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Diplock N, Baudin M, Xiang XD, Liang LY, Dai W, Murphy JM, Lucet IS, Hassan JA, Lewis JD. Molecular dissection of the pseudokinase ZED1 expands effector recognition to the tomato immune receptor ZAR1. PLANT PHYSIOLOGY 2024; 196:651-666. [PMID: 38748589 DOI: 10.1093/plphys/kiae268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Accepted: 04/11/2024] [Indexed: 09/03/2024]
Abstract
The highly conserved angiosperm immune receptor HOPZ-ACTIVATED RESISTANCE 1 (ZAR1) is a bacterial pathogen recognition hub that mediates resistance by guarding host kinases for modification by pathogen effectors. The pseudokinase HOPZ-ETI DEFICIENT 1 (ZED1) is the only known ZAR1-guarded protein that interacts directly with a pathogen effector, HopZ1a, from the bacterial pathogen Pseudomonas syringae, making it a promising system for rational design of effector recognition for plant immunity. Here, we conducted an in-depth molecular analysis of ZED1. We generated a library of 164 random ZED1 mutants and identified 50 mutants that could not recognize the effector HopZ1a when transiently expressed in Nicotiana benthamiana. Based on our random mutants, we generated a library of 27 point mutants and found evidence of minor functional divergence between Arabidopsis (Arabidopsis thaliana) and N. benthamiana ZAR1 orthologs. We leveraged our point mutant library to identify regions in ZED1 critical for ZAR1 and HopZ1a interactions and identified two likely ZED1-HopZ1a binding conformations. We explored ZED1 nucleotide and cation binding activity and showed that ZED1 is a catalytically dead pseudokinase, functioning solely as an allosteric regulator upon effector recognition. We used our library of ZED1 point mutants to identify the ZED1 activation loop regions as the most likely cause of interspecies ZAR1-ZED1 incompatibility. Finally, we identified a mutation that abolished ZAR1-ZED1 interspecies incompatibility while retaining the ability to mediate HopZ1a recognition, which enabled recognition of HopZ1a through tomato (Solanum lycopersicum) ZAR1. This provides an example of expanded effector recognition through a ZAR1 ortholog from a non-model species.
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Affiliation(s)
- Nathan Diplock
- Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, CA 94720, USA
| | - Maël Baudin
- Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, CA 94720, USA
| | - Xincheng Derek Xiang
- Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, CA 94720, USA
| | - Lung-Yu Liang
- Walter and Eliza Hall Institute of Medical Research, Parkville 3052, Australia
- Department of Medical Biology, University of Melbourne, Melbourne 3052, Australia
| | - Weiwen Dai
- Walter and Eliza Hall Institute of Medical Research, Parkville 3052, Australia
- Department of Medical Biology, University of Melbourne, Melbourne 3052, Australia
| | - James M Murphy
- Walter and Eliza Hall Institute of Medical Research, Parkville 3052, Australia
- Department of Medical Biology, University of Melbourne, Melbourne 3052, Australia
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052, Australia
| | - Isabelle S Lucet
- Walter and Eliza Hall Institute of Medical Research, Parkville 3052, Australia
- Department of Medical Biology, University of Melbourne, Melbourne 3052, Australia
| | - Jana A Hassan
- Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, CA 94720, USA
| | - Jennifer D Lewis
- Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, CA 94720, USA
- Plant Gene Expression Center, United States Department of Agriculture, Agriculture Research Service, Albany, CA 94710, USA
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2
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Lonjon F, Lai Y, Askari N, Aiyar N, Bundalovic-Torma C, Laflamme B, Wang PW, Desveaux D, Guttman DS. The effector-triggered immunity landscape of tomato against Pseudomonas syringae. Nat Commun 2024; 15:5102. [PMID: 38877009 PMCID: PMC11178782 DOI: 10.1038/s41467-024-49425-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Accepted: 05/31/2024] [Indexed: 06/16/2024] Open
Abstract
Tomato (Solanum lycopersicum) is one of the world's most important food crops, and as such, its production needs to be protected from infectious diseases that can significantly reduce yield and quality. Here, we survey the effector-triggered immunity (ETI) landscape of tomato against the bacterial pathogen Pseudomonas syringae. We perform comprehensive ETI screens in five cultivated tomato varieties and two wild relatives, as well as an immunodiversity screen on a collection of 149 tomato varieties that includes both wild and cultivated varieties. The screens reveal a tomato ETI landscape that is more limited than what was previously found in the model plant Arabidopsis thaliana. We also demonstrate that ETI eliciting effectors can protect tomato against P. syringae infection when the effector is delivered by a non-virulent strain either prior to or simultaneously with a virulent strain. Overall, our findings provide a snapshot of the ETI landscape of tomatoes and demonstrate that ETI can be used as a biocontrol treatment to protect crop plants.
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Affiliation(s)
- Fabien Lonjon
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
| | - Yan Lai
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
| | - Nasrin Askari
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
| | - Niharikaa Aiyar
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
| | | | - Bradley Laflamme
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
| | - Pauline W Wang
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
- Centre for the Analysis of Genome Evolution & Function, University of Toronto, Toronto, ON, Canada
| | - Darrell Desveaux
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada.
- Centre for the Analysis of Genome Evolution & Function, University of Toronto, Toronto, ON, Canada.
| | - David S Guttman
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada.
- Centre for the Analysis of Genome Evolution & Function, University of Toronto, Toronto, ON, Canada.
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3
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Horton KN, Gassmann W. Greater than the sum of their parts: an overview of the AvrRps4 effector family. FRONTIERS IN PLANT SCIENCE 2024; 15:1400659. [PMID: 38799092 PMCID: PMC11116571 DOI: 10.3389/fpls.2024.1400659] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/14/2024] [Accepted: 04/26/2024] [Indexed: 05/29/2024]
Abstract
Phytopathogenic microbes use secreted effector proteins to increase their virulence in planta. If these effectors or the results of their activity are detected by the plant cell, the plant will mount an immune response which applies evolutionary pressure by reducing growth and success of the pathogen. Bacterial effector proteins in the AvrRps4 family (AvrRps4, HopK1, and XopO) have commonly been used as tools to investigate plant immune components. At the same time, the in planta functions of this family of effectors have yet to be fully characterized. In this minireview we summarize current knowledge about the AvrRps4 effector family with emphasis on properties of the proteins themselves. We hypothesize that the HopK1 C-terminus and the AvrRps4 C-terminus, though unrelated in sequence and structure, are broadly related in functions that counteract plant defense responses.
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Affiliation(s)
| | - Walter Gassmann
- Division of Plant Science and Technology, Bond Life Sciences Center, and Interdisciplinary Plant Group, University of Missouri, Columbia, MO, United States
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4
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Vadillo‐Dieguez A, Zeng Z, Mansfield JW, Grinberg NF, Lynn SC, Gregg A, Connell J, Harrison RJ, Jackson RW, Hulin MT. Genetic dissection of the tissue-specific roles of type III effectors and phytotoxins in the pathogenicity of Pseudomonas syringae pv. syringae to cherry. MOLECULAR PLANT PATHOLOGY 2024; 25:e13451. [PMID: 38590135 PMCID: PMC11002349 DOI: 10.1111/mpp.13451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Revised: 03/13/2024] [Accepted: 03/19/2024] [Indexed: 04/10/2024]
Abstract
When compared with other phylogroups (PGs) of the Pseudomonas syringae species complex, P. syringae pv. syringae (Pss) strains within PG2 have a reduced repertoire of type III effectors (T3Es) but produce several phytotoxins. Effectors within the cherry pathogen Pss 9644 were grouped based on their frequency in strains from Prunus as the conserved effector locus (CEL) common to most P. syringae pathogens; a core of effectors common to PG2; a set of PRUNUS effectors common to cherry pathogens; and a FLEXIBLE set of T3Es. Pss 9644 also contains gene clusters for biosynthesis of toxins syringomycin, syringopeptin and syringolin A. After confirmation of virulence gene expression, mutants with a sequential series of T3E and toxin deletions were pathogenicity tested on wood, leaves and fruits of sweet cherry (Prunus avium) and leaves of ornamental cherry (Prunus incisa). The toxins had a key role in disease development in fruits but were less important in leaves and wood. An effectorless mutant retained some pathogenicity to fruit but not wood or leaves. Striking redundancy was observed amongst effector groups. The CEL effectors have important roles during the early stages of leaf infection and possibly acted synergistically with toxins in all tissues. Deletion of separate groups of T3Es had more effect in P. incisa than in P. avium. Mixed inocula were used to complement the toxin mutations in trans and indicated that strain mixtures may be important in the field. Our results highlight the niche-specific role of toxins in P. avium tissues and the complexity of effector redundancy in the pathogen Pss 9644.
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Affiliation(s)
- Andrea Vadillo‐Dieguez
- NIABCambridgeUK
- School of Biosciences and the Birmingham Institute of Forest ResearchUniversity of BirminghamBirminghamUK
| | | | | | | | | | | | | | - Richard J. Harrison
- NIABCambridgeUK
- School of Biosciences and the Birmingham Institute of Forest ResearchUniversity of BirminghamBirminghamUK
- Faculty of Natural Sciences, Plant Science GroupWageningen University and ResearchWageningenNetherlands
- Present address:
Faculty of Natural Sciences, Plant Science GroupWageningen University and ResearchWageningenNetherlands
| | - Robert W. Jackson
- School of Biosciences and the Birmingham Institute of Forest ResearchUniversity of BirminghamBirminghamUK
| | - Michelle T. Hulin
- NIABCambridgeUK
- Department of Plant Soil & Microbial SciencesMichigan State UniversityEast LansingUSA
- Present address:
Department of Plant Soil & Microbial SciencesMichigan State UniversityEast LansingUSA
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5
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Colombi E, Bertels F, Doulcier G, McConnell E, Pichugina T, Sohn KH, Straub C, McCann HC, Rainey PB. Rapid dissemination of host metabolism-manipulating genes via integrative and conjugative elements. Proc Natl Acad Sci U S A 2024; 121:e2309263121. [PMID: 38457521 PMCID: PMC10945833 DOI: 10.1073/pnas.2309263121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Accepted: 01/08/2024] [Indexed: 03/10/2024] Open
Abstract
Integrative and conjugative elements (ICEs) are self-transmissible mobile elements that transfer functional genetic units across broad phylogenetic distances. Accessory genes shuttled by ICEs can make significant contributions to bacterial fitness. Most ICEs characterized to date encode readily observable phenotypes contributing to symbiosis, pathogenicity, and antimicrobial resistance, yet the majority of ICEs carry genes of unknown function. Recent observations of rapid acquisition of ICEs in a pandemic lineage of Pseudomonas syringae pv. actinidae led to investigation of the structural and functional diversity of these elements. Fifty-three unique ICE types were identified across the P. syringae species complex. Together they form a distinct family of ICEs (PsICEs) that share a distant relationship to ICEs found in Pseudomonas aeruginosa. PsICEs are defined by conserved backbone genes punctuated by an array of accessory cargo genes, are highly recombinogenic, and display distinct evolutionary histories compared to their bacterial hosts. The most common cargo is a recently disseminated 16-kb mobile genetic element designated Tn6212. Deletion of Tn6212 did not alter pathogen growth in planta, but mutants displayed fitness defects when grown on tricarboxylic acid (TCA) cycle intermediates. RNA-seq analysis of a set of nested deletion mutants showed that a Tn6212-encoded LysR regulator has global effects on chromosomal gene expression. We show that Tn6212 responds to preferred carbon sources and manipulates bacterial metabolism to maximize growth.
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Affiliation(s)
- Elena Colombi
- School of Agriculture, Food and Ecosystem Sciences, Faculty of Science, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Frederic Bertels
- Department of Microbial Population Biology, Max Planck Institute for Evolutionary Biology, Plön 24306, Germany
| | - Guilhem Doulcier
- Laboratoire Biophysique et Évolution, Institut Chemie Biologie Innovation, École Supérieure de Physique et de Chemie Industrielles de la Ville de Paris, Université Paris Science et Lettres, Centre National de al Reserche Scientifique, Paris 75005, France
| | - Ellen McConnell
- Department of Microbial Population Biology, Max Planck Institute for Evolutionary Biology, Plön 24306, Germany
| | - Tatyana Pichugina
- Department of Microbial Population Biology, Max Planck Institute for Evolutionary Biology, Plön 24306, Germany
| | - Kee Hoon Sohn
- Plant Immunity Research Center, Seoul National University, Seoul 08826, Republic of Korea
- Department of Agricultural Biotechnology, Seoul National University, Seoul 08826, Republic of Korea
- Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 08826, Republic of Korea
- Plant Genomics and Breeding Institute, Seoul National University, Seoul 08826, Republic of Korea
| | - Christina Straub
- Health and Environment, Institute of Environmental Science and Research, Auckland 1025, New Zealand
- Division of Microbial Ecology, Center for Microbiology and Environmental Systems Science, University of Vienna, Vienna 1030, Austria
| | - Honour C McCann
- Plant Pathogen Evolution Research Group, Max Planck Institute for Biology, Tübingen 72076, Germany
| | - Paul B Rainey
- Department of Microbial Population Biology, Max Planck Institute for Evolutionary Biology, Plön 24306, Germany
- Laboratoire Biophysique et Évolution, Institut Chemie Biologie Innovation, École Supérieure de Physique et de Chemie Industrielles de la Ville de Paris, Université Paris Science et Lettres, Centre National de al Reserche Scientifique, Paris 75005, France
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6
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Guerrero-Egido G, Pintado A, Bretscher KM, Arias-Giraldo LM, Paulson JN, Spaink HP, Claessen D, Ramos C, Cazorla FM, Medema MH, Raaijmakers JM, Carrión VJ. bacLIFE: a user-friendly computational workflow for genome analysis and prediction of lifestyle-associated genes in bacteria. Nat Commun 2024; 15:2072. [PMID: 38453959 PMCID: PMC10920822 DOI: 10.1038/s41467-024-46302-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 02/21/2024] [Indexed: 03/09/2024] Open
Abstract
Bacteria have an extensive adaptive ability to live in close association with eukaryotic hosts, exhibiting detrimental, neutral or beneficial effects on host growth and health. However, the genes involved in niche adaptation are mostly unknown and their functions poorly characterized. Here, we present bacLIFE ( https://github.com/Carrion-lab/bacLIFE ) a streamlined computational workflow for genome annotation, large-scale comparative genomics, and prediction of lifestyle-associated genes (LAGs). As a proof of concept, we analyzed 16,846 genomes from the Burkholderia/Paraburkholderia and Pseudomonas genera, which led to the identification of hundreds of genes potentially associated with a plant pathogenic lifestyle. Site-directed mutagenesis of 14 of these predicted LAGs of unknown function, followed by plant bioassays, showed that 6 predicted LAGs are indeed involved in the phytopathogenic lifestyle of Burkholderia plantarii and Pseudomonas syringae pv. phaseolicola. These 6 LAGs encompassed a glycosyltransferase, extracellular binding proteins, homoserine dehydrogenases and hypothetical proteins. Collectively, our results highlight bacLIFE as an effective computational tool for prediction of LAGs and the generation of hypotheses for a better understanding of bacteria-host interactions.
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Affiliation(s)
- Guillermo Guerrero-Egido
- Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE, Leiden, The Netherlands
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Droevendaalsesteeg 10, 6708 PB, Wageningen, The Netherlands
- Departamento de Microbiología, Facultad de Ciencias, Campus Universitario de Teatinos s/n, Universidad de Málaga, 29010, Málaga, Spain
- Departamento de Protección de Cultivos, Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Campus Universitario de Teatinos, Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), 29010, Málaga, Spain
| | - Adrian Pintado
- Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE, Leiden, The Netherlands
- Departamento de Microbiología, Facultad de Ciencias, Campus Universitario de Teatinos s/n, Universidad de Málaga, 29010, Málaga, Spain
- Departamento de Protección de Cultivos, Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Campus Universitario de Teatinos, Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), 29010, Málaga, Spain
| | - Kevin M Bretscher
- Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE, Leiden, The Netherlands
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Droevendaalsesteeg 10, 6708 PB, Wageningen, The Netherlands
- Departamento de Microbiología, Facultad de Ciencias, Campus Universitario de Teatinos s/n, Universidad de Málaga, 29010, Málaga, Spain
- Departamento de Protección de Cultivos, Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Campus Universitario de Teatinos, Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), 29010, Málaga, Spain
| | - Luisa-Maria Arias-Giraldo
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Droevendaalsesteeg 10, 6708 PB, Wageningen, The Netherlands
| | - Joseph N Paulson
- Department of Data Sciences, N-Power Medicine, Redwood City, CA, 94063, USA
| | - Herman P Spaink
- Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE, Leiden, The Netherlands
| | - Dennis Claessen
- Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE, Leiden, The Netherlands
| | - Cayo Ramos
- Departamento de Protección de Cultivos, Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Campus Universitario de Teatinos, Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), 29010, Málaga, Spain
- Área de Genética, Facultad de Ciencias, Campus Universitario de Teatinos s/n, Universidad de Málaga, 29010, Málaga, Spain
| | - Francisco M Cazorla
- Departamento de Microbiología, Facultad de Ciencias, Campus Universitario de Teatinos s/n, Universidad de Málaga, 29010, Málaga, Spain
- Departamento de Protección de Cultivos, Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Campus Universitario de Teatinos, Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), 29010, Málaga, Spain
| | - Marnix H Medema
- Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE, Leiden, The Netherlands
- Bioinformatics Group, Wageningen University, Droevendaalsesteeg 1, 6708 PB, Wageningen, The Netherlands
| | - Jos M Raaijmakers
- Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE, Leiden, The Netherlands
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Droevendaalsesteeg 10, 6708 PB, Wageningen, The Netherlands
| | - Víctor J Carrión
- Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE, Leiden, The Netherlands.
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Droevendaalsesteeg 10, 6708 PB, Wageningen, The Netherlands.
- Departamento de Microbiología, Facultad de Ciencias, Campus Universitario de Teatinos s/n, Universidad de Málaga, 29010, Málaga, Spain.
- Departamento de Protección de Cultivos, Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Campus Universitario de Teatinos, Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), 29010, Málaga, Spain.
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7
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Holtappels D, Abelson SA, Nouth SC, Rickus GEJ, Amare SZ, Giller JP, Jian DZ, Koskella B. Genomic characterization of Pseudomonas syringae pv. syringae from Callery pear and the efficiency of associated phages in disease protection. Microbiol Spectr 2024; 12:e0283323. [PMID: 38323825 PMCID: PMC10913373 DOI: 10.1128/spectrum.02833-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Accepted: 12/11/2023] [Indexed: 02/08/2024] Open
Abstract
The Pseudomonas syringae species complex is a heterogeneous group of plant pathogenic bacteria associated with a wide distribution of plant species. Advances in genomics are revealing the complex evolutionary history of this species complex and the wide array of genetic adaptations underpinning their diverse lifestyles. Here, we genomically characterize two P. syringae isolates collected from diseased Callery pears (Pyrus calleryana) in Berkeley, California in 2019 and 2022. We also isolated a lytic bacteriophage, which we characterized and evaluated for biocontrol efficiency. Using a multilocus sequence analysis and core genome alignment, we classified the P. syringae isolates as members of phylogroup 2, related to other strains previously isolated from Pyrus and Prunus. An analysis of effector proteins demonstrated an evolutionary conservation of effectoromes across isolates classified in PG2 and yet uncovered unique effector profiles for each, including the two newly identified isolates. Whole-genome sequencing of the associated phage uncovered a novel phage genus related to Pseudomonas syringae pv. actinidiae phage PHB09 and the Flaumdravirus genus. Finally, using in planta infection assays, we demonstrate that the phage was equally useful in symptom mitigation of immature pear fruit regardless of the Pss strain tested. Overall, this study demonstrates the diversity of P. syringae and their viruses associated with ornamental pear trees, posing spill-over risks to commercial pear trees and the possibility of using phages as biocontrol agents to reduce the impact of disease.IMPORTANCEGlobal change exacerbates the spread and impact of pathogens, especially in agricultural settings. There is a clear need to better monitor the spread and diversity of plant pathogens, including in potential spillover hosts, and for the development of novel and sustainable control strategies. In this study, we characterize the first described strains of Pseudomonas syringae pv. syringae isolated from Callery pear in Berkeley, California from diseased tissues in an urban environment. We show that these strains have divergent virulence profiles from previously described strains and that they can cause disease in commercial pears. Additionally, we describe a novel bacteriophage that is associated with these strains and explore its potential to act as a biocontrol agent. Together, the data presented here demonstrate that ornamental pear trees harbor novel P. syringae pv. syringae isolates that potentially pose a risk to local fruit production, or vice versa-but also provide us with novel associated phages, effective in disease mitigation.
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Affiliation(s)
- D. Holtappels
- Integrative Biology University of California, Berkeley, California, USA
| | - S. A. Abelson
- Integrative Biology University of California, Berkeley, California, USA
| | - S. C. Nouth
- Integrative Biology University of California, Berkeley, California, USA
| | - G. E. J. Rickus
- Integrative Biology University of California, Berkeley, California, USA
| | - S. Z. Amare
- Integrative Biology University of California, Berkeley, California, USA
| | - J. P. Giller
- Integrative Biology University of California, Berkeley, California, USA
| | - D. Z. Jian
- Integrative Biology University of California, Berkeley, California, USA
| | - B. Koskella
- Integrative Biology University of California, Berkeley, California, USA
- Chan Zuckerberg Biohub, San Francisco, California, USA
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8
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Lavado-Benito C, Murillo J, Martínez-Gil M, Ramos C, Rodríguez-Moreno L. GacA reduces virulence and increases competitiveness in planta in the tumorigenic olive pathogen Pseudomonas savastanoi pv. savastanoi. FRONTIERS IN PLANT SCIENCE 2024; 15:1347982. [PMID: 38375080 PMCID: PMC10875052 DOI: 10.3389/fpls.2024.1347982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Accepted: 01/08/2024] [Indexed: 02/21/2024]
Abstract
GacS/GacA is a widely distributed two-component system playing an essential role as a key global regulator, although its characterization in phytopathogenic bacteria has been deeply biased, being intensively studied in pathogens of herbaceous plants but barely investigated in pathogens of woody hosts. P. savastanoi pv. savastanoi (Psv) is characterized by inducing tumours in the stem and branches of olive trees. In this work, the model strain Psv NCPPB 3335 and a mutant derivative with a complete deletion of gene gacA were subjected to RNA-Seq analyses in a minimum medium and a medium mimicking in planta conditions, accompanied by RT-qPCR analyses of selected genes and phenotypic assays. These experiments indicated that GacA participates in the regulation of at least 2152 genes in strain NCPPB 3335, representing 37.9 % of the annotated CDSs. GacA also controls the expression of diverse rsm genes, and modulates diverse phenotypes, including motility and resistance to oxidative stresses. As occurs with other P. syringae pathovars of herbaceous plants, GacA regulates the expression of the type III secretion system and cognate effectors. In addition, GacA also regulates the expression of WHOP genes, specifically encoded in P. syringe strains isolated from woody hosts, and genes for the biosynthesis of phytohormones. A gacA mutant of NCPPB 3335 showed increased virulence, producing large immature tumours with high bacterial populations, but showed a significantly reduced competitiveness in planta. Our results further extend the role of the global regulator GacA in the virulence and fitness of a P. syringae pathogen of woody hosts.
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Affiliation(s)
- Carla Lavado-Benito
- Área de Genética, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain
- Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Málaga, Spain
| | - Jesús Murillo
- Institute for Multidisciplinary Research in Applied Biology, Universidad Pública de Navarra (UPNA), Edificio de Agrobiotecnología, Mutilva Baja, Spain
| | - Marta Martínez-Gil
- Área de Genética, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain
| | - Cayo Ramos
- Área de Genética, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain
- Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Málaga, Spain
| | - Luis Rodríguez-Moreno
- Área de Genética, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain
- Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Málaga, Spain
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9
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De la Rubia AG, Largo-Gosens A, Yusta R, Sepúlveda-Orellana P, Riveros A, Centeno ML, Sanhueza D, Meneses C, Saez-Aguayo S, García-Angulo P. A novel pectin methylesterase inhibitor, PMEI3, in common bean suggests a key role of pectin methylesterification in Pseudomonas resistance. JOURNAL OF EXPERIMENTAL BOTANY 2024; 75:364-390. [PMID: 37712879 DOI: 10.1093/jxb/erad362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 09/14/2023] [Indexed: 09/16/2023]
Abstract
The mechanisms underlying susceptibility to and defense against Pseudomonas syringae (Pph) of the common bean (Phaseolus vulgaris) have not yet been clarified. To investigate these, 15-day-old plants of the variety Riñón were infected with Pph and the transcriptomic changes at 2 h and 9 h post-infection were analysed. RNA-seq analysis showed an up-regulation of genes involved in defense/signaling at 2 h, most of them being down-regulated at 9 h, suggesting that Pph inhibits the transcriptomic reprogramming of the plant. This trend was also observed in the modulation of 101 cell wall-related genes. Cell wall composition changes at early stages of Pph infection were associated with homogalacturonan methylation and the formation of egg boxes. Among the cell wall genes modulated, a pectin methylesterase inhibitor 3 (PvPMEI3) gene, closely related to AtPMEI3, was detected. PvPMEI3 protein was located in the apoplast and its pectin methylesterase inhibitory activity was demonstrated. PvPMEI3 seems to be a good candidate to play a key role in Pph infection, which was supported by analysis of an Arabidopsis pmei3 mutant, which showed susceptibility to Pph, in contrast to resistant Arabidopsis Col-0 plants. These results indicate a key role of the degree of pectin methylesterification in host resistance to Pph during the first steps of the attack.
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Affiliation(s)
- Alfonso G De la Rubia
- Área de Fisiología Vegetal, Dpto Ingenieria y Ciencias Agrarias, Universidad de León, León, E-24071, Spain
- Department of Biology, ETH Zurich, 8092 Zurich, Switzerland
| | - Asier Largo-Gosens
- Área de Fisiología Vegetal, Dpto Ingenieria y Ciencias Agrarias, Universidad de León, León, E-24071, Spain
- Centro de Biotecnología Vegetal, Facultad de Ciencias de la Vida, Universidad Andrés Bello, Santiago 8370146, Chile
| | - Ricardo Yusta
- Centro de Biotecnología Vegetal, Facultad de Ciencias de la Vida, Universidad Andrés Bello, Santiago 8370146, Chile
- ANID - Millennium Science Initiative Program - Millennium Institute Center for Genome Regulation (CRG), 7800003, Santiago, Chile
| | - Pablo Sepúlveda-Orellana
- Centro de Biotecnología Vegetal, Facultad de Ciencias de la Vida, Universidad Andrés Bello, Santiago 8370146, Chile
| | - Aníbal Riveros
- Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, 8331150, Chile
- ANID - Millennium Science Initiative Program - Millennium Nucleus for the Development of Super Adaptable Plants (MN-SAP), Santiago, Chile
| | - María Luz Centeno
- Área de Fisiología Vegetal, Dpto Ingenieria y Ciencias Agrarias, Universidad de León, León, E-24071, Spain
| | - Dayan Sanhueza
- Centro de Biotecnología Vegetal, Facultad de Ciencias de la Vida, Universidad Andrés Bello, Santiago 8370146, Chile
| | - Claudio Meneses
- ANID - Millennium Science Initiative Program - Millennium Institute Center for Genome Regulation (CRG), 7800003, Santiago, Chile
- Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, 8331150, Chile
- ANID - Millennium Science Initiative Program - Millennium Nucleus for the Development of Super Adaptable Plants (MN-SAP), Santiago, Chile
- Departamento de Fruticultura y Enología, Facultad de Agronomía e Ingeniería Forestal, Pontificia Universidad Católica de Chile, Santiago, 7820436, Chile
| | - Susana Saez-Aguayo
- Centro de Biotecnología Vegetal, Facultad de Ciencias de la Vida, Universidad Andrés Bello, Santiago 8370146, Chile
- ANID - Millennium Science Initiative Program - Millennium Nucleus for the Development of Super Adaptable Plants (MN-SAP), Santiago, Chile
- Chilean fruits cell wall Components as Biotechnological resources (CHICOBIO), Proyecto Anillo ACT210025, Santiago, Chile
| | - Penélope García-Angulo
- Área de Fisiología Vegetal, Dpto Ingenieria y Ciencias Agrarias, Universidad de León, León, E-24071, Spain
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10
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Zhang N, Gan J, Carneal L, González-Tobón J, Filiatrault M, Martin GB. Helper NLRs Nrc2 and Nrc3 act codependently with Prf/Pto and activate MAPK signaling to induce immunity in tomato. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2024; 117:7-22. [PMID: 37844152 DOI: 10.1111/tpj.16502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 09/27/2023] [Accepted: 10/04/2023] [Indexed: 10/18/2023]
Abstract
Plant intracellular immune receptors, primarily nucleotide-binding, leucine-rich repeat proteins (NLRs), detect pathogen effector proteins and activate NLR-triggered immunity (NTI). Recently, 'sensor' NLRs have been reported to function with 'helper' NLRs to activate immunity. We investigated the role of two helper NLRs, Nrc2 and Nrc3, on immunity in tomato to the bacterial pathogen Pseudomonas syringae pv. tomato (Pst) mediated by the sensor NLR Prf and the Pto kinase. An nrc2/nrc3 mutant no longer activated Prf/Pto-mediated NTI to Pst containing the effectors AvrPto and AvrPtoB. An nrc3 mutant showed intermediate susceptibility between wild-type plants and a Prf mutant, while an nrc2 mutant developed only mild disease. These observations indicate that Nrc2 and Nrc3 act additively in Prf-/Pto-mediated immunity. We examined at what point Nrc2 and Nrc3 act in the Prf/Pto-mediated immune response. In the nrc2/3 mutant, programmed cell death (PCD) normally induced by constitutively active variants of AvrPtoB, Pto, or Prf was abolished, but that induced by M3Kα or Mkk2 was not. PCD induced by a constitutively active Nrc3 was also abolished in a Nicotiana benthamiana line with reduced expression of Prf. MAPK activation triggered by expression of AvrPto in the wild-type tomato plants was completely abolished in the nrc2/3 mutant. These results indicate that Nrc2 and Nrc3 act with Prf/Pto and upstream of MAPK signaling. Nrc2 and Nrc3 were not required for PCD triggered by Ptr1, another sensor NLR-mediating Pst resistance, although these helper NLRs do appear to be involved in resistance to certain Pst race 1 strains.
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Affiliation(s)
- Ning Zhang
- Boyce Thompson Institute for Plant Research, Ithaca, New York, 14853, USA
- Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, New York, 14853, USA
| | - Joyce Gan
- Boyce Thompson Institute for Plant Research, Ithaca, New York, 14853, USA
| | - Lauren Carneal
- Boyce Thompson Institute for Plant Research, Ithaca, New York, 14853, USA
| | - Juliana González-Tobón
- Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, New York, 14853, USA
| | - Melanie Filiatrault
- Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, New York, 14853, USA
- United States Department of Agriculture-Agricultural Research Service, Ithaca, New York, 14853, USA
| | - Gregory B Martin
- Boyce Thompson Institute for Plant Research, Ithaca, New York, 14853, USA
- Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, New York, 14853, USA
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11
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McTavish KJ, Almeida RND, Tersigni J, Raimundi MK, Gong Y, Wang PW, Gontijo GF, de Souza RM, de Resende MLV, Desveaux D, Guttman DS. Pseudomonas syringae coffee blight is associated with the horizontal transfer of plasmid-encoded type III effectors. THE NEW PHYTOLOGIST 2024; 241:409-429. [PMID: 37953378 DOI: 10.1111/nph.19364] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Accepted: 09/29/2023] [Indexed: 11/14/2023]
Abstract
The emergence of new pathogens is an ongoing threat to human health and agriculture. While zoonotic spillovers received considerable attention, the emergence of crop diseases is less well studied. Here, we identify genomic factors associated with the emergence of Pseudomonas syringae bacterial blight of coffee. Fifty-three P. syringae strains from diseased Brazilian coffee plants were sequenced. Comparative and evolutionary analyses were used to identify loci associated with coffee blight. Growth and symptomology assays were performed to validate the findings. Coffee isolates clustered in three lineages, including primary phylogroups PG3 and PG4, and secondary phylogroup PG11. Genome-wide association study of the primary PG strains identified 37 loci, including five effectors, most of which were encoded on a plasmid unique to the PG3 and PG4 coffee strains. Evolutionary analyses support the emergence of coffee blight in PG4 when the coffee-associated plasmid and associated effectors derived from a divergent plasmid carried by strains associated with other hosts. This plasmid was only recently transferred into PG3. Natural diversity and CRISPR-Cas9 plasmid curing were used to show that strains with the coffee-associated plasmid grow to higher densities and cause more severe disease symptoms in coffee. This work identifies possible evolutionary mechanisms underlying the emergence of a new lineage of coffee pathogens.
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Affiliation(s)
- Kathryn J McTavish
- Department of Cell & Systems Biology, University of Toronto, 25 Willcocks St., Toronto, ON, M6S 2Y1, Canada
| | - Renan N D Almeida
- Department of Cell & Systems Biology, University of Toronto, 25 Willcocks St., Toronto, ON, M6S 2Y1, Canada
| | - Jonathan Tersigni
- Department of Cell & Systems Biology, University of Toronto, 25 Willcocks St., Toronto, ON, M6S 2Y1, Canada
| | - Melina K Raimundi
- Department of Phytopathology, Universidade Federal de Lavras, Lavras, MG, CEP 37200-000, Brazil
| | - Yunchen Gong
- Centre for the Analysis of Genome Evolution & Function, University of Toronto, Toronto, ON, M6S 2Y1, Canada
| | - Pauline W Wang
- Department of Cell & Systems Biology, University of Toronto, 25 Willcocks St., Toronto, ON, M6S 2Y1, Canada
- Centre for the Analysis of Genome Evolution & Function, University of Toronto, Toronto, ON, M6S 2Y1, Canada
| | - Guilherme F Gontijo
- Department of Phytopathology, Universidade Federal de Lavras, Lavras, MG, CEP 37200-000, Brazil
| | - Ricardo M de Souza
- Department of Phytopathology, Universidade Federal de Lavras, Lavras, MG, CEP 37200-000, Brazil
| | - Mario L V de Resende
- Department of Phytopathology, Universidade Federal de Lavras, Lavras, MG, CEP 37200-000, Brazil
| | - Darrell Desveaux
- Department of Cell & Systems Biology, University of Toronto, 25 Willcocks St., Toronto, ON, M6S 2Y1, Canada
- Centre for the Analysis of Genome Evolution & Function, University of Toronto, Toronto, ON, M6S 2Y1, Canada
| | - David S Guttman
- Department of Cell & Systems Biology, University of Toronto, 25 Willcocks St., Toronto, ON, M6S 2Y1, Canada
- Centre for the Analysis of Genome Evolution & Function, University of Toronto, Toronto, ON, M6S 2Y1, Canada
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12
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Jiménez‐Guerrero I, López‐Baena FJ, Borrero‐de Acuña JM, Pérez‐Montaño F. Membrane vesicle engineering with "à la carte" bacterial-immunogenic molecules for organism-free plant vaccination. Microb Biotechnol 2023; 16:2223-2235. [PMID: 37530752 PMCID: PMC10686165 DOI: 10.1111/1751-7915.14323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Revised: 07/13/2023] [Accepted: 07/18/2023] [Indexed: 08/03/2023] Open
Abstract
The United Nations heralds a world population exponential increase exceeding 9.7 billion by 2050. This poses the challenge of covering the nutritional needs of an overpopulated world by the hand of preserving the environment. Extensive agriculture practices harnessed the employment of fertilizers and pesticides to boost crop productivity and prevent economic and harvest yield losses attributed to plagues and diseases. Unfortunately, the concomitant hazardous effects stemmed from such agriculture techniques are cumbersome, that is, biodiversity loss, soils and waters contaminations, and human and animal poisoning. Hence, the so-called 'green agriculture' research revolves around designing novel biopesticides and plant growth-promoting bio-agents to the end of curbing the detrimental effects. In this field, microbe-plant interactions studies offer multiple possibilities for reshaping the plant holobiont physiology to its benefit. Along these lines, bacterial extracellular membrane vesicles emerge as an appealing molecular tool to capitalize on. These nanoparticles convey a manifold of molecules that mediate intricate bacteria-plant interactions including plant immunomodulation. Herein, we bring into the spotlight bacterial extracellular membrane vesicle engineering to encase immunomodulatory effectors into their cargo for their application as biocontrol agents. The overarching goal is achieving plant priming by deploying its innate immune responses thereby preventing upcoming infections.
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13
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Kim W, Jeon H, Lee H, Sohn KH, Segonzac C. The Ralstonia pseudosolanacearum Type III Effector RipL Delays Flowering and Promotes Susceptibility to Pseudomonas syringae in Arabidopsis thaliana. Mol Cells 2023; 46:710-724. [PMID: 37968984 PMCID: PMC10654456 DOI: 10.14348/molcells.2023.0127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 09/20/2023] [Accepted: 09/24/2023] [Indexed: 11/17/2023] Open
Abstract
The plant defense responses to microbial infection are tightly regulated and integrated with the developmental program for optimal resources allocation. Notably, the defense- associated hormone salicylic acid (SA) acts as a promoter of flowering while several plant pathogens actively target the flowering signaling pathway to promote their virulence or dissemination. Ralstonia pseudosolanacearum inject tens of effectors in the host cells that collectively promote bacterial proliferation in plant tissues. Here, we characterized the function of the broadly conserved R. pseudosolanacearum effector RipL, through heterologous expression in Arabidopsis thaliana . RipL-expressing transgenic lines presented a delayed flowering, which correlated with a low expression of flowering regulator genes. Delayed flowering was also observed in Nicotiana benthamiana plants transiently expressing RipL. In parallel, RipL promoted plant susceptibility to virulent strains of Pseudomonas syringae in the effector-expressing lines or when delivered by the type III secretion system. Unexpectedly, SA accumulation and SA-dependent immune signaling were not significantly affected by RipL expression. Rather, the RNA-seq analysis of infected RipL-expressing lines revealed that the overall amplitude of the transcriptional response was dampened, suggesting that RipL could promote plant susceptibility in an SA-independent manner. Further elucidation of the molecular mechanisms underpinning RipL effect on flowering and immunity may reveal novel effector functions in host cells.
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Affiliation(s)
- Wanhui Kim
- Plant Immunity Research Center, Seoul National University, Seoul 08826, Korea
| | - Hyelim Jeon
- Plant Immunity Research Center, Seoul National University, Seoul 08826, Korea
- Department of Agriculture, Forestry and Bioresources, Seoul National University, Seoul 08826, Korea
| | - Hyeonjung Lee
- School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, Pohang 37673, Korea
| | - Kee Hoon Sohn
- Plant Immunity Research Center, Seoul National University, Seoul 08826, Korea
- School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, Pohang 37673, Korea
- Department of Agricultural Biotechnology, Seoul National University, Seoul 08826, Korea
- Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 08826, Korea
- Plant Genomics and Breeding Institute, Seoul National University, Seoul 08826, Korea
| | - Cécile Segonzac
- Plant Immunity Research Center, Seoul National University, Seoul 08826, Korea
- Department of Agriculture, Forestry and Bioresources, Seoul National University, Seoul 08826, Korea
- Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 08826, Korea
- Plant Genomics and Breeding Institute, Seoul National University, Seoul 08826, Korea
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14
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Carreón-Anguiano KG, Vila-Luna SE, Sáenz-Carbonell L, Canto-Canche B. PhyEffector, the First Algorithm That Identifies Classical and Non-Classical Effectors in Phytoplasmas. Biomimetics (Basel) 2023; 8:550. [PMID: 37999191 PMCID: PMC10669590 DOI: 10.3390/biomimetics8070550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 11/03/2023] [Accepted: 11/04/2023] [Indexed: 11/25/2023] Open
Abstract
Phytoplasmas are the causal agents of more than 100 plant diseases in economically important crops. Eleven genomes have been fully sequenced and have allowed us to gain a better understanding of the biology and evolution of phytoplasmas. Effectors are key players in pathogenicity and virulence, and their identification and description are becoming an essential practice in the description of phytoplasma genomes. This is of particular importance because effectors are possible candidates for the development of new strategies for the control of plant diseases. To date, the prediction of effectors in phytoplasmas has been a great challenge; the reliable comparison of effectoromes has been hindered because research teams have used the combination of different programs in their predictions. This is not trivial since significant differences in the results can arise, depending on the predictive pipeline used. Here, we tested different predictive pipelines to create the PhyEffector algorithm; the average value of the F1 score for PhyEffector was 0.9761 when applied to different databases or genomes, demonstrating its robustness as a predictive tool. PhyEffector can recover both classical and non-classical phytoplasma effectors, making it an invaluable tool to accelerate effectoromics in phytoplasmas.
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Affiliation(s)
| | | | | | - Blondy Canto-Canche
- Unidad de Biotecnología, Centro de Investigación Científica de Yucatán, A.C., Calle 43 No. 130 x 32 y 34, Colonia Chuburná de Hidalgo, Mérida C.P. 97205, Yucatán, Mexico (S.E.V.-L.); (L.S.-C.)
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15
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Zhao Z, Hu Y, Hu Y, White AP, Wang Y. Features and algorithms: facilitating investigation of secreted effectors in Gram-negative bacteria. Trends Microbiol 2023; 31:1162-1178. [PMID: 37349207 DOI: 10.1016/j.tim.2023.05.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 05/22/2023] [Accepted: 05/22/2023] [Indexed: 06/24/2023]
Abstract
Gram-negative bacteria deliver effector proteins through type III, IV, or VI secretion systems (T3SSs, T4SSs, and T6SSs) into host cells, causing infections and diseases. In general, effector proteins for each of these distinct secretion systems lack homology and are difficult to identify. Sequence analysis has disclosed many common features, helping us to understand the evolution, function, and secretion mechanisms of the effectors. In combination with various algorithms, the known common features have facilitated accurate prediction of new effectors. Ensemblers or integrated pipelines achieve a better prediction of performance, which combines multiple computational models or modules with multidimensional features. Natural language processing (NLP) models also show the merits, which could enable discovery of novel features and, in turn, facilitate more precise effector prediction, extending our knowledge about each secretion mechanism.
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Affiliation(s)
- Ziyi Zhao
- Youth Innovation Team of Medical Bioinformatics, Shenzhen University Medical School, Shenzhen 518060, China
| | - Yixue Hu
- Youth Innovation Team of Medical Bioinformatics, Shenzhen University Medical School, Shenzhen 518060, China
| | - Yueming Hu
- Department of Bioinformatics, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Aaron P White
- Vaccine and Infectious Disease Organization (VIDO), University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Yejun Wang
- Youth Innovation Team of Medical Bioinformatics, Shenzhen University Medical School, Shenzhen 518060, China; Department of Cell Biology and Genetics, College of Basic Medicine, Shenzhen University Medical School, Shenzhen 518060, China.
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16
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Rufián JS, Rueda-Blanco J, Beuzón CR, Ruiz-Albert J. Suppression of NLR-mediated plant immune detection by bacterial pathogens. JOURNAL OF EXPERIMENTAL BOTANY 2023; 74:6069-6088. [PMID: 37429579 PMCID: PMC10575702 DOI: 10.1093/jxb/erad246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Accepted: 07/10/2023] [Indexed: 07/12/2023]
Abstract
The plant immune system is constituted of two functionally interdependent branches that provide the plant with an effective defense against microbial pathogens. They can be considered separate since one detects extracellular pathogen-associated molecular patterns by means of receptors on the plant surface, while the other detects pathogen-secreted virulence effectors via intracellular receptors. Plant defense depending on both branches can be effectively suppressed by host-adapted microbial pathogens. In this review we focus on bacterially driven suppression of the latter, known as effector-triggered immunity (ETI) and dependent on diverse NOD-like receptors (NLRs). We examine how some effectors secreted by pathogenic bacteria carrying type III secretion systems can be subject to specific NLR-mediated detection, which can be evaded by the action of additional co-secreted effectors (suppressors), implying that virulence depends on the coordinated action of the whole repertoire of effectors of any given bacterium and their complex epistatic interactions within the plant. We consider how ETI activation can be avoided by using suppressors to directly alter compromised co-secreted effectors, modify plant defense-associated proteins, or occasionally both. We also comment on the potential assembly within the plant cell of multi-protein complexes comprising both bacterial effectors and defense protein targets.
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Affiliation(s)
- José S Rufián
- Instituto de Hortofruticultura Subtropical y Mediterránea ‘La Mayora’, Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Depto. Biología Celular, Genética y Fisiología, Málaga, Spain
| | | | - Carmen R Beuzón
- Instituto de Hortofruticultura Subtropical y Mediterránea ‘La Mayora’, Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Depto. Biología Celular, Genética y Fisiología, Málaga, Spain
| | - Javier Ruiz-Albert
- Instituto de Hortofruticultura Subtropical y Mediterránea ‘La Mayora’, Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Depto. Biología Celular, Genética y Fisiología, Málaga, Spain
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17
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Ruiz-Bedoya T, McTavish KJ, Av-Shalom TV, Desveaux D, Guttman DS. Towards integrative plant pathology. CURRENT OPINION IN PLANT BIOLOGY 2023; 75:102430. [PMID: 37542739 DOI: 10.1016/j.pbi.2023.102430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 05/03/2023] [Accepted: 07/03/2023] [Indexed: 08/07/2023]
Abstract
The field of plant pathology has revealed many of the mechanisms underlying the arms race, providing crucial knowledge and genetic resources for improving plant health. Although the host-microbe interaction seemingly favors rapidly evolving pathogens, it has also generated a vast evolutionary history of largely unexplored plant immunodiversity. We review studies that characterize the scope and distribution of genetic and ecological diversity in model and non-model systems with specific reference to pathogen effector diversity, plant immunodiversity in both cultivated species and their wild relatives, and diversity in the plant-associated microbiota. We show how the study of evolutionary and ecological processes can reveal patterns of genetic convergence, conservation, and diversification, and that this diversity is increasingly tractable in both experimental and translational systems. Perhaps most importantly, these patterns of diversity provide largely untapped resources that can be deployed for the rational engineering of durable resistance for sustainable agriculture.
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Affiliation(s)
- Tatiana Ruiz-Bedoya
- Department of Cell & Systems Biology, University of Toronto, Toronto, Ontario M5S 3G5, Canada
| | - Kathryn J McTavish
- Department of Cell & Systems Biology, University of Toronto, Toronto, Ontario M5S 3G5, Canada
| | - Tamar V Av-Shalom
- Department of Cell & Systems Biology, University of Toronto, Toronto, Ontario M5S 3G5, Canada
| | - Darrell Desveaux
- Department of Cell & Systems Biology, University of Toronto, Toronto, Ontario M5S 3G5, Canada; Centre for the Analysis of Genome Evolution & Function, University of Toronto, Toronto, Ontario M5S 3B2, Canada.
| | - David S Guttman
- Department of Cell & Systems Biology, University of Toronto, Toronto, Ontario M5S 3G5, Canada; Centre for the Analysis of Genome Evolution & Function, University of Toronto, Toronto, Ontario M5S 3B2, Canada.
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18
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Nielsen TK, Winther-Have CS, Thomsen IM, Jackson RW, Rabiey M, Hennessy RC, Bak F, Kot W, Nicolaisen MH, Carstens AB, Hansen LH. Genetic rearrangements in Pseudomonas amygdali pathovar aesculi shape coronatine plasmids. INFECTION, GENETICS AND EVOLUTION : JOURNAL OF MOLECULAR EPIDEMIOLOGY AND EVOLUTIONARY GENETICS IN INFECTIOUS DISEASES 2023; 113:105486. [PMID: 37541538 DOI: 10.1016/j.meegid.2023.105486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 06/23/2023] [Accepted: 08/01/2023] [Indexed: 08/06/2023]
Abstract
Plant pathogenic Pseudomonas species use multiple classes of toxins and virulence factors during host infection. The genes encoding these pathogenicity factors are often located on plasmids and other mobile genetic elements, suggesting that they are acquired through horizontal gene transfer to confer an evolutionary advantage for successful adaptation to host infection. However, the genetic rearrangements that have led to mobilization of the pathogenicity genes are not fully understood. In this study, we have sequenced and analyzed the complete genome sequences of four Pseudomonas amygdali pv. aesculi (Pae), which infect European horse chestnut trees (Aesculus hippocastanum) and belong to phylogroup 3 of the P. syringae species complex. The four investigated genomes contain six groups of plasmids that all encode pathogenicity factors. Effector genes were found to be mostly associated with insertion sequence elements, suggesting that virulence genes are generally mobilized and potentially undergo horizontal gene transfer after transfer to a conjugative plasmid. We show that the biosynthetic gene cluster encoding the phytotoxin coronatine was recently transferred from a chromosomal location to a mobilizable plasmid that subsequently formed a co-integrate with a conjugative plasmid.
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Affiliation(s)
- Tue Kjærgaard Nielsen
- Department of Plant and Environmental Sciences, University of Copenhagen, 1871 Frederiksberg C, Denmark
| | - Caroline S Winther-Have
- Department of Plant and Environmental Sciences, University of Copenhagen, 1871 Frederiksberg C, Denmark; Globe Institute, University of Copenhagen, 1350 Copenhagen, Denmark
| | - Iben Margrete Thomsen
- Department of Geosciences and Natural Resource Management, University of Copenhagen, 1958 Frederiksberg C, Denmark
| | - Robert W Jackson
- School of Biosciences and the Birmingham Institute of Forest Research, University of Birmingham, Birmingham B15 2TT, United Kingdom
| | - Mojgan Rabiey
- School of Biosciences and the Birmingham Institute of Forest Research, University of Birmingham, Birmingham B15 2TT, United Kingdom
| | | | - Frederik Bak
- Department of Plant and Environmental Sciences, University of Copenhagen, 1871 Frederiksberg C, Denmark
| | - Witold Kot
- Department of Plant and Environmental Sciences, University of Copenhagen, 1871 Frederiksberg C, Denmark
| | - Mette Haubjerg Nicolaisen
- Department of Plant and Environmental Sciences, University of Copenhagen, 1871 Frederiksberg C, Denmark
| | - Alexander Byth Carstens
- Department of Plant and Environmental Sciences, University of Copenhagen, 1871 Frederiksberg C, Denmark
| | - Lars Hestbjerg Hansen
- Department of Plant and Environmental Sciences, University of Copenhagen, 1871 Frederiksberg C, Denmark.
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19
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Fautt C, Hockett KL, Couradeau E. Evaluation of the taxonomic accuracy and pathogenicity prediction power of 16 primer sets amplifying single copy marker genes in the Pseudomonas syringae species complex. MOLECULAR PLANT PATHOLOGY 2023; 24:989-998. [PMID: 37132320 PMCID: PMC10346468 DOI: 10.1111/mpp.13337] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 02/24/2023] [Accepted: 03/23/2023] [Indexed: 05/04/2023]
Abstract
The Pseudomonas syringae species complex is composed of several closely related species of bacterial plant pathogens. Here, we used in silico methods to assess 16 PCR primer sets designed for broad identification of isolates throughout the species complex. We evaluated their in silico amplification rate in 2161 publicly available genomes, the correlation between pairwise amplicon sequence distance and whole genome average nucleotide identity, and trained naive Bayes classification models to quantify classification resolution. Furthermore, we show the potential for using single amplicon sequence data to predict type III effector protein repertoires, which are important determinants of host specificity and range.
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Affiliation(s)
- Chad Fautt
- Department of Plant Pathology and Environmental MicrobiologyPennsylvania State UniversityUniversity ParkPennsylvaniaUSA
- Department of Ecosystem Science and ManagementPennsylvania State UniversityUniversity ParkPennsylvaniaUSA
- Intercollege Graduate Degree Program in EcologyPennsylvania State UniversityUniversity ParkPennsylvaniaUSA
| | - Kevin L. Hockett
- Department of Plant Pathology and Environmental MicrobiologyPennsylvania State UniversityUniversity ParkPennsylvaniaUSA
- Intercollege Graduate Degree Program in EcologyPennsylvania State UniversityUniversity ParkPennsylvaniaUSA
| | - Estelle Couradeau
- Department of Ecosystem Science and ManagementPennsylvania State UniversityUniversity ParkPennsylvaniaUSA
- Intercollege Graduate Degree Program in EcologyPennsylvania State UniversityUniversity ParkPennsylvaniaUSA
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20
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Nikolić I, Glatter T, Ranković T, Berić T, Stanković S, Diepold A. Repertoire and abundance of secreted virulence factors shape the pathogenic capacity of Pseudomonas syringae pv. aptata. Front Microbiol 2023; 14:1205257. [PMID: 37383635 PMCID: PMC10294431 DOI: 10.3389/fmicb.2023.1205257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Accepted: 05/23/2023] [Indexed: 06/30/2023] Open
Abstract
Pseudomonas syringae pv. aptata is a member of the sugar beet pathobiome and the causative agent of leaf spot disease. Like many pathogenic bacteria, P. syringae relies on the secretion of toxins, which manipulate host-pathogen interactions, to establish and maintain an infection. This study analyzes the secretome of six pathogenic P. syringae pv. aptata strains with different defined virulence capacities in order to identify common and strain-specific features, and correlate the secretome with disease outcome. All strains show a high type III secretion system (T3SS) and type VI secretion system (T6SS) activity under apoplast-like conditions mimicking the infection. Surprisingly, we found that low pathogenic strains show a higher secretion of most T3SS substrates, whereas a distinct subgroup of four effectors was exclusively secreted in medium and high pathogenic strains. Similarly, we detected two T6SS secretion patterns: while one set of proteins was highly secreted in all strains, another subset consisting of known T6SS substrates and previously uncharacterized proteins was exclusively secreted in medium and high virulence strains. Taken together, our data show that P. syringae pathogenicity is correlated with the repertoire and fine-tuning of effector secretion and indicate distinct strategies for establishing virulence of P. syringae pv. aptata in plants.
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Affiliation(s)
- Ivan Nikolić
- Department of Ecophysiology, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
- Faculty of Biology, University of Belgrade, Belgrade, Serbia
| | - Timo Glatter
- Core Facility for Mass spectrometry and Proteomics, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Tamara Ranković
- Faculty of Biology, University of Belgrade, Belgrade, Serbia
| | - Tanja Berić
- Faculty of Biology, University of Belgrade, Belgrade, Serbia
| | | | - Andreas Diepold
- Department of Ecophysiology, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
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21
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Pintado A, Domínguez-Cerván H, Pastor V, Vincent M, Lee SG, Flors V, Ramos C. Allelic variation in the indoleacetic acid-lysine synthase gene of the bacterial pathogen Pseudomonas savastanoi and its role in auxin production. FRONTIERS IN PLANT SCIENCE 2023; 14:1176705. [PMID: 37346122 PMCID: PMC10280071 DOI: 10.3389/fpls.2023.1176705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 05/23/2023] [Indexed: 06/23/2023]
Abstract
Indole-3-acetic acid (IAA) production is a pathogenicity/virulence factor in the Pseudomonas syringae complex, including Pseudomonas savastanoi. P. savastanoi pathovars (pvs.) genomes contain the iaaL gene, encoding an enzyme that catalyzes the biosynthesis of the less biologically active compound 3-indole-acetyl-ϵ-L-lysine (IAA-Lys). Previous studies have reported the identification of IAA-Lys in culture filtrates of P. savastanoi strains isolated from oleander (pv. nerii), but the conversion of IAA into a conjugate was not detectable in olive strains (pv. savastanoi). In this paper, we show the distribution of iaaL alleles in all available P. savastanoi genomes of strains isolated from woody hosts. Most strains encode two different paralogs, except for those isolated from broom (pv. retacarpa), which contain a single allele. In addition to the three previously reported iaaL alleles (iaaL Psv, iaaL Psn and iaaL Pto), we identified iaaL Psf, an exclusive allele of strains isolated from ash (pv. fraxini). We also found that the production of IAA-Lys in P. savastanoi pv. savastanoi and pv. nerii depends on a functional iaaL Psn allele, whereas in pv. fraxini depends on iaaL Psf. The production of IAA-Lys was detected in cultures of an olive strain heterologously expressing IaaLPsn-1, IaaLPsf-1 and IaaLPsf-3, but not when expressing IaaLPsv-1. In addition, Arabidopsis seedlings treated with the strains overproducing the conjugate, and thus reducing the free IAA content, alleviated the root elongation inhibitory effect of IAA. IAA-Lys synthase activity assays with purified allozymes confirmed the functionality and specificity of lysine as a substrate of IaaLPsn-1 and IaaLPsf-3, with IaaLPsf-3 showing the highest catalytic efficiency for both substrates. The IAA-Lys synthase activity of IaaLPsn-1 was abolished by the insertion of two additional tyrosine residues encoded in the inactive allozyme IaaLPsv-1. These results highlight the relevance of allelic variation in a phytohormone-related gene for the modulation of auxin production in a bacterial phytopathogen.
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Affiliation(s)
- Adrián Pintado
- Área de Genética, Facultad de Ciencias, Universidad de Málaga (UMA), Málaga, Spain
- Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Málaga, Spain
| | - Hilario Domínguez-Cerván
- Área de Genética, Facultad de Ciencias, Universidad de Málaga (UMA), Málaga, Spain
- Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Málaga, Spain
| | - Victoria Pastor
- Department of Biology, Biochemistry and Natural Sciences, Universitat Jaume I (UJI), Castelló de la Plana, Spain
| | - Marissa Vincent
- Department of Chemistry and Biochemistry, University of North Carolina Wilmington, Wilmington, NC, United States
| | - Soon Goo Lee
- Department of Molecular and Cellular Biology, Kennesaw State University, Kennesaw, GA, United States
| | - Víctor Flors
- Department of Biology, Biochemistry and Natural Sciences, Universitat Jaume I (UJI), Castelló de la Plana, Spain
| | - Cayo Ramos
- Área de Genética, Facultad de Ciencias, Universidad de Málaga (UMA), Málaga, Spain
- Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Málaga, Spain
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22
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Cooperative virulence via the collective action of secreted pathogen effectors. Nat Microbiol 2023; 8:640-650. [PMID: 36782026 DOI: 10.1038/s41564-023-01328-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Accepted: 01/13/2023] [Indexed: 02/15/2023]
Abstract
Although virulence is typically attributed to single pathogenic strains, here we investigated whether effectors secreted by a population of non-virulent strains could function as public goods to enable the emergence of collective virulence. We disaggregated the 36 type III effectors of the phytopathogenic bacterium Pseudomonas syringae strain PtoDC3000 into a 'metaclone' of 36 coisogenic strains, each carrying a single effector in an effectorless background. Each coisogenic strain was individually unfit, but the metaclone was collectively as virulent as the wild-type strain on Arabidopsis thaliana, suggesting that effectors can drive the emergence of cooperation-based virulence through their public action. We show that independently evolved effector suits can equally drive this cooperative behaviour by transferring the effector alleles native to the strain PmaES4326 into the conspecific but divergent strain PtoDC3000. Finally, we transferred the disaggregated PtoDC3000 effector arsenal into Pseudomonas fluorescens and show that their cooperative action was sufficient to convert this rhizosphere-inhabiting beneficial bacterium into a phyllosphere pathogen. These results emphasize the importance of microbial community interactions and expand the ecological scale at which disease may be attributed.
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23
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Pseudomonas aeruginosa and Staphylococcus aureus Display Differential Proteomic Responses to the Silver(I) Compound, SBC3. Antibiotics (Basel) 2023; 12:antibiotics12020348. [PMID: 36830259 PMCID: PMC9952281 DOI: 10.3390/antibiotics12020348] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 01/27/2023] [Accepted: 02/03/2023] [Indexed: 02/10/2023] Open
Abstract
The urgent need to combat antibiotic resistance and develop novel antimicrobial therapies has triggered studies on novel metal-based formulations. N-heterocyclic carbene (NHC) complexes coordinate transition metals to generate a broad range of anticancer and/or antimicrobial agents, with ongoing efforts being made to enhance the lipophilicity and drug stability. The lead silver(I) acetate complex, 1,3-dibenzyl-4,5-diphenylimidazol-2-ylidene (NHC*) (SBC3), has previously demonstrated promising growth and biofilm-inhibiting properties. In this work, the responses of two structurally different bacteria to SBC3 using label-free quantitative proteomics were characterised. Multidrug-resistant Pseudomonas aeruginosa (Gram-negative) and Staphylococcus aureus (Gram-positive) are associated with cystic fibrosis lung colonisation and chronic wound infections, respectively. SBC3 increased the abundance of alginate biosynthesis, the secretion system and drug detoxification proteins in P. aeruginosa, whilst a variety of pathways, including anaerobic respiration, twitching motility and ABC transport, were decreased in abundance. This contrasted the affected pathways in S. aureus, where increased DNA replication/repair and cell redox homeostasis and decreased protein synthesis, lipoylation and glucose metabolism were observed. Increased abundance of cell wall/membrane proteins was indicative of the structural damage induced by SBC3 in both bacteria. These findings show the potential broad applications of SBC3 in treating Gram-positive and Gram-negative bacteria.
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24
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Puttilli MR, Danzi D, Correia C, Brandi J, Cecconi D, Manfredi M, Marengo E, Santos C, Spinelli F, Polverari A, Vandelle E. Plant Signals Anticipate the Induction of the Type III Secretion System in Pseudomonas syringae pv. actinidiae, Facilitating Efficient Temperature-Dependent Effector Translocation. Microbiol Spectr 2022; 10:e0207322. [PMID: 36287008 PMCID: PMC9770001 DOI: 10.1128/spectrum.02073-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2022] [Accepted: 09/15/2022] [Indexed: 01/06/2023] Open
Abstract
Disease resistance in plants depends on a molecular dialogue with microbes that involves many known chemical effectors, but the time course of the interaction and the influence of the environment are largely unknown. The outcome of host-pathogen interactions is thought to reflect the offensive and defensive capabilities of both players. When plants interact with Pseudomonas syringae, several well-characterized virulence factors contribute to early bacterial pathogenicity, including the type III secretion system (T3SS), which must be activated by signals from the plant and environment to allow the secretion of virulence effectors. The manner in which these signals regulate T3SS activity is still unclear. Here, we strengthen the paradigm of the plant-pathogen molecular dialogue by addressing overlooked details concerning the timing of interactions, specifically the role of plant signals and temperature on the regulation of bacterial virulence during the first few hours of the interaction. Whole-genome expression profiling after 1 h revealed that the perception of plant signals from kiwifruit or tomato extracts anticipated T3SS expression in P. syringae pv. actinidiae compared to apoplast-like conditions, facilitating more efficient effector transport in planta, as revealed by the induction of a temperature-dependent hypersensitive response in the nonhost plant Arabidopsis thaliana Columbia-0 (Col-0). Our results show that in the arms race between plants and bacteria, the temperature-dependent timing of bacterial virulence versus the induction of plant defenses is probably one of the fundamental parameters governing the outcome of the interaction. IMPORTANCE Plant diseases-their occurrence and severity-result from the impact of three factors: the host, the pathogen, and the environmental conditions, interconnected in the disease triangle. Time was further included as a fourth factor accounting for plant disease, leading to a more realistic three-dimensional disease pyramid to represent the evolution of disease over time. However, this representation still considers time only as a parameter determining when and to what extent a disease will occur, at a scale from days to months. Here, we show that time is a factor regulating the arms race between plants and pathogens, at a scale from minutes to hours, and strictly depends on environmental factors. Thus, besides the arms possessed by pathogens and plants per se, the opportunity and the timing of arms mobilization make the difference in determining the outcome of an interaction and thus the occurrence of plant disease.
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Affiliation(s)
| | - Davide Danzi
- Department of Biotechnology, University of Verona, Verona, Italy
| | - Cristiana Correia
- Department of Biotechnology, University of Verona, Verona, Italy
- Department of Biology, LAQV-REQUIMTE, Faculty of Sciences, University of Porto, Porto, Portugal
- Department of Agricultural Sciences, Alma Mater Studiorum University of Bologna, Bologna, Italy
| | - Jessica Brandi
- Department of Biotechnology, University of Verona, Verona, Italy
| | - Daniela Cecconi
- Department of Biotechnology, University of Verona, Verona, Italy
| | - Marcello Manfredi
- Department of Translational Medicine, Center for Translational Research on Autoimmune & Allergic Diseases (CAAD), University of Piemonte Orientale, Novara, Italy
| | - Emilio Marengo
- Department of Science and Technological Innovation, University of Piemonte Orientale, Alessandria, Italy
| | - Conceição Santos
- Department of Biology, LAQV-REQUIMTE, Faculty of Sciences, University of Porto, Porto, Portugal
| | - Francesco Spinelli
- Department of Agricultural Sciences, Alma Mater Studiorum University of Bologna, Bologna, Italy
| | | | - Elodie Vandelle
- Department of Biotechnology, University of Verona, Verona, Italy
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25
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Gutiérrez-Barranquero JA, Heredia-Ponce Z, Aguilera-Cobos L, Pintado A, Claros MG, Ramos C, Cazorla FM, de Vicente A. The Genomic Landscape Resource of Pseudomonas syringae pv. syringae Strains Isolated from Mango Trees. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2022; 35:1109-1114. [PMID: 36508485 DOI: 10.1094/mpmi-05-22-0107-a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Affiliation(s)
- José A Gutiérrez-Barranquero
- Instituto de Hortofruticultura Subtropical y Mediterránea La Mayora (IHSM-UMA-CSIC)
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain
| | - Zaira Heredia-Ponce
- Instituto de Hortofruticultura Subtropical y Mediterránea La Mayora (IHSM-UMA-CSIC)
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain
| | | | - Adrián Pintado
- Instituto de Hortofruticultura Subtropical y Mediterránea La Mayora (IHSM-UMA-CSIC)
- Departamento de Biología Celular, Genética y Fisiología, Área de Genética, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain
| | - M Gonzalo Claros
- Instituto de Hortofruticultura Subtropical y Mediterránea La Mayora (IHSM-UMA-CSIC)
- Plataforma Andaluza de Bioinformática-SCBI, Universidad de Málaga, Málaga, Spain
- Departamento de Biología Molecular y Bioquímica, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain
| | - Cayo Ramos
- Instituto de Hortofruticultura Subtropical y Mediterránea La Mayora (IHSM-UMA-CSIC)
- Departamento de Biología Celular, Genética y Fisiología, Área de Genética, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain
| | - Francisco M Cazorla
- Instituto de Hortofruticultura Subtropical y Mediterránea La Mayora (IHSM-UMA-CSIC)
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain
| | - Antonio de Vicente
- Instituto de Hortofruticultura Subtropical y Mediterránea La Mayora (IHSM-UMA-CSIC)
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain
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26
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Djitro N, Roach R, Mann R, Campbell PR, Rodoni B, Gambley C. Comparative genomics and genomic diversity of Pseudomonas syringae clade 2b-a in Australia. BMC Microbiol 2022; 22:278. [PMID: 36411421 PMCID: PMC9677677 DOI: 10.1186/s12866-022-02678-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Accepted: 10/21/2022] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND A zucchini disease outbreak with unusual symptoms associated with Pseudomonas syringae clade 2b was identified in Bundaberg, Australia during autumn 2016. To investigate the genetic diversity of the 11 Australian isolates obtained from the outbreak, the genomes were compared to the publicly available P. syringae strains in phylogroup 2. RESULTS Average nucleotide identity refined the P. syringae clade 2b-a into four clusters (Cluster A, B, C1 and C2), an expansion from the previously identified A, B and C. Australian isolates were in Cluster A, C1 and C2. Genomic analyses highlighted several key factors that may contribute to the virulence of these isolates. Six orthologous groups, including three virulence factors, were associated with P. syringae phylogroup 2 cucurbit-infecting strains. A region of genome plasticity analysis identified a type VI secretion system pathway in clade 2b-a strains which could also contribute to virulence. Pathogenicity assays on isolates KL004-k1, KFR003-1 and 77-4C, as representative isolates of Cluster A, C1 and C2, respectively, determined that all three isolates can infect pumpkin, squash, watermelon and zucchini var. Eva with different levels of disease severity. Subsequently, type III effectors were investigated and four type III effectors (avrRpt2, hopZ5, hopC1 and hopH1) were associated with host range. The hopZ effector family was also predicted to be associated with disease severity. CONCLUSIONS This study refined the taxonomy of the P. syringae clade 2b-a, supported the association between effector profile and pathogenicity in cucurbits established in a previous study and provides new insight into important genomic features of these strains. This study also provided a detailed and comprehensive resource for future genomic and functional studies of these strains.
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Affiliation(s)
- Noel Djitro
- grid.1018.80000 0001 2342 0938School of Applied Systems Biology, La Trobe University, Bundoora, VIC Australia
| | - Rebecca Roach
- grid.492998.70000 0001 0729 4564Department of Agriculture and Fisheries, Ecosciences Precinct, Dutton Park, Australia
| | - Rachel Mann
- grid.511012.60000 0001 0744 2459Agriculture Victoria Research, Department of Jobs, Precincts and Regions, AgriBio, Bundoora, Australia
| | - Paul R. Campbell
- grid.492998.70000 0001 0729 4564Department of Agriculture and Fisheries, Ecosciences Precinct, Dutton Park, Australia
| | - Brendan Rodoni
- grid.511012.60000 0001 0744 2459Agriculture Victoria Research, Department of Jobs, Precincts and Regions, AgriBio, Bundoora, Australia
| | - Cherie Gambley
- Department of Agriculture and Fisheries, Maroochy Research Facility, Nambour, Australia
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27
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Suraby EJ, Sruthi KB, Antony G. Genome-wide identification of type III effectors and other virulence factors in Ralstonia pseudosolanacearum causing bacterial wilt in ginger (Zingiber officinale). Mol Genet Genomics 2022; 297:1371-1388. [PMID: 35879566 DOI: 10.1007/s00438-022-01925-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Accepted: 07/04/2022] [Indexed: 10/16/2022]
Abstract
Ralstonia pseudosolanacearum causes bacterial wilt in ginger, reducing ginger production worldwide. We sequenced the whole genome of a highly virulent phylotype I, race 4, biovar 3 Ralstonia pseudosolanacearum strain GRsMep isolated from a severely infected ginger field in India. R. pseudosolanacearum GRsMep genome is organised into two replicons: chromosome and megaplasmid with a total genome size of 5,810,605 bp. This strain encodes approximately 72 effectors which include a combination of core effectors as well as highly variable, diverse repertoire of type III effectors. Comparative genome analysis with GMI1000 identified conservation in the genes involved in the general virulence mechanism. Our analysis identified type III effectors, RipBJ and RipBO as present in GRsMep but absent in the reported genomes of other strains infecting Zingiberaceae family. GRsMep contains 126 unique genes when compared to the pangenome of the Ralstonia strains that infect the Zingiberaceae family. The whole-genome data of R. pseudosolanacearum strain will serve as a resource for exploring the evolutionary processes that structure and regulate the virulence determinants of the strain. Pathogenicity testing of the transposon insertional mutant library of GRsMep through virulence assay on ginger plants identified a few candidate virulence determinants specific to bacterial wilt in ginger.
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Affiliation(s)
- Erinjery Jose Suraby
- Department of Plant Science, Central University of Kerala, Periye, 671320, Kasaragod, Kerala, India
| | - K Bharathan Sruthi
- Department of Plant Science, Central University of Kerala, Periye, 671320, Kasaragod, Kerala, India
| | - Ginny Antony
- Department of Plant Science, Central University of Kerala, Periye, 671320, Kasaragod, Kerala, India.
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28
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Bundalovic-Torma C, Lonjon F, Desveaux D, Guttman DS. Diversity, Evolution, and Function of Pseudomonas syringae Effectoromes. ANNUAL REVIEW OF PHYTOPATHOLOGY 2022; 60:211-236. [PMID: 35537470 DOI: 10.1146/annurev-phyto-021621-121935] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Pseudomonas syringae is an evolutionarily diverse bacterial species complex and a preeminent model for the study of plant-pathogen interactions due in part to its remarkably broad host range. A critical feature of P. syringae virulence is the employment of suites of type III secreted effector (T3SE) proteins, which vary widely in composition and function. These effectors act on a variety of plant intracellular targets to promote pathogenesis but can also be avirulence factors when detected by host immune complexes. In this review, we survey the phylogenetic diversity (PD) of the P. syringae effectorome, comprising 70 distinct T3SE families identified to date, and highlight how avoidance of host immune detection has shaped effectorome diversity through functional redundancy, diversification, and horizontal transfer. We present emerging avenues for research and novel insights that can be gained via future investigations of plant-pathogen interactions through the fusion of large-scale interaction screens and phylogenomic approaches.
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Affiliation(s)
| | - Fabien Lonjon
- Department of Cell & Systems Biology, University of Toronto, Toronto, Ontario, Canada; ,
| | - Darrell Desveaux
- Department of Cell & Systems Biology, University of Toronto, Toronto, Ontario, Canada; ,
- Centre for the Analysis of Genome Evolution & Function, University of Toronto, Toronto, Ontario, Canada
| | - David S Guttman
- Department of Cell & Systems Biology, University of Toronto, Toronto, Ontario, Canada; ,
- Centre for the Analysis of Genome Evolution & Function, University of Toronto, Toronto, Ontario, Canada
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29
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Pseudomonas ST1 and Pantoea Paga Strains Cohabit in Olive Knots. Microorganisms 2022; 10:microorganisms10081529. [PMID: 36013947 PMCID: PMC9414602 DOI: 10.3390/microorganisms10081529] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 07/22/2022] [Accepted: 07/25/2022] [Indexed: 11/24/2022] Open
Abstract
Two bacteria belonging to the Pseudomonas and Pantoea genera were isolated from olive knots. Both bacterial strains were omnipresent in this study’s olive orchard with high susceptibility of the autochthonous olive genotypes indicating coevolution of bacteria with host plants. Genomes of two endemic bacteria show conserved core genomes and genome plasticity. The Pseudomonas ST1 genome has conserved virulence-related genes including genes for quorum sensing, pilus, and flagella biosynthesis, two copies of indole acetic acid biosynthesis (IAA) operons, type I-VI secretions systems, and genes for alginate and levan biosynthesis. Development of knots depends only on the presence of the Pseudomonas ST1 strain which then allows Pantoea paga strain co-infection and cohabitation in developed knots. The two bacteria are sensitive to a large number of antimicrobials, antibiotics, H2O2, and Cu (II) salts that can be efficiently used in propagation of bacterial free olive cultivars.
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30
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Almeida RND, Greenberg M, Bundalovic-Torma C, Martel A, Wang PW, Middleton MA, Chatterton S, Desveaux D, Guttman DS. Predictive modeling of Pseudomonas syringae virulence on bean using gradient boosted decision trees. PLoS Pathog 2022; 18:e1010716. [PMID: 35877772 PMCID: PMC9352200 DOI: 10.1371/journal.ppat.1010716] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 08/04/2022] [Accepted: 06/30/2022] [Indexed: 11/18/2022] Open
Abstract
Pseudomonas syringae is a genetically diverse bacterial species complex responsible for numerous agronomically important crop diseases. Individual P. syringae isolates are assigned pathovar designations based on their host of isolation and the associated disease symptoms, and these pathovar designations are often assumed to reflect host specificity although this assumption has rarely been rigorously tested. Here we developed a rapid seed infection assay to measure the virulence of 121 diverse P. syringae isolates on common bean (Phaseolus vulgaris). This collection includes P. syringae phylogroup 2 (PG2) bean isolates (pathovar syringae) that cause bacterial spot disease and P. syringae phylogroup 3 (PG3) bean isolates (pathovar phaseolicola) that cause the more serious halo blight disease. We found that bean isolates in general were significantly more virulent on bean than non-bean isolates and observed no significant virulence difference between the PG2 and PG3 bean isolates. However, when we compared virulence within PGs we found that PG3 bean isolates were significantly more virulent than PG3 non-bean isolates, while there was no significant difference in virulence between PG2 bean and non-bean isolates. These results indicate that PG3 strains have a higher level of host specificity than PG2 strains. We then used gradient boosting machine learning to predict each strain’s virulence on bean based on whole genome k-mers, type III secreted effector k-mers, and the presence/absence of type III effectors and phytotoxins. Our model performed best using whole genome data and was able to predict virulence with high accuracy (mean absolute error = 0.05). Finally, we functionally validated the model by predicting virulence for 16 strains and found that 15 (94%) had virulence levels within the bounds of estimated predictions. This study strengthens the hypothesis that P. syringae PG2 strains have evolved a different lifestyle than other P. syringae strains as reflected in their lower level of host specificity. It also acts as a proof-of-principle to demonstrate the power of machine learning for predicting host specific adaptation. Pseudomonas syringae is a genetically diverse Gammaproteobacterial species complex responsible for numerous agronomically important crop diseases. Strains in the P. syringae species complex are frequently categorized into pathovars depending on pathogenic characteristics such as host of isolation and disease symptoms. Common bean pathogens from P. syringae are known to cause two major diseases: (1) pathovar phaseolicola strains from phylogroup 3 cause halo blight disease, characterized by large necrotic lesions surrounded by a chlorotic zone or halo of yellow tissue; and (2) pathovar syringae strains from phylogroup 2 causes bacterial spot disease, characterized by brown leaf spots. While halo blight can cause serious crop losses, bacterial spot disease is generally of minor agronomic concern. Recently, statistical genetic and machine learning approaches have been applied to genomic data to identify genes underlying traits of interest or predict the outcome of host-microbe interactions. Here, we apply machine learning to P. syringae genomic data to predict virulence on bean. We first characterized the virulence of P. syringae isolates on common bean using a seed infection assay and then applied machine learning to the genomic data from the same strains to generate a predictive model for virulence on bean. We found that machine learning models built with k-mers from either full genome data or virulence factors could predict bean virulence with high accuracy. We also confirmed prior work showing that phylogroup 3 halo blight pathogens display a stronger degree of phylogenetic clustering and host specificity compared to phylogroup 2 brown spot pathogens. This works serves as a proof-of-principle for the power of machine learning for predicting host specificity and may find utility in agricultural diagnostic microbiology.
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Affiliation(s)
- Renan N. D. Almeida
- Department of Cell & Systems Biology, University of Toronto, Toronto, Canada
| | - Michael Greenberg
- Department of Cell & Systems Biology, University of Toronto, Toronto, Canada
| | | | - Alexandre Martel
- Department of Cell & Systems Biology, University of Toronto, Toronto, Canada
| | - Pauline W. Wang
- Department of Cell & Systems Biology, University of Toronto, Toronto, Canada
- Centre for the Analysis of Genome Evolution & Function, University of Toronto, Toronto, Canada
| | - Maggie A. Middleton
- Department of Cell & Systems Biology, University of Toronto, Toronto, Canada
- Centre for the Analysis of Genome Evolution & Function, University of Toronto, Toronto, Canada
| | - Syama Chatterton
- Agriculture and Agri-Food Canada, Lethbridge Research and Development Centre, Lethbridge, Canada
| | - Darrell Desveaux
- Department of Cell & Systems Biology, University of Toronto, Toronto, Canada
| | - David S. Guttman
- Department of Cell & Systems Biology, University of Toronto, Toronto, Canada
- Centre for the Analysis of Genome Evolution & Function, University of Toronto, Toronto, Canada
- * E-mail:
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31
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Kotsaridis K, Tsakiri D, Sarris PF. Understanding enemy's weapons to an effective prevention: common virulence effects across microbial phytopathogens kingdoms. Crit Rev Microbiol 2022:1-15. [PMID: 35709325 DOI: 10.1080/1040841x.2022.2083939] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Plant-pathogens interaction is an ongoing confrontation leading to the emergence of new diseases. The majority of the invading microorganisms inject effector proteins into the host cell, to bypass the sophisticated defense system of the host. However, the effectors could also have other specialized functions, which can disrupt various biological pathways of the host cell. Pathogens can enrich their effectors arsenal to increase infection success or expand their host range. This usually is accomplished by the horizontal gene transfer. Nowadays, the development of specialized software that can predict proteins structure, has changed the experimental designing in effectors' function research. Different effectors of distinct plant pathogens tend to fold alike and have the same function and focussed structural studies on microbial effectors can help to uncover their catalytic/functional activities, while the structural similarity can enable cataloguing the great number of pathogens' effectors. In this review, we collectively present phytopathogens' effectors with known enzymatic functions and proteins structure, originated from all the kingdoms of microbial plant pathogens. Presentation of their common domains and motifs is also included. We believe that the in-depth understanding of the enemy's weapons will help the development of new strategies to prevent newly emerging or re-emerging plant pathogens.
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Affiliation(s)
| | | | - Panagiotis F Sarris
- Department of Biology, University of Crete, Crete, Greece.,Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Crete, Greece.,Biosciences, University of Exeter, Exeter, UK
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Kashihara S, Nishimura T, Noutoshi Y, Yamamoto M, Toyoda K, Ichinose Y, Matsui H. HopAZ1, a type III effector of Pseudomonas amygdali pv. tabaci, induces a hypersensitive response in tobacco wildfire-resistant Nicotiana tabacum 'N509'. MOLECULAR PLANT PATHOLOGY 2022; 23:885-894. [PMID: 35233886 PMCID: PMC9104263 DOI: 10.1111/mpp.13198] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 01/31/2022] [Accepted: 02/07/2022] [Indexed: 05/27/2023]
Abstract
Pseudomonas amygdali pv. tabaci (formerly Pseudomonas syringae pv. tabaci; Pta) is a gram-negative bacterium that causes bacterial wildfire disease in Nicotiana tabacum. The pathogen establishes infections by using a type III secretion system to inject type III effector proteins (T3Es) into cells, thereby interfering with the host__s immune system. To counteract the effectors, plants have evolved disease-resistance genes and mechanisms to induce strong resistance on effector recognition. By screening a series of Pta T3E-deficient mutants, we have identified HopAZ1 as the T3E that induces disease resistance in N. tabacum 'N509'. Inoculation with the Pta ∆hopAZ1 mutant did not induce resistance to Pta in N509. We also found that the Pta ∆hopAZ1 mutant did not induce a hypersensitive response and promoted severe disease symptoms in N509. Furthermore, a C-terminal truncated HopAZ1 abolished HopAZ1-dependent cell death in N509. These results indicate that HopAZ1 is the avirulence factor that induces resistance to Pta by N509.
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Affiliation(s)
- Sachi Kashihara
- Graduate School of Environmental and Life ScienceOkayama UniversityOkayamaJapan
| | - Takafumi Nishimura
- Graduate School of Environmental and Life ScienceOkayama UniversityOkayamaJapan
| | - Yoshiteru Noutoshi
- Graduate School of Environmental and Life ScienceOkayama UniversityOkayamaJapan
| | - Mikihiro Yamamoto
- Graduate School of Environmental and Life ScienceOkayama UniversityOkayamaJapan
| | - Kazuhiro Toyoda
- Graduate School of Environmental and Life ScienceOkayama UniversityOkayamaJapan
| | - Yuki Ichinose
- Graduate School of Environmental and Life ScienceOkayama UniversityOkayamaJapan
| | - Hidenori Matsui
- Graduate School of Environmental and Life ScienceOkayama UniversityOkayamaJapan
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33
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Hemara LM, Jayaraman J, Sutherland PW, Montefiori M, Arshed S, Chatterjee A, Chen R, Andersen MT, Mesarich CH, van der Linden O, Yoon M, Schipper MM, Vanneste JL, Brendolise C, Templeton MD. Effector loss drives adaptation of Pseudomonas syringae pv. actinidiae biovar 3 to Actinidia arguta. PLoS Pathog 2022; 18:e1010542. [PMID: 35622878 PMCID: PMC9182610 DOI: 10.1371/journal.ppat.1010542] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 06/09/2022] [Accepted: 04/21/2022] [Indexed: 11/18/2022] Open
Abstract
A pandemic isolate of Pseudomonas syringae pv. actinidiae biovar 3 (Psa3) has devastated kiwifruit orchards growing cultivars of Actinidia chinensis. In contrast, A. arguta (kiwiberry) is not a host of Psa3. Resistance is mediated via effector-triggered immunity, as demonstrated by induction of the hypersensitive response in infected A. arguta leaves, observed by microscopy and quantified by ion-leakage assays. Isolates of Psa3 that cause disease in A. arguta have been isolated and analyzed, revealing a 51 kb deletion in the exchangeable effector locus (EEL). This natural EEL-mutant isolate and strains with synthetic knockouts of the EEL were more virulent in A. arguta plantlets than wild-type Psa3. Screening of a complete library of Psa3 effector knockout strains identified increased growth in planta for knockouts of four effectors–AvrRpm1a, HopF1c, HopZ5a, and the EEL effector HopAW1a –suggesting a resistance response in A. arguta. Hypersensitive response (HR) assays indicate that three of these effectors trigger a host species-specific HR. A Psa3 strain with all four effectors knocked out escaped host recognition, but a cumulative increase in bacterial pathogenicity and virulence was not observed. These avirulence effectors can be used in turn to identify the first cognate resistance genes in Actinidia for breeding durable resistance into future kiwifruit cultivars. Clonally propagated monoculture crop plants facilitate the emergence and spread of new diseases. Plant pathogens cause disease by the secretion of effectors that function by repressing the host defense response. While the last few decades have seen a huge increase in our understanding of the role effectors play in mediating plant-pathogen interactions, the combinations of effectors required for the establishment of plant disease and that account for host specificity are less well understood. Breeding genetic resistance is often used to protect plants from disease but it is frequently evaded by rapidly evolving pathogens. Pseudomonas syringae pv. actinidiae (Psa) which causes bacterial canker disease of kiwifruit has spread rapidly throughout the world’s kiwifruit orchards, particularly those growing cultivars of Actinidia chinensis. Other Actinidia species including A. arguta display strong resistance conferred by recognition of effectors delivered by Psa. We explore the depth and dynamics of Psa effector recognition by A. arguta and show that there is a trade-off between losses of effector recognition by A. arguta versus the retention of pathogenicity. Our findings should aid in the understanding of how to breed durable resistance into perennial plants challenged by swiftly evolving pathogens.
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Affiliation(s)
- Lauren M. Hemara
- The New Zealand Institute for Plant and Food Research Limited, Mt. Albert Research Centre, Auckland, New Zealand
- School of Biological Sciences, University of Auckland, Auckland, New Zealand
- Bioprotection Aoteoroa, New Zealand
| | - Jay Jayaraman
- The New Zealand Institute for Plant and Food Research Limited, Mt. Albert Research Centre, Auckland, New Zealand
- Bioprotection Aoteoroa, New Zealand
| | - Paul W. Sutherland
- The New Zealand Institute for Plant and Food Research Limited, Mt. Albert Research Centre, Auckland, New Zealand
| | - Mirco Montefiori
- The New Zealand Institute for Plant and Food Research Limited, Mt. Albert Research Centre, Auckland, New Zealand
| | - Saadiah Arshed
- The New Zealand Institute for Plant and Food Research Limited, Mt. Albert Research Centre, Auckland, New Zealand
| | - Abhishek Chatterjee
- The New Zealand Institute for Plant and Food Research Limited, Mt. Albert Research Centre, Auckland, New Zealand
| | - Ronan Chen
- The New Zealand Institute for Plant and Food Research Limited, Food Industry Science Centre, Palmerston North, New Zealand
| | - Mark T. Andersen
- The New Zealand Institute for Plant and Food Research Limited, Mt. Albert Research Centre, Auckland, New Zealand
| | - Carl H. Mesarich
- Bioprotection Aoteoroa, New Zealand
- School of Agriculture and Environment, Massey University, Palmerston North, New Zealand
| | - Otto van der Linden
- The New Zealand Institute for Plant and Food Research Limited, Mt. Albert Research Centre, Auckland, New Zealand
| | - Minsoo Yoon
- The New Zealand Institute for Plant and Food Research Limited, Mt. Albert Research Centre, Auckland, New Zealand
| | - Magan M. Schipper
- The New Zealand Institute for Plant and Food Research Limited, Ruakura Campus, Hamilton, New Zealand
| | - Joel L. Vanneste
- The New Zealand Institute for Plant and Food Research Limited, Ruakura Campus, Hamilton, New Zealand
| | - Cyril Brendolise
- The New Zealand Institute for Plant and Food Research Limited, Mt. Albert Research Centre, Auckland, New Zealand
| | - Matthew D. Templeton
- The New Zealand Institute for Plant and Food Research Limited, Mt. Albert Research Centre, Auckland, New Zealand
- School of Biological Sciences, University of Auckland, Auckland, New Zealand
- Bioprotection Aoteoroa, New Zealand
- * E-mail: ,
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34
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Metaeffector interactions modulate the type III effector-triggered immunity load of Pseudomonas syringae. PLoS Pathog 2022; 18:e1010541. [PMID: 35576228 PMCID: PMC9135338 DOI: 10.1371/journal.ppat.1010541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 05/26/2022] [Accepted: 04/21/2022] [Indexed: 11/19/2022] Open
Abstract
The bacterial plant pathogen Pseudomonas syringae requires type III secreted effectors (T3SEs) for pathogenesis. However, a major facet of plant immunity entails the recognition of a subset of P. syringae’s T3SEs by intracellular host receptors in a process called Effector-Triggered Immunity (ETI). Prior work has shown that ETI-eliciting T3SEs are pervasive in the P. syringae species complex raising the question of how P. syringae mitigates its ETI load to become a successful pathogen. While pathogens can evade ETI by T3SE mutation, recombination, or loss, there is increasing evidence that effector-effector (a.k.a., metaeffector) interactions can suppress ETI. To study the ETI-suppression potential of P. syringae T3SE repertoires, we compared the ETI-elicitation profiles of two genetically divergent strains: P. syringae pv. tomato DC3000 (PtoDC3000) and P. syringae pv. maculicola ES4326 (PmaES4326), which are both virulent on Arabidopsis thaliana but harbour largely distinct effector repertoires. Of the 529 T3SE alleles screened on A. thaliana Col-0 from the P. syringae T3SE compendium (PsyTEC), 69 alleles from 21 T3SE families elicited ETI in at least one of the two strain backgrounds, while 50 elicited ETI in both backgrounds, resulting in 19 differential ETI responses including two novel ETI-eliciting families: AvrPto1 and HopT1. Although most of these differences were quantitative, three ETI responses were completely absent in one of the pathogenic backgrounds. We performed ETI suppression screens to test if metaeffector interactions contributed to these ETI differences, and found that HopQ1a suppressed AvrPto1m-mediated ETI, while HopG1c and HopF1g suppressed HopT1b-mediated ETI. Overall, these results show that P. syringae strains leverage metaeffector interactions and ETI suppression to overcome the ETI load associated with their native T3SE repertoires.
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35
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Raman V, Rojas CM, Vasudevan B, Dunning K, Kolape J, Oh S, Yun J, Yang L, Li G, Pant BD, Jiang Q, Mysore KS. Agrobacterium expressing a type III secretion system delivers Pseudomonas effectors into plant cells to enhance transformation. Nat Commun 2022; 13:2581. [PMID: 35546550 PMCID: PMC9095702 DOI: 10.1038/s41467-022-30180-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 04/20/2022] [Indexed: 01/07/2023] Open
Abstract
Agrobacterium-mediated plant transformation (AMT) is the basis of modern-day plant biotechnology. One major drawback of this technology is the recalcitrance of many plant species/varieties to Agrobacterium infection, most likely caused by elicitation of plant defense responses. Here, we develop a strategy to increase AMT by engineering Agrobacterium tumefaciens to express a type III secretion system (T3SS) from Pseudomonas syringae and individually deliver the P. syringae effectors AvrPto, AvrPtoB, or HopAO1 to suppress host defense responses. Using the engineered Agrobacterium, we demonstrate increase in AMT of wheat, alfalfa and switchgrass by ~250%-400%. We also show that engineered A. tumefaciens expressing a T3SS can deliver a plant protein, histone H2A-1, to enhance AMT. This strategy is of great significance to both basic research and agricultural biotechnology for transient and stable transformation of recalcitrant plant species/varieties and to deliver proteins into plant cells in a non-transgenic manner.
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Affiliation(s)
- Vidhyavathi Raman
- Noble Research Institute, LLC, Ardmore, OK, 73401, USA
- Department of Plant and Microbial Biology, University of Minnesota, St. Paul, MN, 55108, USA
| | - Clemencia M Rojas
- Noble Research Institute, LLC, Ardmore, OK, 73401, USA
- Department of Entomology and Plant Pathology, University of Arkansas, Fayetteville, AR, 72701, USA
| | | | - Kevin Dunning
- Noble Research Institute, LLC, Ardmore, OK, 73401, USA
| | | | - Sunhee Oh
- Noble Research Institute, LLC, Ardmore, OK, 73401, USA
| | - Jianfei Yun
- Noble Research Institute, LLC, Ardmore, OK, 73401, USA
| | - Lishan Yang
- Noble Research Institute, LLC, Ardmore, OK, 73401, USA
| | - Guangming Li
- Noble Research Institute, LLC, Ardmore, OK, 73401, USA
| | - Bikram D Pant
- Noble Research Institute, LLC, Ardmore, OK, 73401, USA
- Institute for Agricultural Biosciences, Oklahoma State University, Ardmore, OK, 73401, USA
- Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK, 74078, USA
| | | | - Kirankumar S Mysore
- Noble Research Institute, LLC, Ardmore, OK, 73401, USA.
- Institute for Agricultural Biosciences, Oklahoma State University, Ardmore, OK, 73401, USA.
- Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK, 74078, USA.
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36
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Basu S, Huynh L, Zhang S, Rabara R, Nguyen H, Velásquez Guzmán J, Hao G, Miles G, Shi Q, Stover E, Gupta G. Two Liberibacter Proteins Combine to Suppress Critical Innate Immune Defenses in Citrus. FRONTIERS IN PLANT SCIENCE 2022; 13:869178. [PMID: 35586217 PMCID: PMC9108871 DOI: 10.3389/fpls.2022.869178] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Accepted: 04/04/2022] [Indexed: 06/15/2023]
Abstract
We adopted a systems-based approach to determine the role of two Candidatus Liberibacter asiaticus (CLas) proteins, LasP 235 and Effector 3, in Huanglongbing (HLB) pathogenesis. While a published work suggests the involvement of these CLas proteins HLB pathogenesis, the exact structure-based mechanism of their action has not been elucidated. We conducted the following experiments to determine the structure-based mechanisms of action. First, we immunoprecipitated the interacting citrus protein partners of LasP 235 and Effector 3 from the healthy and CLas-infected Hamlin extracts and identified them by Liquid Chromatography with tandem mass spectrometry (LC-MS/MS). Second, we performed a split green fluorescent protein (GFP) assay in tobacco to validate that the interactions observed in vitro are also retained in planta. The notable in planta citrus targets of LasP 235 and Effector 3 include citrus innate immune proteins. Third, in vitro and in planta studies were performed to show that LasP 235 and Effector 3 interact with and inhibit the functions of multiple citrus proteins belonging to the innate immune pathways. These inhibitory interactions led to a high level of reactive oxygen species, blocking of bactericidal lipid transfer protein (LTP), and induction of premature programed cell death (PCD), all of which are beneficial to CLas lifecycle and HLB pathogenesis. Finally, we performed molecular dynamics simulations to visualize the interactions of LasP 235 and Effector 3, respectively, with LTP and Kunitz protease inhibitor. This led to the design of an LTP mimic, which sequestered and blocked LasP 235 and rescued the bactericidal activity of LTP thereby proving that LasP 235 , indeed, participates in HLB pathogenesis.
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Affiliation(s)
- Supratim Basu
- Biolab, New Mexico Consortium, Los Alamos, NM, United States
| | - Loan Huynh
- Biolab, New Mexico Consortium, Los Alamos, NM, United States
| | - Shujian Zhang
- Biolab, New Mexico Consortium, Los Alamos, NM, United States
| | - Roel Rabara
- Biolab, New Mexico Consortium, Los Alamos, NM, United States
| | - Hau Nguyen
- Biolab, New Mexico Consortium, Los Alamos, NM, United States
| | | | - Guixia Hao
- Horticulture and Breeding, U. S. Horticultural Research Laboratory, Fort Pierce, FL, United States
| | - Godfrey Miles
- Horticulture and Breeding, U. S. Horticultural Research Laboratory, Fort Pierce, FL, United States
| | - Qingchun Shi
- Horticulture and Breeding, U. S. Horticultural Research Laboratory, Fort Pierce, FL, United States
| | - Ed Stover
- Horticulture and Breeding, U. S. Horticultural Research Laboratory, Fort Pierce, FL, United States
| | - Goutam Gupta
- Biolab, New Mexico Consortium, Los Alamos, NM, United States
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37
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Breit-McNally C, Desveaux D, Guttman DS. The Arabidopsis effector-triggered immunity landscape is conserved in oilseed crops. Sci Rep 2022; 12:6534. [PMID: 35444223 PMCID: PMC9021255 DOI: 10.1038/s41598-022-10410-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Accepted: 04/07/2022] [Indexed: 11/15/2022] Open
Abstract
The bacterial phytopathogen Pseudomonas syringae causes disease on a wide array of plants, including the model plant Arabidopsis thaliana and its agronomically important relatives in the Brassicaceae family. To cause disease, P. syringae delivers effector proteins into plant cells through a type III secretion system. In response, plant nucleotide-binding leucine-rich repeat proteins recognize specific effectors and mount effector-triggered immunity (ETI). While ETI is pervasive across A. thaliana, with at least 19 families of P. syringae effectors recognized in this model species, the ETI landscapes of crop species have yet to be systematically studied. Here, we investigated the conservation of the A. thaliana ETI landscape in two closely related oilseed crops, Brassica napus (canola) and Camelina sativa (false flax). We show that the level of immune conservation is inversely related to the degree of evolutionary divergence from A. thaliana, with the more closely related C. sativa losing ETI responses to only one of the 19 P. syringae effectors tested, while the more distantly related B. napus loses ETI responses to four effectors. In contrast to the qualitative conservation of immune response, the quantitative rank order is not as well-maintained across the three species and diverges increasingly with evolutionary distance from A. thaliana. Overall, our results indicate that the A. thaliana ETI profile is qualitatively conserved in oilseed crops, but quantitatively distinct.
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Affiliation(s)
- Clare Breit-McNally
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
| | - Darrell Desveaux
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada.
- Centre for the Analysis of Genome Evolution and Function, University of Toronto, Toronto, ON, Canada.
| | - David S Guttman
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada.
- Centre for the Analysis of Genome Evolution and Function, University of Toronto, Toronto, ON, Canada.
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Turco S, Drais MI, Rossini L, Chaboteaux E, Rahi YJ, Balestra GM, Iacobellis NS, Mazzaglia A. Complete genome assembly of the levan-positive strain PVFi1 of Pseudomonas savastanoi pv. savastanoi isolated from olive knots in Central Italy. ENVIRONMENTAL MICROBIOLOGY REPORTS 2022; 14:274-285. [PMID: 35107220 PMCID: PMC9302664 DOI: 10.1111/1758-2229.13048] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Accepted: 01/23/2022] [Indexed: 05/08/2023]
Abstract
Pseudomonas savastanoi pv. savastanoi, the causal agent of olive knot disease, is a fluorescent Gram-negative bacterium classified, according to the specific LOPAT profile, as Ib. However, during the 90s, a number of atypical non-fluorescent levan-positive strains of Pseudomonas savastanoi pv. savastanoi have been unexpectedly isolated from olive knots in Central Italy. Since its first report, several studies were conducted on this species variant, but its genome sequence has never been reported. The complete genome sequence and two additional plasmids of PVFi1, a representative strain, were here obtained using a hybrid sequencing approach with both Oxford Nanopore Technology and Illumina sequencing. A thorough genomic analysis unravelled several genetic features of this peculiar strain, showing a transposase insertion downstream a fragmented copy of the levansucrase gene. The same features were previously reported on levan-negative Pseudomonas savastanoi pv. savastanoi strains. In addition, a second copy of the levansucrase gene fully equipped for a gene expression and comparable to the levan-positive Pseudomonas savastanoi pv. glycinea, may explain the levan-positive test. This result provides a solid genetic demonstration that the bacterial species Pseudomonas savastanoi contains either levan-positive or levan-negative strains, providing insights for an update of the related LOPAT classification.
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Affiliation(s)
- Silvia Turco
- Dipartimento di Scienze Agrarie e Forestali, Università degli Studi della Tuscia, Via S. Camillo de Lellis sncViterbo01100Italy
| | - Mounira Inas Drais
- Dipartimento di Scienze Agrarie e Forestali, Università degli Studi della Tuscia, Via S. Camillo de Lellis sncViterbo01100Italy
| | - Luca Rossini
- Dipartimento di Scienze Agrarie e Forestali, Università degli Studi della Tuscia, Via S. Camillo de Lellis sncViterbo01100Italy
| | - Elena Chaboteaux
- Dipartimento di Scienze Agrarie e Forestali, Università degli Studi della Tuscia, Via S. Camillo de Lellis sncViterbo01100Italy
| | - Yaseen Jundi Rahi
- Dipartimento di Scienze Agrarie e Forestali, Università degli Studi della Tuscia, Via S. Camillo de Lellis sncViterbo01100Italy
- CIHEAM‐Mediterranean Agronomic Institute of Bari, Via Ceglie 9Valenzano70010Italy
| | - Giorgio Mariano Balestra
- Dipartimento di Scienze Agrarie e Forestali, Università degli Studi della Tuscia, Via S. Camillo de Lellis sncViterbo01100Italy
| | | | - Angelo Mazzaglia
- Dipartimento di Scienze Agrarie e Forestali, Università degli Studi della Tuscia, Via S. Camillo de Lellis sncViterbo01100Italy
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Molecular and Genomic Characterization of the Pseudomonas syringae Phylogroup 4: An Emerging Pathogen of Arabidopsis thaliana and Nicotiana benthamiana. Microorganisms 2022; 10:microorganisms10040707. [PMID: 35456758 PMCID: PMC9030749 DOI: 10.3390/microorganisms10040707] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 03/15/2022] [Accepted: 03/21/2022] [Indexed: 12/10/2022] Open
Abstract
Environmental fluctuations such as increased temperature, water availability, and air CO2 concentration triggered by climate change influence plant disease dynamics by affecting hosts, pathogens, and their interactions. Here, we describe a newly discovered Pseudomonas syringae strain found in a natural population of Arabidopsis thaliana collected from the southwest of France. This strain, called Psy RAYR-BL, is highly virulent on natural Arabidopsis accessions, Arabidopsis model accession Columbia 0, and tobacco plants. Despite the severe disease phenotype caused by the Psy RAYR-BL strain, we identified a reduced repertoire of putative Type III virulence effectors by genomic sequencing compared to P. syringae pv tomato (Pst) DC3000. Furthermore, hopBJ1Psy is found exclusively on the Psy RAYR-BL genome but not in the Pst DC3000 genome. The plant expression of HopBJ1Psy induces ROS accumulation and cell death. In addition, HopBJ1Psy participates as a virulence factor in this plant-pathogen interaction, likely explaining the severity of the disease symptoms. This research describes the characterization of a newly discovered plant pathogen strain and possible virulence mechanisms underlying the infection process shaped by natural and changing environmental conditions.
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Bundalovic-Torma C, Desveaux D, Guttman DS. RecPD: A Recombination-aware measure of phylogenetic diversity. PLoS Comput Biol 2022; 18:e1009899. [PMID: 35192600 PMCID: PMC8896707 DOI: 10.1371/journal.pcbi.1009899] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 03/04/2022] [Accepted: 02/07/2022] [Indexed: 12/22/2022] Open
Abstract
A critical step in studying biological features (e.g., genetic variants, gene families, metabolic capabilities, or taxa) is assessing their diversity and distribution among a sample of individuals. Accurate assessments of these patterns are essential for linking features to traits or outcomes of interest and understanding their functional impact. Consequently, it is of crucial importance that the measures employed for quantifying feature diversity can perform robustly under any evolutionary scenario. However, the standard measures used for quantifying and comparing the distribution of features, such as prevalence, phylogenetic diversity, and related approaches, either do not take into consideration evolutionary history, or assume strictly vertical patterns of inheritance. Consequently, these approaches cannot accurately assess diversity for features that have undergone recombination or horizontal transfer. To address this issue, we have devised RecPD, a novel recombination-aware phylogenetic-diversity statistic for measuring the distribution and diversity of features under all evolutionary scenarios. RecPD utilizes ancestral-state reconstruction to map the presence / absence of features onto ancestral nodes in a species tree, and then identifies potential recombination events in the evolutionary history of the feature. We also derive several related measures from RecPD that can be used to assess and quantify evolutionary dynamics and correlation of feature evolutionary histories. We used simulation studies to show that RecPD reliably reconstructs feature evolutionary histories under diverse recombination and loss scenarios. We then applied RecPD in two diverse real-world scenarios including a preliminary study type III effector protein families secreted by the plant pathogenic bacterium Pseudomonas syringae and growth phenotypes of the Pseudomonas genus and demonstrate that prevalence is an inadequate measure that obscures the potential impact of recombination. We believe RecPD will have broad utility for revealing and quantifying complex evolutionary processes for features at any biological level. Phylogenetic diversity is an important concept utilized in evolutionary ecology which has extensive applications in population genetics to help us understand how evolutionary processes have distributed genetic variation among individuals of a species, and how this impacts phenotypic diversification over time. However, existing approaches for studying phylogenetic diversity largely assume that the genetic features follow vertical inheritance, which is frequently violated in the case of microbial genomes due to horizontal transfer. To address this shortcoming, we present RecPD, a recombination-aware phylogenetic diversity measure, which incorporates ancestral state reconstruction to quantify the phylogenetic diversity of genetic features mapped onto a species phylogeny. Through simulation experiments we show that RecPD robustly reconstructs the evolutionary histories of features evolving under various scenarios of recombination and loss. When applied to a real-world example of type III secreted effector protein families from the plant pathogenic bacterium Pseudomonas syringae, RecPD reveals that horizontal transfer has played an important role in shaping the phylogenetic distributions of a substantial proportion of families across the P. syringae species complex. Furthermore, we demonstrate that the traditional measures of feature prevalence are unsuitable as a measure for comparing feature diversity. We also provide a R package implementation of RecPD for public use: https://github.com/cedatorma/recpd.
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Affiliation(s)
| | - Darrell Desveaux
- Department of Cell & Systems Biology, University of Toronto, Toronto, Ontario, Canada
- Centre for the Analysis of Genome Evolution & Function, University of Toronto, Toronto, Ontario, Canada
| | - David S. Guttman
- Department of Cell & Systems Biology, University of Toronto, Toronto, Ontario, Canada
- Centre for the Analysis of Genome Evolution & Function, University of Toronto, Toronto, Ontario, Canada
- * E-mail:
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Baltrus DA, Feng Q, Kvitko BH. Genome Context Influences Evolutionary Flexibility of Nearly Identical Type III Effectors in Two Phytopathogenic Pseudomonads. Front Microbiol 2022; 13:826365. [PMID: 35250942 PMCID: PMC8895235 DOI: 10.3389/fmicb.2022.826365] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 01/19/2022] [Indexed: 12/02/2022] Open
Abstract
Integrative Conjugative Elements (ICEs) are replicons that can insert and excise from chromosomal locations in a site-specific manner, can conjugate across strains, and which often carry a variety of genes useful for bacterial growth and survival under specific conditions. Although ICEs have been identified and vetted within certain clades of the agricultural pathogen Pseudomonas syringae, the impact of ICE carriage and transfer across the entire P. syringae species complex remains underexplored. Here we identify and vet an ICE (PmaICE-DQ) from P. syringae pv. maculicola ES4326, a strain commonly used for laboratory virulence experiments, demonstrate that this element can excise and conjugate across strains, and highlight that this element contains loci encoding multiple type III effector proteins. Moreover, genome context suggests that another ICE (PmaICE-AOAB) is highly similar in comparison with and found immediately adjacent to PmaICE-DQ within the chromosome of strain ES4326, and also contains multiple type III effectors. Lastly, we present passage data from in planta experiments that suggests that genomic plasticity associated with ICEs may enable strains to more rapidly lose type III effectors that trigger R-gene mediated resistance in comparison to strains where nearly isogenic effectors are not present in active ICEs. Taken together, our study sheds light on a set of ICE elements from P. syringae pv. maculicola ES4326 and suggests how genomic context may lead to different evolutionary dynamics for shared virulence genes between strains.
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Affiliation(s)
- David A. Baltrus
- School of Plant Sciences, University of Arizona, Tucson, AZ, United States
- School of Animal and Comparative Biomedical Sciences, University of Arizona, Tucson, AZ, United States
- *Correspondence: David A. Baltrus,
| | - Qian Feng
- Institute of Plant Breeding, Genetics and Genomics, University of Georgia, Athens, GA, United States
| | - Brian H. Kvitko
- Department of Plant Pathology, University of Georgia, Athens, GA, United States
- Brian H. Kvitko,
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Kandel PP, Naumova M, Fautt C, Patel RR, Triplett LR, Hockett KL. Genome Mining Shows Ubiquitous Presence and Extensive Diversity of Toxin-Antitoxin Systems in Pseudomonas syringae. Front Microbiol 2022; 12:815911. [PMID: 35095819 PMCID: PMC8790059 DOI: 10.3389/fmicb.2021.815911] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 12/13/2021] [Indexed: 11/09/2022] Open
Abstract
Bacterial toxin-antitoxin (TA) systems consist of two or more adjacent genes, encoding a toxin and an antitoxin. TA systems are implicated in evolutionary and physiological functions including genome maintenance, antibiotics persistence, phage defense, and virulence. Eight classes of TA systems have been described, based on the mechanism of toxin neutralization by the antitoxin. Although studied well in model species of clinical significance, little is known about the TA system abundance and diversity, and their potential roles in stress tolerance and virulence of plant pathogens. In this study, we screened the genomes of 339 strains representing the genetic and lifestyle diversity of the Pseudomonas syringae species complex for TA systems. Using bioinformatic search and prediction tools, including SLING, BLAST, HMMER, TADB2.0, and T1TAdb, we show that P. syringae strains encode 26 different families of TA systems targeting diverse cellular functions. TA systems in this species are almost exclusively type II. We predicted a median of 15 TA systems per genome, and we identified six type II TA families that are found in more than 80% of strains, while others are more sporadic. The majority of predicted TA genes are chromosomally encoded. Further functional characterization of the predicted TA systems could reveal how these widely prevalent gene modules potentially impact P. syringae ecology, virulence, and disease management practices.
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Affiliation(s)
- Prem P. Kandel
- Department of Plant Pathology and Environmental Microbiology, Pennsylvania State University, University Park, PA, United States,*Correspondence: Prem P. kandel,
| | - Marina Naumova
- Department of Plant Pathology and Environmental Microbiology, Pennsylvania State University, University Park, PA, United States
| | - Chad Fautt
- Department of Plant Pathology and Environmental Microbiology, Pennsylvania State University, University Park, PA, United States
| | - Ravikumar R. Patel
- Department of Plant Pathology and Ecology, The Connecticut Agricultural Experiment Station, New Haven, CT, United States
| | - Lindsay R. Triplett
- Department of Plant Pathology and Ecology, The Connecticut Agricultural Experiment Station, New Haven, CT, United States
| | - Kevin L. Hockett
- Department of Plant Pathology and Environmental Microbiology, Pennsylvania State University, University Park, PA, United States,The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA, United States,Kevin L. Hockett,
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Zhang J, Zhou M, Liu W, Nie J, Huang L. Pseudomonas syringae pv. actinidiae Effector HopAU1 Interacts with Calcium-Sensing Receptor to Activate Plant Immunity. Int J Mol Sci 2022; 23:508. [PMID: 35008934 PMCID: PMC8745740 DOI: 10.3390/ijms23010508] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 12/30/2021] [Accepted: 12/31/2021] [Indexed: 02/01/2023] Open
Abstract
Kiwifruit canker, caused by Pseudomonas syringae pv. actinidiae (Psa), is a destructive pathogen that globally threatens the kiwifruit industry. Understanding the molecular mechanism of plant-pathogen interaction can accelerate applying resistance breeding and controlling plant diseases. All known effectors secreted by pathogens play an important role in plant-pathogen interaction. However, the effectors in Psa and their function mechanism remain largely unclear. Here, we successfully identified a T3SS effector HopAU1 which had no virulence contribution to Psa, but could, however, induce cell death and activate a series of immune responses by agroinfiltration in Nicotiana benthamiana, including elevated transcripts of immune-related genes, accumulation of reactive oxygen species (ROS), and callose deposition. We found that HopAU1 interacted with a calcium sensing receptor in N. benthamiana (NbCaS) as well as its close homologue in kiwifruit (AcCaS). More importantly, silencing CaS by RNAi in N. benthamiana greatly attenuated HopAU1-triggered cell death, suggesting CaS is a crucial component for HopAU1 detection. Further researches showed that overexpression of NbCaS in N. benthamiana significantly enhanced plant resistance against Sclerotinia sclerotiorum and Phytophthora capsici, indicating that CaS serves as a promising resistance-related gene for disease resistance breeding. We concluded that HopAU1 is an immune elicitor that targets CaS to trigger plant immunity.
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Affiliation(s)
| | | | | | | | - Lili Huang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Xianyang 712100, China; (J.Z.); (M.Z.); (W.L.); (J.N.)
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Becker S, Mücke S, Grau J, Boch J. OUP accepted manuscript. Nucleic Acids Res 2022; 50:2387-2400. [PMID: 35150566 PMCID: PMC8887545 DOI: 10.1093/nar/gkac098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 01/28/2022] [Accepted: 02/02/2022] [Indexed: 11/25/2022] Open
Abstract
Transcription activator-like effectors (TALEs) are bacterial proteins with a programmable DNA-binding domain, which turned them into exceptional tools for biotechnology. TALEs contain a central array of consecutive 34 amino acid long repeats to bind DNA in a simple one-repeat-to-one-nucleotide manner. However, a few naturally occurring aberrant repeat variants break this strict binding mechanism, allowing for the recognition of an additional sequence with a −1 nucleotide frameshift. The limits and implications of this extended TALE binding mode are largely unexplored. Here, we analyse the complete diversity of natural and artificially engineered aberrant repeats for their impact on the DNA binding of TALEs. Surprisingly, TALEs with several aberrant repeats can loop out multiple repeats simultaneously without losing DNA-binding capacity. We also characterized members of the only natural TALE class harbouring two aberrant repeats and confirmed that their target is the major virulence factor OsSWEET13 from rice. In an aberrant TALE repeat, the position and nature of the amino acid sequence strongly influence its function. We explored the tolerance of TALE repeats towards alterations further and demonstrate that inserts as large as GFP can be tolerated without disrupting DNA binding. This illustrates the extraordinary DNA-binding capacity of TALEs and opens new uses in biotechnology.
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Affiliation(s)
- Sebastian Becker
- Department of Plant Biotechnology, Institute of Plant Genetics, Leibniz Universität Hannover, 30419 Hannover, Germany
| | - Stefanie Mücke
- Department of Plant Biotechnology, Institute of Plant Genetics, Leibniz Universität Hannover, 30419 Hannover, Germany
| | - Jan Grau
- Institute of Computer Science, Martin Luther University Halle-Wittenberg, 06120 Halle (Saale), Germany
| | - Jens Boch
- To whom correspondence should be addressed. Tel: +49 511 762 4082; Fax: +49 511 762 4088;
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Lipps SM, Samac DA. Pseudomonas viridiflava: An internal outsider of the Pseudomonas syringae species complex. MOLECULAR PLANT PATHOLOGY 2022; 23:3-15. [PMID: 34463014 PMCID: PMC8659605 DOI: 10.1111/mpp.13133] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 08/07/2021] [Accepted: 08/10/2021] [Indexed: 06/13/2023]
Abstract
UNLABELLED Pseudomonas viridiflava is a gram-negative pseudomonad that is phylogenetically placed within the Pseudomonas syringae species complex. P. viridiflava has a wide host range and causes a variety of symptoms in different plant parts, including stems, leaves, and blossoms. Outside of its role as a pathogen, P. viridiflava also exists as an endophyte, epiphyte, and saprophyte. Increased reports of P. viridiflava causing disease on new hosts in recent years coincide with increased research on its genetic variability, virulence, phylogenetics, and phenotypes. There is high variation in its core genome, virulence factors, and phenotypic characteristics. The main virulence factors of this pathogen include the enzyme pectate lyase and virulence genes encoded within one or two pathogenicity islands. The delineation of P. viridiflava in the P. syringae complex has been investigated using several molecular approaches. P. viridiflava comprises its own species, within the complex. While seemingly an outsider to the complex as a whole due to differences in the core genome and virulence genes, low average nucleotide identity to other of P. syringae complex members, and some phenotypic traits, it remains as part of the complex. Defining phylogenetic, phenotypic, and genomic characteristics of P. viridiflava in comparison to other P. syringae members is important to understanding this pathogen and for the development of disease resistance and management practices. TAXONOMY Kingdom Bacteria; Phylum Proteobacteria; Class Gammaproteobacteria; Family Pseudomonadaceae; Genus Pseudomonas; Species Pseudomonas syringae species complex, Genomospecies 6, Phylogroup 7 and 8. MICROBIOLOGICAL PROPERTIES Gram-negative, fluorescent, aerobic, motile, rod-shaped, oxidase negative, arginine dihydrolase negative, levan production negative (or positive), potato rot positive (or negative), tobacco hypersensitivity positive. GENOME There are two complete genomes, five chromosome-level genomes, and 1,540 genomes composed of multiple scaffolds of P. viridiflava available in the National Center for Biotechnology Information Genome database. The median total length of these assemblies is 5,975,050 bp, the median number of protein coding genes is 5,208, and the median G + C content is 59.3%. DISEASE SYMPTOMS P. viridiflava causes a variety of disease symptoms, including spots, streaks, necrosis, rots, and more in above- and below-ground plant parts on at least 50 hosts. EPIDEMIOLOGY There have been several significant disease outbreaks on field and horticultural crops caused by P. viridiflava since the turn of the century. P. viridiflava has been reported as a pathogen, epiphyte, endophyte, and saprophyte. This species has been isolated from a variety of environmental sources, including asymptomatic wild plants, snow, epilithic biofilms, and icepacks.
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Affiliation(s)
- Savana M. Lipps
- Plant PathologyUniversity of Minnesota Twin CitiesSt PaulMNUSA
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46
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Martel A, Ruiz-Bedoya T, Breit-McNally C, Laflamme B, Desveaux D, Guttman DS. The ETS-ETI cycle: evolutionary processes and metapopulation dynamics driving the diversification of pathogen effectors and host immune factors. CURRENT OPINION IN PLANT BIOLOGY 2021; 62:102011. [PMID: 33677388 DOI: 10.1016/j.pbi.2021.102011] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 01/21/2021] [Accepted: 01/24/2021] [Indexed: 05/13/2023]
Abstract
The natural diversity of pathogen effectors and host immune components represents a snapshot of the underlying evolutionary processes driving the host-pathogen arms race. In plants, this arms race is manifested by an ongoing cycle of disease and resistance driven by pathogenic effectors that promote disease (effector-triggered susceptibility; ETS) and plant resistance proteins that recognize effector activity to trigger immunity (effector-triggered immunity; ETI). Here we discuss how this ongoing ETS-ETI cycle has shaped the natural diversity of both plant resistance proteins and pathogen effectors. We focus on the evolutionary forces that drive the diversification of the molecules that determine the outcome of plant-pathogen interactions and introduce the concept of metapopulation dynamics (i.e., the introduction of genetic variation from conspecific organisms in different populations) as an alternative mechanism that can introduce and maintain diversity in both host and pathogen populations.
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Affiliation(s)
- Alexandre Martel
- Department of Cell & Systems Biology, University of Toronto, Toronto, Ontario M6S2Y1, Canada
| | - Tatiana Ruiz-Bedoya
- Department of Cell & Systems Biology, University of Toronto, Toronto, Ontario M6S2Y1, Canada
| | - Clare Breit-McNally
- Department of Cell & Systems Biology, University of Toronto, Toronto, Ontario M6S2Y1, Canada
| | - Bradley Laflamme
- Department of Cell & Systems Biology, University of Toronto, Toronto, Ontario M6S2Y1, Canada
| | - Darrell Desveaux
- Department of Cell & Systems Biology, University of Toronto, Toronto, Ontario M6S2Y1, Canada; Centre for the Analysis of Genome Evolution & Function, University of Toronto, Toronto, Ontario M6S2Y1, Canada.
| | - David S Guttman
- Department of Cell & Systems Biology, University of Toronto, Toronto, Ontario M6S2Y1, Canada; Centre for the Analysis of Genome Evolution & Function, University of Toronto, Toronto, Ontario M6S2Y1, Canada.
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47
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Talagrand-Reboul E, Colston SM, Graf J, Lamy B, Jumas-Bilak E. Comparative and Evolutionary Genomics of Isolates Provide Insight into the Pathoadaptation of Aeromonas. Genome Biol Evol 2021; 12:535-552. [PMID: 32196086 PMCID: PMC7250499 DOI: 10.1093/gbe/evaa055] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/19/2020] [Indexed: 02/06/2023] Open
Abstract
Aeromonads are ubiquitous aquatic bacteria that cause opportunistic infections in humans, but their pathogenesis remains poorly understood. A pathogenomic approach was undertaken to provide insights into the emergence and evolution of pathogenic traits in aeromonads. The genomes of 64 Aeromonas strains representative of the whole genus were analyzed to study the distribution, phylogeny, and synteny of the flanking sequences of 13 virulence-associated genes. The reconstructed evolutionary histories varied markedly depending on the gene analyzed and ranged from vertical evolution, which followed the core genome evolution (alt and colAh), to complex evolution, involving gene loss by insertion sequence-driven gene disruption, horizontal gene transfer, and paraphyly with some virulence genes associated with a phylogroup (aer, ser, and type 3 secretion system components) or no phylogroup (type 3 secretion system effectors, Ast, ExoA, and RtxA toxins). The general pathogenomic overview of aeromonads showed great complexity with diverse evolution modes and gene organization and uneven distribution of virulence genes in the genus; the results provided insights into aeromonad pathoadaptation or the ability of members of this group to emerge as pathogens. Finally, these findings suggest that aeromonad virulence-associated genes should be examined at the population level and that studies performed on type or model strains at the species level cannot be generalized to the whole species.
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Affiliation(s)
- Emilie Talagrand-Reboul
- Équipe Pathogènes Hydriques Santé Environnements, UMR 5569 HSM, University of Montpellier, France.,Laboratoire de Bactériologie, Hôpitaux universitaires de Strasbourg, France
| | - Sophie M Colston
- US Naval Research Laboratory, National Academy of Sciences, National Research Council, Washington, District of Columbia
| | - Joerg Graf
- Department of Molecular and Cell Biology, University of Connecticut
| | - Brigitte Lamy
- Équipe Pathogènes Hydriques Santé Environnements, UMR 5569 HSM, University of Montpellier, France.,Département de Bactériologie, CHU de Nice and Université Côte d'Azur, INSERM, C3M, Nice, France
| | - Estelle Jumas-Bilak
- Équipe Pathogènes Hydriques Santé Environnements, UMR 5569 HSM, University of Montpellier, France.,Département d'Hygiène Hospitalière, CHRU de Montpellier, France
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48
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Dillon MM, Ruiz-Bedoya T, Bundalovic-Torma C, Guttman KM, Kwak H, Middleton MA, Wang PW, Horuz S, Aysan Y, Guttman DS. Comparative genomic insights into the epidemiology and virulence of plant pathogenic pseudomonads from Turkey. Microb Genom 2021; 7:000585. [PMID: 34227931 PMCID: PMC8477409 DOI: 10.1099/mgen.0.000585] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2020] [Accepted: 04/16/2021] [Indexed: 12/31/2022] Open
Abstract
Pseudomonas is a highly diverse genus that includes species that cause disease in both plants and animals. Recently, pathogenic pseudomonads from the Pseudomonas syringae and Pseudomonas fluorescens species complexes have caused significant outbreaks in several agronomically important crops in Turkey, including tomato, citrus, artichoke and melon. We characterized 169 pathogenic Pseudomonas strains associated with recent outbreaks in Turkey via multilocus sequence analysis and whole-genome sequencing, then used comparative and evolutionary genomics to characterize putative virulence mechanisms. Most of the isolates are closely related to other plant pathogens distributed among the primary phylogroups of P. syringae, although there are significant numbers of P. fluorescens isolates, which is a species better known as a rhizosphere-inhabiting plant-growth promoter. We found that all 39 citrus blast pathogens cluster in P. syringae phylogroup 2, although strains isolated from the same host do not cluster monophyletically, with lemon, mandarin orange and sweet orange isolates all being intermixed throughout the phylogroup. In contrast, 20 tomato pith pathogens are found in two independent lineages: one in the P. syringae secondary phylogroups, and the other from the P. fluorescens species complex. These divergent pith necrosis strains lack characteristic virulence factors like the canonical tripartite type III secretion system, large effector repertoires and the ability to synthesize multiple bacterial phytotoxins, suggesting they have alternative molecular mechanisms to cause disease. These findings highlight the complex nature of host specificity among plant pathogenic pseudomonads.
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Affiliation(s)
- Marcus M. Dillon
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
- Present address: Department of Biology, University of Toronto at Mississauga, Mississauga, Ontario, Canada
| | - Tatiana Ruiz-Bedoya
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | | | - Kevin M. Guttman
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Haejin Kwak
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Maggie A. Middleton
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
- Centre for the Analysis of Genome Evolution and Function, University of Toronto, Toronto, Ontario, Canada
| | - Pauline W. Wang
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
- Centre for the Analysis of Genome Evolution and Function, University of Toronto, Toronto, Ontario, Canada
| | - Sumer Horuz
- Department of Plant Protection, Erciyes University, Kayseri, Turkey
| | - Yesim Aysan
- Department of Plant Protection, University of Çukurova, Adana, Turkey
| | - David S. Guttman
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
- Centre for the Analysis of Genome Evolution and Function, University of Toronto, Toronto, Ontario, Canada
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49
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Sacristán S, Goss EM, Eves-van den Akker S. How Do Pathogens Evolve Novel Virulence Activities? MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2021; 34:576-586. [PMID: 33522842 DOI: 10.1094/mpmi-09-20-0258-ia] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
This article is part of the Top 10 Unanswered Questions in MPMI invited review series.We consider the state of knowledge on pathogen evolution of novel virulence activities, broadly defined as anything that increases pathogen fitness with the consequence of causing disease in either the qualitative or quantitative senses, including adaptation of pathogens to host immunity and physiology, host species, genotypes, or tissues, or the environment. The evolution of novel virulence activities as an adaptive trait is based on the selection exerted by hosts on variants that have been generated de novo or arrived from elsewhere. In addition, the biotic and abiotic environment a pathogen experiences beyond the host may influence pathogen virulence activities. We consider host-pathogen evolution, host range expansion, and external factors that can mediate pathogen evolution. We then discuss the mechanisms by which pathogens generate and recombine the genetic variation that leads to novel virulence activities, including DNA point mutation, transposable element activity, gene duplication and neofunctionalization, and genetic exchange. In summary, if there is an (epi)genetic mechanism that can create variation in the genome, it will be used by pathogens to evolve virulence factors. Our knowledge of virulence evolution has been biased by pathogen evolution in response to major gene resistance, leaving other virulence activities underexplored. Understanding the key driving forces that give rise to novel virulence activities and the integration of evolutionary concepts and methods with mechanistic research on plant-microbe interactions can help inform crop protection.[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)
- Soledad Sacristán
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM)-Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Campus Montegancedo-UPM, 28223-Pozuelo de Alarcón (Madrid), Spain
- Departamento de Biotecnología-Biología Vegetal, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaria y de Biosistemas, Universidad Politécnica de Madrid, 28040-Madrid, Spain
| | - Erica M Goss
- Department of Plant Pathology and Emerging Pathogens Institute, University of Florida, Gainesville, Florida, U.S.A
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50
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Mooney BC, Mantz M, Graciet E, Huesgen PF. Cutting the line: manipulation of plant immunity by bacterial type III effector proteases. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:3395-3409. [PMID: 33640987 DOI: 10.1093/jxb/erab095] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 02/25/2021] [Indexed: 06/12/2023]
Abstract
Pathogens and their hosts are engaged in an evolutionary arms race. Pathogen-derived effectors promote virulence by targeting components of a host's innate immune system, while hosts have evolved proteins that sense effectors and trigger a pathogen-specific immune response. Many bacterial effectors are translocated into host cells using type III secretion systems. Type III effector proteases irreversibly modify host proteins by cleavage of peptide bonds and are prevalent among both plant and animal bacterial pathogens. In plants, the study of model effector proteases has yielded important insights into the virulence mechanisms employed by pathogens to overcome their host's immune response, as well as into the mechanisms deployed by their hosts to detect these effector proteases and counteract their effects. In recent years, the study of a larger number of effector proteases, across a wider range of pathogens, has yielded novel insights into their functions and recognition. One key limitation that remains is the lack of methods to detect protease cleavage at the proteome-wide level. We review known substrates and mechanisms of plant pathogen type III effector proteases and compare their functions with those of known type III effector proteases of mammalian pathogens. Finally, we discuss approaches to uncover their function on a system-wide level.
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Affiliation(s)
- Brian C Mooney
- Department of Biology, Maynooth University, Maynooth, County Kildare, Ireland
| | - Melissa Mantz
- Central Institute for Engineering, Electronics and Analytics, ZEA-3, Forschungszentrum Jülich, Jülich, Germany
- CECAD, Medical Faculty and University Hospital, University of Cologne, Cologne, Germany
| | - Emmanuelle Graciet
- Department of Biology, Maynooth University, Maynooth, County Kildare, Ireland
- Kathleen Lonsdale Institute for Human Health Research, Maynooth University, Maynooth, Co. Kildare, Ireland
| | - Pitter F Huesgen
- Central Institute for Engineering, Electronics and Analytics, ZEA-3, Forschungszentrum Jülich, Jülich, Germany
- CECAD, Medical Faculty and University Hospital, University of Cologne, Cologne, Germany
- Institute for Biochemistry, Faculty of Mathematics and Natural Sciences, University of Cologne, Cologne, Germany
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