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Ibrahim N, Nesbitt D, Guo Q(T, Lin J, Svircev A, Wang Q, Weadge JT, Anany H. Improved Viability of Spray-Dried Pantoea agglomerans for Phage-Carrier Mediated Control of Fire Blight. Viruses 2024; 16:257. [PMID: 38400033 PMCID: PMC10893313 DOI: 10.3390/v16020257] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2023] [Revised: 01/26/2024] [Accepted: 01/30/2024] [Indexed: 02/25/2024] Open
Abstract
Fire blight, caused by Erwinia amylovora, is a devastating bacterial disease that threatens apple and pear production. It is mainly controlled by using antibiotics, such as streptomycin. Due to development of E. amylovora resistant strains and the excessive agricultural use of antibiotics, there is an increased awareness of the possibility of antibiotic resistance gene transfer to other microbes. Urgent development of biocontrol agents (BCAs) is needed that can be incorporated into integrated pest management programs as antibiotic alternatives. A novel phage-carrier system (PCS) that combines an antagonistic bacterium, Pantoea agglomerans, with its ability to act as a phage-carrier bacterium for Erwinia phages has been developed. The low viability of P. agglomerans cells following spray-drying (SD) has been a challenge for the industrial-scale production of this PCS. Here, an SD protocol was developed for P. agglomerans by modifying the growth medium and bacterial cell formulation using D(+)-trehalose and maltodextrin. The developed protocol is amenable to the industrial-scale production of the BCA/PCS. The P. agglomerans viability was greater than 90% after SD and had a shelf life at 4 °C of 4 months, and reconstituted cells showed a 3 log reduction in E. amylovora counts with a pear disc assay.
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Affiliation(s)
- Nassereldin Ibrahim
- Agriculture and Agri-Food Canada (AAFC), Guelph Research and Development Centre (GRDC), 93 Stone Rd W., Guelph, ON N1G 5C9, Canada; (N.I.); (Q.G.); (Q.W.)
- Department of Biology, Wilfrid Laurier University, Waterloo, ON N2L 3C5, Canada;
- Genetic Engineering and Biotechnology Research Institute, University of Sadat City, Sadat City 32897, Egypt
| | - Darlene Nesbitt
- Agriculture and Agri-Food Canada (AAFC), Vineland Station, ON L0R 2E0, Canada; (D.N.); (A.S.)
| | - Qian (Tracy) Guo
- Agriculture and Agri-Food Canada (AAFC), Guelph Research and Development Centre (GRDC), 93 Stone Rd W., Guelph, ON N1G 5C9, Canada; (N.I.); (Q.G.); (Q.W.)
| | - Janet Lin
- National Microbiology Laboratory, National Health Agency, 110 Stone Rd. W., Guelph, ON N1G 3W4, Canada;
| | - Antonet Svircev
- Agriculture and Agri-Food Canada (AAFC), Vineland Station, ON L0R 2E0, Canada; (D.N.); (A.S.)
| | - Qi Wang
- Agriculture and Agri-Food Canada (AAFC), Guelph Research and Development Centre (GRDC), 93 Stone Rd W., Guelph, ON N1G 5C9, Canada; (N.I.); (Q.G.); (Q.W.)
| | - Joel T. Weadge
- Department of Biology, Wilfrid Laurier University, Waterloo, ON N2L 3C5, Canada;
| | - Hany Anany
- Agriculture and Agri-Food Canada (AAFC), Guelph Research and Development Centre (GRDC), 93 Stone Rd W., Guelph, ON N1G 5C9, Canada; (N.I.); (Q.G.); (Q.W.)
- Food Science Department, University of Guelph, Guelph, ON N1G 2W1, Canada
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2
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Yang HW, Thapa R, Johnson K, DuPont ST, Khan A, Zhao Y. Examination of Large Chromosomal Inversions in the Genome of Erwinia amylovora Strains Reveals Worldwide Distribution and North America-Specific Types. Phytopathology 2023; 113:2174-2186. [PMID: 36935376 DOI: 10.1094/phyto-01-23-0004-sa] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [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
Erwinia amylovora is a relatively homogeneous species with low genetic diversity at the nucleotide level. However, phenotypic differences and genomic structural variations among E. amylovora strains have been documented. In this study, we identified 10 large chromosomal inversion (LCI) types in the Spiraeoideae-infecting (SI) E. amylovora strains by combining whole genome sequencing and PCR-based molecular markers. It was found that LCIs were mainly caused by homologous recombination events among seven rRNA operons (rrns) in SI E. amylovora strains. Although ribotyping results identified inter- and intra-variations in the internal transcribed spacer (ITS1 and ITS2) regions among rrns, LCIs tend to occur between rrns transcribed in the opposite directions and with the same tRNA content (tRNA-Glu or tRNA-Ile/Ala) in ITS1. Based on the LCI types, physical/estimated replichore imbalance (PRI/ERI) was examined and calculated. Among the 117 SI strains evaluated, the LCI types of Ea1189, CFBP1430, and Ea273 were the most common, with ERI values at 1.31, 7.87, and 4.47°, respectively. These three LCI types had worldwide distribution, whereas the remaining seven LCI types were restricted to North America (or certain regions of the United States). Our results indicated ongoing chromosomal recombination events in the SI E. amylovora population and showed that LCI events are mostly symmetrical, keeping the ERI less than 15°. These findings provide initial evidence about the prevalence of certain LCI types in E. amylovora strains, how LCI occurs, and its potential evolutionary advantage and history, which might help track the movement of the pathogen.
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Affiliation(s)
- Ho-Wen Yang
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61802
| | - Ranjita Thapa
- School of Integrative Plant Science Plant Pathology and Plant-Microbe Biology, Cornell University, Geneva, NY 14456
| | - Kenneth Johnson
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331
| | | | - Awais Khan
- School of Integrative Plant Science Plant Pathology and Plant-Microbe Biology, Cornell University, Geneva, NY 14456
| | - Youfu Zhao
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61802
- Department of Plant Pathology, WSU-IAREC, Prosser, WA 99350
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3
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Yuan X, Gdanetz K, Outwater CA, Slack SM, Sundin GW. Evaluation of Plant Defense Inducers and Plant Growth Regulators for Fire Blight Management Using Transcriptome Studies and Field Assessments. Phytopathology 2023; 113:2152-2164. [PMID: 37399041 DOI: 10.1094/phyto-04-23-0147-kc] [Citation(s) in RCA: 1] [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: 07/04/2023]
Abstract
Fire blight, caused by Erwinia amylovora, is a destructive disease of pome fruit trees. In the United States, apple and pear growers rely on applications of copper and antibiotics during bloom to control fire blight, but such methods have already led to regional instances of resistance. In this study, we used transcriptome analyses and field trials to evaluate the effectiveness of three commercially available plant defense elicitors and one plant growth regulator for fire blight management. Our data indicated that foliar applications of acibenzolar-S-methyl (ASM; Actigard 50WG) triggered a strong defense-related response in apple leaves, whereas applications of Bacillus mycoides isolate J (LifeGard WG) or Reynoutria sachalinensis extract (Regalia) did not. Genes upregulated by ASM were enriched in the biological processes associated with plant immunity, such as defense response and protein phosphorylation. The expression of several pathogenesis-related (PR) genes was induced by ASM as well. Surprisingly, many differentially expressed genes in ASM-treated apple leaves overlapped with those induced by treatment with prohexadione-calcium (ProCa; Apogee), a plant growth regulator that suppresses shoot elongation. Further analysis suggested that ProCa likely acts similarly to ASM to stimulate plant immunity because genes involved in plant defense were shared and significantly upregulated (more than twofold) by both treatments. Our field trials agreed with the transcriptome study, demonstrating that ASM and ProCa exhibit the best control performance relative to the other biopesticides. Taken together, these data are pivotal for the understanding of plant response and shed light on future improvements of strategies for fire blight management.
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Affiliation(s)
- Xiaochen Yuan
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI 48824
- Department of Plant Pathology, Entomology and Microbiology, Iowa State University, Ames, IA 50011
| | - Kristi Gdanetz
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI 48824
| | - Cory A Outwater
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI 48824
| | - Suzanne M Slack
- Department of Horticulture, Iowa State University, Ames, IA 50011
| | - George W Sundin
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI 48824
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Sundin GW, Peng J, Brown LE, Zeng Q, Förster H, Adaskaveg JE. A Novel IncX Plasmid Mediates High-Level Oxytetracycline and Streptomycin Resistance in Erwinia amylovora from Commercial Pear Orchards in California. Phytopathology 2023; 113:2165-2173. [PMID: 37565835 DOI: 10.1094/phyto-06-23-0190-sa] [Citation(s) in RCA: 1] [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: 08/12/2023]
Abstract
Isolates of the fire blight pathogen Erwinia amylovora with high-level resistance to oxytetracycline (minimal inhibitory concentration [MIC] > 100 μg/ml) and to streptomycin (MIC > 100 μg/ml) were recovered from four commercial pear orchards in California between 2018 and 2020. The two representative oxytetracycline- and streptomycin-resistant (OxyTcR-SmR) strains 32-10 and 33-1 were as virulent as the antibiotic susceptible strain 13-1 in causing blossom blight of pear and were recovered more than 50% of the time 7 days after co-inoculation to pear flowers with strain 13-1. In the field, inoculation of strain 32-10 to pear flowers that were pretreated with oxytetracycline at 200 μg/ml did not reduce disease compared with an untreated control. Four OxyTcR-SmR strains were subjected to draft genome sequencing to identify the genetic determinants of antibiotic resistance and their location. A 43.6-kb IncX plasmid, designated pX11-7, was detected in each of the four strains, and this plasmid encoded the tetracycline-resistance gene tetB and the streptomycin-resistance gene pair strAB within a large putatively mobile genetic element consisting of the transposon Tn10 that had inserted within the streptomycin-resistance transposon Tn6082. We also determined that pX11-7 was conjugative and was transferred at a rate that was 104 to 105 higher into an E. amylovora strain isolated in California compared with an E. amylovora strain that was isolated in Michigan. The occurrence of high levels of resistance to both oxytetracycline and streptomycin in E. amylovora strains from commercial pear orchards in California significantly limits the options for blossom blight management in these locations.
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Affiliation(s)
- George W Sundin
- Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, MI 48824
| | - Jingyu Peng
- Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, MI 48824
| | - Lindsay E Brown
- Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, MI 48824
| | - Quan Zeng
- Department of Plant Pathology and Ecology, The Connecticut Agricultural Experiment Station, New Haven, CT 06511
| | - Helga Förster
- Department of Plant Pathology and Microbiology, University of California, Riverside, CA 92521
| | - James E Adaskaveg
- Department of Plant Pathology and Microbiology, University of California, Riverside, CA 92521
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Emeriewen OF, Richter K, Flachowsky H, Peil A. Quantitative Trait Locus Mapping for Fire Blight Resistance in an F 2 Population of Malus fusca MAL0045 Uncovers Novel Resistance Loci. Phytopathology 2023; 113:2222-2229. [PMID: 37856693 DOI: 10.1094/phyto-05-23-0159-sa] [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: 10/21/2023]
Abstract
Several fire blight resistance loci in Malus genotypes map on different linkage groups (LGs) representing chromosomes of the domesticated apple. Prior genetics studies primarily focused on F1 populations. A strong resistance quantitative trait locus (QTL) explained up to 66% of phenotypic variance in an F1 progeny derived from crossing the highly resistant wild apple genotype Malus fusca MAL0045 and the highly susceptible apple cultivar 'Idared', which was previously mapped on LG10 (Mfu10) of MAL0045. Strains of the causative bacterial pathogen Erwinia amylovora, notably those that show a single nucleotide polymorphism in the avrRpt2EA effector protein sequence at position 156 (e.g., Ea3049), are more virulent and overcome some known fire blight resistance donors and their QTLs. However, MAL0045 is resistant to Ea3049 and Mfu10 is not overcome, but most of the F1 progeny were highly susceptible to this strain. This phenomenon led to the assumption that other putative resistance factors not segregating in the F1 progeny might be present in the genome of MAL0045. Here, we crossed F1 progeny together to obtain 135 F2 individuals. Facilitated by genotyping-by-sequencing and phenotypic assessments, we identified and mapped two novel resistance QTLs in these F2 individuals on LGs 4 and 15, which were not identified in the F1. To our knowledge, these are the first resistance QTLs mapped in F2 progeny in Malus. In addition, we report that neither MAL0045 nor Mfu10 is broken down by a highly aggressive U.S. strain, LA635, after analyses in the original F1 individuals. [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)
- Ofere Francis Emeriewen
- Julius Kühn Institute (JKI)-Federal Research Centre for Cultivated Plants, Institute for Breeding Research on Fruit Crops, Pillnitzer Platz 3a, 01326 Dresden, Germany
| | - Klaus Richter
- Julius Kühn Institute (JKI)-Federal Research Centre for Cultivated Plants, Institute for Resistance Research and Stress Tolerance, Erwin-Baur-Str. 27, 06484, Quedlinburg, Germany
| | - Henryk Flachowsky
- Julius Kühn Institute (JKI)-Federal Research Centre for Cultivated Plants, Institute for Breeding Research on Fruit Crops, Pillnitzer Platz 3a, 01326 Dresden, Germany
| | - Andreas Peil
- Julius Kühn Institute (JKI)-Federal Research Centre for Cultivated Plants, Institute for Breeding Research on Fruit Crops, Pillnitzer Platz 3a, 01326 Dresden, Germany
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Klein-Gordon JM, Johnson KB, Loper JE, Stockwell VO. Contribution of Native Plasmids of Pantoea vagans C9-1 to Epiphytic Fitness and Fire Blight Management on Apple and Pear Flowers and Fruits. Phytopathology 2023; 113:2187-2196. [PMID: 37287124 DOI: 10.1094/phyto-04-23-0144-sa] [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: 06/09/2023]
Abstract
Pantoea vagans C9-1 (C9-1) is a biological control bacterium that is applied to apple and pear trees during bloom for suppression of fire blight, caused by Erwinia amylovora. Strain C9-1 has three megaplasmids: pPag1, pPag2, and pPag3. Prior bioinformatic studies predicted these megaplasmids have a role in environmental fitness and/or biocontrol efficacy. Plasmid pPag3 is part of the large Pantoea plasmid (LPP-1) group that is present in all Pantoea spp. and has been hypothesized to contribute to environmental colonization and persistence, while pPag2 is less common. We assessed fitness of C9-1 derivatives cured of pPag2 and/or pPag3 on pear and apple flowers and fruit in experimental orchards. We also assessed the ability of a C9-1 derivative lacking pPag3 to reduce populations of E. amylovora on flowers and disease incidence. Previously, we determined that tolerance to stresses imposed in vitro was compromised in derivatives of C9-1 lacking pPag2 and/or pPag3; however, in this study, the loss of pPag2 and/or pPag3 did not consistently reduce the fitness of C9-1 on flowers in orchards. Over the summer, pPag3 contributed to survival of C9-1 on developing apple and pear fruit in two of five trials, whereas loss of pPag2 did not significantly affect survival of C9-1. We also found that loss of pPag3 did not affect C9-1's ability to reduce E. amylovora populations or fire blight incidence on apple flowers. Our findings partially support prior hypotheses that LPP-1 in Pantoea species contributes to persistence on plant surfaces but questions whether LPP-1 facilitates host colonization.
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Affiliation(s)
- Jeannie M Klein-Gordon
- Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, MI 48824
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331
| | - Kenneth B Johnson
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331
| | - Joyce E Loper
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331
- United States Department of Agriculture, Agricultural Research Service, Horticultural Crops Disease and Pest Management Research Unit, Corvallis, OR 97330
| | - Virginia O Stockwell
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331
- United States Department of Agriculture, Agricultural Research Service, Horticultural Crops Disease and Pest Management Research Unit, Corvallis, OR 97330
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Zeng Q, Slack S, Amine Hassani M. Pathogen Spotlight on Erwinia amylovora-Recent Advances in Genomics, Resistance Breeding, and Disease Management. Phytopathology 2023; 113:2140-2142. [PMID: 38147406 DOI: 10.1094/phyto-11-23-0439-sa] [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] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2023]
Affiliation(s)
- Quan Zeng
- Department of Plant Pathology and Ecology, The Connecticut Agricultural Experiment Station, New Haven, CT 06511
| | - Suzanne Slack
- Department of Horticulture, Iowa State University, Ames, IA 50011
| | - M Amine Hassani
- Department of Plant Pathology and Ecology, The Connecticut Agricultural Experiment Station, New Haven, CT 06511
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Yuan X, Sundin GW, Zeng Q, Johnson KB, Cox KD, Yu M, Huang J, Yang CH. Erwinia amylovora Type III Secretion System Inhibitors Reduce Fire Blight Infection Under Field Conditions. Phytopathology 2023; 113:2197-2204. [PMID: 37344783 DOI: 10.1094/phyto-04-23-0111-sa] [Citation(s) in RCA: 1] [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: 06/23/2023]
Abstract
Fire blight, caused by Erwinia amylovora, is an economically important disease in apples and pears worldwide. This pathogen relies on the type III secretion system (T3SS) to cause disease. Compounds that inhibit the function of the T3SS (T3SS inhibitors) have emerged as alternative strategies for bacterial plant disease management, as they block bacterial virulence without affecting growth, unlike traditional antibiotics. In this study, we investigated the mode of action of a T3SS inhibitor named TS108, a plant phenolic acid derivative, in E. amylovora. We showed that adding TS108 to an in vitro culture of E. amylovora repressed the expression of several T3SS regulon genes, including the master regulator gene hrpL. Further studies demonstrated that TS108 negatively regulates CsrB, a global regulatory small RNA, at the posttranscriptional level, resulting in a repression of hrpS, which encodes a key activator of hrpL. Additionally, TS108 has no impact on the expression of T3SS in Dickeya dadantii or Pseudomonas aeruginosa, suggesting that its inhibition of the E. amylovora T3SS is likely species specific. To better evaluate the performance of T3SS inhibitors in fire blight management, we conducted five independent field experiments in four states (Michigan, New York, Oregon, and Connecticut) from 2015 to 2022 and observed reductions in blossom blight incidence as high as 96.7% compared with untreated trees. In summary, the T3SS inhibitors exhibited good efficacy against fire blight.
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Affiliation(s)
- Xiaochen Yuan
- Department of Plant Pathology, Entomology and Microbiology, Iowa State University, Ames, IA 50011
| | - George W Sundin
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI 48824
| | - Quan Zeng
- Department of Plant Pathology and Ecology, The Connecticut Agricultural Experiment Station, New Haven, CT 06511
| | - Kenneth B Johnson
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331
| | - Kerik D Cox
- Section of Plant Pathology and Plant-Microbe Biology, School of Integrative Plant Science, Cornell University, Cornell AgriTech, Geneva, NY 14456
| | - Manda Yu
- Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, WI 53211
| | - Jian Huang
- T3 Bioscience, Lapham Hall 181, Milwaukee, WI 53211
| | - Ching-Hong Yang
- Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, WI 53211
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Mansfeld BN, Yocca A, Ou S, Harkess A, Burchard E, Gutierrez B, van Nocker S, Gottschalk C. A haplotype resolved chromosome-scale assembly of North American wild apple Malus fusca and comparative genomics of the fire blight Mfu10 locus. Plant J 2023; 116:989-1002. [PMID: 37639371 DOI: 10.1111/tpj.16433] [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] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 07/08/2023] [Accepted: 08/12/2023] [Indexed: 08/31/2023]
Abstract
SUMMARYThe Pacific crabapple (Malus fusca) is a wild relative of the commercial apple (Malus × domestica). With a range extending from Alaska to Northern California, M. fusca is extremely hardy and disease resistant. The species represents an untapped genetic resource for the development of new apple cultivars with enhanced stress resistance. However, gene discovery and utilization of M. fusca have been hampered by the lack of genomic resources. Here, we present a high‐quality, haplotype‐resolved, chromosome‐scale genome assembly and annotation for M. fusca. The genome was assembled using high‐fidelity long‐reads and scaffolded using genetic maps and high‐throughput chromatin conformation capture sequencing, resulting in one of the most contiguous apple genomes to date. We annotated the genome using public transcriptomic data from the same species taken from diverse plant structures and developmental stages. Using this assembly, we explored haplotypic structural variation within the genome of M. fusca, identifying thousands of large variants. We further showed high sequence co‐linearity with other domesticated and wild Malus species. Finally, we resolve a known quantitative trait locus associated with resistance to fire blight (Erwinia amylovora). Insights gained from the assembly of a reference‐quality genome of this hardy wild apple relative will be invaluable as a tool to facilitate DNA‐informed introgression breeding.
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Affiliation(s)
- Ben N Mansfeld
- Department of Biology, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Alan Yocca
- HudsonAlpha Institute for Biotechnology, Huntsville, Alabama, USA
| | - Shujun Ou
- Department of Molecular Genetics, The Ohio State University, Columbus, Ohio, USA
| | - Alex Harkess
- HudsonAlpha Institute for Biotechnology, Huntsville, Alabama, USA
| | - Erik Burchard
- USDA ARS, Appalachian Fruit Research Station, Kearneysville, West Virginia, USA
| | | | - Steve van Nocker
- Department of Horticulture, Michigan State University, East Lansing, Michigan, USA
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Ham H, Park DS. Novel approach toward the understanding of genetic diversity based on the two types of amino acid repeats in Erwinia amylovora. Sci Rep 2023; 13:17876. [PMID: 37857695 PMCID: PMC10587187 DOI: 10.1038/s41598-023-44558-w] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Accepted: 10/10/2023] [Indexed: 10/21/2023] Open
Abstract
Erwinia amylovora is a notorious plant pathogenic bacterium of global concern that has devastated the apple and pear production industry worldwide. Nevertheless, the approaches available currently to understand the genetic diversity of E. amylovora remain unsatisfactory because of the lack of a trustworthy index and data covering the globally occurring E. amylovora strains; thus, their origin and distribution pattern remains ambiguous. Therefore, there is a growing need for robust approaches for obtaining this information via the comparison of the genomic structure of Amygdaloideae-infecting strains to understand their genetic diversity and distribution. Here, the whole-genome sequences of 245 E. amylovora strains available from the NCBI database were compared to identify intraspecific genes for use as an improved index for the simple classification of E. amylovora strains regarding their distribution. Finally, we discovered two kinds of strain-typing protein-encoding genes, i.e., the SAM-dependent methyltransferase and electron transport complex subunit RsxC. Interestingly, both of these proteins carried an amino acid repeat in these strains: SAM-dependent methyltransferase comprised a single-amino-acid repeat (asparagine), whereas RsxC carried a 40-amino-acid repeat, which was differentially distributed among the strains. These noteworthy findings and approaches may enable the exploration of the genetic diversity of E. amylovora from a global perspective.
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Affiliation(s)
- Hyeonheui Ham
- Crop Protection Division, Department of Agro-Food Safety and Crop Protection, National Institute of Agricultural Sciences, Rural Development Administration, Wanju, 55365, Republic of Korea
| | - Dong Suk Park
- Crop Protection Division, Department of Agro-Food Safety and Crop Protection, National Institute of Agricultural Sciences, Rural Development Administration, Wanju, 55365, Republic of Korea.
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Jin JH, Kim D. Protocol for diagnosing Erwinia amylovora infection using a fluorescent probe. STAR Protoc 2023; 4:102412. [PMID: 37421612 PMCID: PMC10339246 DOI: 10.1016/j.xpro.2023.102412] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2023] [Revised: 05/10/2023] [Accepted: 06/07/2023] [Indexed: 07/10/2023] Open
Abstract
Current fire blight diagnosis techniques are DNA based and require specialized equipment and expertise, or they are less sensitive. Here, we present a protocol for diagnosing fire blight using the fluorescent probe, B-1. We describe steps for Erwinia amylovora culture, implementing a fire blight-infected model, and E. amylovora visualization. This protocol allows for detection of fire blight bacteria of up to 102 CFU/mL on plants or objects in just 10 s with a simple application including spraying and swabbing. For complete details on the use and execution of this protocol, please refer to Jung et al.1.
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Affiliation(s)
- Ji Hye Jin
- Department of Biomedical Science, Graduate School, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Dokyoung Kim
- Department of Biomedical Science, Graduate School, Kyung Hee University, Seoul 02447, Republic of Korea; Department of Anatomy and Neurobiology, College of Medicine, Kyung Hee University, Seoul 02447, Republic of Korea; Medical Research Center for Bioreaction to Reactive Oxygen Species and Biomedical Science Institute, Core Research Institute (CRI), Kyung Hee University, Seoul 02447, Republic of Korea; Center for Converging Humanities, Kyung Hee University, Seoul 02447, Republic of Korea; KHU-KIST Department of Converging Science and Technology, Kyung Hee University, Seoul 02447, Republic of Korea; UC San Diego Materials Research Science and Engineering Center, 9500 Gilman Drive, La Jolla, CA 92093, USA; Department of Precision Medicine, College of Medicine, Kyung Hee University, Seoul 02447, Republic of Korea.
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12
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Jin YJ, Lee SY, Kong HG, Yang SI, Ham H, Lee MH, Park DS. Novel Detection and Quantification Approach of Erwinia amylovora In Vitro and In Planta Using SYBR Green-Based Real-Time PCR Assay. Plant Dis 2023; 107:624-627. [PMID: 35900343 DOI: 10.1094/pdis-05-22-1227-sc] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [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: 06/15/2023]
Abstract
Fire blight, caused by the bacterial pathogen Erwinia amylovora, is a highly destructive disease of apple and pear. Because the apple tree gets systemically infected with E. amylovora and eventually dies, E. amylovora is a considerably important pathogen in the orchard that requires long-term management. In addition, it is crucial to prevent the spread of the pathogen by expeditious diagnosis. In this study, via comparative approaches to the genome sequences of the strains of various Erwinia spp., we designed specific primers targeting a hypothetical gene that is single copy and located in the chromosomal DNA of E. amylovora. This primer set specifically amplified the DNA of E. amylovora but no other bacteria, including E. pyrifoliae, Pectobacterium spp., Pantoea spp., and Dickeya chrysanthemi. Furthermore, the SYBR Green-based real-time PCR using the primer set allowed accurate estimation of the population of E. amylovora. Developing a rapid and accurate diagnostic method using the novel primer set enables effective defense against pathogen spread through continuous monitoring and quick response.
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Affiliation(s)
- Yong Ju Jin
- Crop Protection Division, National Institute of Agricultural Sciences, Rural Development Administration, Wanju-gun, 55365, Republic of Korea
| | - Seung Yeup Lee
- Crop Protection Division, National Institute of Agricultural Sciences, Rural Development Administration, Wanju-gun, 55365, Republic of Korea
| | - Hyun Gi Kong
- College of Agriculture, Life and Environment Sciences, Chungbuk National University, Cheongju, 28644, Republic of Korea
| | - Su In Yang
- Crop Protection Division, National Institute of Agricultural Sciences, Rural Development Administration, Wanju-gun, 55365, Republic of Korea
| | - Hyeonheui Ham
- Crop Protection Division, National Institute of Agricultural Sciences, Rural Development Administration, Wanju-gun, 55365, Republic of Korea
| | - Mi-Hyun Lee
- Crop Protection Division, National Institute of Agricultural Sciences, Rural Development Administration, Wanju-gun, 55365, Republic of Korea
| | - Dong Suk Park
- Crop Protection Division, National Institute of Agricultural Sciences, Rural Development Administration, Wanju-gun, 55365, Republic of Korea
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13
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Yang HW, Lee JH, Zhao Y. RpoN Regulon in Erwinia amylovora Revealed by Transcriptional Profiling and In Silico Binding Site Analysis. Phytopathology 2023; 113:183-193. [PMID: 35994732 DOI: 10.1094/phyto-07-22-0255-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] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Erwinia amylovora causes a devastating fire blight disease in apples and pears. One of the main virulence determinants in E. amylovora is the hypersensitive response (HR) and pathogenicity (hrp)-type III secretion system (T3SS), which is activated by the RpoN-HrpL sigma factor cascade. However, the RpoN regulon in E. amylovora has not been investigated. In this study, we determined the RpoN regulon in E. amylovora by combining RNA-seq transcriptomic analysis with in silico binding site analysis. RNA-seq revealed that 262 genes, approximately 7.5% genes in the genome of E. amylovora, were differentially transcribed in the rpoN mutant as compared with the wild type. Specifically, genes associated with virulence, motility, nitrogen assimilation, the PspF system, stress response, and arginine biosynthesis are positively regulated by RpoN, whereas genes associated with biosynthesis of amino acids and sorbitol transport are negatively regulated by RpoN. In silico binding site analysis identified 46 potential target genes with a putative RpoN binding site, and the upstream sequences of six, three, and three genes also contain putative GlnG, PspF, and YfhA binding sites, respectively. Overall, RpoN directly regulates genes associated with virulence, nitrogen assimilation, the PspF system, motility and the YfhA/YfhK two-component regulatory system.
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Affiliation(s)
- Ho-Wen Yang
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61801, U.S.A
| | - Jae-Hoon Lee
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61801, U.S.A
| | - Youfu Zhao
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61801, U.S.A
- Department of Plant Pathology, WSU-IAREC, Prosser, WA 99350, U.S.A
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14
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Zhang X, Xu W, Ni D, Zhang W, Guang C, Mu W. Successful Manipulation of the Product Spectrum of the Erwinia amylovora Levansucrase by Modifying the Residues around loop1, Loop 3, and Loop 4. J Agric Food Chem 2023; 71:680-689. [PMID: 36538710 DOI: 10.1021/acs.jafc.2c07891] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [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: 06/17/2023]
Abstract
Levansucrase (LS, EC 2.4.1.10) catalyzes the synthesis of levan by successively transferring the fructosyl moiety from sucrose to an elongated fructan chain. Although the product distribution of LS from Erwinia amylovora (Ea-LS) was studied under different sucrose concentrations, the effect of residues on the product formation is yet unknown. The first levanhexaose-complexed structure of LS from Bacillus subtilis (Bs-SacB) provided information on the oligosaccharide binding sites (OB sites), from +1 to +4 subsites. Since Ea-LS would efficiently produce fructooligosaccharides, a substitution mutation of OB sites in Bs-SacB and the corresponding residues of Ea-LS were conducted to investigate how these mutants would influence the product distribution. As a result, a series of mutants with different product spectrum were obtained. Notably, the mutants of G98E, V151F, and N200T around loop 1, loop 3, and loop 4 all showed a significant increase in both the molecular mass and the yield of high-molecular-mass levan, suggesting that the product profile of Ea-LS was significantly modified.
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Affiliation(s)
- Xiaoqi Zhang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, Jiangsu, China
| | - Wei Xu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, Jiangsu, China
| | - Dawei Ni
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, Jiangsu, China
| | - Wenli Zhang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, Jiangsu, China
| | - Cuie Guang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, Jiangsu, China
| | - Wanmeng Mu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, Jiangsu, China
- International Joint Laboratory on Food Safety, Jiangnan University, Wuxi 214122, China
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15
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Ivanov AV, Safenkova IV, Drenova NV, Zherdev AV, Dzantiev BB. Comparison of Biosensing Methods Based on Different Isothermal Amplification Strategies: A Case Study with Erwinia amylovora. Biosensors (Basel) 2022; 12:1174. [PMID: 36551141 PMCID: PMC9776058 DOI: 10.3390/bios12121174] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 12/09/2022] [Accepted: 12/13/2022] [Indexed: 06/17/2023]
Abstract
Isothermal amplifications allow for the highly sensitive detection of nucleic acids, bypassing the use of instrumental thermal cycling. This work aimed to carry out an experimental comparison of the four most promising techniques: recombinase polymerase amplification (RPA) and loop-mediated isothermal amplification (LAMP) coupled with lateral flow test or coupled with additional amplification based on CRISPR/Cas12a resulting from the fluorescence of the Cas12a-cleaved probe. To compare the four amplification techniques, we chose the bacterial phytopathogen Erwinia amylovora (causative agent of fire blight), which has a quarantine significance in many countries and possesses a serious threat to agriculture. Three genes were chosen as the targets and primers were selected for each one (two for RPA and six for LAMP). They were functionalized by labels (biotin, fluorescein) at the 5' ends for amplicons recognition by LFT. As a result, we developed LAMP-LFT, LAMP-CRISPR/Cas, RPA-LFT, and RPA-CRISPR/Cas for E. amylovora detection. The detection limit was 104 CFU/mL for LAMP-LFT, 103 CFU/mL for LAMP-CRISPR/Cas, and 102 CFU/mL for RPA-LFT and RPA-CRISPR/Cas. The results of four developed test systems were verified by qPCR on a panel of real samples. The developed assays based on RPA, LAMP, CRISPR/Cas12a, and LFT are rapid (30-55 min), user-friendly, and highly sensitive for E. amylovora detection. All proposed detection methods can be applied to fire blight diagnosis and effective management of this disease.
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Affiliation(s)
- Aleksandr V. Ivanov
- A.N. Bach Institute of Biochemistry, Research Centre of Biotechnology of the Russian Academy of Sciences, Leninsky Prospect 33, 119071 Moscow, Russia
| | - Irina V. Safenkova
- A.N. Bach Institute of Biochemistry, Research Centre of Biotechnology of the Russian Academy of Sciences, Leninsky Prospect 33, 119071 Moscow, Russia
| | - Natalia V. Drenova
- All-Russian Plant Quarantine Centre, Pogranichnaya Street 32, Bykovo, 140150 Ramenskoe, Moscow Region, Russia
| | - Anatoly V. Zherdev
- A.N. Bach Institute of Biochemistry, Research Centre of Biotechnology of the Russian Academy of Sciences, Leninsky Prospect 33, 119071 Moscow, Russia
| | - Boris B. Dzantiev
- A.N. Bach Institute of Biochemistry, Research Centre of Biotechnology of the Russian Academy of Sciences, Leninsky Prospect 33, 119071 Moscow, Russia
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16
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Sabri M, El Handi K, Valentini F, De Stradis A, Achbani EH, Benkirane R, Resch G, Elbeaino T. Identification and Characterization of Erwinia Phage IT22: A New Bacteriophage-Based Biocontrol against Erwinia amylovora. Viruses 2022; 14:v14112455. [PMID: 36366553 PMCID: PMC9698647 DOI: 10.3390/v14112455] [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: 10/12/2022] [Revised: 11/03/2022] [Accepted: 11/03/2022] [Indexed: 11/09/2022] Open
Abstract
Erwinia amylovora is a quarantine phytopathogenic bacterium that is the causal agent of fire blight, a destructive disease responsible for killing millions of fruit-bearing plants worldwide, including apple, pear, quince, and raspberry. Efficient and sustainable control strategies for this serious bacterial disease are still lacking, and traditional methods are limited to the use of antibiotics and some basic agricultural practices. This study aimed to contribute to the development of a sustainable control strategy through the identification, characterization, and application of bacteriophages (phages) able to control fire blight on pears. Phages isolated from wastewater collected in the Apulia region (southern Italy) were characterized and evaluated as antibacterial agents to treat experimental fire blight caused by E. amylovora. Transmission electron microscopy (TEM) conducted on purified phages (named EP-IT22 for Erwinia phage IT22) showed particles with icosahedral heads of ca. 90 ± 5 nm in length and long contractile tails of 100 ± 10 nm, typical of the Myoviridae family. Whole genome sequencing (WGS), assembly, and analysis of the phage DNA generated a single contig of 174.346 bp representing a complete circular genome composed of 310 open reading frames (ORFs). EP-IT22 was found to be 98.48% identical to the Straboviridae Erwinia phage Cronus (EPC) (GenBank Acc. n° NC_055743) at the nucleotide level. EP-IT22 was found to be resistant to high temperatures (up to 60 °C) and pH values between 4 and 11, and was able to accomplish a complete lytic cycle within one hour. Furthermore, the viability-qPCR and turbidity assays showed that EP-IT22 (MOI = 1) lysed 94% of E. amylovora cells in 20 h. The antibacterial activity of EP-IT22 in planta was evaluated in E. amylovora-inoculated pear plants that remained asymptomatic 40 days post inoculation, similarly to those treated with streptomycin sulphate. This is the first description of the morphological, biological, and molecular features of EP-IT22, highlighting its promising potential for biocontrol of E. amylovora against fire blight disease.
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Affiliation(s)
- Miloud Sabri
- Productions Végétales, Animales et Agro-Industrie, Faculté des Sciences, Ibn Tofail University, Kenitra 14000, Morocco
- Phytobacteriology and Biological Control Laboratory, Regional Center of Agricultural Research of Meknes, National Institute of Agricultural Research, Avenue Ennasr, BP 415 Rabat Principal, Rabat 10090, Morocco
- International Center for Advanced Mediterranean Agronomic Studies (CIHEAM of Bari), Via Ceglie 9, 70010 Valenzano, Italy
| | - Kaoutar El Handi
- Phytobacteriology and Biological Control Laboratory, Regional Center of Agricultural Research of Meknes, National Institute of Agricultural Research, Avenue Ennasr, BP 415 Rabat Principal, Rabat 10090, Morocco
- International Center for Advanced Mediterranean Agronomic Studies (CIHEAM of Bari), Via Ceglie 9, 70010 Valenzano, Italy
- Laboratory of Plant Biotechnology and Valorisation of Bio-Resources, Faculty of Sciences, Moulay Ismail University, Meknes 11201, Morocco
| | - Franco Valentini
- International Center for Advanced Mediterranean Agronomic Studies (CIHEAM of Bari), Via Ceglie 9, 70010 Valenzano, Italy
| | - Angelo De Stradis
- National Research Council of Italy (CNR), Institute for Sustainable Plant Protection (IPSP), University of Bari, Via Amendola 165/A, 70126 Bari, Italy
| | - El Hassan Achbani
- Phytobacteriology and Biological Control Laboratory, Regional Center of Agricultural Research of Meknes, National Institute of Agricultural Research, Avenue Ennasr, BP 415 Rabat Principal, Rabat 10090, Morocco
| | - Rachid Benkirane
- Productions Végétales, Animales et Agro-Industrie, Faculté des Sciences, Ibn Tofail University, Kenitra 14000, Morocco
| | - Grégory Resch
- Center for Research and Innovation in Clinical Pharmaceutical Sciences (CRISP), Lausanne University Hospital (CHUV), 1011 Lausanne, Switzerland
| | - Toufic Elbeaino
- International Center for Advanced Mediterranean Agronomic Studies (CIHEAM of Bari), Via Ceglie 9, 70010 Valenzano, Italy
- Correspondence: ; Tel.: +39-080-46-06-352
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17
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Barbé S, Figàs-Segura À, Benada M, Navarro-Herrero I, Sampaio TM, Biosca EG, Marco-Noales E. Plant-associated microbiota as a source of antagonistic bacteria against the phytopathogen Erwinia amylovora. Environ Microbiol Rep 2022; 14:559-569. [PMID: 35403335 DOI: 10.1111/1758-2229.13064] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 03/21/2022] [Indexed: 06/14/2023]
Abstract
Control of bacterial plant diseases is a major concern, as they affect economically important species and spread easily, such as the case of fire blight of rosaceous caused by Erwinia amylovora. In the search for alternatives to the use of agrochemicals and antibiotics, this work presents a screening of natural bacterial antagonists of this relevant and devastating phytopathogen. We recovered bacterial isolates from different plant tissues and geographical origins and then selected those with the strongest ability to reduce fire blight symptoms ex vivo and remarkable in vitro antagonistic activity against E. amylovora. None of them elicited a hypersensitivity reaction in tobacco leaves, most produced several hydrolytic enzymes and presented other biocontrol and/or plant growth-promoting activities, such as siderophore production and phosphate solubilization. These isolates, considered as biocontrol candidates, were identified by 16S rRNA sequencing as Pseudomonas rhizosphaerae, Curtobacterium flaccumfaciens, Enterobacter cancerogenus, Pseudomonas azotoformans, Rosenbergiella epipactidis and Serratia plymuthica. This is the first time that the last five bacterial species are reported to have biocontrol potential against E. amylovora.
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Affiliation(s)
- Silvia Barbé
- Centro de Protección Vegetal y Biotecnología, Instituto Valenciano de Investigaciones Agrarias (IVIA), CV-315 km 10.7, 46113 Moncada, Valencia, Spain
| | - Àngela Figàs-Segura
- Departamento de Microbiología y Ecología, Facultad de Ciencias Biológicas, Universitat de València, C/Dr. Moliner, 50, 46100 Burjassot, Valencia, Spain
| | - M'hamed Benada
- Centro de Protección Vegetal y Biotecnología, Instituto Valenciano de Investigaciones Agrarias (IVIA), CV-315 km 10.7, 46113 Moncada, Valencia, Spain
- Faculty of Natural Sciences, Earth and the Universe, 8 Mai 1945 University, Guelma, Algeria
| | - Inmaculada Navarro-Herrero
- Centro de Protección Vegetal y Biotecnología, Instituto Valenciano de Investigaciones Agrarias (IVIA), CV-315 km 10.7, 46113 Moncada, Valencia, Spain
| | - Telma Maria Sampaio
- Centro de Protección Vegetal y Biotecnología, Instituto Valenciano de Investigaciones Agrarias (IVIA), CV-315 km 10.7, 46113 Moncada, Valencia, Spain
| | - Elena G Biosca
- Departamento de Microbiología y Ecología, Facultad de Ciencias Biológicas, Universitat de València, C/Dr. Moliner, 50, 46100 Burjassot, Valencia, Spain
| | - Ester Marco-Noales
- Centro de Protección Vegetal y Biotecnología, Instituto Valenciano de Investigaciones Agrarias (IVIA), CV-315 km 10.7, 46113 Moncada, Valencia, Spain
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18
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Albanese D, Cainelli C, Gualandri V, Larger S, Pindo M, Donati C. Genome sequencing provides new insights on the distribution of Erwinia amylovora lineages in northern Italy. Environ Microbiol Rep 2022; 14:584-590. [PMID: 35484918 PMCID: PMC9544390 DOI: 10.1111/1758-2229.13074] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 04/11/2022] [Accepted: 04/13/2022] [Indexed: 06/14/2023]
Abstract
Erwinia amylovora is a Gram-negative bacterium that colonizes a wide variety of plant species causing recurrent local outbreaks of fire blight in crops of the Rosaceae family. Recent genomic surveys have documented the limited genomic diversity of this species, possibly related to a recent evolutionary bottleneck and a strong correlation between geography and phylogenetic structure of the species. Despite its economic importance, little is known about the genetic variability of co-circulating strains during local outbreaks. Here, we report the genome sequences of 82 isolates of E. amylovora, collected from different host plants in a period of 16 years in Trentino, a small region in the Northeastern Italian Alps that has been characterized by recurrent outbreaks of fire blight in apple orchards. While the genome isolated before 2018 are closely related to other strains already present in Europe, we found a novel subclade composed only by isolates that were sampled starting from 2018 and demonstrate that the endemic population of this pathogen can be composed by mixture of strains.
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Affiliation(s)
- Davide Albanese
- Unit of Computational Biology, Research and Innovation Centre, Fondazione Edmund Mach, Via E. Mach 1San Michele all'Adige38010Italy
| | - Christian Cainelli
- Center for Technology Transfer, Fondazione Edmund Mach, Via E. Mach 1San Michele all'Adige38010Italy
| | - Valeria Gualandri
- Center for Technology Transfer, Fondazione Edmund Mach, Via E. Mach 1San Michele all'Adige38010Italy
- Center of Agriculture, Food and Environment (C3A)University of TrentoTrentoItaly
| | - Simone Larger
- Unit of Computational Biology, Research and Innovation Centre, Fondazione Edmund Mach, Via E. Mach 1San Michele all'Adige38010Italy
| | - Massimo Pindo
- Unit of Computational Biology, Research and Innovation Centre, Fondazione Edmund Mach, Via E. Mach 1San Michele all'Adige38010Italy
| | - Claudio Donati
- Unit of Computational Biology, Research and Innovation Centre, Fondazione Edmund Mach, Via E. Mach 1San Michele all'Adige38010Italy
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Gaucher M, Righetti L, Aubourg S, Dugé de Bernonville T, Brisset MN, Chevreau E, Vergne E. An Erwinia amylovora inducible promoter for improvement of apple fire blight resistance. Plant Cell Rep 2022; 41:1499-1513. [PMID: 35385991 PMCID: PMC9270298 DOI: 10.1007/s00299-022-02869-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 03/18/2022] [Indexed: 06/14/2023]
Abstract
pPPO16, the first Ea-inducible promoter cloned from apple, can be a useful component of intragenic strategies to create fire blight resistant apple genotypes. Intragenesis is an important alternative to transgenesis to produce modified plants containing native DNA only. A key point to develop such a strategy is the availability of regulatory sequences controlling the expression of the gene of interest. With the aim of finding apple gene promoters either inducible by the fire blight pathogen Erwinia amylovora (Ea) or moderately constitutive, we focused on polyphenoloxidase genes (PPO). These genes encode oxidative enzymes involved in many physiological processes and have been previously shown to be upregulated during the Ea infection process. We found ten PPO and two PPO-like sequences in the apple genome and characterized the promoters of MdPPO16 (pPPO16) and MdKFDV02 PPO-like (pKFDV02) for their potential as Ea-inducible and low-constitutive regulatory sequences, respectively. Expression levels of reporter genes fused to these promoters and transiently or stably expressed in apple were quantified after various treatments. Unlike pKFDV02 which displayed a variable activity, pPPO16 allowed a fast and strong expression of transgenes in apple following Ea infection in a Type 3 Secretion System dependent manner. Altogether our results does not confirmed pKFDV02 as a constitutive and weak promoter whereas pPPO16, the first Ea-inducible promoter cloned from apple, can be a useful component of intragenic strategies to create fire blight resistant apple genotypes.
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Affiliation(s)
- Matthieu Gaucher
- Univ Angers, Institut Agro, INRAE, IRHS, SFR QUASAV, 49000, Angers, France
| | - Laura Righetti
- Research Centre for Cereal and Industrial Crops (CREA-CI), Council for Agricultural Research and Agricultural Economics Analysis, Via di Corticella 133, 40128, Bologna, Italy
| | - Sébastien Aubourg
- Univ Angers, Institut Agro, INRAE, IRHS, SFR QUASAV, 49000, Angers, France
| | - Thomas Dugé de Bernonville
- EA2106 Biomolécules et Biotechnologies Végétales, UFR Sciences Pharmaceutiques, Université François Rabelais, 31 avenue Monge, 37200, Tours, France
| | | | - Elisabeth Chevreau
- Univ Angers, Institut Agro, INRAE, IRHS, SFR QUASAV, 49000, Angers, France
| | - Emilie Vergne
- Univ Angers, Institut Agro, INRAE, IRHS, SFR QUASAV, 49000, Angers, France.
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20
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Launay A, Jolivet S, Clément G, Zarattini M, Dellero Y, Le Hir R, Jossier M, Hodges M, Expert D, Fagard M. DspA/E-Triggered Non-Host Resistance against E. amylovora Depends on the Arabidopsis GLYCOLATE OXIDASE 2 Gene. Int J Mol Sci 2022; 23:ijms23084224. [PMID: 35457046 PMCID: PMC9029980 DOI: 10.3390/ijms23084224] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [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: 03/01/2022] [Revised: 03/31/2022] [Accepted: 04/03/2022] [Indexed: 12/04/2022] Open
Abstract
DspA/E is a type three effector injected by the pathogenic bacterium Erwinia amylovora inside plant cells. In non-host Arabidopsis thaliana, DspA/E inhibits seed germination, root growth, de novo protein synthesis and triggers localized cell death. To better understand the mechanisms involved, we performed EMS mutagenesis on a transgenic line, 13-1-2, containing an inducible dspA/E gene. We identified three suppressor mutants, two of which belonged to the same complementation group. Both were resistant to the toxic effects of DspA/E. Metabolome analysis showed that the 13-1-2 line was depleted in metabolites of the TCA cycle and accumulated metabolites associated with cell death and defense. TCA cycle and cell-death associated metabolite levels were respectively increased and reduced in both suppressor mutants compared to the 13-1-2 line. Whole genome sequencing indicated that both suppressor mutants displayed missense mutations in conserved residues of Glycolate oxidase 2 (GOX2), a photorespiratory enzyme that we confirmed to be localized in the peroxisome. Leaf GOX activity increased in leaves infected with E. amylovora in a DspA/E-dependent manner. Moreover, the gox2-2 KO mutant was more sensitive to E. amylovora infection and displayed reduced JA-signaling. Our results point to a role for glycolate oxidase in type II non-host resistance and to the importance of central metabolic functions in controlling growth/defense balance.
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Affiliation(s)
- Alban Launay
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), 78000 Versailles, France; (A.L.); (S.J.); (G.C.); (M.Z.); (R.L.H.); (D.E.)
| | - Sylvie Jolivet
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), 78000 Versailles, France; (A.L.); (S.J.); (G.C.); (M.Z.); (R.L.H.); (D.E.)
| | - Gilles Clément
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), 78000 Versailles, France; (A.L.); (S.J.); (G.C.); (M.Z.); (R.L.H.); (D.E.)
| | - Marco Zarattini
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), 78000 Versailles, France; (A.L.); (S.J.); (G.C.); (M.Z.); (R.L.H.); (D.E.)
| | - Younes Dellero
- Université Paris-Saclay, CNRS, INRAE, Université Evry, Institute of Plant Sciences Paris-Saclay (IPS2), 91190 Gif sur Yvette, France; (Y.D.); (M.J.); (M.H.)
- Université Paris Cité, CNRS, INRAE, Institute of Plant Sciences Paris-Saclay (IPS2), 91190 Gif sur Yvette, France
| | - Rozenn Le Hir
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), 78000 Versailles, France; (A.L.); (S.J.); (G.C.); (M.Z.); (R.L.H.); (D.E.)
| | - Mathieu Jossier
- Université Paris-Saclay, CNRS, INRAE, Université Evry, Institute of Plant Sciences Paris-Saclay (IPS2), 91190 Gif sur Yvette, France; (Y.D.); (M.J.); (M.H.)
- Université Paris Cité, CNRS, INRAE, Institute of Plant Sciences Paris-Saclay (IPS2), 91190 Gif sur Yvette, France
| | - Michael Hodges
- Université Paris-Saclay, CNRS, INRAE, Université Evry, Institute of Plant Sciences Paris-Saclay (IPS2), 91190 Gif sur Yvette, France; (Y.D.); (M.J.); (M.H.)
- Université Paris Cité, CNRS, INRAE, Institute of Plant Sciences Paris-Saclay (IPS2), 91190 Gif sur Yvette, France
| | - Dominique Expert
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), 78000 Versailles, France; (A.L.); (S.J.); (G.C.); (M.Z.); (R.L.H.); (D.E.)
| | - Mathilde Fagard
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), 78000 Versailles, France; (A.L.); (S.J.); (G.C.); (M.Z.); (R.L.H.); (D.E.)
- Correspondence:
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21
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Abstract
The accurate assessment of Erwinia amylovora live cell populations in fire blight cankers by classic microbiology methods has major limitations. Some of them are the presence of competitive microbiota in samples that inhibit E. amylovora's growth and the release of toxic compounds by plant material during sample processing, which may hamper the pathogen's ability to form colonies on solid media. Digital PCR (dPCR) combined with the photo-reactive DNA-binding dye propidium monoazide (PMA) allows selective detection and quantification of live E. amylovora cells in woody samples while overcoming the constraints of culture-dependent methods. This work describes a reliable viability dPCR procedure to determine E. amylovora live cell concentrations in fire blight cankers from pome fruit trees. This protocol can be adapted for the analysis of other types of plant material and enables investigation of ecological, epidemiological, and management significance of cankers as a relatively underexplored part of the fire blight disease cycle.
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Affiliation(s)
- Ricardo Delgado Santander
- Cornell University, Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Sciences, Hudson Valley Research Laboratory, Highland, NY, USA
| | - Katarina Gašić
- Cornell University, Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Sciences, Hudson Valley Research Laboratory, Highland, NY, USA
- Institute for Plant Protection and Environment, Department of Plant Diseases, Laboratory for Phytopathology, Belgrade, Serbia
| | - Srđan Goran Aćimović
- CenterVirginia Polytechnic Institute and State University, School of Plant and Environmental Sciences, Alson H. Smith Jr. Agricultural Research and Extension Center, Winchester, VA, USA.
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22
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Wallis A, Yannuzzi IM, Choi MW, Spafford J, Fenn M, Ramachandran P, Timme R, Pettengill JB, Cagle R, Ottesen A, Cox KD. Investigating the Distribution of Strains of Erwinia amylovora and Streptomycin Resistance in Apple Orchards in New York Using Clustered Regularly Interspaced Short Palindromic Repeat Profiles: A 6-Year Follow-Up. Plant Dis 2021; 105:3554-3563. [PMID: 33599513 DOI: 10.1094/pdis-12-20-2585-re] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [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
Fire blight, caused by the bacterium Erwinia amylovora, is one of the most important diseases of apple. The antibiotic streptomycin is routinely used in the commercial apple industries of New York (NY) and New England to manage the disease. In 2002 and again, from 2011 to 2014, outbreaks of streptomycin resistance (SmR) were reported and investigated in NY. Motivated by new grower reports of control failures, we conducted a follow-up investigation of the distribution of SmR and E. amylovora strains for major apple production regions of NY over the last 6 years (2015 to 2020). Characterization of clustered regularly interspaced short palindromic repeat (CRISPR) profiles revealed that a few "cosmopolitan" strains were widely prevalent across regions, whereas many other "resident" strains were confined to one location. In addition, we uncovered novel CRISPR profile diversity in all investigated regions. SmR E. amylovora was detected only in a small area spanning two counties from 2017 to 2020 and was always associated with one CRISPR profile (41:23:38), which matched the profile of SmR E. amylovora, discovered in 2002. This suggests the original SmR E. amylovora was never fully eradicated and went undetected because of several seasons of low disease pressure in this region. Investigation of several representative isolates under controlled greenhouse conditions indicated significant differences in aggressiveness on 'Gala' apples. Potential implications of strain differences include the propensity of strains to become distributed across wide geographic regions and associated resistance management practices. Results from this work will directly influence sustainable fire blight management recommendations for commercial apple industries in NY state and other regions.
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Affiliation(s)
- Anna Wallis
- Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Geneva, NY 14456
| | - Isabella M Yannuzzi
- Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Geneva, NY 14456
| | - Mei-Wah Choi
- Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Geneva, NY 14456
| | - John Spafford
- Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Geneva, NY 14456
| | - Matthew Fenn
- Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Geneva, NY 14456
| | - Padmini Ramachandran
- Molecular Methods and Subtyping Branch, Division of Microbiology, Office of Regulatory Science, Center for Food Safety and Applied Nutrition, Food and Drug Administration, College Park, MD 20740
| | - Ruth Timme
- Molecular Methods and Subtyping Branch, Division of Microbiology, Office of Regulatory Science, Center for Food Safety and Applied Nutrition, Food and Drug Administration, College Park, MD 20740
| | - James B Pettengill
- Molecular Methods and Subtyping Branch, Division of Microbiology, Office of Regulatory Science, Center for Food Safety and Applied Nutrition, Food and Drug Administration, College Park, MD 20740
| | - Robin Cagle
- Department of Microbiology, University of Washington, Seattle, WA 98185
| | - Andrea Ottesen
- Molecular Methods and Subtyping Branch, Division of Microbiology, Office of Regulatory Science, Center for Food Safety and Applied Nutrition, Food and Drug Administration, College Park, MD 20740
| | - Kerik D Cox
- Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Geneva, NY 14456
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23
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Farjad M, Clément G, Launay A, Jeridi R, Jolivet S, Citerne S, Rigault M, Soulie M, Dinant S, Fagard M. Plant nitrate supply regulates Erwinia amylovora virulence gene expression in Arabidopsis. Mol Plant Pathol 2021; 22:1332-1346. [PMID: 34382308 PMCID: PMC8518577 DOI: 10.1111/mpp.13114] [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] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 06/16/2021] [Accepted: 06/26/2021] [Indexed: 05/03/2023]
Abstract
We showed previously that nitrogen (N) limitation decreases Arabidopsis resistance to Erwinia amylovora (Ea). We show that decreased resistance to bacteria in low N is correlated with lower apoplastic reactive oxygen species (ROS) accumulation and lower jasmonic acid (JA) pathway expression. Consistently, pretreatment with methyl jasmonate (Me-JA) increased the resistance of plants grown under low N. In parallel, we show that in planta titres of a nonvirulent type III secretion system (T3SS)-deficient Ea mutant were lower than those of wildtype Ea in low N, as expected, but surprisingly not in high N. This lack of difference in high N was consistent with the low expression of the T3SS-encoding hrp virulence genes by wildtype Ea in plants grown in high N compared to plants grown in low N. This suggests that expressing its virulence factors in planta could be a major limiting factor for Ea in the nonhost Arabidopsis. To test this hypothesis, we preincubated Ea in an inducing medium that triggers expression of hrp genes in vitro, prior to inoculation. This preincubation strongly enhanced Ea titres in planta, independently of the plant N status, and was correlated to a significant repression of JA-dependent genes. Finally, we identify two clusters of metabolites associated with resistance or with susceptibility to Ea. Altogether, our data showed that high susceptibility of Arabidopsis to Ea, under low N or following preincubation in hrp-inducing medium, is correlated with high expression of the Ea hrp genes in planta and low expression of the JA signalling pathway, and is correlated with the accumulation of specific metabolites.
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Affiliation(s)
- Mahsa Farjad
- Institut Jean‐Pierre BourginINRAEAgroParisTechUniversité Paris‐SaclayVersaillesFrance
| | - Gilles Clément
- Institut Jean‐Pierre BourginINRAEAgroParisTechUniversité Paris‐SaclayVersaillesFrance
| | - Alban Launay
- Institut Jean‐Pierre BourginINRAEAgroParisTechUniversité Paris‐SaclayVersaillesFrance
| | - Roua Jeridi
- Institut Jean‐Pierre BourginINRAEAgroParisTechUniversité Paris‐SaclayVersaillesFrance
- Laboratoire des Risques Liés Aux Stress EnvironnementauxFaculté des Sciences de Bizerte, Université de CarthageBizerteTunisia
| | - Sylvie Jolivet
- Institut Jean‐Pierre BourginINRAEAgroParisTechUniversité Paris‐SaclayVersaillesFrance
| | - Sylvie Citerne
- Institut Jean‐Pierre BourginINRAEAgroParisTechUniversité Paris‐SaclayVersaillesFrance
| | - Martine Rigault
- Institut Jean‐Pierre BourginINRAEAgroParisTechUniversité Paris‐SaclayVersaillesFrance
| | - Marie‐Christine Soulie
- Institut Jean‐Pierre BourginINRAEAgroParisTechUniversité Paris‐SaclayVersaillesFrance
- Sorbonne UniversitéUPMC Université Paris 06ParisFrance
| | - Sylvie Dinant
- Institut Jean‐Pierre BourginINRAEAgroParisTechUniversité Paris‐SaclayVersaillesFrance
| | - Mathilde Fagard
- Institut Jean‐Pierre BourginINRAEAgroParisTechUniversité Paris‐SaclayVersaillesFrance
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24
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Yuan X, McGhee GC, Slack SM, Sundin GW. A Novel Signaling Pathway Connects Thiamine Biosynthesis, Bacterial Respiration, and Production of the Exopolysaccharide Amylovoran in Erwinia amylovora. Mol Plant Microbe Interact 2021; 34:1193-1208. [PMID: 34081536 DOI: 10.1094/mpmi-04-21-0095-r] [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] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Erwinia amylovora is a plant pathogen causing necrotrophic fire blight disease of apple, pear, and other rosaceous plants. This bacterium colonizes host vascular tissues via the production of exopolysaccharides (EPSs) including amylovoran. It is well-established that the nearly ubiquitous plasmid pEA29 of E. amylovora is an essential virulence factor, but the underlying mechanism remains uncharacterized. Here, we demonstrated that pEA29 was required for E. amylovora to produce amylovoran and to form a biofilm, and this regulation was dependent on the thiamine biosynthesis operon thiOSGF. We then conducted carbohydrate and genetic analyses demonstrating that the thiamine-mediated effect on amylovoran production was indirect, as cells lacking thiOSGF produced an EPS that did not contain glucuronic acid, one of the key components of amylovoran, whereas the transcriptional activity and RNA levels of the amylovoran biosynthesis genes were not altered. Alternatively, addition of exogenous thiamine restored amylovoran production in the pEA29-cured strain of E. amylovora and positively impacted amylovoran production in a dose-dependent manner. Individual deletion of several chromosomal thiamine biosynthesis genes also affected amylovoran production, implying that a complete thiamine biosynthesis pathway is required for the thiamine-mediated effect on amylovoran production in E. amylovora. Finally, we determined that an imbalanced tricarboxylic acid cycle negatively affected amylovoran production, which was restored by addition of exogenous thiamine or overexpression of the thiOSGF operon. In summary, our report revealed a novel signaling pathway that impacts E. amylovora virulence in which thiamine biosynthesis enhances bacterial respiration that provides energetic requirements for the biosynthesis of EPS amylovoran.[Formula: see text] Copyright © 2021 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)
- Xiaochen Yuan
- Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, MI 48824, U.S.A
| | - Gayle C McGhee
- United States Department of Agriculture, Agriculture Research Service, Horticultural Crops Research Laboratory, Corvallis, OR 97330, U.S.A
| | - Suzanne M Slack
- Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, MI 48824, U.S.A
| | - George W Sundin
- Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, MI 48824, U.S.A
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25
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Cui Z, Huntley RB, Schultes NP, Kakar KU, Yang CH, Zeng Q. Expression of the Type III Secretion System Genes in Epiphytic Erwinia amylovora Cells on Apple Stigmas Benefits Endophytic Infection at the Hypanthium. Mol Plant Microbe Interact 2021; 34:1119-1127. [PMID: 34698527 DOI: 10.1094/mpmi-06-21-0152-r] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [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: 06/13/2023]
Abstract
Erwinia amylovora causes fire blight on rosaceous plants. One of the major entry points of E. amylovora into hosts is flowers, where E. amylovora proliferates epiphytically on stigmatic and hypanthium surfaces and, subsequently, causes endophytic infection at the hypanthium. The type III secretion system (T3SS) is an important virulence factor in E. amylovora. Although the role of T3SS during endophytic infection is well characterized, its expression during epiphytic colonization and role in the subsequent infection is less understood. Here, we investigated T3SS gene expression in epiphytic E. amylovora on stigma and hypanthium of apple flowers under different relative humidities (RH). On stigma surfaces, T3SS was expressed in a high percentage of E. amylovora cells, and its expression promoted epiphytic growth. On hypanthium surfaces, however, T3SS was expressed in fewer E. amylovora cells than on the stigma, and displayed no correlation with epiphytic growth, even though T3SS expression is essential for infection. E. amylovora cells grown on stigmatic surfaces and then flushed down to the hypanthium displayed a higher level of T3SS expression than cells grown on the hypanthium surface alone. Furthermore, E. amylovora cells precultured on stigma had a higher potential to infect flowers than E. amylovora cells precultured in a T3SS-repressive medium. This suggests that T3SS induction during the stigmatic epiphytic colonization may be beneficial for subsequent infection. Finally, epiphytic expression of T3SS was influenced by RH. Higher percentage of stigmatic E. amylovora cells expressed T3SS under high RH than under low RH.[Formula: see text] Copyright © 2021 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)
- Zhouqi Cui
- Department of Plant Pathology and Ecology, The Connecticut Agricultural Experiment Station, New Haven, CT 06504, U.S.A
| | - Regan B Huntley
- Department of Plant Pathology and Ecology, The Connecticut Agricultural Experiment Station, New Haven, CT 06504, U.S.A
| | - Neil P Schultes
- Department of Plant Pathology and Ecology, The Connecticut Agricultural Experiment Station, New Haven, CT 06504, U.S.A
| | - Kaleem U Kakar
- Department of Microbiology, Faculty of Life Sciences and Informatics, Balochistan University of Information Technology, Engineering and Management Sciences (BUITEMS), Quetta, 87300, Pakistan
| | - Ching-Hong Yang
- Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, WI 53211, U.S.A
| | - Quan Zeng
- Department of Plant Pathology and Ecology, The Connecticut Agricultural Experiment Station, New Haven, CT 06504, U.S.A
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26
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Kharadi RR, Schachterle JK, Yuan X, Castiblanco LF, Peng J, Slack SM, Zeng Q, Sundin GW. Genetic Dissection of the Erwinia amylovora Disease Cycle. Annu Rev Phytopathol 2021; 59:191-212. [PMID: 33945696 DOI: 10.1146/annurev-phyto-020620-095540] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [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
Fire blight, caused by the bacterial phytopathogen Erwinia amylovora, is an economically important and mechanistically complex disease that affects apple and pear production in most geographic production hubs worldwide. We compile, assess, and present a genetic outlook on the progression of an E. amylovora infection in the host. We discuss the key aspects of type III secretion-mediated infection and systemic movement, biofilm formation in xylem, and pathogen dispersal via ooze droplets, a concentrated suspension of bacteria and exopolysaccharide components. We present an overall outlook on the genetic elements contributing to E. amylovora pathogenesis, including an exploration of the impact of floral microbiomes on E. amylovora colonization, and summarize the current knowledge of host responses to an incursion and how this response stimulates further infection and systemic spread. We hope to facilitate the identification of new, unexplored areas of research in this pathosystem that can help identify evolutionarily susceptible genetic targets to ultimately aid in the design of sustainable strategies for fire blight disease mitigation.
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Affiliation(s)
- Roshni R Kharadi
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, Michigan 48824, USA;
| | - Jeffrey K Schachterle
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, Michigan 48824, USA;
- Floral and Nursery Plants Research Unit, US National Arboretum, USDA-ARS, Beltsville, Maryland 20705, USA
| | - Xiaochen Yuan
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, Michigan 48824, USA;
| | - Luisa F Castiblanco
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, Michigan 48824, USA;
| | - Jingyu Peng
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, Michigan 48824, USA;
| | - Suzanne M Slack
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, Michigan 48824, USA;
| | - Quan Zeng
- Department of Plant Pathology and Ecology, The Connecticut Agricultural Experiment Station, New Haven, Connecticut 06511, USA
| | - George W Sundin
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, Michigan 48824, USA;
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27
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Thapa R, Singh J, Gutierrez B, Arro J, Khan A. Genome-wide association mapping identifies novel loci underlying fire blight resistance in apple. Plant Genome 2021; 14:e20087. [PMID: 33650322 DOI: 10.1002/tpg2.20087] [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] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 12/17/2020] [Indexed: 05/12/2023]
Abstract
Fire blight, caused by epiphytotic gram-negative bacteria Erwinia amylovora, is the most destructive bacterial disease of apple (Malus spp.). Genetic mechanisms of fire blight resistance have mainly been studied using traditional biparental quantitative trait loci (QTL) mapping approaches. Here, we use large-scale historic shoot and blossom fire blight data collected over multiple years and genotyping-by-sequencing (GBS) markers to identify significant marker-trait associations in a diverse set of 566 apple [Malus domestica (Suckow) Borkh.] accessions. There was large variation in fire blight resistance and susceptibility in these accessions. We identified 23 and 38 QTL significantly (p < .001) associated with shoot and blossom blight resistance, respectively. The QTL are distributed across all 17 chromosomes of apple. Four shoot blight and 19 blossom blight QTL identified in this study colocalized with previously identified QTL associated with resistance to fire blight or apple scab. Using transcriptomics data of two apple cultivars with contrasting fire blight responses, we also identified candidate genes for fire blight resistance that are differentially expressed between resistant and susceptible cultivars and located within QTL intervals for fire blight resistance. However, further experiments are needed to confirm and validate these marker-trait associations and develop diagnostic markers before use in marker-assisted breeding to develop apple cultivars with decreased fire blight susceptibility.
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Affiliation(s)
- Ranjita Thapa
- Plant Pathology and Plant-Microbe Biology Section, Cornell University, Geneva, NY, 14456, USA
| | - Jugpreet Singh
- Plant Pathology and Plant-Microbe Biology Section, Cornell University, Geneva, NY, 14456, USA
| | - Benjamin Gutierrez
- USDA-ARS Plant Genetic Resources Unit, New York State Agricultural Experiment Station, 630 West North Street, Geneva, NY, 14456, USA
| | - Jie Arro
- USDA-ARS Plant Genetic Resources Unit, New York State Agricultural Experiment Station, 630 West North Street, Geneva, NY, 14456, USA
| | - Awais Khan
- Plant Pathology and Plant-Microbe Biology Section, Cornell University, Geneva, NY, 14456, USA
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28
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Bénéjam J, Ravon E, Gaucher M, Brisset MN, Durel CE, Perchepied L. Acibenzolar- S-Methyl and Resistance Quantitative Trait Loci Complement Each Other to Control Apple Scab and Fire Blight. Plant Dis 2021; 105:1702-1710. [PMID: 33190613 DOI: 10.1094/pdis-07-20-1439-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: 06/11/2023]
Abstract
Diversifying disease control methods is a key strategy to sustainably reduce pesticides. Plant genetic resistance has long been used to create resistant varieties. Plant resistance inducers (PRI) are also considered to promote crop health, but their effectiveness is partial and can vary according to the environment and the plant genotype. We investigated the putative interaction between intrinsic (genetic) and PRI-induced resistance in apple when affected by scab and fire blight diseases. A large F1 mapping population was challenged by each disease after a pre-treatment with acibenzolar-S-methyl (ASM) and compared with the water control. Apple scab and fire blight resistance quantitative trait loci (QTLs) were detected in both conditions and compared. ASM exhibited a strong effectiveness in reducing both diseases. When combined, QTL-controlled and ASM-induced resistance acted complementarily to reduce the symptoms from 85 to 100%, depending on the disease. In our conditions, resistance QTLs were only slightly or rarely affected by ASM treatment, despite their probable implication in various stages of the resistance buildup. Implications of these results are discussed considering already known results, the underlying mechanisms, cross protection of both types of resistance against pathogen adaptation, and practical application in orchard conditions.
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Affiliation(s)
- Juliette Bénéjam
- Univ Angers, INRAE, Institut Agro, IRHS, SFR QUASAV, F-49000 Angers, France
| | - Elisa Ravon
- Univ Angers, INRAE, Institut Agro, IRHS, SFR QUASAV, F-49000 Angers, France
| | - Matthieu Gaucher
- Univ Angers, INRAE, Institut Agro, IRHS, SFR QUASAV, F-49000 Angers, France
| | | | - Charles-Eric Durel
- Univ Angers, INRAE, Institut Agro, IRHS, SFR QUASAV, F-49000 Angers, France
| | - Laure Perchepied
- Univ Angers, INRAE, Institut Agro, IRHS, SFR QUASAV, F-49000 Angers, France
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29
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Ya'ar Bar S, Dor S, Erov M, Afriat-Jurnou L. Identification and Characterization of a New Quorum-Quenching N-acyl Homoserine Lactonase in the Plant Pathogen Erwinia amylovora. J Agric Food Chem 2021; 69:5652-5662. [PMID: 33974427 DOI: 10.1021/acs.jafc.1c00366] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [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: 06/12/2023]
Abstract
Quorum quenching (QQ) is the ability to interfere with bacterial cell to cell communication, known as quorum sensing (QS). QQ enzymes that degrade or modify acyl homoserine lactones (AHLs) have been attracting increasing interest as promising agents for inhibiting QS-mediated bacterial pathogenicity. Plant pathogens from the genus Erwinia cause diseases in several economically important crops. Fire blight is a devastating plant disease caused by Erwinia amylovora, affecting a wide range of host species within the Rosaceae and posing a major global threat for commercial apple and pear production. While QS has been described in Erwinia species, no AHL-degrading enzymes were identified and characterized. Here, phylogenetic analysis and structural modeling were applied to identify an AHL lactonase in E. amylovora (dubbed EaAiiA). Following recombinant expression and purification, the enzyme was biochemically characterized. EaAiiA lactonase activity was dependent on metal ions and effectively degraded AHLs with high catalytic efficiency. Its highest specific activity (kcat/KM value) was observed against one of the AHLs (3-oxo-C6-homoserine lactone) secreted from E. amylovora. Exogenous addition of the purified enzyme to cultures of E. amylovora reduced the formation of levan, a QS-regulated virulence factor, by 40% and the transcription level of the levansucrase-encoding gene by 55%. Furthermore, preincubation of E. amylovora cultures with EaAiiA inhibited the progress of fire blight symptoms in immature Pyrus communis fruits. These results demonstrate the ability of the identified enzyme from E. amylovora to act as a quorum-quenching lactonase.
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Affiliation(s)
- Sapir Ya'ar Bar
- Migal-Galilee Research Institute, Kiryat Shmona 11016, Israel
- Faculty of Sciences and Technology, Tel-Hai Academic College, Upper Galilee 1220800, Israel
| | - Shlomit Dor
- Migal-Galilee Research Institute, Kiryat Shmona 11016, Israel
| | - Mayan Erov
- Migal-Galilee Research Institute, Kiryat Shmona 11016, Israel
| | - Livnat Afriat-Jurnou
- Migal-Galilee Research Institute, Kiryat Shmona 11016, Israel
- Faculty of Sciences and Technology, Tel-Hai Academic College, Upper Galilee 1220800, Israel
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30
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Mendes RJ, Luz JP, Santos C, Tavares F. CRISPR genotyping as complementary tool for epidemiological surveillance of Erwinia amylovora outbreaks. PLoS One 2021; 16:e0250280. [PMID: 33861806 PMCID: PMC8051791 DOI: 10.1371/journal.pone.0250280] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [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: 12/21/2020] [Accepted: 04/02/2021] [Indexed: 12/12/2022] Open
Abstract
Fire blight is a destructive plant disease caused by Erwinia amylovora affecting pome fruit trees, and responsible for large yield declines, long phytosanitary confinements, and high economic losses. In Portugal, the first major fire blight outbreaks occurred in 2010 and 2011, and although later considered eradicated, the emergence of other outbreaks in recent years stressed the need to characterize the E. amylovora populations associated with these outbreaks. In this regard, CRISPR genotyping, assessment of three virulence markers, and semi-quantitative virulence bioassays, were carried out to determine the genotype, and assess the virulence of thirty-six E. amylovora isolates associated with outbreaks occurring between 2010 and 2017 and affecting apple and pear orchards located in the country central-west, known as the main producing region of pome fruits in Portugal. The data gathered reveal that 35 E. amylovora isolates belong to one of the widely-distributed CRISPR genotypes (5-24-38 / D-a-α) regardless the host species, year and region. Ea 680 was the single isolate revealing a new CRISPR genotype due to a novel CR2 spacer located closer to the leader sequence and therefore thought to be recently acquired. Regarding pathogenicity, although dot-blot hybridization assays showed the presence of key virulence factors, namely hrpL (T3SS), hrpN (T3E) and amsG from the amylovoran biosynthesis operon in all E. amylovora isolates studied, pathogenicity bioassays on immature pear slices allowed to distinguish four virulence levels, with most of the isolates revealing an intermediate to severe virulence phenotype. Regardless the clonal population structure of the E. amylovora associated to the outbreaks occurring in Portugal between 2010 and 2017, the different virulence phenotypes, suggests that E. amylovora may have been introduced at different instances into the country. This is the first study regarding E. amylovora in Portugal, and it discloses a novel CRISPR genotype for this bacterium.
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Affiliation(s)
- Rafael J. Mendes
- Faculty of Sciences of University of Porto, Porto, Portugal
- LAQV/REQUIMTE, Faculty of Sciences of University of Porto, Porto, Portugal
- CITAB—Centre for the Research and Technology of Agro-Environmental and Biological Sciences, University of Trás-os-Montes e Alto Douro, Vila Real, Portugal
- CIBIO–Research Centre in Biodiversity and Genetic Resources, InBIO, Associated Laboratory, University of Porto, Campus Agrário de Vairão, Vairão, Portugal
| | - João Pedro Luz
- QRural, Polytechnic Institute of Castelo Branco, School of Agriculture, Castelo Branco, Portugal
| | - Conceição Santos
- Faculty of Sciences of University of Porto, Porto, Portugal
- LAQV/REQUIMTE, Faculty of Sciences of University of Porto, Porto, Portugal
| | - Fernando Tavares
- Faculty of Sciences of University of Porto, Porto, Portugal
- CIBIO–Research Centre in Biodiversity and Genetic Resources, InBIO, Associated Laboratory, University of Porto, Campus Agrário de Vairão, Vairão, Portugal
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Song JY, Yun YH, Kim GD, Kim SH, Lee SJ, Kim JF. Genome Analysis of Erwinia amylovora Strains Responsible for a Fire Blight Outbreak in Korea. Plant Dis 2021; 105:1143-1152. [PMID: 32931384 DOI: 10.1094/pdis-06-20-1329-re] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [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: 05/24/2023]
Abstract
Erwinia amylovora is a plant-pathogenic bacterium that causes fire blight disease in Rosaceae plants. Since fire blight is highly contagious and results in serious losses once introduced, it is regulated as a quarantine disease. Recently, for the first time in East Asia, fire blight emerged in Korea with strains of E. amylovora being isolated from lesions of infected trees. Five of those strains were selected and subjected to whole-genome shotgun sequencing. Each strain had two circular replicons, a 3.8-Mb chromosome and a 28-kb plasmid. The genome sequences were compared with those of other E. amylovora strains isolated from different hosts or geographical regions. Genome synteny was analyzed and sequence variations including nucleotide substitutions, inversions, insertions, and deletions were detected. Analysis of the population genomic structure revealed that the five strains form a distinct structural group. Phylogenomic analysis was performed to infer the evolutionary relationships among E. amylovora strains, which indicated that the Korean isolates, all descended from a common ancestor, are closely related to a lineage of North American strains. These results provide useful information for understanding the genomic dynamics of E. amylovora strains including those in Korea, developing genetic markers for surveillance of the pathogen or diagnosis of the disease, and eventually developing measures to eradicate it.
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Affiliation(s)
- Ju Yeon Song
- Department of Systems Biology, Division of Life Sciences, and Institute for Life Science and Biotechnology, Yonsei University, Seodaemun-gu, Seoul 03722, Republic of Korea
| | - Yeo Hong Yun
- Department of Microbiology and Institute for Biodiversity, Dankook University, Dongnam-gu, Cheonan-si, Chungcheongnam-do 31116, Republic of Korea
| | - Gi-Don Kim
- Animal and Plant Quarantine Agency, Gimcheon-si, Gyeongsangbuk-do 39660, Republic of Korea
| | - Seong Hwan Kim
- Department of Microbiology and Institute for Biodiversity, Dankook University, Dongnam-gu, Cheonan-si, Chungcheongnam-do 31116, Republic of Korea
| | - Seong-Jin Lee
- Animal and Plant Quarantine Agency, Gimcheon-si, Gyeongsangbuk-do 39660, Republic of Korea
| | - Jihyun F Kim
- Department of Systems Biology, Division of Life Sciences, and Institute for Life Science and Biotechnology, Yonsei University, Seodaemun-gu, Seoul 03722, Republic of Korea
- Strategic Initiative for Microbiomes in Agriculture and Food, Yonsei University, Seodaemun-gu, Seoul 03722, Republic of Korea
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Peng J, Schachterle JK, Sundin GW. Orchestration of virulence factor expression and modulation of biofilm dispersal in Erwinia amylovora through activation of the Hfq-dependent small RNA RprA. Mol Plant Pathol 2021; 22:255-270. [PMID: 33314618 PMCID: PMC7814967 DOI: 10.1111/mpp.13024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 11/09/2020] [Accepted: 11/09/2020] [Indexed: 06/12/2023]
Abstract
Erwinia amylovora is the causative agent of the devastating disease fire blight of pome fruit trees. After infection of host plant leaves at apple shoot tips, E. amylovora cells form biofilms in xylem vessels, restrict water flow, and cause wilting symptoms. Although E. amylovora is well known to be able to cause systemic infection, how biofilm cells of E. amylovora transit from the sessile mode of growth in xylem to the planktonic mode of growth in cortical parenchyma remains unknown. Increasing evidence has suggested the important modulatory roles of Hfq-dependent small RNAs (sRNAs) in the pathogenesis of E. amylovora. Here, we demonstrate that the sRNA RprA acts as a positive regulator of amylovoran exopolysaccharide production, the type III secretion system (T3SS), and flagellar-dependent motility, and as a negative regulator of levansucrase activity and cellulose production. We also show that RprA affects the promoter activity of multiple virulence factor genes and regulates hrpS, a critical T3SS regulator, at the posttranscriptional level. We determined that rprA expression can be activated by the Rcs phosphorelay, and that expression is active during T3SS-mediated host infection in an immature pear fruit infection model. We further showed that overexpression of rprA activated the in vitro dispersal of E. amylovora cells from biofilms. Thus, our investigation of the varied role of RprA in affecting E. amylovora virulence provides important insights into the functions of this sRNA in biofilm control and systemic infection.
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Affiliation(s)
- Jingyu Peng
- Department of Plant, Soil, and Microbial SciencesMichigan State UniversityEast LansingMichiganUSA
| | - Jeffrey K. Schachterle
- Department of Plant, Soil, and Microbial SciencesMichigan State UniversityEast LansingMichiganUSA
- Present address:
US National Arboretum – Floral and Nursery Plants Research UnitUSDA‐ARSBeltsvilleMarylandUSA
| | - George W. Sundin
- Department of Plant, Soil, and Microbial SciencesMichigan State UniversityEast LansingMichiganUSA
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Tremblay O, Thow Z, Merrill AR. Several New Putative Bacterial ADP-Ribosyltransferase Toxins Are Revealed from In Silico Data Mining, Including the Novel Toxin Vorin, Encoded by the Fire Blight Pathogen Erwinia amylovora. Toxins (Basel) 2020; 12:E792. [PMID: 33322547 PMCID: PMC7764402 DOI: 10.3390/toxins12120792] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 11/28/2020] [Accepted: 12/10/2020] [Indexed: 12/31/2022] Open
Abstract
Mono-ADP-ribosyltransferase (mART) toxins are secreted by several pathogenic bacteria that disrupt vital host cell processes in deadly diseases like cholera and whooping cough. In the last two decades, the discovery of mART toxins has helped uncover the mechanisms of disease employed by pathogens impacting agriculture, aquaculture, and human health. Due to the current abundance of mARTs in bacterial genomes, and an unprecedented availability of genomic sequence data, mART toxins are amenable to discovery using an in silico strategy involving a series of sequence pattern filters and structural predictions. In this work, a bioinformatics approach was used to discover six bacterial mART sequences, one of which was a functional mART toxin encoded by the plant pathogen, Erwinia amylovora, called Vorin. Using a yeast growth-deficiency assay, we show that wild-type Vorin inhibited yeast cell growth, while catalytic variants reversed the growth-defective phenotype. Quantitative mass spectrometry analysis revealed that Vorin may cause eukaryotic host cell death by suppressing the initiation of autophagic processes. The genomic neighbourhood of Vorin indicated that it is a Type-VI-secreted effector, and co-expression experiments showed that Vorin is neutralized by binding of a cognate immunity protein, VorinI. We demonstrate that Vorin may also act as an antibacterial effector, since bacterial expression of Vorin was not achieved in the absence of VorinI. Vorin is the newest member of the mART family; further characterization of the Vorin/VorinI complex may help refine inhibitor design for mART toxins from other deadly pathogens.
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Affiliation(s)
| | | | - A. Rod Merrill
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON N1G 2W1, Canada; (O.T.); (Z.T.)
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Yu M, Singh J, Khan A, Sundin GW, Zhao Y. Complete Genome Sequence of the Fire Blight Pathogen Strain Erwinia amylovora Ea1189. Mol Plant Microbe Interact 2020; 33:1277-1279. [PMID: 32808873 DOI: 10.1094/mpmi-06-20-0158-a] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [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: 05/08/2023]
Abstract
Erwinia amylovora causes fire blight, the most devastating bacterial disease of apples and pears in the United States and worldwide. The model strain E. amylovora Ea1189 has been extensively used to understand bacterial pathogenesis and molecular mechanisms of bacterial-plant interactions. In this work, we sequenced and assembled the de novo genome of Ea1189, using a combination of long Oxford Nanopore Technologies and short Illumina sequence reads. A complete gapless genome assembly of Ea1189 consists of a 3,797,741-bp circular chromosome and a 28,259-bp plasmid with 3,472 predicted genes, including 78 transfer RNAs, 22 ribosomal RNAs, and 20 noncoding RNAs. A comparison of the Ea1189 genome to previously sequenced E. amylovora complete genomes showed 99.94 to 99.97% sequence similarity with 314 to 946 single nucleotide polymorphisms. We believe that the availability of the complete genome sequence of strain Ea1189 will further support studies to understand evolution, diversity and structural variations of Erwinia strains, as well as the molecular basis of E. amylovora pathogenesis and its interactions with host plants, thus facilitating the development of effective management strategies for this important disease.
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Affiliation(s)
- Menghao Yu
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, IL 61801, U.S.A
| | - Jugpreet Singh
- Plant Pathology and Plant-Microbe Biology Section, Cornell University, Geneva, NY 14456, U.S.A
| | - Awais Khan
- Plant Pathology and Plant-Microbe Biology Section, Cornell University, Geneva, NY 14456, U.S.A
| | - George W Sundin
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI 48824, U.S.A
| | - Youfu Zhao
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, IL 61801, U.S.A
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Lee JH, Ancona V, Chatnaparat T, Yang HW, Zhao Y. The RNA-Binding Protein CsrA Controls Virulence in Erwinia amylovora by Regulating RelA, RcsB, and FlhD at the Posttranscriptional Level. Mol Plant Microbe Interact 2019; 32:1448-1459. [PMID: 31140921 DOI: 10.1094/mpmi-03-19-0077-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] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
CsrA, an RNA-binding protein, binds to target transcripts and alters their translation or stability. In Erwinia amylovora, CsrA positively regulates the expression of type III secretion system (T3SS), exopolysaccharide amylovoran, and motility. In this study, the global effect of CsrA and its noncoding small RNA (ncsRNA) csrB in E. amylovora was determined by RNA-seq, and potential molecular mechanisms of CsrA-dependent virulence regulation were examined. Transcriptomic analyses under the T3SS-inducing condition revealed that mutation in the csrA gene led to differential expression of more than 20% of genes in the genome. Among them, T3SS genes and those required for cell growth and viability were significantly downregulated. On the other hand, the csrB mutant exhibited significant upregulation of most major virulence genes, suggesting an antagonistic effect of csrB on CsrA targets. Direct interaction between CsrA protein and csrB was further confirmed through the RNA electrophoretic mobility shift assay (REMSA). However, no direct interaction between CsrA and hrpL and hrpS transcripts was detected, suggesting that HrpL and HrpS are not targets of CsrA, whereas three CsrA targets (relA, rcsB, and flhD) were identified and confirmed by REMSA, site-directed mutagenesis, and LacZ reporter gene assays. These findings might partially explain how CsrA positively controls E. amylovora virulence by targeting major regulators at the posttranscriptional level.
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Affiliation(s)
- Jae Hoon Lee
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61801, U.S.A
| | - Veronica Ancona
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61801, U.S.A
| | - Tiyakhon Chatnaparat
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61801, U.S.A
| | - Ho-Wen Yang
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61801, U.S.A
| | - Youfu Zhao
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61801, U.S.A
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Santander RD, Meredith CL, Aćimović SG. Development of a viability digital PCR protocol for the selective detection and quantification of live Erwinia amylovora cells in cankers. Sci Rep 2019; 9:11530. [PMID: 31395913 PMCID: PMC6687816 DOI: 10.1038/s41598-019-47976-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [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: 04/02/2019] [Accepted: 07/25/2019] [Indexed: 01/28/2023] Open
Abstract
Fire blight is a devastating disease of apple and pear caused by the bacterium Erwinia amylovora. One of its main symptoms is canker formation on perennial tissues which may lead to the death of limbs and/or the entire tree. E. amylovora overwinters in cankers which play an important role in initiating fire blight epidemics. However, knowledge of pathogen biology in cankers is scarce, in part due to limitations of classical microbiology methods and the inability of most molecular techniques to distinguish live from dead cells. In this work, a viability digital PCR (v-dPCR) protocol using propidium monoazide (PMA) was developed, allowing for the first time the selective detection and absolute quantification of E. amylovora live cells in apple and pear cankers collected in two time periods. Some key factors affecting the v-dPCR performance were the maceration buffer composition, the target DNA amplicon length, the thermal cycle number and the use of sodium dodecyl sulfate or PMA enhancer for Gram-negative bacteria to improve the effect of PMA. In the future, this methodology could shed light on E. amylovora population dynamics in cankers and provide clues on the effect of management practices, host cultivar, host water/nutritional status, etc., on bacterial survival.
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Affiliation(s)
- Ricardo D Santander
- Plant Pathology and Plant-Microbe Biology Section, Cornell University, Hudson Valley Research Laboratory, Highland, NY, USA
| | - Christopher L Meredith
- Plant Pathology and Plant-Microbe Biology Section, Cornell University, Hudson Valley Research Laboratory, Highland, NY, USA
| | - Srđan G Aćimović
- Plant Pathology and Plant-Microbe Biology Section, Cornell University, Hudson Valley Research Laboratory, Highland, NY, USA.
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Polsinelli I, Caliandro R, Salomone-Stagni M, Demitri N, Rejzek M, Field RA, Benini S. Comparison of the Levansucrase from the epiphyte Erwinia tasmaniensis vs its homologue from the phytopathogen Erwinia amylovora. Int J Biol Macromol 2019; 127:496-501. [PMID: 30660564 DOI: 10.1016/j.ijbiomac.2019.01.074] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 01/16/2019] [Accepted: 01/16/2019] [Indexed: 11/27/2022]
Abstract
Erwinia tasmaniensis is an epiphytic bacterium related to the plant pathogen Erwinia amylovora, the etiological agent of fire blight. In this study the levansucrase from E. tasmaniensis (EtLsc) has been compared with the homologous enzyme from E. amylovora (EaLsc). We characterized the enzymatic activity and compared the products profile of both enzymes by High Performance Anion Exchange Chromatography coupled with Pulsed Amperometric Detector (HPAEC-PAD). Moreover we determined the crystal structure of EtLsc to understand the structural peculiarity causing the different product profiles of the two homologues. EtLsc exhibits increased efficiency in the production of FOS, resulting in a better catalyst for biotechnological synthesis than EaLsc. Based on our results, we propose that the role of this enzyme in the life cycle of the two bacteria is most likely related to survival, rather than linked to pathogenicity in E. amylovora.
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Affiliation(s)
- Ivan Polsinelli
- Bioorganic Chemistry and Bio-Crystallography laboratory (B(2)Cl), Faculty of Science and Technology, Free University of Bolzano, Piazza Università 5, 39100 Bolzano, Italy
| | - Rosanna Caliandro
- Bioorganic Chemistry and Bio-Crystallography laboratory (B(2)Cl), Faculty of Science and Technology, Free University of Bolzano, Piazza Università 5, 39100 Bolzano, Italy
| | - Marco Salomone-Stagni
- Bioorganic Chemistry and Bio-Crystallography laboratory (B(2)Cl), Faculty of Science and Technology, Free University of Bolzano, Piazza Università 5, 39100 Bolzano, Italy
| | - Nicola Demitri
- Elettra-Sincrotrone Trieste, S.S. 14 Km 163.5 in Area Science Park, Basovizza, Trieste 34149, Italy
| | - Martin Rejzek
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich, NR47UH, United Kingdom
| | - Robert A Field
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich, NR47UH, United Kingdom
| | - Stefano Benini
- Bioorganic Chemistry and Bio-Crystallography laboratory (B(2)Cl), Faculty of Science and Technology, Free University of Bolzano, Piazza Università 5, 39100 Bolzano, Italy.
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Shidore T, Zeng Q, Triplett LR. Survey of Toxin⁻Antitoxin Systems in Erwinia amylovora Reveals Insights into Diversity and Functional Specificity. Toxins (Basel) 2019; 11:toxins11040206. [PMID: 30959879 PMCID: PMC6521040 DOI: 10.3390/toxins11040206] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [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: 03/13/2019] [Revised: 03/29/2019] [Accepted: 04/04/2019] [Indexed: 11/16/2022] Open
Abstract
Toxin–antitoxin (TA) systems are diverse genetic modules with demonstrated roles in plasmid stability, stress management, biofilm formation and antibiotic persistence. However, relatively little is known about their functional significance in plant pathogens. In this study we characterize type II and IV TA systems in the economically important plant pathogen Erwinia amylovora. Hidden Markov Model (HMM) and BLAST-based programs were used to predict the identity and distribution of putative TA systems among sequenced genomes of E. amylovora and other plant-associated Erwinia spp. Of six conserved TA systems tested for function from E. amylovora, three (CbtA/CbeA, ParE/RHH and Doc/PhD) were validated as functional. CbtA was toxic to E. amylovora, but not to Escherichia coli. While the E. coli homolog of CbtA elicits the formation of lemon-shaped cells upon overexpression and targets cytoskeletal proteins FtsZ and MreB, E. amylovora CbtA led to cell elongation and did not interact with these cytoskeletal proteins. Phylogenetic analysis revealed that E. amylovora CbtA belongs to a distinct clade from the CbtA of pathogenic E. coli. This study expands the repertoire of experimentally validated TA systems in plant pathogenic bacteria, and suggests that the E. amylovora homolog of CbtA is functionally distinct from that of E. coli.
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Affiliation(s)
- Teja Shidore
- Department of Plant Pathology and Ecology, the Connecticut Agricultural Experiment Station, New Haven, CT 06511, USA.
| | - Quan Zeng
- Department of Plant Pathology and Ecology, the Connecticut Agricultural Experiment Station, New Haven, CT 06511, USA.
| | - Lindsay R Triplett
- Department of Plant Pathology and Ecology, the Connecticut Agricultural Experiment Station, New Haven, CT 06511, USA.
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Abstract
Fire blight is a perennial disease affecting apple and pear production worldwide. Development of resistant cultivars and disease control measures are crucial aspects of managing fire blight. Furthermore, the study of the causal agent, the Gram-negative bacterium Erwinia amylovora, has led to important insights into molecular plant-microbe interactions. However, fire blight does not have a suitable model host, since its host range is limited to plants with complex genetics and relatively limited resources for genetic analysis. Here, we present a rationale for using apple fruitlets as a potential fire blight model host system, and describe a protocol for quantitative fruit inoculation, bacterial growth measurement, and symptom assessment. The use of apple fruitlets is applicable to the molecular genetic analysis of E. amylovora, including high-throughput genetic screens for E. amylovora virulence-defective mutants, and is potentially useful to study host resistance and responses to E. amylovora as well.
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Affiliation(s)
- Sara M Klee
- Department of Plant Pathology & Environmental Microbiology, The Pennsylvania State University, University Park, PA, USA
| | - Judith P Sinn
- Department of Plant Pathology & Environmental Microbiology, The Pennsylvania State University, University Park, PA, USA
| | - Timothy W McNellis
- Department of Plant Pathology & Environmental Microbiology, The Pennsylvania State University, University Park, PA, USA.
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Schröpfer S, Böttcher C, Wöhner T, Richter K, Norelli J, Rikkerink EHA, Hanke MV, Flachowsky H. A Single Effector Protein, AvrRpt2 EA, from Erwinia amylovora Can Cause Fire Blight Disease Symptoms and Induces a Salicylic Acid-Dependent Defense Response. Mol Plant Microbe Interact 2018; 31:1179-1191. [PMID: 30204065 DOI: 10.1094/mpmi-12-17-0300-r] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The AvrRpt2EA effector protein of Erwinia amylovora is important for pathogen recognition in the fire blight-resistant crabapple Malus × robusta 5; however, little is known about its role in susceptible apples. To study its function in planta, we expressed a plant-optimized version of AvrRpt2EA driven by a heat shock-inducible promoter in transgenic plants of the fire blight-susceptible cultivar Pinova. After induced expression of AvrRpt2EA, transgenic lines showed shoot necrosis and browning of older leaves, with symptoms similar to natural fire blight infections. Transgenic expression of this effector protein resulted in an increase in the expression of the salicylic acid (SA)-responsive PR-1 gene but, also, in the levels of SA and its derivatives, with diverse kinetics in leaves of different ages. In contrast, no increase of expression levels of VSP2 paralogs, used as marker genes for the activation of the jasmonic acid (JA)-dependent defense pathway, could be detected, which is in agreement with metabolic profiling of JA and its derivatives. Our work demonstrates that AvrRpt2EA acts as a virulence factor and induces the formation of SA and SA-dependent systemic acquired resistance.
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Affiliation(s)
- Susan Schröpfer
- 1 Julius Kühn-Institut (JKI), Federal Research Centre for Cultivated Plants, Institute for Breeding Research on Fruit Crops, Pillnitzer Platz 3a, 01326 Dresden-Pillnitz, Germany
| | - Christoph Böttcher
- 2 Julius Kühn-Institut, Federal Research Centre for Cultivated Plants, Institute for Ecological Chemistry, Plant Analysis and Stored Product Protection, Königin-Luise-Str. 19, 14195 Berlin, Germany
| | - Thomas Wöhner
- 1 Julius Kühn-Institut (JKI), Federal Research Centre for Cultivated Plants, Institute for Breeding Research on Fruit Crops, Pillnitzer Platz 3a, 01326 Dresden-Pillnitz, Germany
| | - Klaus Richter
- 3 Julius Kühn-Institut (JKI), Federal Research Centre for Cultivated Plants, Institute for Resistance Research and Stress Tolerance, Erwin-Baur-Str. 27, 06484 Quedlinburg, Germany
| | - John Norelli
- 4 USDA-ARS, Appalachian Fruit Research Station, 2217 Wiltshire Road, Kearneysville, WV 25430, U.S.A.; and
| | - Erik H A Rikkerink
- 5 The New Zealand Institute for Plant and Food Research Limited, Auckland, New Zealand
| | - Magda-Viola Hanke
- 1 Julius Kühn-Institut (JKI), Federal Research Centre for Cultivated Plants, Institute for Breeding Research on Fruit Crops, Pillnitzer Platz 3a, 01326 Dresden-Pillnitz, Germany
| | - Henryk Flachowsky
- 1 Julius Kühn-Institut (JKI), Federal Research Centre for Cultivated Plants, Institute for Breeding Research on Fruit Crops, Pillnitzer Platz 3a, 01326 Dresden-Pillnitz, Germany
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Klee SM, Mostafa I, Chen S, Dufresne C, Lehman BL, Sinn JP, Peter KA, McNellis TW. An Erwinia amylovora yjeK mutant exhibits reduced virulence, increased chemical sensitivity and numerous environmentally dependent proteomic alterations. Mol Plant Pathol 2018; 19:1667-1678. [PMID: 29232043 PMCID: PMC6638024 DOI: 10.1111/mpp.12650] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Revised: 12/04/2017] [Accepted: 12/05/2017] [Indexed: 05/02/2023]
Abstract
The Gram-negative bacterium Erwinia amylovora causes fire blight, an economically important disease of apples and pears. Elongation factor P (EF-P) is a highly conserved protein that stimulates the formation of the first peptide bond of certain proteins and facilitates the translation of certain proteins, including those with polyproline motifs. YjeK and YjeA are two enzymes involved in the essential post-translational β-lysylation of EF-P at a conserved lysine residue, K34. EF-P, YjeA and YjeK have been shown to be essential for the full virulence of Escherichia coli, Salmonella species and Agrobacterium tumefaciens, with efp, yjeA and yjeK mutants having highly similar phenotypes. Here, we identified an E. amylovora yjeK::Tn5 transposon mutant with decreased virulence in apple fruit and trees. The yjeK::Tn5 mutant also showed pleiotropic phenotypes, including reduced growth in rich medium, lower extracellular polysaccharide production, reduced swimming motility and increased chemical sensitivity compared with the wild-type, whilst maintaining wild-type level growth in minimal medium. All yjeK::Tn5 mutant phenotypes were complemented in trans with a plasmid bearing a wild-type copy of yjeK. Comprehensive, quantitative proteomics analyses revealed numerous, environmentally dependent changes in the prevalence of a wide range of proteins, in higher abundance and lower abundance, in yjeK::Tn5 compared with the wild-type, and many of these alterations could be linked to yjeK::Tn5 mutant phenotypes. The environmental dependence of the yjeK::Tn5 mutant proteomic alterations suggests that YjeK could be required for aspects of the environmentally dependent regulation of protein translation. YjeK activity may be critical to overcoming stress, including the challenging host environment faced by invading pathogenic bacteria.
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Affiliation(s)
- Sara M. Klee
- Department of Plant Pathology & Environmental MicrobiologyThe Pennsylvania State UniversityUniversity ParkPA 16802USA
- Graduate Program in Plant PathologyThe Pennsylvania State UniversityUniversity ParkPA 16802USA
| | - Islam Mostafa
- Department of BiologyUniversity of FloridaGainesvilleFL 32611USA
- Genetics InstituteUniversity of FloridaGainesvilleFL 32611USA
- Department of Pharmacognosy, Faculty of PharmacyZagazig UniversityZagazig 44519Egypt
| | - Sixue Chen
- Department of BiologyUniversity of FloridaGainesvilleFL 32611USA
- Genetics InstituteUniversity of FloridaGainesvilleFL 32611USA
- Plant Molecular and Cellular Biology ProgramUniversity of FloridaGainesvilleFL 32611USA
- Interdisciplinary Center for Biotechnology ResearchUniversity of FloridaGainesvilleFL 32611USA
| | | | - brian L. Lehman
- The Pennsylvania State University Fruit Research and Extension CenterBiglervillePA 17307USA
| | - Judith P. Sinn
- Department of Plant Pathology & Environmental MicrobiologyThe Pennsylvania State UniversityUniversity ParkPA 16802USA
| | - Kari A. Peter
- Department of Plant Pathology & Environmental MicrobiologyThe Pennsylvania State UniversityUniversity ParkPA 16802USA
- The Pennsylvania State University Fruit Research and Extension CenterBiglervillePA 17307USA
| | - Timothy W. McNellis
- Department of Plant Pathology & Environmental MicrobiologyThe Pennsylvania State UniversityUniversity ParkPA 16802USA
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Zeng Q, Cui Z, Wang J, Childs KL, Sundin GW, Cooley DR, Yang C, Garofalo E, Eaton A, Huntley RB, Yuan X, Schultes NP. Comparative genomics of Spiraeoideae-infecting Erwinia amylovora strains provides novel insight to genetic diversity and identifies the genetic basis of a low-virulence strain. Mol Plant Pathol 2018; 19:1652-1666. [PMID: 29178620 PMCID: PMC6638132 DOI: 10.1111/mpp.12647] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 11/21/2017] [Accepted: 11/22/2017] [Indexed: 05/24/2023]
Abstract
Erwinia amylovora is the causal agent of fire blight, one of the most devastating diseases of apple and pear. Erwinia amylovora is thought to have originated in North America and has now spread to at least 50 countries worldwide. An understanding of the diversity of the pathogen population and the transmission to different geographical regions is important for the future mitigation of this disease. In this research, we performed an expanded comparative genomic study of the Spiraeoideae-infecting (SI) E. amylovora population in North America and Europe. We discovered that, although still highly homogeneous, the genetic diversity of 30 E. amylovora genomes examined was about 30 times higher than previously determined. These isolates belong to four distinct clades, three of which display geographical clustering and one of which contains strains from various geographical locations ('Widely Prevalent' clade). Furthermore, we revealed that strains from the Widely Prevalent clade displayed a higher level of recombination with strains from a clade strictly from the eastern USA, which suggests that the Widely Prevalent clade probably originated from the eastern USA before it spread to other locations. Finally, we detected variations in virulence in the SI E. amylovora strains on immature pear, and identified the genetic basis of one of the low-virulence strains as being caused by a single nucleotide polymorphism in hfq, a gene encoding an important virulence regulator. Our results provide insights into the population structure, distribution and evolution of SI E. amylovora in North America and Europe.
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Affiliation(s)
- Quan Zeng
- Department of Plant Pathology and EcologyThe Connecticut Agricultural Experiment StationNew Haven 06511CTUSA
| | - Zhouqi Cui
- Department of Plant Pathology and EcologyThe Connecticut Agricultural Experiment StationNew Haven 06511CTUSA
- Department of Biological SciencesUniversity of Wisconsin‐MilwaukeeMilwaukee 53211WIUSA
| | - Jie Wang
- Department of Plant BiologyMichigan State UniversityEast Lansing 48824MIUSA
| | - Kevin L. Childs
- Department of Plant BiologyMichigan State UniversityEast Lansing 48824MIUSA
| | - George W. Sundin
- Department of Plant, Soil, and Microbial SciencesMichigan State UniversityEast Lansing 48824MIUSA
| | - Daniel R. Cooley
- Stockbridge School of AgricultureUniversity of MassachusettsAmherst 01003MAUSA
| | - Ching‐Hong Yang
- Department of Biological SciencesUniversity of Wisconsin‐MilwaukeeMilwaukee 53211WIUSA
| | - Elizabeth Garofalo
- Stockbridge School of AgricultureUniversity of MassachusettsAmherst 01003MAUSA
| | - Alan Eaton
- Department of Agriculture, Nutrition, and Food SystemsUniversity of New HampshireDurham 03824NHUSA
| | - Regan B. Huntley
- Department of Plant Pathology and EcologyThe Connecticut Agricultural Experiment StationNew Haven 06511CTUSA
| | - Xiaochen Yuan
- Department of Biological SciencesUniversity of Wisconsin‐MilwaukeeMilwaukee 53211WIUSA
| | - Neil P. Schultes
- Department of Plant Pathology and EcologyThe Connecticut Agricultural Experiment StationNew Haven 06511CTUSA
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Castiblanco LF, Sundin GW. Cellulose production, activated by cyclic di-GMP through BcsA and BcsZ, is a virulence factor and an essential determinant of the three-dimensional architectures of biofilms formed by Erwinia amylovora Ea1189. Mol Plant Pathol 2018; 19:90-103. [PMID: 27753193 PMCID: PMC6638026 DOI: 10.1111/mpp.12501] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [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: 07/14/2016] [Revised: 10/10/2016] [Accepted: 10/13/2016] [Indexed: 05/04/2023]
Abstract
Bacterial biofilms are multicellular aggregates encased in an extracellular matrix mainly composed of exopolysaccharides (EPSs), protein and nucleic acids, which determines the architecture of the biofilm. Erwinia amylovora Ea1189 forms a biofilm inside the xylem of its host, which results in vessel plugging and water transport impairment. The production of the EPSs amylovoran and levan is critical for the formation of a mature biofilm. In addition, cyclic dimeric GMP (c-di-GMP) has been reported to positively regulate amylovoran biosynthesis and biofilm formation in E. amylovora Ea1189. In this study, we demonstrate that cellulose is synthesized by E. amylovora Ea1189 and is a major modulator of the three-dimensional characteristics of biofilms formed by this bacterium, and also contributes to virulence during systemic host invasion. In addition, we demonstrate that the activation of cellulose biosynthesis in E. amylovora is a c-di-GMP-dependent process, through allosteric binding to the cellulose catalytic subunit BcsA. We also report that the endoglucanase BcsZ is a key player in c-di-GMP activation of cellulose biosynthesis. Our results provide evidence of the complex composition of the extracellular matrix produced by E. amylovora and the implications of cellulose biosynthesis in shaping the architecture of the biofilm and in the expression of one of the main virulence phenotypes of this pathogen.
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Affiliation(s)
- Luisa F. Castiblanco
- Department of Plant, Soil and Microbial Sciences and Center for Microbial PathogenesisMichigan State UniversityEast LansingMI48824USA
| | - George W. Sundin
- Department of Plant, Soil and Microbial Sciences and Center for Microbial PathogenesisMichigan State UniversityEast LansingMI48824USA
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Águila‐Clares B, Castiblanco LF, Quesada JM, Penyalver R, Carbonell J, López MM, Marco‐Noales E, Sundin GW. Transcriptional response of Erwinia amylovora to copper shock: in vivo role of the copA gene. Mol Plant Pathol 2018; 19:169-179. [PMID: 27862834 PMCID: PMC6638137 DOI: 10.1111/mpp.12510] [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] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Revised: 10/03/2016] [Accepted: 11/06/2016] [Indexed: 05/28/2023]
Abstract
Fire blight is a devastating plant disease caused by the bacterium Erwinia amylovora, and its control is frequently based on the use of copper-based compounds whose mechanisms of action are not well known. Consequently, in this article, we investigate the response of E. amylovora to copper shock by a whole-genome microarray approach. Transcriptional analyses showed that, in the presence of copper, 23 genes were increased in expression; these genes were classified mainly into the transport and stress functional categories. Among them, the copA gene was strongly induced and regulated in a finely tuned manner by copper. Mutation of copA, soxS, arcB, yjcE, ygcF, yhhQ, galF and EAM_3469 genes revealed that tolerance to copper in E. amylovora can be achieved by complex physiological mechanisms, including: (i) the control of copper homeostasis through, at least, the extrusion of Cu(I) by a P-type ATPase efflux pump CopA; and (ii) the overcoming of copper toxicity caused by oxidative stress by the expression of several reactive oxygen species (ROS)-related genes, including the two major transcriptional factors SoxS and ArcB. Furthermore, complementation analyses demonstrated the important role of copA for copper tolerance in E. amylovora, not only in vitro, but also in inoculated pear shoots.
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Affiliation(s)
- Begoña Águila‐Clares
- Instituto Valenciano de Investigaciones Agrarias MoncadaCentro de Protección Vegetal y BiotecnologíaValencia46113Spain
- Department of Plant, Soil, and Microbial SciencesMichigan State UniversityEast LansingMI48824USA
| | - Luisa F. Castiblanco
- Department of Plant, Soil, and Microbial SciencesMichigan State UniversityEast LansingMI48824USA
| | - José Miguel Quesada
- Department of Environmental ProtectionEstación Experimental del Zaidín, CSICGranada18008Spain
| | - Ramón Penyalver
- Instituto Valenciano de Investigaciones Agrarias MoncadaCentro de Protección Vegetal y BiotecnologíaValencia46113Spain
| | - Juan Carbonell
- Instituto de Biologia Molecular y Celular de Plantas (IBMCP), University of ValenciaValenciaSpain
| | - María M. López
- Instituto Valenciano de Investigaciones Agrarias MoncadaCentro de Protección Vegetal y BiotecnologíaValencia46113Spain
| | - Ester Marco‐Noales
- Instituto Valenciano de Investigaciones Agrarias MoncadaCentro de Protección Vegetal y BiotecnologíaValencia46113Spain
| | - George W. Sundin
- Department of Plant, Soil, and Microbial SciencesMichigan State UniversityEast LansingMI48824USA
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Borruso L, Salomone-Stagni M, Polsinelli I, Schmitt AO, Benini S. Conservation of Erwinia amylovora pathogenicity-relevant genes among Erwinia genomes. Arch Microbiol 2017; 199:1335-1344. [PMID: 28695265 PMCID: PMC5663808 DOI: 10.1007/s00203-017-1409-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Revised: 05/10/2017] [Accepted: 07/03/2017] [Indexed: 11/28/2022]
Abstract
The Erwinia genus comprises species that are plant pathogens, non-pathogen, epiphytes, and opportunistic human pathogens. Within the genus, Erwinia amylovora ranks among the top 10 plant pathogenic bacteria. It causes the fire blight disease and is a global threat to commercial apple and pear production. We analyzed the presence/absence of the E. amylovora genes reported to be important for pathogenicity towards Rosaceae within various Erwinia strains genomes. This simple bottom-up approach, allowed us to correlate the analyzed genes to pathogenicity, host specificity, and make useful considerations to drive targeted studies.
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Affiliation(s)
- Luigimaria Borruso
- Bioorganic Chemistry and Bio-Crystallography Laboratory (B2Cl), Faculty of Science and Technology, Free University of Bolzano, Piazza Università 5, 39100, Bolzano, Italy
| | - Marco Salomone-Stagni
- Bioorganic Chemistry and Bio-Crystallography Laboratory (B2Cl), Faculty of Science and Technology, Free University of Bolzano, Piazza Università 5, 39100, Bolzano, Italy
| | - Ivan Polsinelli
- Bioorganic Chemistry and Bio-Crystallography Laboratory (B2Cl), Faculty of Science and Technology, Free University of Bolzano, Piazza Università 5, 39100, Bolzano, Italy
| | - Armin Otto Schmitt
- Department of Nutztierwissenschaften, Breeding Informatics, Georg-August-Universität Göttingen, Carl-Sprengel-Weg 1, 37075, Göttingen, Germany
| | - Stefano Benini
- Bioorganic Chemistry and Bio-Crystallography Laboratory (B2Cl), Faculty of Science and Technology, Free University of Bolzano, Piazza Università 5, 39100, Bolzano, Italy.
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Lee JH, Zhao Y. ClpXP-Dependent RpoS Degradation Enables Full Activation of Type III Secretion System, Amylovoran Production, and Motility in Erwinia amylovora. Phytopathology 2017; 107:1346-1352. [PMID: 28691868 DOI: 10.1094/phyto-06-17-0198-r] [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] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Erwinia amylovora, the causal agent of fire blight disease of apple and pear, employs intracellular proteases, including Lon and ClpXP, for posttranslational regulation of various cellular proteins. It has been shown that Lon plays a critical role in E. amylovora virulence by directly targeting type III secretion system (T3SS) proteins and the Rcs phosphorelay system. In this study, we genetically examined the role of ClpXP and its potential interaction with Lon in E. amylovora. Mutation in clpXP diminished the expression of the T3SS, reduced exopolysaccharide amylovoran production and motility, and resulted in delayed disease progress. Western blot analyses showed highly accumulated RpoS proteins in the clpXP mutant. Moreover, mutation of rpoS in the clpXP mutant background rescued the expression of the T3SS and amylovoran production, suggesting that ClpXP-dependent RpoS degradation positively affects virulence traits. Interestingly, lack of both ClpXP and Lon resulted in significantly reduced virulence but increased expression of the T3SS and amylovoran production. However, this phenomenon was independent of RpoS accumulation, suggesting that ClpXP and Lon are indispensable for full virulence in E. amylovora.
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Affiliation(s)
- Jae Hoon Lee
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana 61801
| | - Youfu Zhao
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana 61801
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Tian Y, Zhao Y, Shi L, Cui Z, Hu B, Zhao Y. Type VI Secretion Systems of Erwinia amylovora Contribute to Bacterial Competition, Virulence, and Exopolysaccharide Production. Phytopathology 2017; 107:654-661. [PMID: 28421913 DOI: 10.1094/phyto-11-16-0393-r] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [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: 06/07/2023]
Abstract
The type VI secretion system (T6SS) plays a major role in mediating interbacterial competition and might contribute to virulence in plant pathogenic bacteria. However, the role of T6SS in Erwinia amylovora remains unknown. In this study, 33 deletion mutants within three T6SS clusters were generated in E. amylovora strain NCPPB1665. Our results showed that all 33 mutants displayed reduced antibacterial activities against Escherichia coli as compared with that of the wild-type (WT) strain, indicating that Erwinia amylovora T6SS are functional. Of the 33 mutants, 19 exhibited reduced virulence on immature pear fruit as compared with that of the WT strain. Among them, 6, 1, and 12 genes belonged to T6SS-1, T6SS-2, and T6SS-3 clusters, respectively. Interestingly, these 19 mutants also produced less amylovoran or levan or both. These findings suggest that E. amylovora T6SS play a role in bacterial competition and virulence possibly by influencing exopolysaccharide production.
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Affiliation(s)
- Yanli Tian
- First, third, and fifth authors: College of Plant Protection and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing Agricultural University, Nanjing 210095, China; second author: Institute of Botany, Jiangsu Province and the Chinese Academy of Sciences (Nanjing Botanical Garden Mem. Sun Yat-Sen), Nanjing 210014, China; fourth author: College of Life Sciences and Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, China; and sixth author: Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana
| | - Yuqiang Zhao
- First, third, and fifth authors: College of Plant Protection and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing Agricultural University, Nanjing 210095, China; second author: Institute of Botany, Jiangsu Province and the Chinese Academy of Sciences (Nanjing Botanical Garden Mem. Sun Yat-Sen), Nanjing 210014, China; fourth author: College of Life Sciences and Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, China; and sixth author: Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana
| | - Linye Shi
- First, third, and fifth authors: College of Plant Protection and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing Agricultural University, Nanjing 210095, China; second author: Institute of Botany, Jiangsu Province and the Chinese Academy of Sciences (Nanjing Botanical Garden Mem. Sun Yat-Sen), Nanjing 210014, China; fourth author: College of Life Sciences and Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, China; and sixth author: Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana
| | - Zhongli Cui
- First, third, and fifth authors: College of Plant Protection and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing Agricultural University, Nanjing 210095, China; second author: Institute of Botany, Jiangsu Province and the Chinese Academy of Sciences (Nanjing Botanical Garden Mem. Sun Yat-Sen), Nanjing 210014, China; fourth author: College of Life Sciences and Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, China; and sixth author: Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana
| | - Baishi Hu
- First, third, and fifth authors: College of Plant Protection and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing Agricultural University, Nanjing 210095, China; second author: Institute of Botany, Jiangsu Province and the Chinese Academy of Sciences (Nanjing Botanical Garden Mem. Sun Yat-Sen), Nanjing 210014, China; fourth author: College of Life Sciences and Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, China; and sixth author: Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana
| | - Youfu Zhao
- First, third, and fifth authors: College of Plant Protection and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing Agricultural University, Nanjing 210095, China; second author: Institute of Botany, Jiangsu Province and the Chinese Academy of Sciences (Nanjing Botanical Garden Mem. Sun Yat-Sen), Nanjing 210014, China; fourth author: College of Life Sciences and Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, China; and sixth author: Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana
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Abstract
Fire blight, caused by the pathogen Erwinia amylovora, is the most devastating bacterial disease of pome fruit in North America and worldwide. The primary method of dispersal for E. amylovora is through ooze, a mass of exopolysaccharides and bacterial cells that is exuded as droplets from infected host tissue. During the 2013 and 2014 field seasons, 317 ooze droplets were collected from field-inoculated apple trees. Populations of E. amylovora in ooze droplets were 108 CFU/μl on average. Ooze droplets harboring larger (>108 CFU/μl) cell populations were typically smaller in total volume and had darker coloring, such as orange, red, or dark red hues. Examination of apple host tissue at the site of emergence of ooze droplets using scanning electron microscopy revealed that ooze was not exuding through natural openings; instead, it was found on erumpent mounds and small (10-μm) tears in tissue. These observations suggested that E. amylovora-induced wounds in tissue provided the exit holes for ooze extrusion from the host. Analyses of E. amylovora populations in ooze droplets and within the stems from which ooze droplets emerged indicated that approximately 9% of the total bacterial population from infected stems is diverted to ooze. Gene expression analyses indicated that E. amylovora cells in stem sections located above ooze droplets and in ooze droplets were actively expressing critical pathogenicity genes such as hrpL, dspE, and amsK. Thus, our study identified ooze as a source of large, concentrated populations of E. amylovora that emerged from the host by rupturing host tissue. Because the cells in ooze droplets are expressing genes required for pathogenesis, they are already primed for infection should they be dispersed from ooze to new infection courts.
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Affiliation(s)
- Suzanne M Slack
- All authors: Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing 48824; and second author: Department of Plant Pathology and Ecology, Connecticut Agricultural Experiment Station, New Haven 06504
| | - Quan Zeng
- All authors: Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing 48824; and second author: Department of Plant Pathology and Ecology, Connecticut Agricultural Experiment Station, New Haven 06504
| | - Cory A Outwater
- All authors: Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing 48824; and second author: Department of Plant Pathology and Ecology, Connecticut Agricultural Experiment Station, New Haven 06504
| | - George W Sundin
- All authors: Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing 48824; and second author: Department of Plant Pathology and Ecology, Connecticut Agricultural Experiment Station, New Haven 06504
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Lee JH, Sundin GW, Zhao Y. Identification of the HrpS binding site in the hrpL promoter and effect of the RpoN binding site of HrpS on the regulation of the type III secretion system in Erwinia amylovora. Mol Plant Pathol 2016; 17:691-702. [PMID: 26440313 PMCID: PMC6638409 DOI: 10.1111/mpp.12324] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
The type III secretion system (T3SS) is a key pathogenicity factor in Erwinia amylovora. Previous studies have demonstrated that the T3SS in E. amylovora is transcriptionally regulated by an RpoN-HrpL sigma factor cascade, which is activated by the bacterial alarmone (p)ppGpp. In this study, the binding site of HrpS, an enhancer binding protein, was identified for the first time in plant-pathogenic bacteria. Complementation of the hrpL mutant with promoter deletion constructs of the hrpL gene and promoter activity analyses using various lengths of the hrpL promoter fused to a promoter-less green fluorescent protein (gfp) reporter gene delineated the upstream region for HrpS binding. Sequence analysis revealed a dyad symmetry sequence between -138 and -125 nucleotides (TGCAA-N4-TTGCA) as the potential HrpS binding site, which is conserved in the promoter of the hrpL gene among plant enterobacterial pathogens. Results of quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR) and electrophoresis mobility shift assay coupled with site-directed mutagenesis (SDM) analysis showed that the intact dyad symmetry sequence was essential for HrpS binding, full activation of T3SS gene expression and virulence. In addition, the role of the GAYTGA motif (RpoN binding site) of HrpS in the regulation of T3SS gene expression in E. amylovora was characterized by complementation of the hrpS mutant using mutant variants generated by SDM. Results showed that a Y100F substitution of HrpS complemented the hrpS mutant, whereas Y100A and Y101A substitutions did not. These results suggest that tyrosine (Y) and phenylalanine (F) function interchangeably in the conserved GAYTGA motif of HrpS in E. amylovora.
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Affiliation(s)
- Jae Hoon Lee
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - George W Sundin
- Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, MI, 48824, USA
| | - Youfu Zhao
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
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Peña-Castillo L, Grüell M, Mulligan ME, Lang AS. DETECTION OF BACTERIAL SMALL TRANSCRIPTS FROM RNA-SEQ DATA: A COMPARATIVE ASSESSMENT. Pac Symp Biocomput 2016; 21:456-467. [PMID: 26776209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Small non-coding RNAs (sRNAs) are regulatory RNA molecules that have been identified in a multitude of bacterial species and shown to control numerous cellular processes through various regulatory mechanisms. In the last decade, next generation RNA sequencing (RNA-seq) has been used for the genome-wide detection of bacterial sRNAs. Here we describe sRNA-Detect, a novel approach to identify expressed small transcripts from prokaryotic RNA-seq data. Using RNA-seq data from three bacterial species and two sequencing platforms, we performed a comparative assessment of five computational approaches for the detection of small transcripts. We demonstrate that sRNA-Detect improves upon current standalone computational approaches for identifying novel small transcripts in bacteria.
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Affiliation(s)
- Lourdes Peña-Castillo
- Department of Computer Science, Memorial University of Newfoundland, St. John's, NL, Canada2Department of Biology, Memorial University of Newfoundland, St. John's, NL, Canada,
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