1
|
Sharma A, Timilsina S, Abrahamian P, Minsavage GV, Jones JB, Vallad GE, Goss EM. Bacterial Mutation During Seasonal Epidemics. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2024; 37:93-97. [PMID: 38105425 DOI: 10.1094/mpmi-10-23-0164-sc] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
Rapidly evolving bacterial pathogens pose a unique challenge for long-term plant disease management. In this study, we investigated the types and rate of mutations in bacterial populations during seasonal disease epidemics. Two phylogenetically distinct strains of the bacterial spot pathogen, Xanthomonas perforans, were marked, released in tomato fields, and recaptured at several time points during the growing season. Genomic variations in recaptured isolates were identified by comparative analysis of their whole-genome sequences. In total, 180 unique variations (116 substitutions, 57 insertions/deletions, and 7 structural variations) were identified from 300 genomes, resulting in the overall host-associated mutation rate of ∼0.3 to 0.9/genome/week. This result serves as a benchmark for bacterial mutation during epidemics in similar pathosystems. [Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
Collapse
Affiliation(s)
- Anuj Sharma
- Department of Plant Pathology, University of Florida, Gainesville, FL, U.S.A
- Gulf Coast Research and Education Center, University of Florida, Wimauma, FL, U.S.A
| | - Sujan Timilsina
- Department of Plant Pathology, University of Florida, Gainesville, FL, U.S.A
| | - Peter Abrahamian
- Gulf Coast Research and Education Center, University of Florida, Wimauma, FL, U.S.A
| | - Gerald V Minsavage
- Department of Plant Pathology, University of Florida, Gainesville, FL, U.S.A
| | - Jeffrey B Jones
- Department of Plant Pathology, University of Florida, Gainesville, FL, U.S.A
| | - Gary E Vallad
- Gulf Coast Research and Education Center, University of Florida, Wimauma, FL, U.S.A
| | - Erica M Goss
- Department of Plant Pathology, University of Florida, Gainesville, FL, U.S.A
- Emerging Pathogens Institute, University of Florida, Gainesville, FL, U.S.A
| |
Collapse
|
2
|
Ahn YJ, Kim H, Choi S, Mazo-Molina C, Prokchorchik M, Zhang N, Kim B, Mang H, Koehler N, Kim J, Lee S, Yoon H, Choi D, Kim MS, Segonzac C, Martin GB, Schultink A, Sohn KH. Ptr1 and ZAR1 immune receptors confer overlapping and distinct bacterial pathogen effector specificities. THE NEW PHYTOLOGIST 2023; 239:1935-1953. [PMID: 37334551 DOI: 10.1111/nph.19073] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2023] [Accepted: 05/22/2023] [Indexed: 06/20/2023]
Abstract
Some nucleotide-binding and leucine-rich repeat receptors (NLRs) indirectly detect pathogen effectors by monitoring their host targets. In Arabidopsis thaliana, RIN4 is targeted by multiple sequence-unrelated effectors and activates immune responses mediated by RPM1 and RPS2. These effectors trigger cell death in Nicotiana benthamiana, but the corresponding NLRs have yet not been identified. To identify N. benthamiana NLRs (NbNLRs) that recognize Arabidopsis RIN4-targeting effectors, we conducted a rapid reverse genetic screen using an NbNLR VIGS library. We identified that the N. benthamiana homolog of Ptr1 (Pseudomonas tomato race 1) recognizes the Pseudomonas effectors AvrRpt2, AvrRpm1, and AvrB. We demonstrated that recognition of the Xanthomonas effector AvrBsT and the Pseudomonas effector HopZ5 is conferred independently by the N. benthamiana homolog of Ptr1 and ZAR1. Interestingly, the recognition of HopZ5 and AvrBsT is contributed unequally by Ptr1 and ZAR1 in N. benthamiana and Capsicum annuum. In addition, we showed that the RLCK XII family protein JIM2 is required for the NbZAR1-dependent recognition of AvrBsT and HopZ5. The recognition of sequence-unrelated effectors by NbPtr1 and NbZAR1 provides an additional example of convergently evolved effector recognition. Identification of key components involved in Ptr1 and ZAR1-mediated immunity could reveal unique mechanisms of expanded effector recognition.
Collapse
Affiliation(s)
- Ye Jin Ahn
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, 37673, Korea
| | - Haseong Kim
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, 37673, Korea
- Plant Immunity Research Center, Seoul National University, Seoul, 08826, Korea
| | - Sera Choi
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, 37673, Korea
| | - Carolina Mazo-Molina
- Boyce Thompson Institute for Plant Research, Ithaca, NY, 14853, USA
- Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, 14853, USA
| | - Maxim Prokchorchik
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, 37673, Korea
| | - Ning Zhang
- Boyce Thompson Institute for Plant Research, Ithaca, NY, 14853, USA
- Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, 14853, USA
| | - Boyoung Kim
- Plant Immunity Research Center, Seoul National University, Seoul, 08826, Korea
- Department of Agriculture, Forestry and Bioresources, Seoul National University, Seoul, 08826, Korea
| | - Hyunggon Mang
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, 37673, Korea
| | - Naio Koehler
- Fortiphyte Inc., 3071 Research Drive, Richmond, CA, 94806, USA
| | - Jieun Kim
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, 37673, Korea
| | - Soeui Lee
- Plant Immunity Research Center, Seoul National University, Seoul, 08826, Korea
- Department of Agriculture, Forestry and Bioresources, Seoul National University, Seoul, 08826, Korea
| | - Hayeon Yoon
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, 37673, Korea
| | - Doil Choi
- Plant Immunity Research Center, Seoul National University, Seoul, 08826, Korea
- Department of Agriculture, Forestry and Bioresources, Seoul National University, Seoul, 08826, Korea
| | - Min-Sung Kim
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, 37673, Korea
| | - Cécile Segonzac
- Plant Immunity Research Center, Seoul National University, Seoul, 08826, Korea
- Department of Agriculture, Forestry and Bioresources, Seoul National University, Seoul, 08826, Korea
- Plant Genomics and Breeding Institute, Seoul National University, Seoul, 08826, Korea
- Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, 08826, Korea
| | - Gregory B Martin
- Boyce Thompson Institute for Plant Research, Ithaca, NY, 14853, USA
- Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, 14853, USA
| | - Alex Schultink
- Fortiphyte Inc., 3071 Research Drive, Richmond, CA, 94806, USA
| | - Kee Hoon Sohn
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, 37673, Korea
- Plant Immunity Research Center, Seoul National University, Seoul, 08826, Korea
- Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, 08826, Korea
- Department of Agricultural Biotechnology, Seoul National University, Seoul, 08826, Korea
| |
Collapse
|
3
|
Bibi S, Weis K, Kaur A, Bhandari R, Goss E, Jones JB, Potnis N. A Brief Evaluation of a Copper Resistance Mobile Genetic Island in the Bacterial Leaf Spot Pathogen Xanthomonas euvesicatoria pv. perforans. PHYTOPATHOLOGY 2023; 113:1394-1398. [PMID: 37097444 DOI: 10.1094/phyto-02-23-0077-sc] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Due to the continuous use of copper containing bactericides without effective alternative bactericides, copper resistance has become more prevalent in plant pathogens, including Xanthomonas euvesicatoria pv. perforans (formerly Xanthomonas perforans), a predominant cause of bacterial leaf spot disease of tomato and pepper in the Southeastern United States. Previously, reports of copper resistance have been associated with a large conjugative plasmid. However, we have characterized a copper resistance genomic island located within the chromosome of multiple X. euvesicatoria pv. perforans strains. The island is distinct from a previously described chromosomally encoded copper resistance island in X. vesicatoria strain XVP26. Computational analysis revealed the genomic island to contain multiple genes associated with genetic mobility, including both phage-related genes and transposase. Among copper-tolerant strains of X. euvesicatoria pv. perforans isolated from Florida, the majority of strains were found to have the copper resistance chromosomally encoded rather than plasmid borne. Our results suggest that this copper resistance island may have two modes of horizontal gene transfer and that chromosomally encoded copper resistance genes may provide a fitness advantage over plasmid-borne resistance.
Collapse
Affiliation(s)
- Shaheen Bibi
- Department of Plant Pathology, University of Florida, Gainesville, FL 32611
| | - Kylie Weis
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL 36849
| | - Amandeep Kaur
- Department of Plant Pathology, University of Florida, Gainesville, FL 32611
| | - Rishi Bhandari
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL 36849
| | - Erica Goss
- Department of Plant Pathology, University of Florida, Gainesville, FL 32611
| | - Jeffrey B Jones
- Department of Plant Pathology, University of Florida, Gainesville, FL 32611
| | - Neha Potnis
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL 36849
| |
Collapse
|
4
|
Kim H, Ahn YJ, Lee H, Chung EH, Segonzac C, Sohn KH. Diversified host target families mediate convergently evolved effector recognition across plant species. CURRENT OPINION IN PLANT BIOLOGY 2023; 74:102398. [PMID: 37295296 DOI: 10.1016/j.pbi.2023.102398] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 05/13/2023] [Accepted: 05/15/2023] [Indexed: 06/12/2023]
Abstract
Recognition of pathogen effectors is a crucial step for triggering plant immunity. Resistance (R) genes often encode for nucleotide-binding leucine-rich repeat receptors (NLRs), and NLRs detect effectors from pathogens to trigger effector-triggered immunity (ETI). NLR recognition of effectors is observed in diverse forms where NLRs directly interact with effectors or indirectly detect effectors by monitoring host guardees/decoys (HGDs). HGDs undergo different biochemical modifications by diverse effectors and expand the effector recognition spectrum of NLRs, contributing robustness to plant immunity. Interestingly, in many cases of the indirect recognition of effectors, HGD families targeted by effectors are conserved across the plant species while NLRs are not. Notably, a family of diversified HGDs can activate multiple non-orthologous NLRs across plant species. Further investigation on HGDs would reveal the mechanistic basis of how the diversification of HGDs confers novel effector recognition by NLRs.
Collapse
Affiliation(s)
- Haseong Kim
- Plant Immunity Research Center, Seoul National University, Seoul, 08826, Republic of Korea
| | - Ye Jin Ahn
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, 37673, Republic of Korea
| | - Hyeonjung Lee
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, 37673, Republic of Korea
| | - Eui-Hwan Chung
- Department of Plant Biotechnology, Korea University, Seoul, 02841, Republic of Korea
| | - Cécile Segonzac
- Plant Immunity Research Center, Seoul National University, Seoul, 08826, Republic of Korea; Department of Agriculture, Forestry and Bioresources, Seoul National University, Seoul, 08826, Republic of Korea; Plant Genomics and Breeding Institute, Seoul National University, Seoul, 08826, Republic of Korea; Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, 08826, Republic of Korea
| | - Kee Hoon Sohn
- Plant Immunity Research Center, Seoul National University, Seoul, 08826, Republic of Korea; Plant Genomics and Breeding Institute, Seoul National University, Seoul, 08826, Republic of Korea; Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, 08826, Republic of Korea; Department of Agricultural Biotechnology, Seoul National University, Seoul, 08826, Republic of Korea.
| |
Collapse
|
5
|
Newberry EA, Minsavage GV, Holland A, Jones JB, Potnis N. Genome-Wide Association to Study the Host-Specificity Determinants of Xanthomonas perforans. PHYTOPATHOLOGY 2023; 113:400-412. [PMID: 36318253 DOI: 10.1094/phyto-08-22-0294-r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Xanthomonas perforans and X. euvesicatoria are the causal agents of bacterial spot disease of tomato and pepper, endemic to the Southeastern United States. Although very closely related, the two bacterial species differ in host specificity, where X. perforans is the dominant pathogen of tomato and X. euvesicatoria that of pepper. This is in part due to the activity of avirulence proteins that are secreted by X. perforans strains and elicit effector-triggered immunity in pepper leaves, thereby restricting pathogen growth. In recent years, the emergence of several pepper-pathogenic X. perforans lineages has revealed variability within the bacterial species to multiply and cause disease in pepper, even in the absence of avirulence gene activity. Here, we investigated the basal evolutionary processes underlying the host range of this species using multiple genome-wide association analyses. Surprisingly, we identified two novel gene candidates that were significantly associated with pepper-pathogenic X. perforans and X. euvesicatoria. Both candidates were predicted to be involved in the transport/acquisition of nutrients common to the plant cell wall or apoplast and included a TonB-dependent receptor, which was disrupted through independent mutations within the X. perforans lineage. The other included a symporter of protons/glutamate, gltP, enriched with pepper-associated mutations near the promoter and start codon of the gene. Functional analysis of these candidates revealed that only the TonB-dependent receptor had a minor effect on the symptom development and growth of X. perforans in pepper leaves, indicating that pathogenicity to this host might have evolved independently within the bacterial species and is likely a complex, multigenic trait.
Collapse
Affiliation(s)
- Eric A Newberry
- Department of Entomology and Plant Pathology, Auburn University, AL 36849
| | | | - Auston Holland
- Department of Entomology and Plant Pathology, Auburn University, AL 36849
| | - Jeffrey B Jones
- Department of Plant Pathology, University of Florida, FL 32611
| | - Neha Potnis
- Department of Entomology and Plant Pathology, Auburn University, AL 36849
| |
Collapse
|
6
|
Klein-Gordon JM, Guingab-Cagmat J, Minsavage GV, Meke L, Vallad GE, Goss EM, Garrett TJ, Jones JB. Strength in Numbers: Density-Dependent Volatile-Induced Antimicrobial Activity by Xanthomonas perforans. PHYTOPATHOLOGY 2023; 113:160-169. [PMID: 36129764 DOI: 10.1094/phyto-04-22-0131-r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
For most of the 20th century, Xanthomonas euvesicatoria was the only known bacterium associated with bacterial spot of tomato in Florida. X. perforans quickly replaced X. euvesicatoria, mainly because of production of three bacteriocins (BCNs) against X. euvesicatoria; however, X. perforans outcompeted X. euvesicatoria even when the three known BCNs were deleted. Surprisingly, we observed antimicrobial activity against X. euvesicatoria in the BCN triple mutant when the triple mutant was grown in Petri plates containing multiple spots but not in Petri plates containing only one spot. We determined that changes in the headspace composition (i.e., volatiles) rather than a diffusible signal in the agar were required for induction of the antimicrobial activity. Other Xanthomonas species also produced volatile-induced antimicrobial compounds against X. euvesicatoria and elicited antimicrobial activity by X. perforans. A wide range of plant pathogenic bacteria, including Clavibacter michiganensis subsp. michiganensis, Pantoea stewartii, and Pseudomonas cichorii, also elicited antimicrobial activity by X. perforans when multiple spots of the species were present. To identify potential antimicrobial compounds, we performed liquid chromatography with high-resolution mass spectrometry of the agar surrounding the spot in the high cell density Petri plates where the antimicrobial activity was present compared with agar surrounding the spot in Petri plates with one spot where antimicrobial activity was not observed. Among the compounds identified in the zone of inhibition were N-butanoyl-L-homoserine lactone and N-(3-hydroxy-butanoyl)-homoserine lactone, which are known quorum-sensing metabolites in other bacteria.
Collapse
Affiliation(s)
- Jeannie M Klein-Gordon
- Department of Plant Pathology, IFAS, University of Florida, Gainesville, FL
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI
| | - Joy Guingab-Cagmat
- Southeast Center for Integrated Metabolomics (SECIM), University of Florida, Gainesville, FL
| | - Gerald V Minsavage
- Department of Plant Pathology, IFAS, University of Florida, Gainesville, FL
| | - Laurel Meke
- Southeast Center for Integrated Metabolomics (SECIM), University of Florida, Gainesville, FL
| | - Gary E Vallad
- Department of Plant Pathology, IFAS, University of Florida, Gainesville, FL
- Gulf Coast Research and Education Center, IFAS, University of Florida, Balm, FL
| | - Erica M Goss
- Department of Plant Pathology, IFAS, University of Florida, Gainesville, FL
- Emerging Pathogens Institute, University of Florida, Gainesville, FL
| | - Timothy J Garrett
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI
- Department of Pathology, Immunology and Laboratory Medicine, University of Florida, Gainesville, FL
| | - Jeffrey B Jones
- Department of Plant Pathology, IFAS, University of Florida, Gainesville, FL
| |
Collapse
|
7
|
Jibrin MO, Timilsina S, Minsavage GV, Vallad GE, Roberts PD, Goss EM, Jones JB. Bacterial Spot of Tomato and Pepper in Africa: Diversity, Emergence of T5 Race, and Management. Front Microbiol 2022; 13:835647. [PMID: 35509307 PMCID: PMC9058171 DOI: 10.3389/fmicb.2022.835647] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 01/21/2022] [Indexed: 11/13/2022] Open
Abstract
Bacterial spot disease was first reported from South Africa by Ethel M. Doidge in 1920. In the ensuing century after the initial discovery, the pathogen has gained global attention in plant pathology research, providing insights into host-pathogen interactions, pathogen evolution, and effector discovery, such as the first discovery of transcription activation-like effectors, among many others. Four distinct genetic groups, including Xanthomonas euvesicatoria (proposed name: X. euvesicatoria pv. euvesicatoria), Xanthomonas perforans (proposed name: X. euvesicatoria pv. perforans), Xanthomonas gardneri (proposed name: Xanthomonas hortorum pv. gardneri), and Xanthomonas vesicatoria, are known to cause bacterial spot disease. Recently, a new race of a bacterial spot pathogen, race T5, which is a product of recombination between at least two Xanthomonas species, was reported in Nigeria. In this review, our focus is on the progress made on the African continent, vis-à-vis progress made in the global bacterial spot research community to provide a body of information useful for researchers in understanding the diversity, evolutionary changes, and management of the disease in Africa.
Collapse
Affiliation(s)
- Mustafa Ojonuba Jibrin
- Tree Fruit Research and Extension Center, Washington State University, Wenatchee, WA, United States
- Department of Crop Protection, Ahmadu Bello University, Zaria, Nigeria
| | - Sujan Timilsina
- Plant Pathology Department, University of Florida, Gainesville, FL, United States
| | - Gerald V. Minsavage
- Plant Pathology Department, University of Florida, Gainesville, FL, United States
| | - Garry E. Vallad
- Plant Pathology Department, University of Florida, Gainesville, FL, United States
- Gulf Coast Research and Education Center, University of Florida, Wimauma, FL, United States
| | - Pamela D. Roberts
- Plant Pathology Department, University of Florida, Gainesville, FL, United States
- UF/IFAS Southwest Florida Research and Education Center, Immokalee, FL, United States
| | - Erica M. Goss
- Plant Pathology Department, University of Florida, Gainesville, FL, United States
- Emerging Pathogens Institute, University of Florida, Gainesville, FL, United States
| | - Jeffrey B. Jones
- Plant Pathology Department, University of Florida, Gainesville, FL, United States
| |
Collapse
|
8
|
Bernal E, Rotondo F, Roman-Reyna V, Klass T, Timilsina S, Minsavage GV, Iruegas-Bocardo F, Goss EM, Jones JB, Jacobs JM, Miller SA, Francis DM. Migration Drives the Replacement of Xanthomonas perforans Races in the Absence of Widely Deployed Resistance. Front Microbiol 2022; 13:826386. [PMID: 35369455 PMCID: PMC8971904 DOI: 10.3389/fmicb.2022.826386] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 02/09/2022] [Indexed: 11/13/2022] Open
Abstract
Changes in Xanthomonas race and species composition causing bacterial spot of tomato have occurred throughout the world and are often associated with epidemics. Knowledge of bacterial population structure is key for resistance discovery and deployment. We surveyed Xanthomonas spp. composition from processing tomato fields in the Midwestern United States over a 4-year period between 2017 and 2020, compared these to strains collected previously, and found that X. perforans is currently the most prevalent species. We characterized 564 X. perforans isolates for sequence variation in avrXv3 to distinguish between race T3 and T4 and validated race designation using hypersensitive response (HR) assays for 106 isolates. Race T4 accounted for over 95% of X. perforans isolates collected in the Midwest between 2017 and 2020. Whole genome sequencing, Average Nucleotide Identity (ANI) analysis, core genome alignment and single nucleotide polymorphism (SNP) detection relative to a reference strain, and phylogenomic analysis suggest that the majority of Midwestern X. perforans strains collected between 2017 and 2020 were nearly identical, with greater than 99.99% ANI to X. perforans isolates collected from Collier County, Florida in 2012. These isolates shared a common SNP variant resulting an a premature stop codon in avrXv3. One sequenced isolate was identified with a deletion of avrXv3 and shared 99.99% ANI with a strain collected in Collier Co., Florida in 2006. A population shift to X. perforans T4 occurred in the absence of widely deployed resistance, with only 7% of tomato varieties tested having the resistant allele at the Xv3/Rx-4 locus. The persistence of nearly identical strains over multiple years suggests that migration led to the establishment of an endemic population. Our findings validate a genomics-based framework to track shifts in X. perforans populations due to migration, mutation, drift, or selection based on comparisons to 146 genomes.
Collapse
Affiliation(s)
- Eduardo Bernal
- Department of Horticulture and Crop Science, College of Food, Agricultural, and Environmental Sciences, The Ohio State University, Wooster, OH, United States
| | - Francesca Rotondo
- Department of Plant Pathology, College of Food, Agricultural, and Environmental Sciences, The Ohio State University, Wooster, OH, United States
| | - Veronica Roman-Reyna
- Department of Plant Pathology, College of Food, Agricultural, and Environmental Sciences, The Ohio State University, Columbus, OH, United States
- Infectious Diseases Institute, The Ohio State University, Columbus, OH, United States
| | - Taylor Klass
- Department of Plant Pathology, College of Food, Agricultural, and Environmental Sciences, The Ohio State University, Columbus, OH, United States
- Infectious Diseases Institute, The Ohio State University, Columbus, OH, United States
| | - Sujan Timilsina
- Department of Plant Pathology, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, United States
| | - Gerald V. Minsavage
- Department of Plant Pathology, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, United States
| | - Fernanda Iruegas-Bocardo
- Department of Plant Pathology, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, United States
| | - Erica M. Goss
- Department of Plant Pathology, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, United States
- Emerging Pathogens Institute, University of Florida, Gainesville, FL, United States
| | - Jeffrey B. Jones
- Department of Plant Pathology, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, United States
| | - Jonathan M. Jacobs
- Department of Plant Pathology, College of Food, Agricultural, and Environmental Sciences, The Ohio State University, Columbus, OH, United States
- Infectious Diseases Institute, The Ohio State University, Columbus, OH, United States
| | - Sally A. Miller
- Department of Plant Pathology, College of Food, Agricultural, and Environmental Sciences, The Ohio State University, Wooster, OH, United States
| | - David M. Francis
- Department of Horticulture and Crop Science, College of Food, Agricultural, and Environmental Sciences, The Ohio State University, Wooster, OH, United States
- *Correspondence: David M. Francis,
| |
Collapse
|
9
|
Osdaghi E, Jones JB, Sharma A, Goss EM, Abrahamian P, Newberry EA, Potnis N, Carvalho R, Choudhary M, Paret ML, Timilsina S, Vallad GE. A centenary for bacterial spot of tomato and pepper. MOLECULAR PLANT PATHOLOGY 2021; 22:1500-1519. [PMID: 34472193 PMCID: PMC8578828 DOI: 10.1111/mpp.13125] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 08/03/2021] [Accepted: 08/05/2021] [Indexed: 05/08/2023]
Abstract
DISEASE SYMPTOMS Symptoms include water-soaked areas surrounded by chlorosis turning into necrotic spots on all aerial parts of plants. On tomato fruits, small, water-soaked, or slightly raised pale-green spots with greenish-white halos are formed, ultimately becoming dark brown and slightly sunken with a scabby or wart-like surface. HOST RANGE Main and economically important hosts include different types of tomatoes and peppers. Alternative solanaceous and nonsolanaceous hosts include Datura spp., Hyoscyamus spp., Lycium spp., Nicotiana rustica, Physalis spp., Solanum spp., Amaranthus lividus, Emilia fosbergii, Euphorbia heterophylla, Nicandra physaloides, Physalis pubescens, Sida glomerata, and Solanum americanum. TAXONOMIC STATUS OF THE PATHOGEN Domain, Bacteria; phylum, Proteobacteria; class, Gammaproteobacteria; order, Xanthomonadales; family, Xanthomonadaceae; genus, Xanthomonas; species, X. euvesicatoria, X. hortorum, X. vesicatoria. SYNONYMS (NONPREFERRED SCIENTIFIC NAMES) Bacterium exitiosum, Bacterium vesicatorium, Phytomonas exitiosa, Phytomonas vesicatoria, Pseudomonas exitiosa, Pseudomonas gardneri, Pseudomonas vesicatoria, Xanthomonas axonopodis pv. vesicatoria, Xanthomonas campestris pv. vesicatoria, Xanthomonas cynarae pv. gardneri, Xanthomonas gardneri, Xanthomonas perforans. MICROBIOLOGICAL PROPERTIES Colonies are gram-negative, oxidase-negative, and catalase-positive and have oxidative metabolism. Pale-yellow domed circular colonies of 1-2 mm in diameter grow on general culture media. DISTRIBUTION The bacteria are widespread in Africa, Brazil, Canada and the USA, Australia, eastern Europe, and south-east Asia. Occurrence in western Europe is restricted. PHYTOSANITARY CATEGORIZATION A2 no. 157, EU Annex designation II/A2. EPPO CODES XANTEU, XANTGA, XANTPF, XANTVE.
Collapse
Affiliation(s)
- Ebrahim Osdaghi
- Department of Plant ProtectionCollege of AgricultureUniversity of TehranKarajIran
| | - Jeffrey B. Jones
- Plant Pathology DepartmentUniversity of FloridaGainesvilleFloridaUSA
| | - Anuj Sharma
- Plant Pathology DepartmentUniversity of FloridaGainesvilleFloridaUSA
| | - Erica M. Goss
- Plant Pathology DepartmentUniversity of FloridaGainesvilleFloridaUSA
- Emerging Pathogens InstituteUniversity of FloridaGainesvilleFloridaUSA
| | - Peter Abrahamian
- Plant Pathology DepartmentUniversity of FloridaGainesvilleFloridaUSA
- Gulf Coast Research and Education CenterUniversity of FloridaWimaumaFloridaUSA
| | - Eric A. Newberry
- Department of Entomology and Plant PathologyAuburn UniversityAuburnAlabamaUSA
| | - Neha Potnis
- Department of Entomology and Plant PathologyAuburn UniversityAuburnAlabamaUSA
| | - Renato Carvalho
- Plant Pathology DepartmentUniversity of FloridaGainesvilleFloridaUSA
| | - Manoj Choudhary
- Plant Pathology DepartmentUniversity of FloridaGainesvilleFloridaUSA
| | - Mathews L. Paret
- Department of Plant PathologyNorth Florida Research and Education CenterUniversity of FloridaQuincyFloridaUSA
| | - Sujan Timilsina
- Plant Pathology DepartmentUniversity of FloridaGainesvilleFloridaUSA
| | - Gary E. Vallad
- Gulf Coast Research and Education CenterUniversity of FloridaWimaumaFloridaUSA
| |
Collapse
|
10
|
Sharma A, Timilsina S, Abrahamian P, Minsavage GV, Colee J, Ojiambo PS, Goss EM, Vallad GE, Jones JB. Need for speed: bacterial effector XopJ2 is associated with increased dispersal velocity of Xanthomonas perforans. Environ Microbiol 2021; 23:5850-5865. [PMID: 33891376 PMCID: PMC8597037 DOI: 10.1111/1462-2920.15541] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 04/20/2021] [Indexed: 11/28/2022]
Abstract
Bacterial spot caused by Xanthomonas perforans (Xp) is an economically important disease in tomato. Previous studies have shown that the recently isolated Xp strains have acquired and retained the effector gene, xopJ2, which has been reported to increase fitness of the pathogen in the field. To elucidate the fitness benefit of xopJ2, we quantified the effect of xopJ2 on the dispersal and evolution of Xp populations on tomato. We compared movement of two wild-type Xp strains expressing xopJ2 to their respective xopJ2 mutants when co-inoculated in the field. We developed a binary logistic model to predict the presence of Xp over spatial and temporal dimensions with or without xopJ2. Based on the model, wild-type bacteria were dispersed approximately three times faster than the xopJ2 mutants. In a simulation experiment, the selective advantage due to increased dispersal velocity led to an increase in the frequency of xopJ2 gene in the Xp population and its apparent fixation within 10 to 12 cropping seasons of the tomato crop. Our results show that the presence of a single gene can affect the dispersal of a bacterial pathogen and significantly alter its population dynamics.
Collapse
Affiliation(s)
- Anuj Sharma
- Department of Plant PathologyUniversity of FloridaGainesvilleFloridaUSA
| | - Sujan Timilsina
- Department of Plant PathologyUniversity of FloridaGainesvilleFloridaUSA
| | - Peter Abrahamian
- Gulf Coast Research and Education CenterUniversity of FloridaWimaumaFloridaUSA
| | | | - James Colee
- Statistics Consulting Unit, Institute of Food and Agricultural SciencesUniversity of FloridaGainesvilleFloridaUSA
| | - Peter S. Ojiambo
- Department of Entomology and Plant PathologyNorth Carolina State UniversityRaleighNorth CarolinaUSA
| | - Erica M. Goss
- Department of Plant PathologyUniversity of FloridaGainesvilleFloridaUSA
- Emerging Pathogens InstituteUniversity of FloridaGainesvilleFloridaUSA
| | - Gary E. Vallad
- Gulf Coast Research and Education CenterUniversity of FloridaWimaumaFloridaUSA
| | - Jeffrey B. Jones
- Department of Plant PathologyUniversity of FloridaGainesvilleFloridaUSA
| |
Collapse
|
11
|
Potnis N. Harnessing Eco-Evolutionary Dynamics of Xanthomonads on Tomato and Pepper to Tackle New Problems of an Old Disease. ANNUAL REVIEW OF PHYTOPATHOLOGY 2021; 59:289-310. [PMID: 34030449 DOI: 10.1146/annurev-phyto-020620-101612] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Bacterial spot is an endemic seedborne disease responsible for recurring outbreaks on tomato and pepper around the world. The disease is caused by four diverse species, Xanthomonas gardneri, Xanthomonas euvesicatoria, Xanthomonas perforans, and Xanthomonas vesicatoria. There are no commercially available disease-resistant tomato varieties, and the disease is managed by chemical/biological control options, although these have not reduced the incidence of outbreaks. The disease on peppers is managed by disease-resistant cultivars that are effective against X. euvesicatoria but not X. gardneri. A significant shift in composition and prevalence of different species and races of the pathogen has occurred over the past century. Here, I attempt to review ecological and evolutionary processes associated with the population dynamics leading to disease emergence and spread. The goal of this review is to integrate the knowledge on population genomics and molecular plant-microbe interactions for this pathosystem to tailor disease management strategies.
Collapse
Affiliation(s)
- Neha Potnis
- Department of Entomology and Plant Pathology, Auburn University, Auburn, Alabama 36849, USA;
| |
Collapse
|
12
|
Abrahamian P, Klein-Gordon JM, Jones JB, Vallad GE. Epidemiology, diversity, and management of bacterial spot of tomato caused by Xanthomonas perforans. Appl Microbiol Biotechnol 2021; 105:6143-6158. [PMID: 34342710 DOI: 10.1007/s00253-021-11459-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 07/05/2021] [Accepted: 07/09/2021] [Indexed: 11/28/2022]
Abstract
Tomato is an important crop grown worldwide. Various plant diseases cause massive losses in tomato plants due to diverse biotic agents. Bacterial spot of tomato (BST) is a worldwide disease that results in high losses in processed and fresh tomato. Xanthomonas perforans, an aerobic, single-flagellated, rod-shaped, Gram-negative plant pathogenic bacterium, is one of the leading causes of BST. Over the past three decades, X. perforans has increasingly been reported from tomato-growing regions and became a major bacterial disease. X. perforans thrives under high humidity and high temperature, which is commonplace in tropical and subtropical climates. Distinguishing symptoms of BST are necrotic lesions that can coalesce and cause a shot-hole appearance. X. perforans can occasionally cause fruit symptoms depending on disease pressure during fruit development. Short-distance movement in the field is mainly dependent on wind-driven rain, whereas long distance movement occurs through contaminated seed or plant material. X. perforans harbors a suite of effectors that increase pathogen virulence, fitness, and dissemination. BST management mainly relies on copper-based compounds; however, resistance is widespread. Alternative compounds, such as nanomaterials, are currently being evaluated and show high potential for BST management. Resistance breeding remains difficult to attain due to limited resistant germplasm. While the increased genetic diversity and gain and loss of effectors in X. perforans limits the success of single-gene resistance, the adoption of effector-specific transgenes and quantitative resistance may lead to durable host resistance. However, further research that aims to more effectively implement novel management tools is required to curb disease spread. KEY POINTS: • Xanthomonas perforans causes bacterial spot on tomato epidemics through infected seedlings and movement of plant material. • Genetic diversity plays a major role in shaping populations which is evident in loss and gain of effectors. • Management relies on copper sprays, but nanoparticles are a promising alternative to reduce copper toxicity.
Collapse
Affiliation(s)
- Peter Abrahamian
- Beltsville Agricultural Research Center, Molecular Plant Pathology Laboratory, USDA-ARS, Beltsville, MD, 20705, USA.
| | | | - Jeffrey B Jones
- Department of Plant Pathology, University of Florida, Gainesville, FL, 32611, USA
| | - Gary E Vallad
- Gulf Coast Research and Education Center, University of Florida, Wimauma, FL, 33598, USA.
| |
Collapse
|
13
|
Vinatzer BA. The Power of a Statewide Survey When Phenotypic Testing Is Combined with Genomics-Enabled Molecular Characterization and Network Analyses. PHYTOPATHOLOGY 2021; 111:904-905. [PMID: 34281354 DOI: 10.1094/phyto-01-21-0025-ia] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Affiliation(s)
- Boris A Vinatzer
- School of Plant and Environmental Sciences, Virginia Tech, Blacksburg, VA
| |
Collapse
|
14
|
Klein-Gordon JM, Xing Y, Garrett KA, Abrahamian P, Paret ML, Minsavage GV, Strayer-Scherer AL, Fulton JC, Timilsina S, Jones JB, Goss EM, Vallad GE. Assessing Changes and Associations in the Xanthomonas perforans Population Across Florida Commercial Tomato Fields Via a Statewide Survey. PHYTOPATHOLOGY 2021; 111:1029-1041. [PMID: 33048630 DOI: 10.1094/phyto-09-20-0402-r] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Before 1991, Xanthomonas euvesicatoria was the causal agent of bacterial spot of tomato in Florida but was quickly replaced by X. perforans. The X. perforans population has changed in genotype and phenotype despite lack of a clear selection pressure. To determine the current Xanthomonas population in Florida, we collected 585 Xanthomonas strains from 70 tomato fields, representing 22 farms across eight counties, in the Florida tomato production region. Strains were isolated from 23 cultivars across eight seed producers and were associated with eight transplant facilities during the fall 2017 season. Our collection was phenotypically and genotypically characterized. Only X. perforans was identified, and all strains except one (99.8%) were tolerant to copper sulfate and 25% of strains were resistant to streptomycin sulfate. Most of the strains (99.3%) that were resistant to streptomycin sulfate were sequence type 1. The X. perforans population consisted of tomato races 3 (8%) and 4 (92%) and all three previously reported sequence types, ranging from 22 to 46% frequency. Approximately half of all strains, none of which were sequence type 2, produced bacteriocins against X. euvesicatoria. Effector profiles were highly variable among strains, which could impact the strains' host range. The effector xopJ4, which was previously thought to be conserved in X. perforans tomato pathogens, was absent in 19 strains. Nonmetric multidimensional scaling and network analyses show how strains and strain traits were associated with production system variables, including anonymized farms and transplant facilities. These analyses show that the composition of the Florida X. perforans population is diverse and complex.
Collapse
Affiliation(s)
- Jeannie M Klein-Gordon
- Department of Plant Pathology, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32611
- Emerging Pathogens Institute, University of Florida, Gainesville, FL 32611
| | - Yanru Xing
- Department of Plant Pathology, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32611
- Emerging Pathogens Institute, University of Florida, Gainesville, FL 32611
- Food Systems Institute, University of Florida, Gainesville, FL 32611
| | - Karen A Garrett
- Department of Plant Pathology, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32611
- Emerging Pathogens Institute, University of Florida, Gainesville, FL 32611
- Food Systems Institute, University of Florida, Gainesville, FL 32611
| | - Peter Abrahamian
- Department of Plant Pathology, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32611
- Gulf Coast Research and Education Center, Institute of Food and Agricultural Sciences, University of Florida, Balm, FL 33598
| | - Matthews L Paret
- Department of Plant Pathology, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32611
- North Florida Research and Education Center, Institute of Food and Agricultural Sciences, University of Florida, Quincy, FL 32351
| | - Gerald V Minsavage
- Department of Plant Pathology, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32611
| | | | - James C Fulton
- Department of Plant Pathology, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32611
| | - Sujan Timilsina
- Department of Plant Pathology, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32611
| | - Jeffrey B Jones
- Department of Plant Pathology, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32611
| | - Erica M Goss
- Department of Plant Pathology, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32611
- Emerging Pathogens Institute, University of Florida, Gainesville, FL 32611
| | - Gary E Vallad
- Department of Plant Pathology, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32611
- Gulf Coast Research and Education Center, Institute of Food and Agricultural Sciences, University of Florida, Balm, FL 33598
| |
Collapse
|
15
|
Abrahamian P, Sharma A, Jones JB, Vallad GE. Dynamics and Spread of Bacterial Spot Epidemics in Tomato Transplants Grown for Field Production. PLANT DISEASE 2021; 105:566-575. [PMID: 32865478 DOI: 10.1094/pdis-05-20-0945-re] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Tomato transplants are the primary means of establishing commercial tomato production fields in the eastern United States. Transplants are often suspected as the source of inoculum for major outbreaks in production fields of bacterial spot of tomato (BST) caused by Xanthomonas perforans (Xp). A combination of high plant densities with overhead irrigation, high humidity, and high temperatures are conducive to BST outbreaks during transplant production. In addition to chemical control, transplant growers use roguing to remove diseased transplants, as a primary way to manage BST during transplant production. The value of roguing is often questioned, because information about the rate of pathogen spread and the incubation period between infection and symptom development is limited. In this study, we evaluated the extent of X. perforans spread on tomato transplants relative to symptom development by using a rifampicin-resistant X. perforans strain and conducting experiments in an environmentally controlled greenhouse simulating grower practices and also at a commercial transplant facility in Florida. BST symptom development typically lagged behind X. perforans dispersal by at least 5 to 7 days depending on environmental conditions. Furthermore, X. perforans was capable of aerosolization, which resulted in long-distance dispersal of ≤2 m under highly favorable conditions. Growers should rogue diseased plants and surrounding nonsymptomatic plants by >1 and ≤3 m, depending on outbreak severity, to limit disease spread. As a result, proper disease management should reduce introduction of nonsymptomatic transplants into the field and subsequently reduce pesticide applications.
Collapse
Affiliation(s)
| | - Anuj Sharma
- Department of Plant Pathology, University of Florida, Gainesville, FL 32611
| | - Jeffrey B Jones
- Department of Plant Pathology, University of Florida, Gainesville, FL 32611
| | - Gary E Vallad
- Gulf Coast Research and Education Center, Wimauma, FL 33598
| |
Collapse
|
16
|
Klein JM, Stockwell VO, Minsavage GV, Vallad GE, Goss EM, Jones JB. Improved deferred antagonism technique for detecting antibiosis. Lett Appl Microbiol 2020; 71:330-336. [PMID: 32506499 DOI: 10.1111/lam.13339] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 05/12/2020] [Accepted: 05/28/2020] [Indexed: 11/29/2022]
Abstract
The deferred antagonism technique has been utilized for several decades for detecting antibiosis activity. Most protocols require the elimination of antibiotic-producing cells by exposing them to chloroform vapour, UV radiation or filter sterilizing the filtrate steps that require additional time and expense to complete. We provide a modified approach to current soft agar overlay practices, which involves addition of antibiotics to the soft agar overlay to inhibit growth of the producer but not the indicator strain. This technique can be used to reproducibly and efficiently screen for antibiotic production with ease. We demonstrate the effectiveness of this technique with three bacterial systems: inhibition of the bacterial spot of tomato pathogen, Xanthomonas euvesicatoria, by its pathogenic competitor Xanthomonas perforans; and inhibition of the fire blight pathogen, Erwinia amylovora, by Pantoea vagans C9-1 or Pseudomonas fluorescens A506. SIGNIFICANCE AND IMPACT OF THE STUDY: Deferred antagonism assays are used commonly to observe antibiotic production by micro-organisms. Killing or removing the producer cells prior to introduction of the indicator strain is a standard practice but requires additional time and special handling procedures. We evaluated a modification of the assay, where the overlay medium is amended with an antibiotic to which the indicator strain is resistant and the producer strain is sensitive. This modification obviates extra steps to kill the producer strain prior to overlaying with the indicator strain and provides a rapid, consistent and cost-effective method to detect antibiosis.
Collapse
Affiliation(s)
- J M Klein
- Department of Plant Pathology, University of Florida, Gainesville, Florida, USA
| | - V O Stockwell
- United States Department of Agriculture, Agricultural Research Service, Horticultural Crops Research Unit, Corvallis, Oregon, USA
| | - G V Minsavage
- Department of Plant Pathology, University of Florida, Gainesville, Florida, USA
| | - G E Vallad
- Department of Plant Pathology, University of Florida, Gainesville, Florida, USA.,Gulf Coast Research and Education Center, University of Florida, Wimauma, Florida, USA
| | - E M Goss
- Department of Plant Pathology, University of Florida, Gainesville, Florida, USA.,Emerging Pathogens Institute, University of Florida, Gainesville, Florida, USA
| | - J B Jones
- Department of Plant Pathology, University of Florida, Gainesville, Florida, USA
| |
Collapse
|
17
|
Timilsina S, Potnis N, Newberry EA, Liyanapathiranage P, Iruegas-Bocardo F, White FF, Goss EM, Jones JB. Xanthomonas diversity, virulence and plant-pathogen interactions. Nat Rev Microbiol 2020; 18:415-427. [PMID: 32346148 DOI: 10.1038/s41579-020-0361-8] [Citation(s) in RCA: 132] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/19/2020] [Indexed: 12/19/2022]
Abstract
Xanthomonas spp. encompass a wide range of plant pathogens that use numerous virulence factors for pathogenicity and fitness in plant hosts. In this Review, we examine recent insights into host-pathogen co-evolution, diversity in Xanthomonas populations and host specificity of Xanthomonas spp. that have substantially improved our fundamental understanding of pathogen biology. We emphasize the virulence factors in xanthomonads, such as type III secreted effectors including transcription activator-like effectors, type II secretion systems, diversity resulting in host specificity, evolution of emerging strains, activation of susceptibility genes and strategies of host evasion. We summarize the genomic diversity in several Xanthomonas spp. and implications for disease outbreaks, management strategies and breeding for disease resistance.
Collapse
Affiliation(s)
- Sujan Timilsina
- Plant Pathology Department, University of Florida, Gainesville, FL, USA
| | - Neha Potnis
- Entomology and Plant Pathology, Auburn University, Auburn, AL, USA
| | - Eric A Newberry
- Entomology and Plant Pathology, Auburn University, Auburn, AL, USA
| | | | | | - Frank F White
- Plant Pathology Department, University of Florida, Gainesville, FL, USA
| | - Erica M Goss
- Plant Pathology Department, University of Florida, Gainesville, FL, USA. .,Emerging Pathogens Institute, University of Florida, Gainesville, FL, USA.
| | - Jeffrey B Jones
- Plant Pathology Department, University of Florida, Gainesville, FL, USA.
| |
Collapse
|
18
|
Newberry E, Bhandari R, Kemble J, Sikora E, Potnis N. Genome-resolved metagenomics to study co-occurrence patterns and intraspecific heterogeneity among plant pathogen metapopulations. Environ Microbiol 2020; 22:2693-2708. [PMID: 32207218 DOI: 10.1111/1462-2920.14989] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 03/09/2020] [Accepted: 03/18/2020] [Indexed: 01/12/2023]
Abstract
Assessment of pathogen diversity in agricultural fields is essential for informing management decisions and the development of resistant plant varieties. However, many population genomic studies have relied on culture-based approaches that do not provide quantitative assessment of pathogen populations at the field-level or the associated host microbiome. Here, we applied whole-genome shotgun sequencing of microbial DNA extracted directly from the washings of pooled leaf samples, collected from individual tomato and pepper fields in Alabama that displayed the classical symptoms of bacterial spot disease caused by Xanthomonas spp. Our results revealed that while the occurrence of both X. perforans and X. euvesicatoria within fields was limited, evidence of co-occurrence of up to three distinct X. perforans genotypes was obtained in 7 of 10 tomato fields sampled. These population dynamics were accompanied by the corresponding type 3 secreted effector repertoires associated with the co-occurring X. perforans genotypes, indicating that metapopulation structure within fields should be considered when assessing the adaptive potential of X. perforans. Finally, analysis of microbial community composition revealed that co-occurrence of the bacterial spot pathogens Pseudomonas cichorii and Xanthomonas spp. is common in Alabama fields and provided evidence for the non-random association of several other human and plant opportunists.
Collapse
Affiliation(s)
- Eric Newberry
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL, USA
| | - Rishi Bhandari
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL, USA
| | - Joseph Kemble
- Department of Horticulture, Auburn University, Auburn, AL, USA
| | - Edward Sikora
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL, USA.,Alabama Cooperative Extension System, Auburn, AL, USA
| | - Neha Potnis
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL, USA
| |
Collapse
|
19
|
Bernal E, Liabeuf D, Francis DM. Evaluating Quantitative Trait Locus Resistance in Tomato to Multiple Xanthomonas spp. PLANT DISEASE 2020; 104:423-429. [PMID: 31804901 DOI: 10.1094/pdis-03-19-0669-re] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Bacterial spot of tomato is a foliar disease caused by four Xanthomonas species. Identifying genetic resistance in wild tomatoes and subsequent breeding of varieties has been a strategy to reduce the loss from this disease because control using pesticides has been ineffective. Three independent sources of resistance have been identified with quantitative trait loci (QTL) mapping to the centromeric region on chromosome 11. These sources are derived from Hawaii 7998 (QTL-11A), PI 114490 (QTL-11B), and LA2533 (QTL-11C). To determine which QTL introgression from chromosome 11 provides the greatest resistance to multiple species, we developed near-isogenic lines (NILs) using marker-assisted backcrossing. In parallel, we developed an NIL that contains Rx-4/Xv3, which provides major gene resistance to Xanthomonas perforans. Additionally, we combined Rx-4/Xv3 resistance with QTL-11A. These sources of resistance were independently introduced into the susceptible parent, OH88119. During a 3-year period from 2016 to 2018, we evaluated backcross-derived families and NILs from each source in independent field trials inoculated with X. perforans, X. euvesicatoria, or X. gardneri. Our results suggest that both QTL-11C and QTL-11A combined with Rx-4/Xv3 provide effective genetic resistance against multiple Xanthomonas species. In addition, we provide evidence for additive to dominant genetic action for the QTL introgressions.
Collapse
Affiliation(s)
- Eduardo Bernal
- Department of Horticulture and Crop Science, The Ohio State University, Wooster, OH 44691
| | - Debora Liabeuf
- Department of Horticulture and Crop Science, The Ohio State University, Wooster, OH 44691
| | - David M Francis
- Department of Horticulture and Crop Science, The Ohio State University, Wooster, OH 44691
| |
Collapse
|
20
|
Abstract
Approaches to manipulating disease resistance in plants is expanding exponentially due to advances in our understanding of plant defense mechanisms and new tools for manipulating the plant genome. The application of effective strategies is only limited now by adoption of rapid classical genetic techniques and the acceptance of genetically engineered traits for some problems. The use of genome editing and cis-genetics, where possible, may facilitate applications that otherwise require considerable time or genetic engineering, depending on settling legal definitions of the products. Nonetheless, the variety of approaches to developing disease resistance has never been greater.
Collapse
Affiliation(s)
- Anuj Sharma
- Department of Plant Pathology, University of Florida, Gainesville, FL, USA
| | - Jeffrey B. Jones
- Department of Plant Pathology, University of Florida, Gainesville, FL, USA
| | - Frank F. White
- Department of Plant Pathology, University of Florida, Gainesville, FL, USA
| |
Collapse
|
21
|
Independent Evolution with the Gene Flux Originating from Multiple Xanthomonas Species Explains Genomic Heterogeneity in Xanthomonas perforans. Appl Environ Microbiol 2019; 85:AEM.00885-19. [PMID: 31375496 DOI: 10.1128/aem.00885-19] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Accepted: 07/31/2019] [Indexed: 12/31/2022] Open
Abstract
Xanthomonas perforans is the predominant pathogen responsible for bacterial leaf spot of tomato and X. euvesicatoria for that of pepper in the southeast United States. Previous studies have indicated significant changes in the X. perforans population collected from Florida tomato fields over the span of 2 decades, including a shift in race and diversification into three phylogenetic groups driven by genome-wide homologous-recombination events derived from X. euvesicatoria In our sampling of Xanthomonas strains associated with bacterial spot disease in Alabama, we were readily able to isolate X. perforans from symptomatic pepper plants grown in several Alabama counties, indicating a recent shift in the host range of the pathogen. To investigate the diversity of these pepper-pathogenic strains and their relation to populations associated with tomatoes grown in the southeast United States, we sequenced the genomes of eight X. perforans strains isolated from tomatoes and peppers grown in Alabama and compared them with previously published genome data available from GenBank. Surprisingly, reconstruction of the X. perforans core genome revealed the presence of two novel genetic groups in Alabama that each harbored a different transcription activation-like effector (TALE). While one TALE, AvrHah1, was associated with an emergent lineage pathogenic to both tomato and pepper, the other was identified as a new class within the AvrBs3 family, here designated PthXp1, and was associated with enhanced symptom development on tomato. Examination of patterns of homologous recombination across the larger X. euvesicatoria species complex revealed a dynamic pattern of gene flow, with multiple donors of Xanthomonas spp. associated with diverse hosts of isolation.IMPORTANCE Bacterial leaf spot of tomato and pepper is an endemic plant disease with a global distribution. In this study, we investigated the evolutionary processes leading to the emergence of novel X. perforans lineages identified in Alabama. While one lineage was isolated from symptomatic tomato and pepper plants, confirming the host range expansion of X. perforans, the other lineage was isolated from tomato and acquired a novel transcription activation-like effector, here designated PthXp1. Functional analysis of PthXp1 indicated that it does not induce Bs4-mediated resistance in tomato and contributes to virulence, providing an adaptive advantage to strains on tomato. Our findings also show that different phylogenetic groups of the pathogen have experienced independent recombination events originating from multiple Xanthomonas species. This suggests a continuous gene flux between related xanthomonads associated with diverse plant hosts that results in the emergence of novel pathogen lineages and associated phenotypes, including host range.
Collapse
|
22
|
Adhikari P, Adhikari TB, Timilsina S, Meadows I, Jones JB, Panthee DR, Louws FJ. Phenotypic and Genetic Diversity of Xanthomonas perforans Populations from Tomato in North Carolina. PHYTOPATHOLOGY 2019; 109:1533-1543. [PMID: 31038016 DOI: 10.1094/phyto-01-19-0019-r] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Bacterial spot caused by Xanthomonas spp. is one of the most devastating diseases of tomato in North Carolina (NC). In total, 290 strains of Xanthomonas spp. from tomato in NC collected over 2 years (2015 and 2016) were analyzed for phenotypic and genetic diversity. In vitro copper and streptomycin sensitivity assays revealed that >95% (n = 290) of the strains were copper tolerant in both years, whereas 25% (n = 127) and 46% (n = 163) were streptomycin tolerant in 2016 and 2015, respectively. Using BOX repetitive element PCR assay, fingerprint patterns showed four haplotypes (H1, H2, H3, and H4) among the strains analyzed. The multiplex real-time quantitative PCR on a subset of representative strains (n = 45) targeting the highly conserved hrcN gene identified Xanthomonas strains from tomato in NC that belonged to X. perforans. Race profiling of the representative strains (n = 45) on tomato and pepper differentials confirmed that ∼9 and 91% of strains are tomato races T3 and T4, respectively. Additionally, PCR assays and sequence alignments confirmed that the copL, copA, copB (copLAB copper tolerance gene cluster), and avrXv4 genes are present in the strains analyzed. Phylogenetic and comparative sequence analyses of six genomic regions (elongation factor G [fusA], glyceraldehyde-3-phosphate dehydrogenase A [gapA], citrate synthase [gltA], gyrase subunit B [gyrB], ABC transporter sugar permease [lacF], and GTP binding protein [lepA]) suggested that 13 and 74% of X. perforans strains from NC were genetically similar to races T3 and T4 from Florida, respectively. Our results provide insights that bacterial spot management practices in tomato should focus on deploying resistance genes to combat emerging pathogenic races of X. perforans and overcome the challenges currently posed by intense use of copper-based bactericides.
Collapse
Affiliation(s)
- Pragya Adhikari
- Department of Horticultural Science, North Carolina State University, Raleigh, NC 27695
| | - Tika B Adhikari
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC 27695
| | - Sujan Timilsina
- Department of Plant Pathology, University of Florida, Gainesville, FL 32611
| | - Inga Meadows
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC 27695
| | - Jeffrey B Jones
- Department of Plant Pathology, University of Florida, Gainesville, FL 32611
| | - Dilip R Panthee
- Department of Horticultural Science, North Carolina State University, Raleigh, NC 27695
| | - Frank J Louws
- Department of Horticultural Science, North Carolina State University, Raleigh, NC 27695
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC 27695
| |
Collapse
|
23
|
Roach R, Mann R, Gambley CG, Chapman T, Shivas RG, Rodoni B. Genomic sequence analysis reveals diversity of Australian Xanthomonas species associated with bacterial leaf spot of tomato, capsicum and chilli. BMC Genomics 2019; 20:310. [PMID: 31014247 PMCID: PMC6480910 DOI: 10.1186/s12864-019-5600-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 03/12/2019] [Indexed: 01/03/2023] Open
Abstract
Background The genetic diversity in Australian populations of Xanthomonas species associated with bacterial leaf spot in tomato, capsicum and chilli were compared to worldwide bacterial populations. The aim of this study was to confirm the identities of these Australian Xanthomonas species and classify them in comparison to overseas isolates. Analysis of whole genome sequence allows for the investigation of bacterial population structure, pathogenicity and gene exchange, resulting in better management strategies and biosecurity. Results Phylogenetic analysis of the core genome alignments and SNP data grouped strains in distinct clades. Patterns observed in average nucleotide identity, pan genome structure, effector and carbohydrate active enzyme profiles reflected the whole genome phylogeny and highlight taxonomic issues in X. perforans and X. euvesicatoria. Circular sequences with similarity to previously characterised plasmids were identified, and plasmids of similar sizes were isolated. Potential false positive and false negative plasmid assemblies were discussed. Effector patterns that may influence virulence on host plant species were analysed in pathogenic and non-pathogenic xanthomonads. Conclusions The phylogeny presented here confirmed X. vesicatoria, X. arboricola, X. euvesicatoria and X. perforans and a clade of an uncharacterised Xanthomonas species shown to be genetically distinct from all other strains of this study. The taxonomic status of X. perforans and X. euvesicatoria as one species is discussed in relation to whole genome phylogeny and phenotypic traits. The patterns evident in enzyme and plasmid profiles indicate worldwide exchange of genetic material with the potential to introduce new virulence elements into local bacterial populations. Electronic supplementary material The online version of this article (10.1186/s12864-019-5600-x) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- R Roach
- Department of Agriculture and Fisheries, Ecosciences Precinct, Brisbane, QLD, Australia. .,Agriculture Victoria Research Division, Department of Economic Development, Jobs, Transport & Resources, AgriBio, La Trobe University, Bundoora, Victoria, 3083, Australia.
| | - R Mann
- Agriculture Victoria Research Division, Department of Economic Development, Jobs, Transport & Resources, AgriBio, La Trobe University, Bundoora, Victoria, 3083, Australia
| | - C G Gambley
- Department of Agriculture and Fisheries, Applethorpe Research Facility, Applethorpe, QLD, Australia
| | - T Chapman
- Department of Primary Industries, Elizabeth Macarthur Agricultural Institute, Menangle, NSW, Australia
| | - R G Shivas
- Centre for Crop Health, University of Southern Queensland, Toowoomba, QLD, Australia
| | - B Rodoni
- Agriculture Victoria Research Division, Department of Economic Development, Jobs, Transport & Resources, AgriBio, La Trobe University, Bundoora, Victoria, 3083, Australia
| |
Collapse
|
24
|
Timilsina S, Pereira-Martin JA, Minsavage GV, Iruegas-Bocardo F, Abrahamian P, Potnis N, Kolaczkowski B, Vallad GE, Goss EM, Jones JB. Multiple Recombination Events Drive the Current Genetic Structure of Xanthomonas perforans in Florida. Front Microbiol 2019; 10:448. [PMID: 30930868 PMCID: PMC6425879 DOI: 10.3389/fmicb.2019.00448] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 02/20/2019] [Indexed: 11/23/2022] Open
Abstract
Prior to the identification of Xanthomonas perforans associated with bacterial spot of tomato in 1991, X. euvesicatoria was the only known species in Florida. Currently, X. perforans is the Xanthomonas sp. associated with tomato in Florida. Changes in pathogenic race and sequence alleles over time signify shifts in the dominant X. perforans genotype in Florida. We previously reported recombination of X. perforans strains with closely related Xanthomonas species as a potential driving factor for X. perforans evolution. However, the extent of recombination across the X. perforans genomes was unknown. We used a core genome multilocus sequence analysis approach to identify conserved genes and evaluated recombination-associated evolution of these genes in X. perforans. A total of 1,356 genes were determined to be "core" genes conserved among the 58 X. perforans genomes used in the study. Our approach identified three genetic groups of X. perforans in Florida based on the principal component analysis (PCA) using core genes. Nucleotide variation in 241 genes defined these groups, that are referred as Phylogenetic-group Defining (PgD) genes. Furthermore, alleles of many of these PgD genes showed 100% sequence identity with X. euvesicatoria, suggesting that variation likely has been introduced by recombination at multiple locations throughout the bacterial chromosome. Site-specific recombinase genes along with plasmid mobilization and phage associated genes were observed at different frequencies in the three phylogenetic groups and were associated with clusters of recombinant genes. Our analysis of core genes revealed the extent, source, and mechanisms of recombination events that shaped the current population and genomic structure of X. perforans in Florida.
Collapse
Affiliation(s)
- Sujan Timilsina
- Department of Plant Pathology, University of Florida, Gainesville, FL, United States
| | | | - Gerald V. Minsavage
- Department of Plant Pathology, University of Florida, Gainesville, FL, United States
| | | | - Peter Abrahamian
- Gulf Coast Research and Education Center, University of Florida, Gainesville, FL, United States
| | - Neha Potnis
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL, United States
| | - Bryan Kolaczkowski
- Microbiology and Cell Science, University of Florida, Gainesville, FL, United States
| | - Gary E. Vallad
- Gulf Coast Research and Education Center, University of Florida, Gainesville, FL, United States
| | - Erica M. Goss
- Department of Plant Pathology, University of Florida, Gainesville, FL, United States
- Emerging Pathogens Institute, University of Florida, Gainesville, FL, United States
| | - Jeffrey B. Jones
- Department of Plant Pathology, University of Florida, Gainesville, FL, United States
| |
Collapse
|
25
|
Schultink A, Qi T, Bally J, Staskawicz B. Using forward genetics in Nicotiana benthamiana to uncover the immune signaling pathway mediating recognition of the Xanthomonas perforans effector XopJ4. THE NEW PHYTOLOGIST 2019; 221:1001-1009. [PMID: 30156705 DOI: 10.1111/nph.15411] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2018] [Accepted: 07/23/2018] [Indexed: 05/22/2023]
Abstract
The immune pathway responsible for perception of the Xanthomonas perforans effector XopJ4 was identified in the plant Nicotiana benthamiana. This pathogen causes significant yield loss in commercial tomato cultivation. Genetic mapping and viral-induced gene silencing were used to identify immune signaling components of the XopJ4 perception pathway in N. benthamiana. Transient complementation assays were performed to determine the functionality of gene variants and co-immunoprecipitation assays were used to gain insight into the molecular mechanism of the pathway. Two N. benthamiana ethyl methanesulfonate (EMS) mutants deficient for XopJ4 perception were identified as having loss-of-function mutations in the gene encoding the nucleotide binding, leucine-rich repeat (NLR) protein NbZAR1. Silencing of a receptor-like cytoplasmic kinase family XII gene, subsequently named XOPJ4 IMMUNITY 2 (JIM2), blocks perception of XopJ4. This study demonstrates the feasibility of conducting mutant screens in N. benthamiana to investigate the genetic basis of the plant immune system and other processes. The identification of NbZAR1 and JIM2 as mediating XopJ4 perception in N. benthamiana supports the model of ZAR1 being involved in the perception of many different pathogen effector proteins with specificity dictated by associated receptor-like cytoplasmic kinases.
Collapse
Affiliation(s)
- Alex Schultink
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, 94720, USA
| | - Tiancong Qi
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, 94720, USA
| | - Julia Bally
- Centre for Tropical Crops and Biocommodities, Queensland University of Technology, Brisbane, Qld, 4001, Australia
| | - Brian Staskawicz
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, 94720, USA
| |
Collapse
|
26
|
Abrahamian P, Timilsina S, Minsavage GV, Kc S, Goss EM, Jones JB, Vallad GE. The Type III Effector AvrBsT Enhances Xanthomonas perforans Fitness in Field-Grown Tomato. PHYTOPATHOLOGY 2018; 108:1355-1362. [PMID: 29905507 DOI: 10.1094/phyto-02-18-0052-r] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Type III secretion system effectors contribute to pathogenicity through various mechanisms. Recent surveys showed an increasing prevalence of the type III secretion effector avrBsT among Xanthomonas perforans strains. We hypothesized that the acquisition of avrBsT has a fitness advantage for the pathogen. The contribution of avrBsT to fitness on tomato was evaluated based on disease severity, in planta growth, competition, and recovery rates of wild-type (WT) and avrBsT mutant strains in greenhouse and field plants. GEV872 and GEV1001, representative strains of two phylogenomic groups of X. perforans, were selected for generating avrBsT mutants. Disease severity was higher for WT strains compared with the avrBsT mutant strains. X. perforans WT and avrBsT mutant strains did not differ following leaf infiltration of greenhouse plants in direct competition and in planta growth assays. The effect of avrBsT on pathogen fitness was noticeable under field conditions. Differences in strain recovery were significant, with WT being recovered two to eight times more than avrBsT mutant strains in the case of both strains GEV872 and GEV1001. WT strains were capable of spreading longer distances across field plots compared with avrBsT mutant strains. Findings suggest that the functional AvrBsT affects the fitness of X. perforans under field conditions, making it an ideal candidate for bacterial spot resistance breeding efforts in tomato.
Collapse
Affiliation(s)
- Peter Abrahamian
- First, second, fourth, and seventh authors; Gulf Coast and Research Education Center, Wimauma, FL; first, second, third, fifth, sixth, and seventh authors: Department of Plant Pathology, University of Florida, Gainesville; and fifth author: Emerging Pathogens Institute, University of Florida, Gainesville
| | - Sujan Timilsina
- First, second, fourth, and seventh authors; Gulf Coast and Research Education Center, Wimauma, FL; first, second, third, fifth, sixth, and seventh authors: Department of Plant Pathology, University of Florida, Gainesville; and fifth author: Emerging Pathogens Institute, University of Florida, Gainesville
| | - Gerald V Minsavage
- First, second, fourth, and seventh authors; Gulf Coast and Research Education Center, Wimauma, FL; first, second, third, fifth, sixth, and seventh authors: Department of Plant Pathology, University of Florida, Gainesville; and fifth author: Emerging Pathogens Institute, University of Florida, Gainesville
| | - Sushmita Kc
- First, second, fourth, and seventh authors; Gulf Coast and Research Education Center, Wimauma, FL; first, second, third, fifth, sixth, and seventh authors: Department of Plant Pathology, University of Florida, Gainesville; and fifth author: Emerging Pathogens Institute, University of Florida, Gainesville
| | - Erica M Goss
- First, second, fourth, and seventh authors; Gulf Coast and Research Education Center, Wimauma, FL; first, second, third, fifth, sixth, and seventh authors: Department of Plant Pathology, University of Florida, Gainesville; and fifth author: Emerging Pathogens Institute, University of Florida, Gainesville
| | - Jeffrey B Jones
- First, second, fourth, and seventh authors; Gulf Coast and Research Education Center, Wimauma, FL; first, second, third, fifth, sixth, and seventh authors: Department of Plant Pathology, University of Florida, Gainesville; and fifth author: Emerging Pathogens Institute, University of Florida, Gainesville
| | - Gary E Vallad
- First, second, fourth, and seventh authors; Gulf Coast and Research Education Center, Wimauma, FL; first, second, third, fifth, sixth, and seventh authors: Department of Plant Pathology, University of Florida, Gainesville; and fifth author: Emerging Pathogens Institute, University of Florida, Gainesville
| |
Collapse
|
27
|
Jibrin MO, Potnis N, Timilsina S, Minsavage GV, Vallad GE, Roberts PD, Jones JB, Goss EM. Genomic Inference of Recombination-Mediated Evolution in Xanthomonas euvesicatoria and X. perforans. Appl Environ Microbiol 2018; 84:e00136-18. [PMID: 29678917 PMCID: PMC6007113 DOI: 10.1128/aem.00136-18] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Accepted: 04/06/2018] [Indexed: 01/23/2023] Open
Abstract
Recombination is a major driver of evolution in bacterial populations, because it can spread and combine independently evolved beneficial mutations. Recombinant lineages of bacterial pathogens of plants are typically associated with the colonization of novel hosts and the emergence of new diseases. Here we show that recombination between evolutionarily and phenotypically distinct plant-pathogenic lineages generated recombinant lineages with unique combinations of pathogenicity and virulence factors. Xanthomonas euvesicatoria and Xanthomonas perforans are two closely related lineages causing bacterial spot disease on tomato and pepper worldwide. We sequenced the genomes of atypical strains collected from tomato in Nigeria and observed recombination in the type III secretion system and effector genes, which showed alleles from both X. euvesicatoria and X. perforans Wider horizontal gene transfer was indicated by the fact that the lipopolysaccharide cluster of one strain was most similar to that of a distantly related Xanthomonas pathogen of barley. This strain and others have experienced extensive genomewide homologous recombination, and both species exhibited dynamic open pangenomes. Variation in effector gene repertoires within and between species must be taken into consideration when one is breeding tomatoes for disease resistance. Resistance breeding strategies that target specific effectors must consider possibly dramatic variation in bacterial spot populations across global production regions, as illustrated by the recombinant strains observed here.IMPORTANCE The pathogens that cause bacterial spot of tomato and pepper are extensively studied models of plant-microbe interactions and cause problematic disease worldwide. Atypical bacterial spot strains collected from tomato in Nigeria, and other strains from Italy, India, and Florida, showed evidence of genomewide recombination that generated genetically distinct pathogenic lineages. The strains from Nigeria and Italy were found to have a mix of type III secretion system genes from X. perforans and X. euvesicatoria, as well as effectors from Xanthomonas gardneri These genes and effectors are important in the establishment of disease, and effectors are common targets of resistance breeding. Our findings point to global diversity in the genomes of bacterial spot pathogens, which is likely to affect the host-pathogen interaction and influence management decisions.
Collapse
Affiliation(s)
- Mustafa O Jibrin
- Department of Plant Pathology, University of Florida, Gainesville, Florida, USA
- Southwest Research and Education Center, University of Florida, Immokalee, Florida, USA
- Department of Crop Protection, Ahmadu Bello University, Zaria, Nigeria
| | - Neha Potnis
- Department of Entomology and Plant Pathology, Auburn University, Auburn, Alabama, USA
| | - Sujan Timilsina
- Department of Plant Pathology, University of Florida, Gainesville, Florida, USA
| | - Gerald V Minsavage
- Department of Plant Pathology, University of Florida, Gainesville, Florida, USA
| | - Gary E Vallad
- Department of Plant Pathology, University of Florida, Gainesville, Florida, USA
- Gulf Coast Research and Education Center, University of Florida, Wimauma, Florida, USA
| | - Pamela D Roberts
- Department of Plant Pathology, University of Florida, Gainesville, Florida, USA
- Southwest Research and Education Center, University of Florida, Immokalee, Florida, USA
| | - Jeffrey B Jones
- Department of Plant Pathology, University of Florida, Gainesville, Florida, USA
| | - Erica M Goss
- Department of Plant Pathology, University of Florida, Gainesville, Florida, USA
- Emerging Pathogens Institute, University of Florida, Gainesville, Florida, USA
| |
Collapse
|
28
|
Burlakoti RR, Hsu CF, Chen JR, Wang JF. Population Dynamics of Xanthomonads Associated with Bacterial Spot of Tomato and Pepper during 27 Years across Taiwan. PLANT DISEASE 2018; 102:1348-1356. [PMID: 30673574 DOI: 10.1094/pdis-04-17-0465-re] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Bacterial spot caused by Xanthomonas spp. is the second most important bacterial disease after bacterial wilt of tomato and pepper in Taiwan. To determine the species composition of the Xanthomonas population over 27 years (1989 to 2016) across the country, a large collections of strains from tomato (n = 292) and pepper (n = 198) were examined. In the 1989 to 1999 population, all strains (n = 147) from pepper and 95% strains (n = 198) from tomato were Xanthomonas euvesicatoria. The remaining 5% of strains from tomato were X. vesicatoria. In a 2000 to 2009 population from tomato (n = 36), 22% of the strains were X. perforans and the remaining 78% strains were X. euvesicatoria. In the 2010 to 2016 population, 92% of the strains (n = 50) from pepper were still X. euvesicatoria and the remaining 8% of the strains were X. perforans; however, 99% (n = 58) of the strains from tomato were X. perforans. All of the evaluated (n = 25) strains of X. euvesicatoria collected during 1990 to 2006 were tomato race T1. Four pepper races (P1, P2, P7, and P8) were identified in the X. euvesicatoria population. The strains of X. vesicatoria collected during 1989 to 1999 (n = 8) were tomato race T2 and strains of X. perforans from tomato collected during 2010 to 2016 (n = 12) were race T4 (83%) and race T3 (17%). Four strains of X. perforans from pepper were race T4. All of the strains of X. vesicatoria and X. perforans caused a hypersensitive response in all pepper differentials. Biochemical characterization of representative strains (n = 48) showed that strains of X. euvesicatoria were negative on and amylolytic test and positive on lipase and oxidative-fermentative (OF) tests. The strains of X. vesicatoria were positive on amylolytic and OF tests and were negative on the lipase test. All X. perforans strains showed positive reactions on three tests. Evaluation of the same 48 strains for the sensitivity to copper sulfate (50, 100, 200, 300, and 400 mg liter-1) revealed that the majority of X. euvesicatoria (86%) and X. perforans (94%) strains in the 2010 to 2016 population were tolerant to copper sulfate. The findings suggest that management strategies and breeding programs should consider the new X. perforans species and their new races. The increased number of copper-sulfate-tolerant strains in the 2010 to 2016 population further shows the need for alternative options to copper for managing bacterial spot of tomato and pepper.
Collapse
Affiliation(s)
| | - Chiou-Fen Hsu
- World Vegetable Center, P. O. Box 42, Shanhua, Tainan, 74199, Taiwan
| | - Jaw-Rong Chen
- World Vegetable Center, P. O. Box 42, Shanhua, Tainan, 74199, Taiwan
| | - Jaw-Fen Wang
- World Vegetable Center, P. O. Box 42, Shanhua, Tainan, 74199, Taiwan
| |
Collapse
|
29
|
XVII Congress on Molecular Plant-Microbe Interactions Meeting Report. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2016; 29:S1-S22. [PMID: 28384051 DOI: 10.1094/mpmi-29-12-s1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
|
30
|
Klosterman SJ, Rollins JR, Sudarshana MR, Vinatzer BA. Disease Management in the Genomics Era-Summaries of Focus Issue Papers. PHYTOPATHOLOGY 2016; 106:1068-1070. [PMID: 27482626 DOI: 10.1094/phyto-07-16-0276-fi] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The genomics revolution has contributed enormously to research and disease management applications in plant pathology. This development has rapidly increased our understanding of the molecular mechanisms underpinning pathogenesis and resistance, contributed novel markers for rapid pathogen detection and diagnosis, and offered further insights into the genetics of pathogen populations on a larger scale. The availability of whole genome resources coupled with next-generation sequencing (NGS) technologies has helped fuel genomics-based approaches to improve disease resistance in crops. NGS technologies have accelerated the pace at which whole plant and pathogen genomes have become available, and made possible the metagenomic analysis of plant-associated microbial communities. Furthermore, NGS technologies can now be applied routinely and cost effectively to rapidly generate plant and/or pathogen genome or transcriptome marker sequences associated with virulence phenotypes in the pathogen or resistance phenotypes in the plant, potentially leading to improvements in plant disease management. In some systems, investments in plant and pathogen genomics have led to immediate, tangible benefits. This focus issue covers some of the systems. The articles in this focus issue range from overall perspective articles to research articles describing specific genomics applications for detection and control of diseases caused by nematode, viral, bacterial, fungal, and oomycete pathogens. The following are representative short summaries of the articles that appear in this Focus Issue .
Collapse
Affiliation(s)
- S J Klosterman
- 2016 Focus Issue Senior Editors First author: U.S. Department of Agriculture-Agriculture Research Service (USDA-ARS), 1636 E. Alisal Street, Salinas, CA 93905; second author: Department of Plant Pathology, University of Florida, Gainesville 32611; third author: USDA-ARS, One Shields Avenue, Davis, CA 95616; and fourth author: Department of Plant Pathology, Physiology, and Weed Science, Virginia Tech, Blacksburg 24061
| | - J R Rollins
- 2016 Focus Issue Senior Editors First author: U.S. Department of Agriculture-Agriculture Research Service (USDA-ARS), 1636 E. Alisal Street, Salinas, CA 93905; second author: Department of Plant Pathology, University of Florida, Gainesville 32611; third author: USDA-ARS, One Shields Avenue, Davis, CA 95616; and fourth author: Department of Plant Pathology, Physiology, and Weed Science, Virginia Tech, Blacksburg 24061
| | - M R Sudarshana
- 2016 Focus Issue Senior Editors First author: U.S. Department of Agriculture-Agriculture Research Service (USDA-ARS), 1636 E. Alisal Street, Salinas, CA 93905; second author: Department of Plant Pathology, University of Florida, Gainesville 32611; third author: USDA-ARS, One Shields Avenue, Davis, CA 95616; and fourth author: Department of Plant Pathology, Physiology, and Weed Science, Virginia Tech, Blacksburg 24061
| | - B A Vinatzer
- 2016 Focus Issue Senior Editors First author: U.S. Department of Agriculture-Agriculture Research Service (USDA-ARS), 1636 E. Alisal Street, Salinas, CA 93905; second author: Department of Plant Pathology, University of Florida, Gainesville 32611; third author: USDA-ARS, One Shields Avenue, Davis, CA 95616; and fourth author: Department of Plant Pathology, Physiology, and Weed Science, Virginia Tech, Blacksburg 24061
| |
Collapse
|