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Orfei B, Pothier JF, Fenske L, Blom J, Moretti C, Buonaurio R, Smits THM. Race-specific genotypes of Pseudomonas syringae pv. tomato are defined by the presence of mobile DNA elements within the genome. FRONTIERS IN PLANT SCIENCE 2023; 14:1197706. [PMID: 37476164 PMCID: PMC10354423 DOI: 10.3389/fpls.2023.1197706] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 06/19/2023] [Indexed: 07/22/2023]
Abstract
Pseudomonas syringae pv. tomato is the causal agent of bacterial speck of tomato, an important disease that results in severe crop production losses worldwide. Currently, two races within phylogroup 01a (PG01a) are described for this pathogen. Race 0 strains have avirulence genes for the expression of type III system-associated effectors AvrPto1 and AvrPtoB, that are recognized and targeted by the effector-triggered immunity in tomato cultivars having the pto race-specific resistance gene. Race 1 strains instead lack the avrPto1 and avrPtoB genes and are therefore capable to aggressively attack all tomato cultivars. Here, we have performed the complete genome sequencing and the analysis of P. syringae pv. tomato strain DAPP-PG 215, which was described as a race 0 strain in 1996. Our analysis revealed that its genome comprises a 6.2 Mb circular chromosome and two plasmids (107 kb and 81 kb). The results indicate that the strain is phylogenetically closely related to strains Max13, K40, T1 and NYS-T1, all known race 1 strains. The chromosome of DAPP-PG 215 encodes race 1-associated genes like avrA and hopW1 and lacks race 0-associated genes like hopN1, giving it a race 1 genetic background. However, the genome harbors a complete ortholog of avrPto1, which allows the strain to display a race 0 phenotype. Comparative genomics with several PG01a genomes revealed that mobile DNA elements are rather involved in the evolution of the two different races.
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Affiliation(s)
- Benedetta Orfei
- Dipartimento di Scienze Agrarie, Alimentari e Ambientali (DSA3), Università degli Studi di Perugia, Perugia, Italy
| | - Joël F. Pothier
- Environmental Genomics and Systems Biology Research Group, Institute of Natural Resource Sciences (IUNR), Zurich University of Applied Sciences ZHAW, Wädenswil, Switzerland
| | - Linda Fenske
- Bioinformatics and Systems Biology, Justus-Liebig University Giessen, Giessen, Germany
| | - Jochen Blom
- Bioinformatics and Systems Biology, Justus-Liebig University Giessen, Giessen, Germany
| | - Chiaraluce Moretti
- Dipartimento di Scienze Agrarie, Alimentari e Ambientali (DSA3), Università degli Studi di Perugia, Perugia, Italy
| | - Roberto Buonaurio
- Dipartimento di Scienze Agrarie, Alimentari e Ambientali (DSA3), Università degli Studi di Perugia, Perugia, Italy
| | - Theo H. M. Smits
- Environmental Genomics and Systems Biology Research Group, Institute of Natural Resource Sciences (IUNR), Zurich University of Applied Sciences ZHAW, Wädenswil, Switzerland
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2
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Jeleńska J, Lee J, Manning AJ, Wolfgeher DJ, Ahn Y, Walters-Marrah G, Lopez IE, Garcia L, McClerklin SA, Michelmore RW, Kron SJ, Greenberg JT. Pseudomonas syringae effector HopZ3 suppresses the bacterial AvrPto1-tomato PTO immune complex via acetylation. PLoS Pathog 2021; 17:e1010017. [PMID: 34724007 PMCID: PMC8584673 DOI: 10.1371/journal.ppat.1010017] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 11/11/2021] [Accepted: 10/07/2021] [Indexed: 11/23/2022] Open
Abstract
The plant pathogen Pseudomonas syringae secretes multiple effectors that modulate plant defenses. Some effectors trigger defenses due to specific recognition by plant immune complexes, whereas others can suppress the resulting immune responses. The HopZ3 effector of P. syringae pv. syringae B728a (PsyB728a) is an acetyltransferase that modifies not only components of plant immune complexes, but also the Psy effectors that activate these complexes. In Arabidopsis, HopZ3 acetylates the host RPM1 complex and the Psy effectors AvrRpm1 and AvrB3. This study focuses on the role of HopZ3 during tomato infection. In Psy-resistant tomato, the main immune complex includes PRF and PTO, a RIPK-family kinase that recognizes the AvrPto effector. HopZ3 acts as a virulence factor on tomato by suppressing AvrPto1Psy-triggered immunity. HopZ3 acetylates AvrPto1Psy and the host proteins PTO, SlRIPK and SlRIN4s. Biochemical reconstruction and site-directed mutagenesis experiments suggest that acetylation acts in multiple ways to suppress immune signaling in tomato. First, acetylation disrupts the critical AvrPto1Psy-PTO interaction needed to initiate the immune response. Unmodified residues at the binding interface of both proteins and at other residues needed for binding are acetylated. Second, acetylation occurs at residues important for AvrPto1Psy function but not for binding to PTO. Finally, acetylation reduces specific phosphorylations needed for promoting the immune-inducing activity of HopZ3’s targets such as AvrPto1Psy and PTO. In some cases, acetylation competes with phosphorylation. HopZ3-mediated acetylation suppresses the kinase activity of SlRIPK and the phosphorylation of its SlRIN4 substrate previously implicated in PTO-signaling. Thus, HopZ3 disrupts the functions of multiple immune components and the effectors that trigger them, leading to increased susceptibility to infection. Finally, mass spectrometry used to map specific acetylated residues confirmed HopZ3’s unusual capacity to modify histidine in addition to serine, threonine and lysine residues. By secreting virulence proteins (effectors) into their hosts, pathogenic bacteria hijack host cellular processes to promote bacterial colonization and disease development. For the plant pathogen Pseudomonas syringae, the coordinated action of effectors often mediates modifications of host defense proteins to inhibit their function. However, plants have evolved the ability to induce innate immunity upon recognition of effector-induced modifications of host proteins. How do pathogens circumvent the immune-inducing activity of certain effectors? They deploy more effectors to suppress these defenses. HopZ3, an acetyltransferase from P. syringae, is unique among plant pathogen effectors characterized so far in its ability to modify not only multiple components of the effector-triggered immune pathway, but also the triggering effector itself. Through the direct acetylation of residues involved in the interaction and activation of the bacterial effector AvrPto1Psy and tomato kinase PTO, HopZ3 modifications disrupt their binding and block phosphorylations necessary for immune induction. Additionally, HopZ3 acetylates other possible components in the PTO signaling pathway, including activation sites in SlRIPK kinase, leading to suppression of its activity and reduced phosphorylation of SlRIN4s. Our study emphasizes the importance of HopZ3-dependent acetylation of immune complexes and bacterial effectors across plant species in the suppression of effector-induced immunity.
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Affiliation(s)
- Joanna Jeleńska
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, Illinois, United States of America
| | - Jiyoung Lee
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, Illinois, United States of America
| | - Andrew J. Manning
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, Illinois, United States of America
| | - Donald J. Wolfgeher
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, Illinois, United States of America
| | - Youngjoo Ahn
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, Illinois, United States of America
| | - George Walters-Marrah
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, Illinois, United States of America
| | - Ivan E. Lopez
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, Illinois, United States of America
| | - Lissette Garcia
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, Illinois, United States of America
| | - Sheri A. McClerklin
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, Illinois, United States of America
| | - Richard W. Michelmore
- The Genome Center & Department of Plant Sciences, University of California, Davis, California, United States of America
| | - Stephen J. Kron
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, Illinois, United States of America
| | - Jean T. Greenberg
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, Illinois, United States of America
- * E-mail:
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3
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Gimenez-Ibanez S, Hann DR, Chang JH, Segonzac C, Boller T, Rathjen JP. Differential Suppression of Nicotiana benthamiana Innate Immune Responses by Transiently Expressed Pseudomonas syringae Type III Effectors. FRONTIERS IN PLANT SCIENCE 2018; 9:688. [PMID: 29875790 PMCID: PMC5974120 DOI: 10.3389/fpls.2018.00688] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Accepted: 05/04/2018] [Indexed: 05/13/2023]
Abstract
The plant pathogen Pseudomonas syringae injects about 30 different virulence proteins, so-called effectors, via a type III secretion system into plant cells to promote disease. Although some of these effectors are known to suppress either pattern-triggered immunity (PTI) or effector-triggered immunity (ETI), the mode of action of most of them remains unknown. Here, we used transient expression in Nicotiana benthamiana, to test the abilities of type III effectors of Pseudomonas syringae pv. tomato (Pto) DC3000 and Pseudomonas syringae pv. tabaci (Pta) 11528 to interfere with plant immunity. We monitored the sequential and rapid bursts of cytoplasmic Ca2+ and reactive oxygen species (ROS), the subsequent induction of defense gene expression, and promotion of cell death. We found that several effector proteins caused cell death, but independently of the known plant immune regulator NbSGT1, a gene essential for ETI. Furthermore, many effectors delayed or blocked the cell death-promoting activity of other effectors, thereby potentially contributing to pathogenesis. Secondly, a large number of effectors were able to suppress PAMP-induced defense responses. In the majority of cases, this resulted in suppression of all studied PAMP responses, suggesting that these effectors target common elements of PTI. However, effectors also targeted different steps within defense pathways and could be divided into three major groups based on their suppressive activities. Finally, the abilities of effectors of both Pto DC3000 and Pta 11528 to suppress plant immunity was conserved in most but not all cases. Overall, our data present a comprehensive picture of the mode of action of these effectors and indicate that most of them suppress plant defenses in various ways.
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Affiliation(s)
- Selena Gimenez-Ibanez
- The Sainsbury Laboratory, Norwich, United Kingdom
- Plant Molecular Genetics Department, Centro Nacional de Biotecnología-Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Dagmar R Hann
- The Sainsbury Laboratory, Norwich, United Kingdom
- Department of Environmental Sciences, Botanical Institute, University of Basel, Basel, Switzerland
- Institute of Genetics, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Jeff H Chang
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR, United States
- Center for Genome Research and Biocomputing, Oregon State University, Corvallis, OR, United States
| | - Cécile Segonzac
- The Sainsbury Laboratory, Norwich, United Kingdom
- Department of Plant Science, Plant Genomics and Breeding Institute and Research Institute of Agriculture and Life Sciences, College of Agriculture and Life Sciences, Seoul National University, Seoul, South Korea
| | - Thomas Boller
- Department of Environmental Sciences, Botanical Institute, University of Basel, Basel, Switzerland
| | - John P Rathjen
- The Sainsbury Laboratory, Norwich, United Kingdom
- Research School of Biology, Australian National University, Acton, ACT, Australia
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Venkatesh J, Jahn M, Kang BC. Genome-Wide Analysis and Evolution of the Pto-Like Protein Kinase (PLPK) Gene Family in Pepper. PLoS One 2016; 11:e0161545. [PMID: 27536870 PMCID: PMC4990186 DOI: 10.1371/journal.pone.0161545] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 08/08/2016] [Indexed: 11/19/2022] Open
Abstract
The tomato Pto gene, which encodes a serine/threonine kinase (STK) domain-containing protein, confers resistance to bacterial speck disease caused by Pseudomonas syringae pv. tomato (Pst). In this study, in vivo recognition assays using PVX constructs showed that AvrPto was specifically recognized in the pepper genotypes. This AvrPto recognition caused a nonhost hypersensitive response (HR) and localization of the PVX::AvrPto fusion protein to inoculated pepper leaf tissues, which indicates the presence of a similar Pto recognition mechanism in pepper as in tomato. However, genome-wide analysis in pepper revealed no Pto clade corresponding to that in tomato, suggesting an alternative system for Pto recognition in pepper. Nevertheless, 25 Pto-like protein kinases (PLPKs) with a highly conserved STK domain have been identified in the pepper genome. For the majority of the amino acid sites in the STK domain of Ptos and PLPKs, nonsynonymous (dN) to synonymous (dS) nucleotide substitution ratios (ω) were less than one, suggesting that purifying selection played a predominant role in the evolutionary process. However, some amino acid sites were found to be subjected to episodic positive selection in the course of evolution of Pto homologs, and, thus, different evolutionary processes might have shaped the Pto gene family in plants. Based on RNA-seq data, PLPK genes and other Pto pathway genes, such as Prf, Pti1, Pti5, and Pti6 were expressed in all tested pepper genotypes. Therefore, the nonhost HR against Pst in pepper may be due to the recognition of the AvrPto effector by a PLPK homolog, and subsequent action of downstream components of the Pto signaling pathway. However, the possibility remains that the recognition of AvrPto in pepper plants may involve activities of other receptor like kinases (RLKs). The identification of the PLPKs in this study will serve as a foundation for further efforts to understand the roles of PLPKs in nonhost resistance.
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Affiliation(s)
- Jelli Venkatesh
- Department of Plant Science and Plant Genomics and Breeding Institute, Vegetable Breeding Research Center, Seoul National University, Seoul, 151–921, Korea
| | - Molly Jahn
- University of Wisconsin, Madison, Wisconsin, WI 53706, United States of America
| | - Byoung-Cheorl Kang
- Department of Plant Science and Plant Genomics and Breeding Institute, Vegetable Breeding Research Center, Seoul National University, Seoul, 151–921, Korea
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5
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Kraus CM, Munkvold KR, Martin GB. Natural Variation in Tomato Reveals Differences in the Recognition of AvrPto and AvrPtoB Effectors from Pseudomonas syringae. MOLECULAR PLANT 2016; 9:639-649. [PMID: 26993968 DOI: 10.1016/j.molp.2016.03.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Revised: 03/03/2016] [Accepted: 03/04/2016] [Indexed: 05/13/2023]
Abstract
The Pto protein kinase from Solanum pimpinellifolium interacts with Pseudomonas syringae effectors AvrPto or AvrPtoB to activate effector-triggered immunity. The previously solved crystal structures of the AvrPto-Pto and AvrPtoB-Pto complexes revealed that Pto binds each effector through both a shared and a unique interface. Here we use natural variation in wild species of tomato to further investigate Pto recognition of these two effectors. One species, Solanum chmielewskii, was found to have many accessions that recognize only AvrPtoB. The Pto ortholog from one of these accessions was responsible for recognition of AvrPtoB and it differed from Solanum pimpinellifolium Pto by only 14 amino acids, including two in the AvrPto-specific interface, glutamate-49/glycine-51. Converting these two residues to those in Pto (histidine-49/valine-51) did not restore recognition of AvrPto. Subsequent experiments revealed that a single substitution of a histidine-to-aspartate at position 193 in Pto, which is not near the AvrPto-specific interface, was sufficient for conferring recognition of AvrPto in plant cells. The reciprocal substitution of aspartate-to-histidine-193 in Pto abolished AvrPto recognition, confirming the importance of this residue. Our results reveal new aspects about effector recognition by Pto and demonstrate the value of using natural variation to understand the interaction between resistance proteins and pathogen effectors.
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Affiliation(s)
- Christine M Kraus
- Boyce Thompson Institute for Plant Research, Ithaca, NY 14853, USA; Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY 14853, USA
| | - Kathy R Munkvold
- Boyce Thompson Institute for Plant Research, Ithaca, NY 14853, USA
| | - Gregory B Martin
- Boyce Thompson Institute for Plant Research, Ithaca, NY 14853, USA; Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY 14853, USA.
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6
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Marín M, Ott T. Intrinsic disorder in plant proteins and phytopathogenic bacterial effectors. Chem Rev 2014; 114:6912-32. [PMID: 24697726 DOI: 10.1021/cr400488d] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Macarena Marín
- Genetics Institute, Faculty of Biology, Ludwig-Maximilians-University of Munich , Grosshaderner Strasse 2-4, 82152 Martinsried, Germany
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7
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Baltrus DA, Nishimura MT, Romanchuk A, Chang JH, Mukhtar MS, Cherkis K, Roach J, Grant SR, Jones CD, Dangl JL. Dynamic evolution of pathogenicity revealed by sequencing and comparative genomics of 19 Pseudomonas syringae isolates. PLoS Pathog 2011; 7:e1002132. [PMID: 21799664 PMCID: PMC3136466 DOI: 10.1371/journal.ppat.1002132] [Citation(s) in RCA: 296] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Accepted: 05/06/2011] [Indexed: 11/18/2022] Open
Abstract
Closely related pathogens may differ dramatically in host range, but the molecular, genetic, and evolutionary basis for these differences remains unclear. In many Gram- negative bacteria, including the phytopathogen Pseudomonas syringae, type III effectors (TTEs) are essential for pathogenicity, instrumental in structuring host range, and exhibit wide diversity between strains. To capture the dynamic nature of virulence gene repertoires across P. syringae, we screened 11 diverse strains for novel TTE families and coupled this nearly saturating screen with the sequencing and assembly of 14 phylogenetically diverse isolates from a broad collection of diseased host plants. TTE repertoires vary dramatically in size and content across all P. syringae clades; surprisingly few TTEs are conserved and present in all strains. Those that are likely provide basal requirements for pathogenicity. We demonstrate that functional divergence within one conserved locus, hopM1, leads to dramatic differences in pathogenicity, and we demonstrate that phylogenetics-informed mutagenesis can be used to identify functionally critical residues of TTEs. The dynamism of the TTE repertoire is mirrored by diversity in pathways affecting the synthesis of secreted phytotoxins, highlighting the likely role of both types of virulence factors in determination of host range. We used these 14 draft genome sequences, plus five additional genome sequences previously reported, to identify the core genome for P. syringae and we compared this core to that of two closely related non-pathogenic pseudomonad species. These data revealed the recent acquisition of a 1 Mb megaplasmid by a sub-clade of cucumber pathogens. This megaplasmid encodes a type IV secretion system and a diverse set of unknown proteins, which dramatically increases both the genomic content of these strains and the pan-genome of the species. Breakthroughs in genomics have unleashed a new suite of tools for studying the genetic bases of phenotypic differences across diverse bacterial isolates. Here, we analyze 19 genomes of P. syringae, a pathogen of many crop species, to reveal the genetic changes underlying differences in virulence across host plants ranging from rice to maple trees. Surprisingly, a pair of strains diverged dramatically via the acquisition of a 1 Mb megaplasmid, which constitutes roughly 14% of the genome. Novel plasmids and horizontal genetic exchange have contributed extensively to species-wide diversification. Type III effector proteins are essential for pathogenicity, exhibit wide diversity between strains and are present in distinct higher-level patterns across the species. Furthermore, we use sequence comparisons within an evolutionary context to identify functional changes in multiple virulence genes. Overall, our data provide a unique overview of evolutionary pressures within P. syringae and an important resource for the phytopathogen research community.
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Affiliation(s)
- David A. Baltrus
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Marc T. Nishimura
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Artur Romanchuk
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Jeff H. Chang
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - M. Shahid Mukhtar
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Karen Cherkis
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Jeff Roach
- Research Computing Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Sarah R. Grant
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Corbin D. Jones
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- Carolina Center for Genome Sciences, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- * E-mail: (CDJ, computational queries); (JLD, biological queries)
| | - Jeffery L. Dangl
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- Carolina Center for Genome Sciences, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- * E-mail: (CDJ, computational queries); (JLD, biological queries)
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Nguyen HP, Yeam I, Angot A, Martin GB. Two virulence determinants of type III effector AvrPto are functionally conserved in diverse Pseudomonas syringae pathovars. THE NEW PHYTOLOGIST 2010; 187:969-982. [PMID: 20122130 DOI: 10.1111/j.1469-8137.2009.03175.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
*The Pseudomonas syringae pv. tomato type III effector protein AvrPto has two functional domains that contribute additively to its ability to promote pathogen virulence in susceptible tomato plants and also defense responses in resistant tomato and tobacco genotypes. Here, we test the hypothesis that key amino acid residues in these two domains will be conserved even in sequence-divergent AvrPto proteins expressed by diverse P. syringae pathovars. *We cloned avrPto homologs from diverse P. syringae pathovars and characterized the four most diverse homologs from P. syringae pathovars mori, lachrymans, myricae and oryzae for their virulence activity and ability to elicit resistance in tomato and tobacco. *Key residues within the two AvrPto domains are conserved in three of the four homologs and are required for virulence activity and defense elicitation. AvrPto(oryzae), lacks conserved residues in each domain, but was found to be recognized by a previously unknown resistance gene in both tomato and tobacco. *Our results indicate that the two virulence domains of AvrPto are conserved in diverse pathovars despite the fact these domains are recognized by certain plant species. AvrPto may therefore function in pathovars infecting diverse plant species by targeting conserved host processes.
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Affiliation(s)
- Hanh P Nguyen
- Boyce Thompson Institute for Plant Research, Ithaca, NY 14853, USA
- Department of Plant Biology, Cornell University, Ithaca, NY 14853, USA
| | - Inhwa Yeam
- Boyce Thompson Institute for Plant Research, Ithaca, NY 14853, USA
| | - Aurelie Angot
- Boyce Thompson Institute for Plant Research, Ithaca, NY 14853, USA
| | - Gregory B Martin
- Boyce Thompson Institute for Plant Research, Ithaca, NY 14853, USA
- Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, NY 14853, USA
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9
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Yeam I, Nguyen HP, Martin GB. Phosphorylation of the Pseudomonas syringae effector AvrPto is required for FLS2/BAK1-independent virulence activity and recognition by tobacco. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2010; 61:16-24. [PMID: 19793077 DOI: 10.1111/j.1365-313x.2009.04028.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The type III effector protein AvrPto from Pseudomonas syringae pv. tomato is secreted into plant cells where it promotes bacterial growth and enhances symptoms of speck disease on susceptible tomato plants. The virulence activity of AvrPto is due, in part, to its interaction with components of host pattern recognition receptor complexes, which disrupts pathogen-associated molecular pattern-triggered immunity. This disruption mechanism requires a structural element of the AvrPto protein, the CD loop, which is also required for triggering Pto/Prf-mediated resistance in tomato. We have shown previously that the carboxyl-terminal domain (CTD) of AvrPto is phosphorylated and also contributes to bacterial virulence. Here we report that phosphorylation of the CTD on S147 and S149 promotes bacterial virulence in an FLS2/BAK1-independent manner, which is mechanistically distinct from the CD loop. In a striking corollary with Pto recognition of the CD loop in tomato, the tobacco species Nicotiana sylvestris and Nicotiana tabacum have a recognition mechanism that specifically detects the phosphorylation status of the CTD. Thus different species in the Solanaceae family have evolved distinct recognition mechanisms to monitor the same type III effector.
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Affiliation(s)
- Inhwa Yeam
- Boyce Thompson Institute for Plant Research, Ithaca, NY 14853, USA
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10
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Luo Y, Caldwell KS, Wroblewski T, Wright ME, Michelmore RW. Proteolysis of a negative regulator of innate immunity is dependent on resistance genes in tomato and Nicotiana benthamiana and induced by multiple bacterial effectors. THE PLANT CELL 2009; 21:2458-72. [PMID: 19671880 PMCID: PMC2751963 DOI: 10.1105/tpc.107.056044] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2007] [Revised: 06/17/2009] [Accepted: 07/16/2009] [Indexed: 05/19/2023]
Abstract
RPM1-interacting protein 4 (RIN4), a negative regulator of the basal defense response in plants, is targeted by multiple bacterial virulence effectors. We show that RIN4 degradation is induced by the effector AvrPto from Pseudomonas syringae and that this degradation in Solanaceous plants is dependent on the resistance protein, Pto, a protein kinase, and Prf, a nucleotide binding site-leucine-rich repeat protein. Our data demonstrate overlap between two of the best-characterized pathways for recognition of pathogen virulence effectors in plants. RIN4 interacts with multiple plant signaling components and bacterial effectors in yeast and in planta. AvrPto induces an endogenous proteolytic activity in both tomato (Solanum lycopersicum) and Nicotiana benthamiana that degrades RIN4 and requires the consensus site cleaved by the protease effector AvrRpt2. The interaction between AvrPto and Pto, but not the kinase activity of Pto, is required for proteolysis of RIN4. Analysis of many of the effectors comprising the secretome of P. syringae pv tomato DC3000 led to the identification of two additional sequence-unrelated effectors that can also induce degradation of RIN4. Therefore, multiple bacterial effectors besides AvrRpt2 elicit proteolysis of RIN4 in planta.
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Affiliation(s)
- Yao Luo
- The Genome Center, University of California, Davis, California 95616, USA
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11
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Dong J, Xiao F, Fan F, Gu L, Cang H, Martin GB, Chai J. Crystal structure of the complex between Pseudomonas effector AvrPtoB and the tomato Pto kinase reveals both a shared and a unique interface compared with AvrPto-Pto. THE PLANT CELL 2009; 21:1846-59. [PMID: 19509331 PMCID: PMC2714939 DOI: 10.1105/tpc.109.066878] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2009] [Revised: 05/11/2009] [Accepted: 05/19/2009] [Indexed: 05/18/2023]
Abstract
Resistance to bacterial speck disease in tomato (Solanum lycopersicum) is activated upon recognition by the host Pto kinase of either one of two sequence-unrelated effector proteins, AvrPto or AvrPtoB, from Pseudomonas syringae pv tomato (Pst). Pto induces Pst immunity by acting in concert with the Prf protein. The recently reported structure of the AvrPto-Pto complex revealed that interaction of AvrPto with Pto appears to relieve an inhibitory effect of Pto, allowing Pto to activate Prf. Here, we present the crystal structure of the Pto binding domain of AvrPtoB (residues 121 to 205) at a resolution of 1.9A and of the AvrPtoB(121-205)-Pto complex at a resolution of 3.3 A. AvrPtoB(121-205) exhibits a tertiary fold that is completely different from that of AvrPto, and its conformation remains largely unchanged upon binding to Pto. In common with AvrPto-Pto, the AvrPtoB-Pto complex relies on two interfaces. One of these interfaces is similar in both complexes, although the primary amino acid sequences from the two effector proteins are very different. Amino acid substitutions in Pto at the other interface disrupt the interaction of AvrPtoB-Pto but not that of AvrPto-Pto. Interestingly, substitutions in Pto affecting this unique interface also cause Pto to induce Prf-dependent host cell death independently of either effector protein.
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Affiliation(s)
- Jing Dong
- Institute of Biophysics, Chinese Academy of Sciences, Beijing 100875, China
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12
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Xiao F, He P, Abramovitch RB, Dawson JE, Nicholson LK, Sheen J, Martin GB. The N-terminal region of Pseudomonas type III effector AvrPtoB elicits Pto-dependent immunity and has two distinct virulence determinants. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2007; 52:595-614. [PMID: 17764515 PMCID: PMC2265002 DOI: 10.1111/j.1365-313x.2007.03259.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Resistance to bacterial speck disease in tomato is activated by the physical interaction of the host Pto kinase with either of the sequence-dissimilar type III effector proteins AvrPto or AvrPtoB (HopAB2) from Pseudomonas syringae pv. tomato. Pto-mediated immunity requires Prf, a protein with a nucleotide-binding site and leucine-rich repeats. The N-terminal 307 amino acids of AvrPtoB were previously reported to interact with the Pto kinase, and we show here that this region (AvrPtoB(1-307)) is sufficient for eliciting Pto/Prf-dependent immunity against P. s. pv. tomato. AvrPtoB(1-307) was also found to be sufficient for a virulence activity that enhances ethylene production and increases growth of P. s. pv. tomato and severity of speck disease on susceptible tomato lines lacking either Pto or Prf. Moreover, we found that residues 308-387 of AvrPtoB are required for the previously reported ability of AvrPtoB to suppress pathogen-associated molecular patterns-induced basal defenses in Arabidopsis. Thus, the N-terminal region of AvrPtoB has two structurally distinct domains involved in different virulence-promoting mechanisms. Random and targeted mutagenesis identified five tightly clustered residues in AvrPtoB(1-307) that are required for interaction with Pto and for elicitation of immunity to P. s. pv. tomato. Mutation of one of the five clustered residues abolished the ethylene-associated virulence activity of AvrPtoB(1-307). However, individual mutations of the other four residues, despite abolishing interaction with Pto and avirulence activity, had no effect on AvrPtoB(1-307) virulence activity. None of these mutations affected the basal defense-suppressing activity of AvrPtoB(1-387). Based on sequence alignments, estimates of helical propensity, and the previously reported structure of AvrPto, we hypothesize that the Pto-interacting domains of AvrPto and AvrPtoB(1-307) have structural similarity. Together, these data support a model in which AvrPtoB(1-307) promotes ethylene-associated virulence by interaction not with Pto but with another unknown host protein.
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Affiliation(s)
- Fangming Xiao
- Boyce Thompson Institute for Plant Research, Tower Road, Ithaca, NY 14853, USA
| | - Ping He
- Department of Molecular Biology, Massachusetts General Hospital and Department of Genetics, Harvard Medical School, Boston, MA 02114, USA
| | - Robert B. Abramovitch
- Boyce Thompson Institute for Plant Research, Tower Road, Ithaca, NY 14853, USA
- Department of Plant Pathology, Cornell University, Ithaca, NY 14853, USA
| | - Jennifer E. Dawson
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - Linda K. Nicholson
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - Jen Sheen
- Department of Molecular Biology, Massachusetts General Hospital and Department of Genetics, Harvard Medical School, Boston, MA 02114, USA
| | - Gregory B. Martin
- Boyce Thompson Institute for Plant Research, Tower Road, Ithaca, NY 14853, USA
- Department of Plant Pathology, Cornell University, Ithaca, NY 14853, USA
- *For correspondence (fax +1 607 255 6695; e-mail )
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13
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Anderson JC, Pascuzzi PE, Xiao F, Sessa G, Martin GB. Host-mediated phosphorylation of type III effector AvrPto promotes Pseudomonas virulence and avirulence in tomato. THE PLANT CELL 2006; 18:502-14. [PMID: 16399801 PMCID: PMC1356555 DOI: 10.1105/tpc.105.036590] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2005] [Revised: 11/29/2005] [Accepted: 12/12/2005] [Indexed: 05/06/2023]
Abstract
The AvrPto protein from Pseudomonas syringae pv tomato is delivered into plant cells by the bacterial type III secretion system, where it either promotes host susceptibility or, in tomato plants expressing the Pto kinase, elicits disease resistance. Using two-dimensional gel electrophoresis, we obtained evidence that AvrPto is phosphorylated when expressed in plant leaves. In vitro phosphorylation of AvrPto by plant extracts occurs independently of Pto and is due to a kinase activity that is conserved in tomato (Solanum lycopersicum), tobacco (Nicotiana tabacum), and Arabidopsis thaliana. Three Ser residues clustered in the C-terminal 18 amino acids of AvrPto were identified in vitro as putative phosphorylation sites, and one site at S149 was directly confirmed as an in vivo phosphorylation site by mass spectrometry. Substitution of Ala for S149 significantly decreased the ability of AvrPto to enhance disease symptoms and promote growth of P. s. tomato in susceptible tomato leaves. In addition, S149A significantly decreased the avirulence activity of AvrPto in resistant tomato plants. Our observations support a model in which AvrPto has evolved to mimic a substrate of a highly conserved plant kinase to enhance its virulence activity. Furthermore, residues of AvrPto that promote virulence are also monitored by plant defenses.
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Affiliation(s)
- Jeffrey C Anderson
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York 14853-2703, USA
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14
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Singer AU, Desveaux D, Betts L, Chang JH, Nimchuk Z, Grant SR, Dangl JL, Sondek J. Crystal structures of the type III effector protein AvrPphF and its chaperone reveal residues required for plant pathogenesis. Structure 2005; 12:1669-81. [PMID: 15341731 DOI: 10.1016/j.str.2004.06.023] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2004] [Revised: 06/17/2004] [Accepted: 06/24/2004] [Indexed: 12/31/2022]
Abstract
The avrPphF locus from Pseudomonas syringae pv. phaseolicola, the causative agent of bean halo-blight disease, encodes proteins which either enhance virulence on susceptible hosts or elicit defense responses on hosts carrying the R1 resistance gene. Here we present the crystal structures of the two proteins from the avrPphF operon. The structure of AvrPphF ORF1 is strikingly reminiscent of type III chaperones from bacterial pathogens of animals, indicating structural conservation of these specialized chaperones, despite high sequence divergence. The AvrPphF ORF2 effector adopts a novel "mushroom"-like structure containing "head" and "stalk" subdomains. The head subdomain possesses limited structural homology to the catalytic domain of bacterial ADP-ribosyltransferases (ADP-RTs), though no ADP-RT activity was detected for AvrPphF ORF2 in standard assays. Nonetheless, this structural similarity identified two clusters of conserved surface-exposed residues important for both virulence mediated by AvrPphF ORF2 and recognition of this effector by bean plants expressing the R1 resistance gene.
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Affiliation(s)
- Alex U Singer
- Department of Pharmacology, University of North Carolina at Chapel Hill, 27599, USA
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15
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Bernal AJ, Pan Q, Pollack J, Rose L, Kozik A, Willits N, Luo Y, Guittet M, Kochetkova E, Michelmore RW. Functional analysis of the plant disease resistance gene Pto using DNA shuffling. J Biol Chem 2005; 280:23073-83. [PMID: 15790558 DOI: 10.1074/jbc.m500992200] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Pto is a serine/threonine kinase that mediates resistance in tomato to strains of Pseudomonas syringae pv. tomato expressing the (a)virulence proteins AvrPto or AvrPtoB. DNA shuffling was used as a combinatorial in vitro genetic approach to dissect the functional regions of Pto. The Pto gene was shuffled with four of its paralogs from a resistant haplotype to create a library of recombinant products that was screened for interaction with AvrPto in yeast. All interacting clones and a representative sample of noninteracting clones were sequenced, and their ability to signal downstream was tested by the elicitation of a hypersensitive response in an AvrPto-dependent or -independent manner in planta. Eight candidate regions important for binding to AvrPto or for downstream signaling were identified by statistical correlations between individual amino acid positions and phenotype. A subset of the regions had previously been identified as important for recognition, confirming the validity of the shuffling approach. Three novel regions important for Pto function were validated by site-directed mutagenesis. Several chimeras and point mutants exhibited a differential interaction with (a)virulence proteins in the AvrPto and VirPphA family, demonstrating distinct binding requirements for different ligands. Additionally, the identification of chimeras that are both constitutively active as well as capable of binding AvrPto indicates that elicitation of downstream signaling does not involve a conformational change that precludes binding of AvrPto, as previously hypothesized. The correlations between phenotypes and variation generated by DNA shuffling paralleled natural variation observed between orthologs of Pto from Lycopersicon spp.
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Affiliation(s)
- Adriana J Bernal
- Department of Plant Pathology, University of California, Davis, 95616, USA
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16
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Wulf J, Pascuzzi PE, Fahmy A, Martin GB, Nicholson LK. The solution structure of type III effector protein AvrPto reveals conformational and dynamic features important for plant pathogenesis. Structure 2005; 12:1257-68. [PMID: 15242602 DOI: 10.1016/j.str.2004.04.017] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2004] [Revised: 04/28/2004] [Accepted: 04/28/2004] [Indexed: 12/01/2022]
Abstract
Pseudomonas syringae pv. tomato, the causative agent of bacterial speck disease of tomato, uses a type III secretion system (TTSS) to deliver effector proteins into the host cell. In resistant plants, the bacterial effector protein AvrPto physically interacts with the host Pto kinase and elicits antibacterial defense responses. In susceptible plants, which lack the Pto kinase, AvrPto acts as a virulence factor to promote bacterial growth. The solution structure of AvrPto reveals a functional core consisting of a three-helix bundle motif flanked by disordered N- and C-terminal tails. Residues required for Pto binding lie in a 19 residue Omega loop. Modeling suggests a hydrophobic patch involving the activation loop of Pto forms a contact surface with the AvrPto Omega loop and that helix packing mediates interactions between AvrPto and putative virulence targets Api2 and Api3. The AvrPto structure has a low stability that may facilitate chaperone-independent secretion by the TTSS.
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Affiliation(s)
- Jennifer Wulf
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
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17
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Horita DA. Attack of the Killer Tomato Pathogens. Structure 2004; 12:1122-3. [PMID: 15242585 DOI: 10.1016/j.str.2004.06.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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18
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Martin GB, Bogdanove AJ, Sessa G. Understanding the functions of plant disease resistance proteins. ANNUAL REVIEW OF PLANT BIOLOGY 2003; 54:23-61. [PMID: 14502984 DOI: 10.1146/annurev.arplant.54.031902.135035] [Citation(s) in RCA: 523] [Impact Index Per Article: 24.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Many disease resistance (R) proteins of plants detect the presence of disease-causing bacteria, viruses, or fungi by recognizing specific pathogen effector molecules that are produced during the infection process. Effectors are often pathogen proteins that probably evolved to subvert various host processes for promotion of the pathogen life cycle. Five classes of effector-specific R proteins are known, and their sequences suggest roles in both effector recognition and signal transduction. Although some R proteins may act as primary receptors of pathogen effector proteins, most appear to play indirect roles in this process. The functions of various R proteins require phosphorylation, protein degradation, or specific localization within the host cell. Some signaling components are shared by many R gene pathways whereas others appear to be pathway specific. New technologies arising from the genomics and proteomics revolution will greatly expand our ability to investigate the role of R proteins in plant disease resistance.
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Affiliation(s)
- Gregory B Martin
- Boyce Thompson Institute for Plant Research and Department of Plant Pathology, Cornell University, Ithaca, New York 14853, USA.
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19
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Pedley KF, Martin GB. Molecular basis of Pto-mediated resistance to bacterial speck disease in tomato. ANNUAL REVIEW OF PHYTOPATHOLOGY 2003; 41:215-43. [PMID: 14527329 DOI: 10.1146/annurev.phyto.41.121602.143032] [Citation(s) in RCA: 139] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
The Pto gene in tomato confers gene-for-gene resistance to Pseudomonas syringae pv. tomato, the causative agent of bacterial speck disease. Pto was first introgressed from a wild species of tomato into cultivated tomato varieties over 60 years ago and is now widely used to control speck disease. Cloning of the Pto gene revealed that it encodes a cytoplasmically localized serine-threonine protein kinase. The molecular basis of gene-for-gene recognition in this pathosystem is the direct physical interaction of the Pto kinase with either of two Pseudomonas effector proteins, AvrPto and AvrPtoB. Upon recognition of AvrPto or AvrPtoB, the Pto kinase acts in concert with Prf, a leucine-rich repeat-containing protein, to activate multiple signal transduction pathways. There has been much progress in understanding the evolutionary origin of the Pto gene, structural details about how the Pto kinase interacts with AvrPto and AvrPtoB, signaling steps downstream of Pto, and defense responses activated by the Pto pathway. Future work on this model system will focus on how the interaction of the Pto kinase with bacterial effector proteins activates signal transduction, defining the specific role of signaling components, and ultimately, determining which host defense responses are most responsible for inhibiting growth of the pathogen and suppressing symptoms of bacterial speck disease.
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Affiliation(s)
- Kerry F Pedley
- Boyce Thompson Institute for Plant Research, Cornell University, Ithaca, NY 14853, USA.
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20
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Bogdanove AJ. Pto update: recent progress on an ancient plant defence response signalling pathway. MOLECULAR PLANT PATHOLOGY 2002; 3:283-288. [PMID: 20569336 DOI: 10.1046/j.1364-3703.2002.00117.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Summary The Pto resistance gene in a gene-for-gene interaction with the avrPto avirulence gene governs resistance to bacterial speck of tomato. A member of a small gene family in tomato, Pto encodes a serine/threonine kinase that interacts in the yeast two-hybrid system with the product of avrPto, an 18-kDa hydrophilic protein. Over the past decade, studies of these genes, their products, and the defence response signalling pathway they govern have led to significant advances in our understanding of the biochemistry of Pto, the bacterial delivery and Pto recognition specificity for AvrPto, and candidate components in the pathway and their potential functions. This article provides an update of recent advances, which include the discovery of AvrPto structure-function relationships in disease and resistance, discovery of a second avirulence protein (AvrPtoB) recognized by Pto and its limited similarity to AvrPto, expression analysis and functional characterization of transcription factors Pti4, Pti5, and Pti6 that interact with Pto, analyses of Pto over-expression that activates defence responses independent of AvrPto, and comparisons of Pto gene family members and homologues in tomato and other Solanaceae, as well as other plant species. These comparisons, in particular, have provided exciting new insight into the antiquity of the Pto gene family and of the capacity for specific recognition of AvrPto that activates plant defence.
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Affiliation(s)
- Adam J Bogdanove
- Department of Plant Pathology, 351 Bessey Hall, Iowa State University, Ames, IA 50011, USA
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21
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Kim YJ, Lin NC, Martin GB. Two distinct Pseudomonas effector proteins interact with the Pto kinase and activate plant immunity. Cell 2002; 109:589-98. [PMID: 12062102 DOI: 10.1016/s0092-8674(02)00743-2] [Citation(s) in RCA: 229] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The Pto serine/threonine kinase of tomato confers resistance to speck disease by recognizing strains of Pseudomonas syringae that express the protein AvrPto. Pto and AvrPto physically interact, and this interaction is required for activation of host resistance. We identified a second Pseudomonas protein, AvrPtoB, that interacts specifically with Pto and is widely distributed among plant pathogens. AvrPtoB is delivered into the plant cell by the bacterial type III secretion system, and it elicits Pto-specific defenses. AvrPtoB has little overall sequence similarity with AvrPto. However, AvrPto amino acids, which are required for interaction with Pto, are present in AvrPtoB and required for its interaction with Pto. Thus, two distinct bacterial effectors activate plant immunity by interacting with the same host protein kinase through a similar structural mechanism.
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Affiliation(s)
- Young Jin Kim
- Boyce Thompson Institute for Plant Research, Ithaca, NY 14853, USA
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22
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Nimchuk Z, Rohmer L, Chang JH, Dangl JL. Knowing the dancer from the dance: R-gene products and their interactions with other proteins from host and pathogen. CURRENT OPINION IN PLANT BIOLOGY 2001; 4:288-294. [PMID: 11418337 DOI: 10.1016/s1369-5266(00)00175-8] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Cloning of plant disease resistance genes is now commonplace in model plants. Recent attention has turned to how the proteins that they encode function biochemically to recognize their cognate Avirulence protein and to initiate the disease-resistance response. In addition, attention has turned to how the Avirulence proteins of pathogens might alter susceptible hosts for the benefit of the pathogen, and what plant proteins might be required for that process.
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Affiliation(s)
- Z Nimchuk
- Department of Biology and Curriculum in Genetics, Coker Hall, Room 108, CB#3280, University of North Carolina, Chapel Hill, North Carolina 27599-3280, USA
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