macroconidia via microcycle conidiation on water agar. BLASTn searches of the whole genome sequence of F. austroafricanum NRRL 53441 were conducted to predict mycotoxin potential, using genes known to be essential for the synthesis of several mycotoxins and biologically active metabolites. Based on the presence of intact gene clusters that confer the ability to synthesize mycotoxins and pigments, we analyzed cracked corn kernel cultures of F. austroafricanum via liquid chromatography-mass spectrometry (LC-MS) but failed to detect these metabolites in vitro.
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Affiliation(s)
- Adriaana Jacobs-Venter
- a Biosystematics Unit, Plant Health and Protection, Agricultural Research Council , Pretoria , 0001 South Africa
| | - Imane Laraba
- b Laboratoire de phytopathologie et de biologie moléculaire, département de botanique, Ecole Nationale Supérieure Agronomique , Algiers , Algeria
| | - David M Geiser
- c Department of Plant Pathology and Environmental Microbiology , Pennsylvania State University, University Park , Pennsylvania 16802
| | - Mark Busman
- d Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, US Department of Agriculture , Peoria , Illinois 60604-3999
| | - Martha M Vaughan
- d Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, US Department of Agriculture , Peoria , Illinois 60604-3999
| | - Robert H Proctor
- d Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, US Department of Agriculture , Peoria , Illinois 60604-3999
| | - Susan P McCormick
- d Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, US Department of Agriculture , Peoria , Illinois 60604-3999
| | - Kerry O'Donnell
- d Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, US Department of Agriculture , Peoria , Illinois 60604-3999
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Pereira CB, Ward TJ, Tessmann DJ, Del Ponte EM, Laraba I, Vaughan MM, McCormick SP, Busman M, Kelly A, Proctor RH, O'Donnell K. Fusarium subtropicale, sp. nov., a novel nivalenol mycotoxin-producing species isolated from barley (Hordeum vulgare) in Brazil and sister to F. praegraminearum. Mycologia 2018; 110:860-871. [PMID: 30303468 DOI: 10.1080/00275514.2018.1512296] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Surveys were conducted in commercial wheat and barley fields in the south central production regions of state of Paraná, Brazil, from 2011 to 2015. Spikes displaying visible Fusarium head blight symptoms were collected and the pathogen isolated from the tissues. The 754 Fusarium isolates recovered were identified by a high-throughput multilocus genotyping assay (MLGT) designed to identify trichothecene toxin-producing fusaria (i.e., formerly B-clade, but referred to here as F. sambucinum species complex lineage 1 [FSAMSC-1]) together with sequencing a portion of the translation elongation factor 1-α (TEF1) gene. One strain was discovered that appeared to be closely related to but phylogenetically distinct from F. praegraminearum based on the relatively low 97.7% TEF1 identity and positive genotype obtained with one of the two F. praegraminearum species-specific MLGT probes. Molecular phylogenetic analyses of a 10-gene data set resolved this novel FSAMSC-1 species and F. praegraminearum as sisters. Formally described herein as F. subtropicale, it is phenotypically distinct from the 22 other FSAMSC-1 species in that it produces mostly 1-3-septate macroconidia. Whole-genome sequence data were used to predict its potential to produce mycotoxins. Chemical analyses confirmed that F. subtropicale could produce the mycotoxins 4,15-diacetylnivalenol, butenolide, culmorin, and fusarin C in vitro, and the pathogenicity experiment revealed that F. subtropicale could infect but not spread in susceptible hard red spring wheat cultivar "Norm."
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Affiliation(s)
- Carolina B Pereira
- a Departmento de Agronomia , Universidade Estadual de Maringá , Maringá , Paraná , Brazil 87020-900
| | - Todd J Ward
- b Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service , US Department of Agriculture , Peoria , Illinois 61604-3999
| | - Dauri J Tessmann
- a Departmento de Agronomia , Universidade Estadual de Maringá , Maringá , Paraná , Brazil 87020-900
| | - Emerson M Del Ponte
- c Departmento de Fitopatologia , Universidade Federal de Viçosa , Viçosa , MG , Brazil
| | - Imane Laraba
- b Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service , US Department of Agriculture , Peoria , Illinois 61604-3999
| | - Martha M Vaughan
- b Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service , US Department of Agriculture , Peoria , Illinois 61604-3999
| | - Susan P McCormick
- b Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service , US Department of Agriculture , Peoria , Illinois 61604-3999
| | - Mark Busman
- b Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service , US Department of Agriculture , Peoria , Illinois 61604-3999
| | - Amy Kelly
- b Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service , US Department of Agriculture , Peoria , Illinois 61604-3999
| | - Robert H Proctor
- b Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service , US Department of Agriculture , Peoria , Illinois 61604-3999
| | - Kerry O'Donnell
- b Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service , US Department of Agriculture , Peoria , Illinois 61604-3999
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Abstract
The germ tube burst method (GTBM) was employed to examine karyotypes of 33 Fusarium species representative of 11 species complexes that span the phylogenetic breadth of the genus. The karyotypes revealed that the nucleolar organizing region (NOR), which includes the ribosomal rDNA region, was telomeric in the species where it was discernible. Variable karyotypes were detected in eight species due to variation in numbers of putative core and/or supernumerary chromosomes. The putative core chromosome number (CN) was most variable in the F. solani (CN = 9‒12) and F. buharicum (CN = 9+1 and 18-20) species complexes. Quantitative real-time PCR and genome sequence analysis rejected the hypothesis that the latter variation in CN was due to diploidization. The core CN in six other species complexes where two or more karyotypes were obtained was less variable or fixed. Karyotypes of 10 species in the sambucinum species complex, which is the most derived lineage of Fusarium, revealed that members of this complex possess the lowest CN in the genus. When viewed in context of the species phylogeny, karyotype evolution in Fusarium appears to have been dominated by a reduction in core CN in five closely related complexes that share a most recent common ancestor (tricinctum and incarnatum-equiseti CN = 8-9, chlamydosporum CN = 8, heterosporum CN = 7, sambucinum CN = 4-5) but not in the sister to these complexes (nisikadoi CN = 11, oxysporum CN = 11 and fujikuroi CN = 10-12). CN stability is best illustrated by the F. sambucinum subclade, where the only changes observed since it diverged from other fusaria appear to have involved two independent putative telomere to telomere fusions that reduced the core CN from five to four, once each in the sambucinum and graminearum subclades. Results of the present study indicate a core CN of 4 may be fixed in the latter subclade, which is further distinguished by the absence of putative supernumerary chromosomes. Karyotyping of fusaria in the not too distant future will be done by whole-genome sequencing such that each scaffold represents a complete chromosome from telomere to telomere. The CN data presented here should be of value to assist such full genome assembling.
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Affiliation(s)
- Cees Waalwijk
- Businessunit Biointeractions & Plant Health, Wageningen Plant Research, P.O. Box 16, 6700AA, Wageningen, The Netherlands
| | - Masatoki Taga
- Division of Biological Sciences, Graduate School of Natural Science and Technology, Okayama University, 3-1-1 Tsushima-naka, Kita-ku, Okayama 700-8530, Japan
| | - Song-Lin Zheng
- Division of Biological Sciences, Graduate School of Natural Science and Technology, Okayama University, 3-1-1 Tsushima-naka, Kita-ku, Okayama 700-8530, Japan
| | - Robert H Proctor
- Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, US Department of Agriculture, Peoria, Illinois 61604-3999, USA
| | - Martha M Vaughan
- Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, US Department of Agriculture, Peoria, Illinois 61604-3999, USA
| | - Kerry O'Donnell
- Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, US Department of Agriculture, Peoria, Illinois 61604-3999, USA
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30
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Christensen SA, Huffaker A, Sims J, Hunter CT, Block A, Vaughan MM, Willett D, Romero M, Mylroie JE, Williams WP, Schmelz EA. Fungal and herbivore elicitation of the novel maize sesquiterpenoid, zealexin A4, is attenuated by elevated CO 2. Planta 2018; 247:863-873. [PMID: 29260396 DOI: 10.1007/s00425-017-2830-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Chemical isolation and NMR-based structure elucidation revealed a novel keto-acidic sesquiterpenoid, termed zealexin A4 (ZA4). ZA4 is elicited by pathogens and herbivory, but attenuated by heightened levels of CO 2 . The identification of the labdane-related diterpenoids, termed kauralexins and acidic sesquiterpenoids, termed zealexins, demonstrated the existence of at least ten novel stress-inducible maize metabolites with diverse antimicrobial activity. Despite these advances, the identity of co-occurring and predictably related analytes remains largely unexplored. In the current effort, we identify and characterize the first sesquiterpene keto acid derivative of β-macrocarpene, named zealexin A4 (ZA4). Evaluation of diverse maize inbreds revealed that ZA4 is commonly produced in maize scutella during the first 14 days of seedling development; however, ZA4 production in the scutella was markedly reduced in seedlings grown in sterile soil. Elevated ZA4 production was observed in response to inoculation with adventitious fungal pathogens, such as Aspergillus flavus and Rhizopus microsporus, and a positive relationship between ZA4 production and expression of the predicted zealexin biosynthetic genes, terpene synthases 6 and 11 (Tps6 and Tps11), was observed. ZA4 exhibited significant antimicrobial activity against the mycotoxigenic pathogen A. flavus; however, ZA4 activity against R. microsporus was minimal, suggesting the potential of some fungi to detoxify ZA4. Significant induction of ZA4 production was also observed in response to infestation with the stem tunneling herbivore Ostrinia nubilalis. Examination of the interactive effects of elevated CO2 (E-CO2) on both fungal and herbivore-elicited ZA4 production revealed significantly reduced levels of inducible ZA4 accumulation, consistent with a negative role for E-CO2 on ZA4 production. Collectively, these results describe a novel β-macrocarpene-derived antifungal defense in maize and expand the established diversity of zealexins that are differentially regulated in response to biotic/abiotic stress.
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Affiliation(s)
- Shawn A Christensen
- Chemistry Research Unit, Center for Medical, Agricultural, and Veterinary Entomology, United States Department of Agriculture, Agricultural Research Service, Gainesville, FL, 32608, USA.
| | - Alisa Huffaker
- Section of Cell and Developmental Biology, University of California at San Diego, La Jolla, CA, 92093-0380, USA
| | - James Sims
- Department of Environmental Systems Science, ETH Zurich, 8092, Zurich, Switzerland
| | - Charles T Hunter
- Chemistry Research Unit, Center for Medical, Agricultural, and Veterinary Entomology, United States Department of Agriculture, Agricultural Research Service, Gainesville, FL, 32608, USA
| | - Anna Block
- Chemistry Research Unit, Center for Medical, Agricultural, and Veterinary Entomology, United States Department of Agriculture, Agricultural Research Service, Gainesville, FL, 32608, USA
| | - Martha M Vaughan
- Mycotoxin Prevention and Applied Microbiology Research, United States Department of Agriculture, Agricultural Research Service, 1815 N. University St., Peoria, IL, 61604, USA
| | - Denis Willett
- Chemistry Research Unit, Center for Medical, Agricultural, and Veterinary Entomology, United States Department of Agriculture, Agricultural Research Service, Gainesville, FL, 32608, USA
| | - Maritza Romero
- Chemistry Research Unit, Center for Medical, Agricultural, and Veterinary Entomology, United States Department of Agriculture, Agricultural Research Service, Gainesville, FL, 32608, USA
| | - J Erik Mylroie
- Bennett Aerospace, Engineer and Research Development Center, Vicksburg, MS, 39180, USA
| | - W Paul Williams
- Crop Science Research Laboratory, United States Department of Agriculture, Agricultural Research Service, Dorman Hall, Stone Blvd., Starkville, MS, 39762, USA
| | - Eric A Schmelz
- Section of Cell and Developmental Biology, University of California at San Diego, La Jolla, CA, 92093-0380, USA.
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Christensen SA, Sims J, Vaughan MM, Hunter C, Block A, Willett D, Alborn HT, Huffaker A, Schmelz EA. Commercial hybrids and mutant genotypes reveal complex protective roles for inducible terpenoid defenses in maize. J Exp Bot 2018; 69:1693-1705. [PMID: 29361044 DOI: 10.1093/jxb/erx495] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2017] [Accepted: 12/21/2017] [Indexed: 06/07/2023]
Abstract
Plant defense research is facilitated by the use of genome-sequenced inbred lines; however, a foundational knowledge of interactions in commercial hybrids remains relevant to understanding mechanisms present in crops. Using an array of commercial maize hybrids, we quantified the accumulation patterns of defense-related metabolites and phytohormones in tissues challenged with diverse fungal pathogens. Across hybrids, Southern leaf blight (Cochliobolus heterostrophus) strongly elicited specific sesqui- and diterpenoid defenses, namely zealexin A4 (ZA4) and kauralexin diacids, compared with the stalk-rotting agents Fusarium graminearum and Colletotrichum graminicola. With respect to biological activity, ZA4 and kauralexin diacids demonstrated potent antimicrobial action against F. graminearum. Unexpectedly, ZA4 displayed an opposite effect on C. graminicola by promoting growth. Overall, a negative correlation was observed between total analyzed terpenoids and fungal growth. Statistical analyses highlighted kauralexin A3 and abscisic acid as metabolites most associated with fungal suppression. As an empirical test, mutants of the ent-copalyl diphosphate synthase Anther ear 2 (An2) lacking kauralexin biosynthetic capacity displayed increased susceptibility to C. heterostrophus and Fusarium verticillioides. Our results highlight a widely occurring defensive function of acidic terpenoids in commercial hybrids and the complex nature of elicited pathway products that display selective activities on fungal pathogen species.
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Affiliation(s)
- Shawn A Christensen
- Chemistry Research Unit, Center for Medical, Agricultural, and Veterinary Entomology, United States Department of Agriculture - Agricultural Research Service, Gainesville, FL, USA
| | - James Sims
- Department of Environmental Systems Science, ETH Zurich, Zurich, Switzerl
| | - Martha M Vaughan
- Mycotoxin Prevention and Applied Microbiology Research, United States Department of Agriculture - Agricultural Research Service, N. University St. Peoria, IL, USA
| | - Charles Hunter
- Chemistry Research Unit, Center for Medical, Agricultural, and Veterinary Entomology, United States Department of Agriculture - Agricultural Research Service, Gainesville, FL, USA
| | - Anna Block
- Chemistry Research Unit, Center for Medical, Agricultural, and Veterinary Entomology, United States Department of Agriculture - Agricultural Research Service, Gainesville, FL, USA
| | - Denis Willett
- Chemistry Research Unit, Center for Medical, Agricultural, and Veterinary Entomology, United States Department of Agriculture - Agricultural Research Service, Gainesville, FL, USA
| | - Hans T Alborn
- Chemistry Research Unit, Center for Medical, Agricultural, and Veterinary Entomology, United States Department of Agriculture - Agricultural Research Service, Gainesville, FL, USA
| | - Alisa Huffaker
- Section of Cell and Developmental Biology, University of California at San Diego, La Jolla, CA, USA
| | - Eric A Schmelz
- Section of Cell and Developmental Biology, University of California at San Diego, La Jolla, CA, USA
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Laraba I, Keddad A, Boureghda H, Abdallah N, Vaughan MM, Proctor RH, Busman M, O’Donnell K. Fusarium algeriense, sp. nov., a novel toxigenic crown rot pathogen of durum wheat from Algeria is nested in the Fusarium burgessii species complex. Mycologia 2018. [DOI: 10.1080/00275514.2018.1425067] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Imane Laraba
- Laboratoire de Phytopathologie et de Biologie Moléculaire, Département de Botanique, École Nationale Supérieure Agronomique, Algiers, Algeria
| | - Abdelaziz Keddad
- Laboratoire de Phytopathologie et de Biologie Moléculaire, Département de Botanique, École Nationale Supérieure Agronomique, Algiers, Algeria
| | - Houda Boureghda
- Laboratoire de Phytopathologie et de Biologie Moléculaire, Département de Botanique, École Nationale Supérieure Agronomique, Algiers, Algeria
| | - Nora Abdallah
- Laboratoire de Phytopathologie et de Biologie Moléculaire, Département de Botanique, École Nationale Supérieure Agronomique, Algiers, Algeria
| | - Martha M. Vaughan
- Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, US Department of Agriculture, Peoria, Illinois 60604-3999
| | - Robert H. Proctor
- Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, US Department of Agriculture, Peoria, Illinois 60604-3999
| | - Mark Busman
- Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, US Department of Agriculture, Peoria, Illinois 60604-3999
| | - Kerry O’Donnell
- Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, US Department of Agriculture, Peoria, Illinois 60604-3999
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Gräfenhan T, Johnston PR, Vaughan MM, McCormick SP, Proctor RH, Busman M, Ward TJ, O'Donnell K. Fusarium praegraminearum sp. nov., a novel nivalenol mycotoxin-producing pathogen from New Zealand can induce head blight on wheat. Mycologia 2018; 108:1229-1239. [PMID: 27621289 DOI: 10.3852/16-110] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
We report on the molecular and morphological characterization of a novel type B trichothecene toxin-producing species (i.e. B clade) recovered from litter in a maize field near Wellington, New Zealand, which is described as Fusarium praegraminearum sp. nov. This species was initially identified as F. acuminatum based on morphological characters. However, it differs from this species by producing longer, slightly asymmetrically curved macroconidia in which the apical cell is not as pointed and by its much faster colony growth rate on agar. Molecular phylogenetic analyses of portions of 13 genes resolved F. praegraminearum as the most basal species within the B clade. Mycotoxin analyses demonstrated that it was able to produce 4-acetylnivalenol and 4,15-diacetylnivalenol trichothecenes, the nontrichothecene sesquiterpenes culmorin and hydroxy-culmorins, and the estrogen zearalenone in vitro. Results of a pathogenicity experiment revealed that F. praegraminearum induced moderate head blight on wheat.
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Affiliation(s)
- Tom Gräfenhan
- a Grain Research Laboratory, Canadian Grain Commission, Winnipeg, Manitoba R3C 3G8, Canada
| | - Peter R Johnston
- b Landcare Research Manaaki Whenua, Private Bag 92170, Auckland 1142, New Zealand
| | - Martha M Vaughan
- c Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, US Department of Agriculture, Peoria, Illinois 61604
| | - Susan P McCormick
- c Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, US Department of Agriculture, Peoria, Illinois 61604
| | - Robert H Proctor
- a Grain Research Laboratory, Canadian Grain Commission, Winnipeg, Manitoba R3C 3G8, Canada
| | - Mark Busman
- a Grain Research Laboratory, Canadian Grain Commission, Winnipeg, Manitoba R3C 3G8, Canada
| | - Todd J Ward
- a Grain Research Laboratory, Canadian Grain Commission, Winnipeg, Manitoba R3C 3G8, Canada
| | - Kerry O'Donnell
- c Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, US Department of Agriculture, Peoria, Illinois 61604
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Block A, Vaughan MM, Christensen SA, Alborn HT, Tumlinson JH. Elevated carbon dioxide reduces emission of herbivore-induced volatiles in Zea mays. Plant Cell Environ 2017; 40:1725-1734. [PMID: 28436049 DOI: 10.1111/pce.12976] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Revised: 04/03/2017] [Accepted: 04/07/2017] [Indexed: 06/07/2023]
Abstract
Terpene volatiles produced by sweet corn (Zea mays) upon infestation with pests such as beet armyworm (Spodoptera exigua) function as part of an indirect defence mechanism by attracting parasitoid wasps; yet little is known about the impact of climate change on this form of plant defence. To investigate how a central component of climate change affects indirect defence, we measured herbivore-induced volatile emissions in plants grown under elevated carbon dioxide (CO2 ). We found that S. exigua infested or elicitor-treated Z. mays grown at elevated CO2 had decreased emission of its major sesquiterpene, (E)-β-caryophyllene and two homoterpenes, (3E)-4,8-dimethyl-1,3,7-nonatriene and (3E,7E)-4,8,12-trimethyl-1,3,7,11-tridecatetraene. In contrast, inside the leaves, elicitor-induced (E)-β-caryophyllene hyper-accumulated at elevated CO2 , while levels of homoterpenes were unaffected. Furthermore, gene expression analysis revealed that the induction of terpene synthase genes following treatment was lower in plants grown at elevated CO2 . Our data indicate that elevated CO2 leads both to a repression of volatile synthesis at the transcriptional level and to limitation of volatile release through effects of CO2 on stomatal conductance. These findings suggest that elevated CO2 may alter the ability of Z. mays to utilize volatile terpenes to mediate indirect defenses.
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Affiliation(s)
- Anna Block
- Center for Medical, Agricultural and Veterinary Entomology, U.S. Department of Agriculture - Agricultural Research Service, Gainesville, FL, 32608, USA
| | - Martha M Vaughan
- National Center for Agricultural Utilization Research, U.S. Department of Agriculture - Agricultural Research Service, Peoria, IL, 61604, USA
| | - Shawn A Christensen
- Center for Medical, Agricultural and Veterinary Entomology, U.S. Department of Agriculture - Agricultural Research Service, Gainesville, FL, 32608, USA
| | - Hans T Alborn
- Center for Medical, Agricultural and Veterinary Entomology, U.S. Department of Agriculture - Agricultural Research Service, Gainesville, FL, 32608, USA
| | - James H Tumlinson
- Center for Chemical Ecology, Penn State University, University Park, PA, 16802, USA
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Tewoldemedhin YT, Lamprecht SC, Vaughan MM, Doehring G, O'Donnell K. Soybean SDS in South Africa is Caused by Fusarium brasiliense and a Novel Undescribed Fusarium sp. Plant Dis 2017; 101:150-157. [PMID: 30682303 DOI: 10.1094/pdis-05-16-0729-re] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Soybean sudden death syndrome (SDS) was detected in South Africa for the first time during pathogen surveys conducted in 2013 to 2014. The primary objective of this study was to characterize the 16 slow-growing Fusarium strains that were isolated from the roots of symptomatic plants. Molecular phylogenetic analyses of a portion of translation elongation factor 1-α (TEF1) and the nuclear ribosomal intergenic spacer region (IGS rDNA) indicated that the etiological agents were Fusarium brasiliense and a novel, undescribed Fusarium sp. This is the first report of F. brasiliense outside of Brazil and Argentina and the novel Fusarium sp. causing soybean SDS. Koch's postulates were completed for both fusaria on seven soybean cultivars that are commercially available in South Africa. Results of the pathogenicity experiment revealed that the strains of F. brasiliense and Fusarium sp. differed in aggressiveness to soybean, as reflected in differences in foliar symptoms, root rot, and reduction in shoot length. Cell-free culture filtrates of the two soybean SDS pathogens from South Africa and two positive control strains of F. virguliforme from the United States induced typical SDS symptoms on susceptible soybean cultivars in a whole-seedling assay, indicating that they contained phytotoxins.
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Affiliation(s)
- Yared T Tewoldemedhin
- ARC-Plant Protection Research Institute, Private Bag X5017, Stellenbosch, 7599, Western Cape, South Africa
| | - Sandra C Lamprecht
- ARC-Plant Protection Research Institute, Private Bag X5017, Stellenbosch, 7599, Western Cape, South Africa
| | - Martha M Vaughan
- Mycotoxin Prevention and Applied Microbiology Research Unit, Agricultural Research Service, United States Department of Agriculture, Peoria, IL 61604
| | - Gail Doehring
- Mycotoxin Prevention and Applied Microbiology Research Unit, Agricultural Research Service, United States Department of Agriculture, Peoria, IL 61604
| | - Kerry O'Donnell
- Mycotoxin Prevention and Applied Microbiology Research Unit, Agricultural Research Service, United States Department of Agriculture, Peoria, IL 61604
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Abstract
The fungus Fusarium is an agricultural problem because it can cause disease on most crop plants and can contaminate crops with mycotoxins. There is considerable variation in the presence/absence and genomic location of gene clusters responsible for synthesis of mycotoxins and other secondary metabolites among species of Fusarium. Here, we describe a quantitative real-time PCR (qPCR) method for distinguishing between and estimating the biomass of two closely related species, F. proliferatum and F. verticillioides, that are pathogens of maize. The qPCR assay is based on differences in the two species with respect to the genomic location of the gene cluster responsible for synthesis of fumonisins, a family of carcinogenic mycotoxins. Species-specific qPCR primers were designed from unique sequences that flank one end of the cluster in each species. The primers were used in qPCR to estimate the biomass of each Fusarium species using DNA isolated from pure cultures and from maize seedlings resulting from seeds inoculated with F. proliferatum alone, F. verticillioides alone, or a 1:1 mixture of the two species. Biomass estimations from seedlings were expressed as the amount of DNA of each Fusarium species per amount of maize DNA, as determined using maize-specific qPCR primers designed from the ribosomal gene L17. Analyses of qPCR experiments using the primers indicated that the assay could distinguish between and quantify the biomass of the two Fusarium species. This finding indicates that genetic diversity resulting from variation in the presence/absence and genomic location of SM biosynthetic gene clusters can be a valuable resource for development of qPCR assays for distinguishing between and quantifying fungi in plants.
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Affiliation(s)
- Robert H Proctor
- USDA ARS NCAUR, 1815 N. University St., Peoria, IL, 61604, USA.
- United States Department of Agriculture, National Center for Agricultural Utilization Research, Peoria, IL, USA.
| | - Martha M Vaughan
- United States Department of Agriculture, National Center for Agricultural Utilization Research, Peoria, IL, USA
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Vaughan MM, Huffaker A, Schmelz EA, Dafoe NJ, Christensen SA, McAuslane HJ, Alborn HT, Allen LH, Teal PEA. Interactive Effects of Elevated [CO2] and Drought on the Maize Phytochemical Defense Response against Mycotoxigenic Fusarium verticillioides. PLoS One 2016; 11:e0159270. [PMID: 27410032 PMCID: PMC4943682 DOI: 10.1371/journal.pone.0159270] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Accepted: 06/29/2016] [Indexed: 01/21/2023] Open
Abstract
Changes in climate due to rising atmospheric carbon dioxide concentration ([CO2]) are predicted to intensify episodes of drought, but our understanding of how these combined conditions will influence crop-pathogen interactions is limited. We recently demonstrated that elevated [CO2] alone enhances maize susceptibility to the mycotoxigenic pathogen, Fusarium verticillioides (Fv) but fumonisin levels remain unaffected. In this study we show that maize simultaneously exposed to elevated [CO2] and drought are even more susceptible to Fv proliferation and also prone to higher levels of fumonisin contamination. Despite the increase in fumonisin levels, the amount of fumonisin produced in relation to pathogen biomass remained lower than corresponding plants grown at ambient [CO2]. Therefore, the increase in fumonisin contamination was likely due to even greater pathogen biomass rather than an increase in host-derived stimulants. Drought did not negate the compromising effects of elevated [CO2] on the accumulation of maize phytohormones and metabolites. However, since elevated [CO2] does not influence the drought-induced accumulation of abscisic acid (ABA) or root terpenoid phytoalexins, the effects elevated [CO2] are negated belowground, but the stifled defense response aboveground may be a consequence of resource redirection to the roots.
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Affiliation(s)
- Martha M. Vaughan
- Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, United States Department of Agriculture, Agricultural Research Service, 1815 N University St, Peoria, Illinois, 61604, United States of America
| | - Alisa Huffaker
- Chemistry Research Unit, Center of Medical, Agricultural, and Veterinary Entomology, United States Department of Agriculture, Agricultural Research Service, 1600 SW 23 Drive, Gainesville, Florida, 32608, United States of America
| | - Eric A. Schmelz
- Chemistry Research Unit, Center of Medical, Agricultural, and Veterinary Entomology, United States Department of Agriculture, Agricultural Research Service, 1600 SW 23 Drive, Gainesville, Florida, 32608, United States of America
| | - Nicole J. Dafoe
- Chemistry Research Unit, Center of Medical, Agricultural, and Veterinary Entomology, United States Department of Agriculture, Agricultural Research Service, 1600 SW 23 Drive, Gainesville, Florida, 32608, United States of America
| | - Shawn A. Christensen
- Chemistry Research Unit, Center of Medical, Agricultural, and Veterinary Entomology, United States Department of Agriculture, Agricultural Research Service, 1600 SW 23 Drive, Gainesville, Florida, 32608, United States of America
| | - Heather J. McAuslane
- Department of Nematology and Entomology, University of Florida, Gainesville, Florida, 32610, United States of America
| | - Hans T. Alborn
- Chemistry Research Unit, Center of Medical, Agricultural, and Veterinary Entomology, United States Department of Agriculture, Agricultural Research Service, 1600 SW 23 Drive, Gainesville, Florida, 32608, United States of America
| | - Leon Hartwell Allen
- Chemistry Research Unit, Center of Medical, Agricultural, and Veterinary Entomology, United States Department of Agriculture, Agricultural Research Service, 1600 SW 23 Drive, Gainesville, Florida, 32608, United States of America
| | - Peter E. A. Teal
- Chemistry Research Unit, Center of Medical, Agricultural, and Veterinary Entomology, United States Department of Agriculture, Agricultural Research Service, 1600 SW 23 Drive, Gainesville, Florida, 32608, United States of America
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Li N, Alfiky A, Vaughan MM, Kang S. Stop and smell the fungi: Fungal volatile metabolites are overlooked signals involved in fungal interaction with plants. FUNGAL BIOL REV 2016. [DOI: 10.1016/j.fbr.2016.06.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Vaughan MM, Christensen S, Schmelz EA, Huffaker A, McAuslane HJ, Alborn HT, Romero M, Allen LH, Teal PEA. Accumulation of terpenoid phytoalexins in maize roots is associated with drought tolerance. Plant Cell Environ 2015; 38:2195-207. [PMID: 25392907 DOI: 10.1111/pce.12482] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Revised: 11/04/2014] [Accepted: 11/05/2014] [Indexed: 05/25/2023]
Abstract
Maize (Zea mays) production, which is of global agro-economic importance, is largely limited by herbivore pests, pathogens and environmental conditions, such as drought. Zealexins and kauralexins belong to two recently identified families of acidic terpenoid phytoalexins in maize that mediate defence against both pathogen and insect attacks in aboveground tissues. However, little is known about their function in belowground organs and their potential to counter abiotic stress. In this study, we show that zealexins and kauralexins accumulate in roots in response to both biotic and abiotic stress including, Diabrotica balteata herbivory, Fusarium verticillioides infection, drought and high salinity. We find that the quantity of drought-induced phytoalexins is positively correlated with the root-to-shoot ratio of different maize varieties, and further demonstrate that mutant an2 plants deficient in kauralexin production are more sensitive to drought. The induction of phytoalexins in response to drought is root specific and does not influence phytoalexin levels aboveground; however, the accumulation of phytoalexins in one tissue may influence the induction capacity of other tissues.
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Affiliation(s)
- Martha M Vaughan
- Bacterial Foodborne Pathogens and Mycology, Agricultural Research Service, United States Department of Agriculture, Peoria, IL, 61604, USA
| | - Shawn Christensen
- Chemistry Research Unit, Center of Medical, Agricultural, and Veterinary Entomology, Agricultural Research Service, United States Department of Agriculture, Gainesville, FL, 32608, USA
| | - Eric A Schmelz
- Chemistry Research Unit, Center of Medical, Agricultural, and Veterinary Entomology, Agricultural Research Service, United States Department of Agriculture, Gainesville, FL, 32608, USA
| | - Alisa Huffaker
- Chemistry Research Unit, Center of Medical, Agricultural, and Veterinary Entomology, Agricultural Research Service, United States Department of Agriculture, Gainesville, FL, 32608, USA
| | - Heather J McAuslane
- Department of Entomology and Nematology, University of Florida, Gainesville, FL, 32611, USA
| | - Hans T Alborn
- Chemistry Research Unit, Center of Medical, Agricultural, and Veterinary Entomology, Agricultural Research Service, United States Department of Agriculture, Gainesville, FL, 32608, USA
| | - Maritza Romero
- Chemistry Research Unit, Center of Medical, Agricultural, and Veterinary Entomology, Agricultural Research Service, United States Department of Agriculture, Gainesville, FL, 32608, USA
| | - Leon Hartwell Allen
- Chemistry Research Unit, Center of Medical, Agricultural, and Veterinary Entomology, Agricultural Research Service, United States Department of Agriculture, Gainesville, FL, 32608, USA
| | - Peter E A Teal
- Chemistry Research Unit, Center of Medical, Agricultural, and Veterinary Entomology, Agricultural Research Service, United States Department of Agriculture, Gainesville, FL, 32608, USA
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Marques de Carvalho L, Benda ND, Vaughan MM, Cabrera AR, Hung K, Cox T, Abdo Z, Allen LH, Teal PEA. Mi-1-Mediated Nematode Resistance in Tomatoes is Broken by Short-Term Heat Stress but Recovers Over Time. J Nematol 2015; 47:133-40. [PMID: 26170475 PMCID: PMC4492288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Indexed: 06/04/2023] Open
Abstract
Tomato (Solanum lycopersicum L.) is among the most valuable agricultural products, but Meloidogyne spp. (root-knot nematode) infestations result in serious crop losses. In tomato, resistance to root-knot nematodes is controlled by the gene Mi-1, but heat stress interferes with Mi-1-associated resistance. Inconsistent results in published field and greenhouse experiments led us to test the effect of short-term midday heat stress on tomato susceptibility to Meloidogyne incognita race 1. Under controlled day/night temperatures of 25°C/21°C, 'Amelia', which was verified as possessing the Mi-1 gene, was deemed resistant (4.1 ± 0.4 galls/plant) and Rutgers, which does not possess the Mi-1 gene, was susceptible (132 ± 9.9 galls/plant) to M. incognita infection. Exposure to a single 3 hr heat spike of 35°C was sufficient to increase the susceptibility of 'Amelia' but did not affect Rutgers. Despite this change in resistance, Mi-1 gene expression was not affected by heat treatment, or nematode infection. The heat-induced breakdown of Mi-1 resistance in 'Amelia' did recover with time regardless of additional heat exposures and M. incognita infection. These findings would aid in the development of management strategies to protect the tomato crop at times of heightened M. incognita susceptibility.
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Affiliation(s)
| | - Nicole D Benda
- Entomology and Nematology Department, University of Florida, Gainesville, FL. ; These authors contributed equally to this work
| | - Martha M Vaughan
- National Center for Agricultural Utilization Research USDA-ARS, Peoria, IL
| | - Ana R Cabrera
- Entomology and Nematology Department, University of Florida, Gainesville, FL
| | - Kaddie Hung
- Center for Medical and Veterinary Entomology USDA-ARS, Gainesville, FL
| | - Thomas Cox
- Center for Medical and Veterinary Entomology USDA-ARS, Gainesville, FL
| | - Zaid Abdo
- Area Directors Office USDA-ARS, Athens, GA
| | - L Hartwell Allen
- Center for Medical and Veterinary Entomology USDA-ARS, Gainesville, FL
| | - Peter E A Teal
- Center for Medical and Veterinary Entomology USDA-ARS, Gainesville, FL
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Aoki T, Vaughan MM, McCormick SP, Busman M, Ward TJ, Kelly A, O'Donnell K, Johnston PR, Geiser DM. Fusarium dactylidis sp. nov., a novel nivalenol toxin-producing species sister to F. pseudograminearum isolated from orchard grass (Dactylis glomerata) in Oregon and New Zealand. Mycologia 2014; 107:409-18. [PMID: 25550300 DOI: 10.3852/14-213] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The B trichothecene toxin-producing clade (B clade) of Fusarium includes the etiological agents of Fusarium head blight, crown rot of wheat and barley and stem and ear rot of maize. B clade isolates also have been recovered from several wild and cultivated grasses, including Dactylis glomerata (orchard grass or cock's foot), one of the world's most important forage grasses. Two isolates from the latter host are formally described here as F. dactylidis. Phenotypically F. dactylidis most closely resembles F. ussurianum from the Russian Far East. Both species produce symmetrical sporodochial conidia that are similar in size and curved toward both ends. However, conidia of F. ussurianum typically end in a narrow apical beak while the apical cell of F. dactylidis is acute. Fusarium dactylidis produced nivalenol mycotoxin in planta as well as low but detectable amounts of the estrogenic mycotoxin zearalenone in vitro. Results of a pathogenicity test revealed that F. dactylidis induced mild head blight on wheat.
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Affiliation(s)
- Takayuki Aoki
- Genetic Resources Center (MAFF), National Institute of Agrobiological Sciences, 2-1-2 Kannondai, Tsukuba, Ibaraki 305-8602, Japan
| | - Martha M Vaughan
- Bacterial Foodborne Pathogens and Mycology Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, US Department of Agriculture, Peoria, Illinois 60604-3999
| | - Susan P McCormick
- Bacterial Foodborne Pathogens and Mycology Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, US Department of Agriculture, Peoria, Illinois 60604-3999
| | - Mark Busman
- Bacterial Foodborne Pathogens and Mycology Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, US Department of Agriculture, Peoria, Illinois 60604-3999
| | - Todd J Ward
- Bacterial Foodborne Pathogens and Mycology Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, US Department of Agriculture, Peoria, Illinois 60604-3999
| | - Amy Kelly
- Bacterial Foodborne Pathogens and Mycology Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, US Department of Agriculture, Peoria, Illinois 60604-3999
| | - Kerry O'Donnell
- Bacterial Foodborne Pathogens and Mycology Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, US Department of Agriculture, Peoria, Illinois 60604-3999
| | - Peter R Johnston
- Landcare Research Manaaki Whenua, Private Bag 92170, Auckland 1142, New Zealand
| | - David M Geiser
- Department of Plant Pathology and Environmental Microbiology, Pennsylvania State University, University Park, Pennsylvania 16802
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Vaughan MM, Huffaker A, Schmelz EA, Dafoe NJ, Christensen S, Sims J, Martins VF, Swerbilow J, Romero M, Alborn HT, Allen LH, Teal PEA. Effects of elevated [CO2 ] on maize defence against mycotoxigenic Fusarium verticillioides. Plant Cell Environ 2014; 37:2691-706. [PMID: 24689748 PMCID: PMC4278449 DOI: 10.1111/pce.12337] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2013] [Accepted: 03/23/2014] [Indexed: 05/18/2023]
Abstract
Maize is by quantity the most important C4 cereal crop; however, future climate changes are expected to increase maize susceptibility to mycotoxigenic fungal pathogens and reduce productivity. While rising atmospheric [CO2 ] is a driving force behind the warmer temperatures and drought, which aggravate fungal disease and mycotoxin accumulation, our understanding of how elevated [CO2 ] will effect maize defences against such pathogens is limited. Here we report that elevated [CO2 ] increases maize susceptibility to Fusarium verticillioides proliferation, while mycotoxin levels are unaltered. Fumonisin production is not proportional to the increase in F. verticillioides biomass, and the amount of fumonisin produced per unit pathogen is reduced at elevated [CO2 ]. Following F. verticillioides stalk inoculation, the accumulation of sugars, free fatty acids, lipoxygenase (LOX) transcripts, phytohormones and downstream phytoalexins is dampened in maize grown at elevated [CO2 ]. The attenuation of maize 13-LOXs and jasmonic acid production correlates with reduced terpenoid phytoalexins and increased susceptibility. Furthermore, the attenuated induction of 9-LOXs, which have been suggested to stimulate mycotoxin biosynthesis, is consistent with reduced fumonisin per unit fungal biomass at elevated [CO2 ]. Our findings suggest that elevated [CO2 ] will compromise maize LOX-dependent signalling, which will influence the interactions between maize and mycotoxigenic fungi.
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Affiliation(s)
- Martha M Vaughan
- Chemistry Research Unit, Center of Medical, Agricultural, and Veterinary Entomology, U.S. Department of Agriculture, Agricultural Research Service, Gainesville, FL, 32608, USA
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Lisko KA, Torres R, Harris RS, Belisle M, Vaughan MM, Jullian B, Chevone BI, Mendes P, Nessler CL, Lorence A. Elevating vitamin C content via overexpression of myo-inositol oxygenase and l-gulono-1,4-lactone oxidase in Arabidopsis leads to enhanced biomass and tolerance to abiotic stresses. In Vitro Cell Dev Biol Plant 2013; 49:643-655. [PMID: 25767369 PMCID: PMC4354779 DOI: 10.1007/s11627-013-9568-y] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
l-Ascorbic acid (vitamin C) is an abundant metabolite in plant cells and tissues. Ascorbate functions as an antioxidant, as an enzyme cofactor, and plays essential roles in multiple physiological processes including photosynthesis, photoprotection, control of cell cycle and cell elongation, and modulation of flowering time, gene regulation, and senescence. The importance of this key molecule in regulating whole plant morphology, cell structure, and plant development has been clearly established via characterization of low vitamin C mutants of Arabidopsis, potato, tobacco, tomato, and rice. However, the consequences of elevating ascorbate content in plant growth and development are poorly understood. Here we demonstrate that Arabidopsis lines over-expressing a myo-inositol oxygenase or an l-gulono-1,4-lactone oxidase, containing elevated ascorbate, display enhanced growth and biomass accumulation of both aerial and root tissues. To our knowledge this is the first study demonstrating such a marked positive effect in plant growth in lines engineered to contain elevated vitamin C content. In addition, we present evidence showing that these lines are tolerant to a wide range of abiotic stresses including salt, cold, and heat. Total ascorbate content of the transgenic lines remained higher than those of controls under the abiotic stresses tested. Interestingly, exposure to pyrene, a polycyclic aromatic hydrocarbon and known inducer of oxidative stress in plants, leads to stunted growth of the aerial tissue, reduction in the number of root hairs, and inhibition of leaf expansion in wild type plants, while these symptoms are less severe in the over-expressers. Our results indicate the potential of this metabolic engineering strategy to develop crops with enhanced biomass, abiotic stress tolerance, and phytoremediation capabilities.
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Affiliation(s)
- Katherine A Lisko
- Arkansas Biosciences Institute, Arkansas State University, P.O. Box 639, State University, AR 72467, USA
| | - Raquel Torres
- Arkansas Biosciences Institute, Arkansas State University, P.O. Box 639, State University, AR 72467, USA
| | - Rodney S Harris
- Arkansas Biosciences Institute, Arkansas State University, P.O. Box 639, State University, AR 72467, USA
| | - Melinda Belisle
- Arkansas Biosciences Institute, Arkansas State University, P.O. Box 639, State University, AR 72467, USA
- Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA 01609-2280, USA
| | - Martha M Vaughan
- Department of Plant Pathology, Physiology and Weed Science, Virginia Tech, Blacksburg, VA 24061, USA
| | - Berangère Jullian
- Department of Plant Pathology, Physiology and Weed Science, Virginia Tech, Blacksburg, VA 24061, USA
| | - Boris I Chevone
- Department of Plant Pathology, Physiology and Weed Science, Virginia Tech, Blacksburg, VA 24061, USA
| | - Pedro Mendes
- Virginia Bioinformatics Institute, Virginia Tech, Blacksburg, VA 24061, USA
| | - Craig L Nessler
- Department of Plant Pathology, Physiology and Weed Science, Virginia Tech, Blacksburg, VA 24061, USA
| | - Argelia Lorence
- Arkansas Biosciences Institute, Arkansas State University, P.O. Box 639, State University, AR 72467, USA
- Department of Chemistry and Physics, Arkansas State University, P.O. Box 419, State University, AR 72467, USA
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Vaughan MM, Wang Q, Webster FX, Kiemle D, Hong YJ, Tantillo DJ, Coates RM, Wray AT, Askew W, O’Donnell C, Tokuhisa JG, Tholl D. Formation of the unusual semivolatile diterpene rhizathalene by the Arabidopsis class I terpene synthase TPS08 in the root stele is involved in defense against belowground herbivory. Plant Cell 2013; 25:1108-25. [PMID: 23512856 PMCID: PMC3634680 DOI: 10.1105/tpc.112.100057] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2012] [Revised: 01/13/2013] [Accepted: 03/01/2013] [Indexed: 05/20/2023]
Abstract
Secondary metabolites are major constituents of plant defense against herbivore attack. Relatively little is known about the cell type-specific formation and antiherbivore activities of secondary compounds in roots despite the substantial impact of root herbivory on plant performance and fitness. Here, we describe the constitutive formation of semivolatile diterpenes called rhizathalenes by the class I terpene synthase (TPS) 08 in roots of Arabidopsis thaliana. The primary enzymatic product of TPS08, rhizathalene A, which is produced from the substrate all-trans geranylgeranyl diphosphate, represents a so far unidentified class of tricyclic diterpene carbon skeletons with an unusual tricyclic spiro-hydrindane structure. Protein targeting and administration of stable isotope precursors indicate that rhizathalenes are biosynthesized in root leucoplasts. TPS08 expression is largely localized to the root stele, suggesting a centric and gradual release of its diterpene products into the peripheral root cell layers. We demonstrate that roots of Arabidopsis tps08 mutant plants, grown aeroponically and in potting substrate, are more susceptible to herbivory by the opportunistic root herbivore fungus gnat (Bradysia spp) and suffer substantial removal of peripheral tissue at larval feeding sites. Our work provides evidence for the in vivo role of semivolatile diterpene metabolites as local antifeedants in belowground direct defense against root-feeding insects.
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Affiliation(s)
- Martha M. Vaughan
- Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia 24061
| | - Qiang Wang
- Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia 24061
| | - Francis X. Webster
- Department of Chemistry, State University of New York–Environmental Science and Forestry, Syracuse, New York 13210
| | - Dave Kiemle
- Department of Chemistry, State University of New York–Environmental Science and Forestry, Syracuse, New York 13210
| | - Young J. Hong
- Department of Chemistry, University of California, Davis, California 95616
| | - Dean J. Tantillo
- Department of Chemistry, University of California, Davis, California 95616
| | - Robert M. Coates
- Department of Chemistry, University of Illinois, Urbana, Illinois 61801
| | - Austin T. Wray
- Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia 24061
| | - Whitnee Askew
- Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia 24061
| | | | - James G. Tokuhisa
- Department of Horticulture, Virginia Tech, Blacksburg, Virginia 24061
| | - Dorothea Tholl
- Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia 24061
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Anderson RG, Casady MS, Fee RA, Vaughan MM, Deb D, Fedkenheuer K, Huffaker A, Schmelz EA, Tyler BM, McDowell JM. Homologous RXLR effectors from Hyaloperonospora arabidopsidis and Phytophthora sojae suppress immunity in distantly related plants. Plant J 2012; 72:882-93. [PMID: 22709376 DOI: 10.1111/j.1365-313x.2012.05079.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Diverse pathogens secrete effector proteins into plant cells to manipulate host cellular processes. Oomycete pathogens contain large complements of predicted effector genes defined by an RXLR host cell entry motif. The genome of Hyaloperonospora arabidopsidis (Hpa, downy mildew of Arabidopsis) contains at least 134 candidate RXLR effector genes. Only a small subset of these genes is conserved in related oomycetes from the Phytophthora genus. Here, we describe a comparative functional characterization of the Hpa RXLR effector gene HaRxL96 and a homologous gene, PsAvh163, from the Glycine max (soybean) pathogen Phytophthora sojae. HaRxL96 and PsAvh163 are induced during the early stages of infection and carry a functional RXLR motif that is sufficient for protein uptake into plant cells. Both effectors can suppress immune responses in soybean. HaRxL96 suppresses immunity in Nicotiana benthamiana, whereas PsAvh163 induces an HR-like cell death response in Nicotiana that is dependent on RAR1 and Hsp90.1. Transgenic Arabidopsis plants expressing HaRxL96 or PsAvh163 exhibit elevated susceptibility to virulent and avirulent Hpa, as well as decreased callose deposition in response to non-pathogenic Pseudomonas syringae. Both effectors interfere with defense marker gene induction, but do not affect salicylic acid biosynthesis. Together, these experiments demonstrate that evolutionarily conserved effectors from different oomycete species can suppress immunity in plant species that are divergent from the source pathogen's host.
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Affiliation(s)
- Ryan G Anderson
- Department of Plant Pathology, Physiology and Weed Science, Virginia Tech, Blacksburg, VA 24061-0329, USAChemistry Research Unit, Center of Medical, Agricultural, and Veterinary Entomology, US Department of Agriculture, Agricultural Research Service, Gainesville, FL 32608, USAVirginia Bioinformatics Institute, Virginia Tech, Blacksburg, VA 24061-0329, USA
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Huffaker A, Kaplan F, Vaughan MM, Dafoe NJ, Ni X, Rocca JR, Alborn HT, Teal PEA, Schmelz EA. Novel acidic sesquiterpenoids constitute a dominant class of pathogen-induced phytoalexins in maize. Plant Physiol 2011; 156:2082-97. [PMID: 21690302 PMCID: PMC3149930 DOI: 10.1104/pp.111.179457] [Citation(s) in RCA: 137] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2011] [Accepted: 06/18/2011] [Indexed: 05/18/2023]
Abstract
Nonvolatile terpenoid phytoalexins occur throughout the plant kingdom, but until recently were not known constituents of chemical defense in maize (Zea mays). We describe a novel family of ubiquitous maize sesquiterpenoid phytoalexins, termed zealexins, which were discovered through characterization of Fusarium graminearum-induced responses. Zealexins accumulate to levels greater than 800 μg g⁻¹ fresh weight in F. graminearum-infected tissue. Their production is also elicited by a wide variety of fungi, Ostrinia nubilalis herbivory, and the synergistic action of jasmonic acid and ethylene. Zealexins exhibit antifungal activity against numerous phytopathogenic fungi at physiologically relevant concentrations. Structural elucidation of four members of this complex family revealed that all are acidic sesquiterpenoids containing a hydrocarbon skeleton that resembles β-macrocarpene. Induced zealexin accumulation is preceded by increased expression of the genes encoding TERPENE SYNTHASE6 (TPS6) and TPS11, which catalyze β-macrocarpene production. Furthermore, zealexin accumulation displays direct positive relationships with the transcript levels of both genes. Microarray analysis of F. graminearum-infected tissue revealed that Tps6/Tps11 were among the most highly up-regulated genes, as was An2, an ent-copalyl diphosphate synthase associated with production of kauralexins. Transcript profiling suggests that zealexins cooccur with a number of antimicrobial proteins, including chitinases and pathogenesis-related proteins. In addition to zealexins, kauralexins and the benzoxazinoid 2-hydroxy-4,7-dimethoxy-1,4-benzoxazin-3-one-glucose (HDMBOA-glucose) were produced in fungal-infected tissue. HDMBOA-glucose accumulation occurred in both wild-type and benzoxazine-deficient1 (bx1) mutant lines, indicating that Bx1 gene activity is not required for HDMBOA biosynthesis. Together these results indicate an important cooperative role of terpenoid phytoalexins in maize biochemical defense.
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Affiliation(s)
- Alisa Huffaker
- Center for Medical, Agricultural, and Veterinary Entomology, United States Department of Agriculture, Agricultural Research Service, Chemistry Research Unit, Gainesville, Florida 32608, USA.
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Schmelz EA, Kaplan F, Huffaker A, Dafoe NJ, Vaughan MM, Ni X, Rocca JR, Alborn HT, Teal PE. Identity, regulation, and activity of inducible diterpenoid phytoalexins in maize. Proc Natl Acad Sci U S A 2011; 108:5455-60. [PMID: 21402917 PMCID: PMC3069164 DOI: 10.1073/pnas.1014714108] [Citation(s) in RCA: 172] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Phytoalexins constitute a broad category of pathogen- and insect-inducible biochemicals that locally protect plant tissues. Because of their agronomic significance, maize and rice have been extensively investigated for their terpenoid-based defenses, which include insect-inducible monoterpene and sesquiterpene volatiles. Rice also produces a complex array of pathogen-inducible diterpenoid phytoalexins. Despite the demonstration of fungal-induced ent-kaur-15-ene production in maize over 30 y ago, the identity of functionally analogous maize diterpenoid phytoalexins has remained elusive. In response to stem attack by the European corn borer (Ostrinia nubilalis) and fungi, we observed the induced accumulation of six ent-kaurane-related diterpenoids, collectively termed kauralexins. Isolation and identification of the predominant Rhizopus microsporus-induced metabolites revealed ent-kaur-19-al-17-oic acid and the unique analog ent-kaur-15-en-19-al-17-oic acid, assigned as kauralexins A3 and B3, respectively. Encoding an ent-copalyl diphosphate synthase, fungal-induced An2 transcript accumulation precedes highly localized kauralexin production, which can eventually exceed 100 μg · g(-1) fresh weight. Pharmacological applications of jasmonic acid and ethylene also synergize the induced accumulation of kauralexins. Occurring at elevated levels in the scutella of all inbred lines examined, kauralexins appear ubiquitous in maize. At concentrations as low as 10 μg · mL(-1), kauralexin B3 significantly inhibited the growth of the opportunistic necrotroph R. microsporus and the causal agent of anthracnose stalk rot, Colletotrichum graminicola. Kauralexins also exhibited significant O. nubilalis antifeedant activity. Our work establishes the presence of diterpenoid defenses in maize and enables a more detailed analysis of their biosynthetic pathways, regulation, and crop defense function.
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Affiliation(s)
- Eric A Schmelz
- Chemistry Research Unit, Center of Medical, Agricultural, and Veterinary Entomology, US Department of Agriculture, Agricultural Research Service, Gainesville, FL 32608, USA.
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48
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Vaughan MM, Tholl D, Tokuhisa JG. An aeroponic culture system for the study of root herbivory on Arabidopsis thaliana. Plant Methods 2011; 7:5. [PMID: 21392399 PMCID: PMC3064660 DOI: 10.1186/1746-4811-7-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2010] [Accepted: 03/10/2011] [Indexed: 05/09/2023]
Abstract
BACKGROUND Plant defense against herbivory has been studied primarily in aerial tissues. However, complex defense mechanisms have evolved in all parts of the plant to combat herbivore attack and these mechanisms are likely to differ in the aerial and subterranean environment. Research investigating defense responses belowground has been hindered by experimental difficulties associated with the accessibility and quality of root tissue and the lack of bioassays using model plants with altered defense profiles. RESULTS We have developed an aeroponic culture system based on a calcined clay substrate that allows insect herbivores to feed on plant roots while providing easy recovery of the root tissue. The culture method was validated by a root-herbivore system developed for Arabidopsis thaliana and the herbivore Bradysia spp. (fungus gnat). Arabidopsis root mass obtained from aeroponically grown plants was comparable to that from other culture systems, and the plants were morphologically normal. Bradysia larvae caused considerable root damage resulting in reduced root biomass and water absorption. After feeding on the aeroponically grown root tissue, the larvae pupated and emerged as adults. Root damage of mature plants cultivated in aeroponic substrate was compared to that of Arabidopsis seedlings grown in potting mix. Seedlings were notably more susceptible to Bradysia feeding than mature plants and showed decreased overall growth and survival rates. CONCLUSIONS A root-herbivore system consisting of Arabidopsis thaliana and larvae of the opportunistic herbivore Bradysia spp. has been established that mimics herbivory in the rhizosphere. Bradysia infestation of Arabidopsis grown in this culture system significantly affects plant performance. The culture method will allow simple profiling and in vivo functional analysis of root defenses such as chemical defense metabolites that are released in response to belowground insect attack.
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Affiliation(s)
- Martha M Vaughan
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA
- USDA Agricultural Research Service Center for Medical, Agricultural and Veterinary Entomology, Chemistry Research Unit, Gainesville, FL 32608, USA
| | - Dorothea Tholl
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA
| | - James G Tokuhisa
- Department of Horticulture, Virginia Tech, Blacksburg, VA 24061, USA
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Russell DS, Rassnick KM, Erb HN, Vaughan MM, McDonough SP. An immunohistochemical study of vitamin D receptor expression in canine cutaneous mast cell tumours. J Comp Pathol 2010; 143:223-6. [PMID: 20334872 DOI: 10.1016/j.jcpa.2010.01.019] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2009] [Revised: 01/13/2010] [Accepted: 01/30/2010] [Indexed: 10/19/2022]
Abstract
The active form of vitamin D (1alpha, 25-dihydroxycholecalciferol; calcitriol) has potent anti-neoplastic activity in the management of a number of human malignancies. Despite promising data to suggest that calcitriol is an effective adjunct to current chemotherapy modalities, the role of calcitriol in animal neoplasia is poorly understood. Vitamin D inhibits growth of canine mast cell tumours (MCTs) in vitro, presumably due to ligand-mediated activation of the vitamin D receptor (VDR). The aim of the present study was to examine immunohistochemically the expression of the VDR by reactive and neoplastic canine cutaneous mast cells. Expression was graded according to frequency, intensity and score (frequency x intensity). VDR expression was found in all samples containing reactive mast cells (n=9), and in 67 of 69 (97%) MCTs selected from each of the three Patnaik grades. The frequency and score of VDR labelling was greater in MCTs compared with reactive mast cells (P=0.0005 and 0.001, respectively). There was no difference in VDR frequency between the MCT grades, but the frequency of labelling in grade 3 MCTs was higher than for reactive mast cells (P=0.001). There was no association between tumour mitotic index and any of the three VDR variables (all P>0.16). VDR is widely expressed by reactive and neoplastic canine mast cells in vivo. VDR expression is unlikely to represent an independent prognostic factor, but its presence within biopsy specimens might be used to identify patients that are suited to high-dose vitamin D therapeutic trials.
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Affiliation(s)
- D S Russell
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
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50
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Hess V, Verrill MW, Bomphray CC, Vaughan MM, Allen M, Gore ME. Phase I study of carboplatin, doxorubicin and weekly paclitaxel in patients with advanced ovarian carcinoma. Ann Oncol 2003; 14:638-42. [PMID: 12649113 DOI: 10.1093/annonc/mdg176] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Doxorubicin is an active compound in epithelial ovarian cancer (EOC), but adding it to carboplatin-paclitaxel causes toxicity. Toxicity can be reduced by weekly administration. We examined the tolerability of weekly paclitaxel in combination with carboplatin and doxorubicin. PATIENTS AND METHODS Chemotherapy naïve patients with EOC were treated with doxorubicin (50 mg/m(2) day 1), carboplatin (AUC 6 day 1) and paclitaxel (days 1, 8, 15, 21), 28-day cycle. Three patients were treated at each paclitaxel dose level, starting at 60, 75 and 90 mg/m(2)/week. If more than two patients in a cohort experienced dose-limiting toxicity (DLT) three more patients were treated at the dose level below. RESULTS Twelve patients with advanced EOC received a median of six cycles (range 2-6) of the three-drug combination. DLT occurred at dose level 3: prolonged grade 4 febrile neutropenia, 1 patient; grade 3 peripheral neuropathy, 1 patient. All six patients treated at dose level 2 experienced short-lived grade 4 neutropenia, which led to dose modifications resulting in an actual delivered dose of paclitaxel of 64 mg/m(2)/week. Eight out of 12 patients had measurable disease on CT scan: four obtained a partial remission; three had stable disease. CONCLUSIONS The combination of carboplatin, doxorubicin and paclitaxel in patients with EOC is active and its main toxicity is myelosuppression. Dose intensity of paclitaxel can be maintained in a three-drug combination through weekly administration (65 mg/m(2)).
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Affiliation(s)
- V Hess
- Royal Marsden Hospital, London, UK
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