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Pal G, Ingole KD, Yavvari PS, Verma P, Kumari A, Chauhan C, Chaudhary D, Srivastava A, Bajaj A, Vemanna RS. Exogenous application of nanocarrier-mediated double-stranded RNA manipulates physiological traits and defence response against bacterial diseases. Mol Plant Pathol 2024; 25:e13417. [PMID: 38279851 PMCID: PMC10799200 DOI: 10.1111/mpp.13417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 12/09/2023] [Accepted: 12/17/2023] [Indexed: 01/29/2024]
Abstract
Stability and delivery are major challenges associated with exogenous double-stranded RNA (dsRNA) application into plants. We report the encapsulation and delivery of dsRNA in cationic poly-aspartic acid-derived polymer (CPP6) into plant cells. CPP6 stabilizes the dsRNAs during long exposure at varied temperatures and pH, and protects against RNase A degradation. CPP6 helps dsRNA uptake through roots or foliar spray and facilitates systemic movement to induce endogenous gene silencing. The fluorescence of Arabidopsis GFP-overexpressing transgenic plants was significantly reduced after infiltration with gfp-dsRNA-CPP6 by silencing of the transgene compared to plants treated only with gfp-dsRNA. The plant endogenous genes flowering locus T (FT) and phytochrome interacting factor 4 (PIF4) were downregulated by a foliar spray of ft-dsRNA-CPP6 and pif4-dsRNA-CPP6 in Arabidopsis, with delayed flowering and enhanced biomass. The rice PDS gene targeted by pds-dsRNA-CPP6 through root uptake was effectively silenced and plants showed a dwarf and albino phenotype. The NaCl-induced OsbZIP23 was targeted through root uptake of bzip23-dsRNA-CPP6 and showed reduced transcripts and seedling growth compared to treatment with naked dsRNA. The negative regulators of plant defence SDIR1 and SWEET14 were targeted through foliar spray to provide durable resistance against bacterial leaf blight disease caused by Xanthomonas oryzae pv. oryzae (Xoo). Overall, the study demonstrates that transient silencing of plant endogenous genes using polymer-encapsulated dsRNA provides prolonged and durable resistance against Xoo, which could be a promising tool for crop protection and for sustaining productivity.
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Affiliation(s)
- Garima Pal
- Laboratory of Plant Functional GenomicsRegional Centre for Biotechnology, NCR Biotech Science ClusterFaridabadIndia
| | - Kishor D. Ingole
- Laboratory of Plant Functional GenomicsRegional Centre for Biotechnology, NCR Biotech Science ClusterFaridabadIndia
| | | | - Priyanka Verma
- Laboratory of Nanotechnology and Chemical BiologyRegional Centre for Biotechnology, NCR Biotech Science ClusterFaridabadIndia
| | - Ankit Kumari
- Plant Genetic Engineering LabCentre for Biotechnology, Maharshi Dayananda UniversityRohtakIndia
| | - Chetan Chauhan
- Laboratory of Plant Functional GenomicsRegional Centre for Biotechnology, NCR Biotech Science ClusterFaridabadIndia
| | - Darshna Chaudhary
- Plant Genetic Engineering LabCentre for Biotechnology, Maharshi Dayananda UniversityRohtakIndia
| | - Aasheesh Srivastava
- Department of ChemistryIndian Institute of Science Education and ResearchBhopalIndia
| | - Avinash Bajaj
- Laboratory of Nanotechnology and Chemical BiologyRegional Centre for Biotechnology, NCR Biotech Science ClusterFaridabadIndia
| | - Ramu S. Vemanna
- Laboratory of Plant Functional GenomicsRegional Centre for Biotechnology, NCR Biotech Science ClusterFaridabadIndia
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2
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Zárate-Chaves CA, Audran C, Medina Culma CA, Escalon A, Javegny S, Gagnevin L, Thomas E, Pimparé LL, López CE, Jacobs JM, Noël LD, Koebnik R, Bernal AJ, Szurek B. CRISPRi in Xanthomonas demonstrates functional convergence of transcription activator-like effectors in two divergent pathogens. New Phytol 2023; 238:1593-1604. [PMID: 36764921 DOI: 10.1111/nph.18808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Accepted: 02/02/2023] [Indexed: 06/18/2023]
Abstract
Functional analysis of large gene families in plant pathogens can be cumbersome using classical insertional mutagenesis. Additionally, Cas9 toxicity has limited the application of CRISPR-Cas9 for directed mutagenesis in bacteria. Here, we successfully applied a CRISPR interference strategy to investigate the cryptic role of the transcription activator-like effector (tale) multigene family in several plant-pathogenic Xanthomonas bacterial species, owing to their contribution to pathogen virulence. Single guide RNAs (sgRNAs) designed against Xanthomonas phaseoli pv manihotis tale conserved gene sequences efficiently silenced expression of all tales, with concomitant decrease in virulence and TALE-induced host gene expression. The system is readily translatable to other Xanthomonas species infecting rice, citrus, Brassica, and cassava, silencing up to 16 tales in a given strain using a single sgRNA. Complementation with plasmid-borne designer tales lacking the sgRNA-targeted sequence restored molecular and virulence phenotypes in all pathosystems. Our results evidenced that X. campestris pv campestris CN08 tales are relevant for symptom development in cauliflower. They also show that the MeSWEET10a sugar transporter is surprisingly targeted by the nonvascular cassava pathogen X. cassavae, highlighting a new example of TALE functional convergence between phylogenetically distant Xanthomonas. Overall, this novel technology provides a platform for discovery and rapid functional understanding of highly conserved gene families.
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Affiliation(s)
| | - Corinne Audran
- LIPME, Université de Toulouse, INRAE, CNRS, Castanet-Tolosan, 31326, France
| | - César Augusto Medina Culma
- Laboratorio de interacciones moleculares de microorganismos agrícolas (LIMMA), Universidad de los Andes, Bogotá, 111711, Colombia
| | - Aline Escalon
- CIRAD, UMR PVBMT, Saint-Pierre, 97410, La Réunion, France
| | | | - Lionel Gagnevin
- PHIM, Univ Montpellier, IRD, CIRAD, INRAE, Institut Agro, Montpellier, 34394, France
| | - Emilie Thomas
- PHIM, Univ Montpellier, IRD, CIRAD, INRAE, Institut Agro, Montpellier, 34394, France
| | - Léa-Lou Pimparé
- PHIM, Univ Montpellier, IRD, CIRAD, INRAE, Institut Agro, Montpellier, 34394, France
| | - Camilo E López
- Manihot Biotec, Departamento de Biología, Universidad Nacional de Colombia, Bogotá, 111321, Colombia
| | - Jonathan M Jacobs
- PHIM, Univ Montpellier, IRD, CIRAD, INRAE, Institut Agro, Montpellier, 34394, France
- Department of Plant Pathology, The Ohio State University, Columbus, OH, 43210, USA
- Infectious Diseases Institute, The Ohio State University, Columbus, OH, 43210-1358, USA
| | - Laurent D Noël
- LIPME, Université de Toulouse, INRAE, CNRS, Castanet-Tolosan, 31326, France
| | - Ralf Koebnik
- PHIM, Univ Montpellier, IRD, CIRAD, INRAE, Institut Agro, Montpellier, 34394, France
| | - Adriana Jimena Bernal
- Laboratorio de interacciones moleculares de microorganismos agrícolas (LIMMA), Universidad de los Andes, Bogotá, 111711, Colombia
| | - Boris Szurek
- PHIM, Univ Montpellier, IRD, CIRAD, INRAE, Institut Agro, Montpellier, 34394, France
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3
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Schenstnyi K, Strauß A, Dressel A, Morbitzer R, Wunderlich M, Andrade AG, Phan TTT, Aguilera PDLA, Brancato C, Berendzen KW, Lahaye T. The tomato resistance gene Bs4 suppresses leaf watersoaking phenotypes induced by AvrHah1, a transcription activator-like effector from tomato-pathogenic xanthomonads. New Phytol 2022; 236:1856-1870. [PMID: 36056465 DOI: 10.1111/nph.18456] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 08/19/2022] [Indexed: 06/15/2023]
Abstract
The Xanthomonas transcription activator-like effector (TALE) protein AvrBs3 transcriptionally activates the executor-type resistance (R) gene Bs3 from pepper (Capsicum annuum), thereby triggering a hypersensitive cell death reaction (HR). AvrBs3 also triggers an HR in tomato (Solanum lycopersicum) upon recognition by the nucleotide-binding leucine-rich repeat (NLR) R protein Bs4. Whether the executor-type R protein Bs3 and the NLR-type R protein Bs4 use common or distinct signalling components to trigger an HR remains unclear. CRISPR/Cas9-mutagenesis revealed, that the immune signalling node EDS1 is required for Bs4- but not for Bs3-dependent HR, suggesting that NLR- and executor-type R proteins trigger an HR via distinct signalling pathways. CRISPR/Cas9-mutagenesis also revealed that tomato Bs4 suppresses the virulence function of both TALEs, the HR-inducing AvrBs3 protein and of AvrHah1, a TALE that does not trigger an HR in tomato. Analysis of AvrBs3- and AvrHah1-induced host transcripts and disease phenotypes in CRISPR/Cas9-induced bs4 mutant plants indicates that both TALEs target orthologous transcription factor genes to promote disease in tomato and pepper host plants. Our studies display that tomato mutants lacking the TALE-sensing Bs4 protein provide a novel platform to either uncover TALE-induced disease phenotypes or genetically dissect components of executor-triggered HR.
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Affiliation(s)
- Kyrylo Schenstnyi
- University of Tübingen, ZMBP - General Genetics, Auf der Morgenstelle 32, 72076, Tuebingen, Germany
| | - Annett Strauß
- University of Tübingen, ZMBP - General Genetics, Auf der Morgenstelle 32, 72076, Tuebingen, Germany
| | - Angela Dressel
- University of Tübingen, ZMBP - General Genetics, Auf der Morgenstelle 32, 72076, Tuebingen, Germany
| | - Robert Morbitzer
- University of Tübingen, ZMBP - General Genetics, Auf der Morgenstelle 32, 72076, Tuebingen, Germany
| | - Markus Wunderlich
- University of Tübingen, ZMBP - General Genetics, Auf der Morgenstelle 32, 72076, Tuebingen, Germany
| | - Ana Gabriela Andrade
- University of Tübingen, ZMBP - General Genetics, Auf der Morgenstelle 32, 72076, Tuebingen, Germany
| | - Trang-Thi-Thu Phan
- University of Tübingen, ZMBP - General Genetics, Auf der Morgenstelle 32, 72076, Tuebingen, Germany
| | | | - Caterina Brancato
- University of Tübingen, ZMBP - Central Facilities, Auf der Morgenstelle 32, 72076, Tuebingen, Germany
| | - Kenneth Wayne Berendzen
- University of Tübingen, ZMBP - Central Facilities, Auf der Morgenstelle 32, 72076, Tuebingen, Germany
| | - Thomas Lahaye
- University of Tübingen, ZMBP - General Genetics, Auf der Morgenstelle 32, 72076, Tuebingen, Germany
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Yoshihisa A, Yoshimura S, Shimizu M, Sato S, Matsuno S, Mine A, Yamaguchi K, Kawasaki T. The rice OsERF101 transcription factor regulates the NLR Xa1-mediated immunity induced by perception of TAL effectors. New Phytol 2022; 236:1441-1454. [PMID: 36050871 PMCID: PMC9826229 DOI: 10.1111/nph.18439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 08/08/2022] [Indexed: 06/15/2023]
Abstract
Plant nucleotide-binding leucine-rich repeat receptors (NLRs) initiate immune responses by recognizing pathogen effectors. The rice gene Xa1 encodes an NLR with an N-terminal BED domain, and recognizes transcription activator-like (TAL) effectors of Xanthomonas oryzae pv oryzae (Xoo). Our goal here was to elucidate the molecular mechanisms controlling the induction of immunity by Xa1. We used yeast two-hybrid assays to screen for host factors that interact with Xa1 and identified the AP2/ERF-type transcription factor OsERF101/OsRAP2.6. Molecular complementation assays were used to confirm the interactions among Xa1, OsERF101 and two TAL effectors. We created OsERF101-overexpressing and knockout mutant lines in rice and identified genes differentially regulated in these lines, many of which are predicted to be involved in the regulation of response to stimulus. Xa1 interacts in the nucleus with the TAL effectors and OsERF101 via the BED domain. Unexpectedly, both the overexpression and the knockout lines of OsERF101 displayed Xa1-dependent, enhanced resistance to an incompatible Xoo strain. Different sets of genes were up- or downregulated in the overexpression and knockout lines. Our results indicate that OsERF101 regulates the recognition of TAL effectors by Xa1, and functions as a positive regulator of Xa1-mediated immunity. Furthermore, an additional Xa1-mediated immune pathway is negatively regulated by OsERF101.
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Affiliation(s)
- Ayaka Yoshihisa
- Department of Advanced Bioscience, Graduate School of AgricultureKindai UniversityNakamachiNara631‐8505Japan
| | - Satomi Yoshimura
- Department of Advanced Bioscience, Graduate School of AgricultureKindai UniversityNakamachiNara631‐8505Japan
| | - Motoki Shimizu
- Division of Genomics and BreedingIwate Biotechnology Research CenterIwate024‐0003Japan
| | - Sayaka Sato
- Department of Advanced Bioscience, Graduate School of AgricultureKindai UniversityNakamachiNara631‐8505Japan
| | - Shogo Matsuno
- Department of Advanced Bioscience, Graduate School of AgricultureKindai UniversityNakamachiNara631‐8505Japan
| | - Akira Mine
- Graduate School of AgricultureKyoto UniversityKyoto606‐8502Japan
| | - Koji Yamaguchi
- Department of Advanced Bioscience, Graduate School of AgricultureKindai UniversityNakamachiNara631‐8505Japan
| | - Tsutomu Kawasaki
- Department of Advanced Bioscience, Graduate School of AgricultureKindai UniversityNakamachiNara631‐8505Japan
- Agricultural Technology and Innovation Research InstituteKindai UniversityNakamachiNara631‐8505Japan
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5
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Luneau JS, Baudin M, Quiroz Monnens T, Carrère S, Bouchez O, Jardinaud M, Gris C, François J, Ray J, Torralba B, Arlat M, Lewis JD, Lauber E, Deutschbauer AM, Noël LD, Boulanger A. Genome-wide identification of fitness determinants in the Xanthomonas campestris bacterial pathogen during early stages of plant infection. New Phytol 2022; 236:235-248. [PMID: 35706385 PMCID: PMC9543026 DOI: 10.1111/nph.18313] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 06/07/2022] [Indexed: 05/31/2023]
Abstract
Plant diseases are an important threat to food production. While major pathogenicity determinants required for disease have been extensively studied, less is known on how pathogens thrive during host colonization, especially at early infection stages. Here, we used randomly barcoded-transposon insertion site sequencing (RB-TnSeq) to perform a genome-wide screen and identify key bacterial fitness determinants of the vascular pathogen Xanthomonas campestris pv campestris (Xcc) during infection of the cauliflower host plant (Brassica oleracea). This high-throughput analysis was conducted in hydathodes, the natural entry site of Xcc, in xylem sap and in synthetic media. Xcc did not face a strong bottleneck during hydathode infection. In total, 181 genes important for fitness were identified in plant-associated environments with functional enrichment in genes involved in metabolism but only few genes previously known to be involved in virulence. The biological relevance of 12 genes was independently confirmed by phenotyping single mutants. Notably, we show that XC_3388, a protein with no known function (DUF1631), plays a key role in the adaptation and virulence of Xcc possibly through c-di-GMP-mediated regulation. This study revealed yet unsuspected social behaviors adopted by Xcc individuals when confined inside hydathodes at early infection stages.
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Affiliation(s)
- Julien S. Luneau
- LIPME, Université de Toulouse, INRAE, CNRSUniversité Paul Sabatier31320Castanet‐TolosanFrance
| | - Maël Baudin
- Plant Gene Expression Center, USDAAlbanyCA94710USA
- Department of Plant and Microbial BiologyUniversity of CaliforniaBerkeleyCA94720USA
| | - Thomas Quiroz Monnens
- LIPME, Université de Toulouse, INRAE, CNRSUniversité Paul Sabatier31320Castanet‐TolosanFrance
| | - Sébastien Carrère
- LIPME, Université de Toulouse, INRAE, CNRSUniversité Paul Sabatier31320Castanet‐TolosanFrance
| | - Olivier Bouchez
- Genotoul Genome & Transcriptome (GeT‐PlaGe), INRAE31320Castanet‐TolosanFrance
| | | | - Carine Gris
- LIPME, Université de Toulouse, INRAE, CNRSUniversité Paul Sabatier31320Castanet‐TolosanFrance
| | - Jonas François
- LIPME, Université de Toulouse, INRAE, CNRSUniversité Paul Sabatier31320Castanet‐TolosanFrance
| | - Jayashree Ray
- Environmental Genomics and Systems Biology DivisionLawrence Berkeley National LaboratoryBerkeleyCA94720USA
| | - Babil Torralba
- LIPME, Université de Toulouse, INRAE, CNRSUniversité Paul Sabatier31320Castanet‐TolosanFrance
| | - Matthieu Arlat
- LIPME, Université de Toulouse, INRAE, CNRSUniversité Paul Sabatier31320Castanet‐TolosanFrance
| | - Jennifer D. Lewis
- Plant Gene Expression Center, USDAAlbanyCA94710USA
- Department of Plant and Microbial BiologyUniversity of CaliforniaBerkeleyCA94720USA
| | - Emmanuelle Lauber
- LIPME, Université de Toulouse, INRAE, CNRSUniversité Paul Sabatier31320Castanet‐TolosanFrance
| | - Adam M. Deutschbauer
- Department of Plant and Microbial BiologyUniversity of CaliforniaBerkeleyCA94720USA
- Environmental Genomics and Systems Biology DivisionLawrence Berkeley National LaboratoryBerkeleyCA94720USA
| | - Laurent D. Noël
- LIPME, Université de Toulouse, INRAE, CNRSUniversité Paul Sabatier31320Castanet‐TolosanFrance
| | - Alice Boulanger
- LIPME, Université de Toulouse, INRAE, CNRSUniversité Paul Sabatier31320Castanet‐TolosanFrance
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6
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Nathawat R, Maku RV, Patel HK, Sankaranarayanan R, Sonti RV. Role of the FnIII domain associated with a cell wall-degrading enzyme cellobiosidase of Xanthomonas oryzae pv. oryzae. Mol Plant Pathol 2022; 23:1011-1021. [PMID: 35278018 PMCID: PMC9190976 DOI: 10.1111/mpp.13205] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 02/15/2022] [Accepted: 02/15/2022] [Indexed: 06/14/2023]
Abstract
Cellobiosidase (CbsA) is an important secreted virulence factor of Xanthomonas oryzae pv. oryzae (Xoo), which causes bacterial blight of rice. CbsA is one of several cell wall-degrading enzymes secreted by Xoo via the type II secretion system (T2SS). CbsA is considered a fundamental virulence factor for vascular pathogenesis. CbsA has an N-terminal glycosyl hydrolase domain and a C-terminal fibronectin type III (FnIII) domain. Interestingly, the secreted form of CbsA lacks the FnIII domain during in planta growth. Here we show that the presence of the FnIII domain inhibits the enzyme activity of CbsA on polysaccharide substrates like carboxymethylcellulose. The FnIII domain is required for the interaction of CbsA with SecB chaperone, and this interaction is crucial for the stability and efficient transport of CbsA across the inner membrane. Deletion of the FnIII domain reduced virulence similar to ΔcbsA Xoo, which corroborates the importance of the FnIII domain in CbsA. Our work elucidates a hitherto unknown function of the FnIII domain in enabling the virulence-promoting activity of CbsA.
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Affiliation(s)
| | - Roshan V. Maku
- CSIR – Centre for Cellular and Molecular BiologyHyderabadIndia
- Present address:
DBT – National Institute of Animal BiotechnologyHyderabadIndia
| | | | | | - Ramesh V. Sonti
- CSIR – Centre for Cellular and Molecular BiologyHyderabadIndia
- Present address:
Indian Institute of Science Education and Research TirupatiTirupatiIndia
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7
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Marash I, Leibman‐Markus M, Gupta R, Avni A, Bar M. TOR inhibition primes immunity and pathogen resistance in tomato in a salicylic acid-dependent manner. Mol Plant Pathol 2022; 23:1035-1047. [PMID: 35441436 PMCID: PMC9190978 DOI: 10.1111/mpp.13207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 02/08/2022] [Accepted: 02/18/2022] [Indexed: 06/14/2023]
Abstract
All organisms need to sense and process information about the availability of nutrients, energy status, and environmental cues to determine the best time for growth and development. The conserved target of rapamycin (TOR) protein kinase has a central role in sensing and perceiving nutritional information. TOR connects environmental information about nutrient availability to developmental and metabolic processes to maintain cellular homeostasis. Under favourable energy conditions, TOR is activated and promotes anabolic processes such as cell division, while suppressing catabolic processes. Conversely, when nutrients are limited or environmental stresses are present, TOR is inactivated, and catabolic processes are promoted. Given the central role of TOR in regulating metabolism, several previous works have examined whether TOR is wired to plant defence. To date, the mechanisms by which TOR influences plant defence are not entirely clear. Here, we addressed this question by testing the effect of inhibiting TOR on immunity and pathogen resistance in tomato. Examining which hormonal defence pathways are influenced by TOR, we show that tomato immune responses and disease resistance to several pathogens increase on TOR inhibition, and that TOR inhibition-mediated resistance probably requires a functional salicylic acid, but not jasmonic acid, pathway. Our results support the notion that TOR is a master regulator of the development-defence switch in plants.
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Affiliation(s)
- Iftah Marash
- Department of Plant Pathology and Weed ResearchAgricultural Research OrganizationVolcani InstituteBet DaganIsrael
- School of Plant Science and Food SecurityTel‐Aviv UniversityTel‐AvivIsrael
| | - Meirav Leibman‐Markus
- Department of Plant Pathology and Weed ResearchAgricultural Research OrganizationVolcani InstituteBet DaganIsrael
| | - Rupali Gupta
- Department of Plant Pathology and Weed ResearchAgricultural Research OrganizationVolcani InstituteBet DaganIsrael
| | - Adi Avni
- School of Plant Science and Food SecurityTel‐Aviv UniversityTel‐AvivIsrael
| | - Maya Bar
- Department of Plant Pathology and Weed ResearchAgricultural Research OrganizationVolcani InstituteBet DaganIsrael
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8
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Li R, Ren P, Liu Q, Yao J, Wu L, Zhu G, Xian X, Tang J, Lu G. McvR, a single domain response regulator regulates motility and virulence in the plant pathogen Xanthomonas campestris. Mol Plant Pathol 2022; 23:649-663. [PMID: 35152521 PMCID: PMC8995066 DOI: 10.1111/mpp.13186] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 12/19/2021] [Accepted: 01/07/2022] [Indexed: 06/14/2023]
Abstract
Signal transduction pathways mediated by sensor histidine kinases and cognate response regulators control a variety of physiological processes in response to environmental conditions in most bacteria. Comparatively little is known about the mechanism(s) by which single-domain response regulators (SD-RRs), which lack a dedicated output domain but harbour a phosphoryl receiver domain, exert their various regulatory effects in bacteria. Here we have examined the role of the SD-RR proteins encoded by the phytopathogen Xanthomonas campestris pv. campestris (Xcc). We describe the identification and characterization of a SD-RR protein named McvR (motility, chemotaxis, and virulence-related response regulator) that is required for virulence and motility regulation in Xcc. Deletion of the mcvR open reading frame caused reduced motility, chemotactic movement, and virulence in Xcc. Global transcriptome analyses revealed the McvR had a broad regulatory role and that most motility and pathogenicity genes were down-regulated in the mcvR mutant. Bacterial two-hybrid and protein pull-down assays revealed that McvR did not physically interact with components of the bacterial flagellum but interacts with other SD-RR proteins (like CheY) and the subset of DNA-binding proteins involved in gene regulation. Site-directed mutagenesis and phosphor-transfer experiments revealed that the aspartyl residue at position 55 of the receiver domain is important for phosphorylation and the regulatory activity of McvR protein. Taken together, the findings describe a previously unrecognized class of SD-RR protein that contributes to the regulation of motility and virulence in Xcc.
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Affiliation(s)
- Rui‐Fang Li
- Guangxi Key Laboratory of Biology for Crop Diseases and Insect PestsPlant Protection Research InstituteGuangxi Academy of Agricultural SciencesNanningChina
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐bioresourcesCollege of Life Science and TechnologyGuangxi UniversityNanningChina
| | - Pei‐Dong Ren
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐bioresourcesCollege of Life Science and TechnologyGuangxi UniversityNanningChina
| | - Qian‐Qian Liu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐bioresourcesCollege of Life Science and TechnologyGuangxi UniversityNanningChina
| | - Jia‐Li Yao
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐bioresourcesCollege of Life Science and TechnologyGuangxi UniversityNanningChina
| | - Liu Wu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐bioresourcesCollege of Life Science and TechnologyGuangxi UniversityNanningChina
| | - Gui‐Ning Zhu
- Guangxi Key Laboratory of Biology for Crop Diseases and Insect PestsPlant Protection Research InstituteGuangxi Academy of Agricultural SciencesNanningChina
| | - Xiao‐Yong Xian
- Guangxi Key Laboratory of Biology for Crop Diseases and Insect PestsPlant Protection Research InstituteGuangxi Academy of Agricultural SciencesNanningChina
| | - Ji‐Liang Tang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐bioresourcesCollege of Life Science and TechnologyGuangxi UniversityNanningChina
| | - Guang‐Tao Lu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐bioresourcesCollege of Life Science and TechnologyGuangxi UniversityNanningChina
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9
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Wu LB, Eom JS, Isoda R, Li C, Char SN, Luo D, Schepler-Luu V, Nakamura M, Yang B, Frommer WB. OsSWEET11b, a potential sixth leaf blight susceptibility gene involved in sugar transport-dependent male fertility. New Phytol 2022; 234:975-989. [PMID: 35211968 DOI: 10.1111/nph.18054] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2021] [Accepted: 02/14/2022] [Indexed: 06/14/2023]
Abstract
SWEETs play important roles in intercellular sugar transport. Induction of SWEET sugar transporters by Transcription Activator-Like effectors (TALe) of Xanthomonas ssp. is key for virulence in rice, cassava and cotton. We identified OsSWEET11b with roles in male fertility and potential bacterial blight (BB) susceptibility in rice. While single ossweet11a or 11b mutants were fertile, double mutants were sterile. As clade III SWEETs can transport gibberellin (GA), a key hormone for spikelet fertility, sterility and BB susceptibility might be explained by GA transport deficiencies. However, in contrast with the Arabidopsis homologues, OsSWEET11b did not mediate detectable GA transport. Fertility and susceptibility therefore are likely to depend on sucrose transport activity. Ectopic induction of OsSWEET11b by designer TALe enabled TALe-free Xanthomonas oryzae pv. oryzae (Xoo) to cause disease, identifying OsSWEET11b as a potential BB susceptibility gene and demonstrating that the induction of host sucrose uniporter activity is key to virulence of Xoo. Notably, only three of six clade III SWEETs are targeted by known Xoo strains from Asia and Africa. The identification of OsSWEET11b is relevant for fertility and for protecting rice against emerging Xoo strains that target OsSWEET11b.
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Affiliation(s)
- Lin-Bo Wu
- Institute for Molecular Physiology, Heinrich Heine University Düsseldorf, Düsseldorf, 40225, Germany
- Department of Agronomy and Crop Physiology, Institute for Agronomy and Plant Breeding I, Justus-Liebig University Giessen, Giessen, 35392, Germany
| | - Joon-Seob Eom
- Institute for Molecular Physiology, Heinrich Heine University Düsseldorf, Düsseldorf, 40225, Germany
| | - Reika Isoda
- Institute of Transformative Bio-Molecules (WPI-ITbM), Nagoya University, Chikusa, Nagoya, 464-8601, Japan
| | - Chenhao Li
- Division of Plant Science and Technology, Bond Life Sciences Center, University of Missouri, Columbia, MO, 65211, USA
| | - Si Nian Char
- Division of Plant Science and Technology, Bond Life Sciences Center, University of Missouri, Columbia, MO, 65211, USA
| | - Dangping Luo
- Division of Plant Science and Technology, Bond Life Sciences Center, University of Missouri, Columbia, MO, 65211, USA
| | - Van Schepler-Luu
- Institute for Molecular Physiology, Heinrich Heine University Düsseldorf, Düsseldorf, 40225, Germany
| | - Masayoshi Nakamura
- Institute of Transformative Bio-Molecules (WPI-ITbM), Nagoya University, Chikusa, Nagoya, 464-8601, Japan
| | - Bing Yang
- Division of Plant Science and Technology, Bond Life Sciences Center, University of Missouri, Columbia, MO, 65211, USA
- Donald Danforth Plant Science Center, St Louis, MO, 63132, USA
| | - Wolf B Frommer
- Institute for Molecular Physiology, Heinrich Heine University Düsseldorf, Düsseldorf, 40225, Germany
- Institute of Transformative Bio-Molecules (WPI-ITbM), Nagoya University, Chikusa, Nagoya, 464-8601, Japan
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10
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Zárate‐Chaves CA, Gómez de la Cruz D, Verdier V, López CE, Bernal A, Szurek B. Cassava diseases caused by Xanthomonas phaseoli pv. manihotis and Xanthomonas cassavae. Mol Plant Pathol 2021; 22:1520-1537. [PMID: 34227737 PMCID: PMC8578842 DOI: 10.1111/mpp.13094] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 05/04/2021] [Accepted: 05/04/2021] [Indexed: 05/27/2023]
Abstract
Xanthomonas phaseoli pv. manihotis (Xpm) and X. cassavae (Xc) are two bacterial pathogens attacking cassava. Cassava bacterial blight (CBB) is a systemic disease caused by Xpm, which might have dramatic effects on plant growth and crop production. Cassava bacterial necrosis is a nonvascular disease caused by Xc with foliar symptoms similar to CBB, but its impacts on the plant vigour and the crop are limited. In this review, we describe the epidemiology and ecology of the two pathogens, the impacts and management of the diseases, and the main research achievements for each pathosystem. Because Xc data are sparse, our main focus is on Xpm and CBB.
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Affiliation(s)
| | | | - Valérie Verdier
- PHIMUniversité MontpellierCIRADINRAeIRDInstitut AgroMontpellierFrance
| | - Camilo E. López
- Manihot Biotec, Departamento de BiologíaUniversidad Nacional de ColombiaBogotáColombia
| | - Adriana Bernal
- Laboratorio de Interacciones Moleculares de Microorganismos AgrícolasDepartamento de Ciencias BásicasUniversidad de los AndesBogotáColombia
| | - Boris Szurek
- PHIMUniversité MontpellierCIRADINRAeIRDInstitut AgroMontpellierFrance
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11
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Chen NWG, Ruh M, Darrasse A, Foucher J, Briand M, Costa J, Studholme DJ, Jacques M. Common bacterial blight of bean: a model of seed transmission and pathological convergence. Mol Plant Pathol 2021; 22:1464-1480. [PMID: 33942466 PMCID: PMC8578827 DOI: 10.1111/mpp.13067] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 03/22/2021] [Accepted: 03/22/2021] [Indexed: 05/31/2023]
Abstract
BACKGROUND Xanthomonas citri pv. fuscans (Xcf) and Xanthomonas phaseoli pv. phaseoli (Xpp) are the causal agents of common bacterial blight of bean (CBB), an important disease worldwide that remains difficult to control. These pathogens belong to distinct species within the Xanthomonas genus and have undergone a dynamic evolutionary history including the horizontal transfer of genes encoding factors probably involved in adaptation to and pathogenicity on common bean. Seed transmission is a key point of the CBB disease cycle, favouring both vertical transmission of the pathogen and worldwide distribution of the disease through global seed trade. TAXONOMY Kingdom: Bacteria; phylum: Proteobacteria; class: Gammaproteobacteria; order: Lysobacterales (also known as Xanthomonadales); family: Lysobacteraceae (also known as Xanthomonadaceae); genus: Xanthomonas; species: X. citri pv. fuscans and X. phaseoli pv. phaseoli (Xcf-Xpp). HOST RANGE The main host of Xcf-Xpp is the common bean (Phaseolus vulgaris). Lima bean (Phaseolus lunatus) and members of the Vigna genus (Vigna aconitifolia, Vigna angularis, Vigna mungo, Vigna radiata, and Vigna umbellata) are also natural hosts of Xcf-Xpp. Natural occurrence of Xcf-Xpp has been reported for a handful of other legumes such as Calopogonium sp., Pueraria sp., pea (Pisum sativum), Lablab purpureus, Macroptilium lathyroides, and Strophostyles helvola. There are conflicting reports concerning the natural occurrence of CBB agents on tepary bean (Phaseolus acutifolius) and cowpea (Vigna unguiculata subsp. unguiculata). SYMPTOMS CBB symptoms occur on all aerial parts of beans, that is, seedlings, leaves, stems, pods, and seeds. Symptoms initially appear as water-soaked spots evolving into necrosis on leaves, pustules on pods, and cankers on twigs. In severe infections, defoliation and wilting may occur. DISTRIBUTION CBB is distributed worldwide, meaning that it is frequently encountered in most places where bean is cultivated in the Americas, Asia, Africa, and Oceania, except for arid tropical areas. Xcf-Xpp are regulated nonquarantine pathogens in Europe and are listed in the A2 list by the European and Mediterranean Plant Protection Organization (EPPO). GENOME The genome consists of a single circular chromosome plus one to four extrachromosomal plasmids of various sizes, for a total mean size of 5.27 Mb with 64.7% GC content and an average predicted number of 4,181 coding sequences. DISEASE CONTROL Management of CBB is based on integrated approaches that comprise measures aimed at avoiding Xcf-Xpp introduction through infected seeds, cultural practices to limit Xcf-Xpp survival between host crops, whenever possible the use of tolerant or resistant bean genotypes, and chemical treatments, mainly restricted to copper compounds. The use of pathogen-free seeds is essential in an effective management strategy and requires appropriate sampling, detection, and identification methods. USEFUL WEBSITES: https://gd.eppo.int/taxon/XANTPH, https://gd.eppo.int/taxon/XANTFF, and http://www.cost.eu/COST_Actions/ca/CA16107.
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Affiliation(s)
- Nicolas W. G. Chen
- Univ Angers, Institut Agro, INRAE, IRHS, SFR QUASAV, F‐49000 Angers, France
| | - Mylène Ruh
- Univ Angers, Institut Agro, INRAE, IRHS, SFR QUASAV, F‐49000 Angers, France
| | - Armelle Darrasse
- Univ Angers, Institut Agro, INRAE, IRHS, SFR QUASAV, F‐49000 Angers, France
| | - Justine Foucher
- Univ Angers, Institut Agro, INRAE, IRHS, SFR QUASAV, F‐49000 Angers, France
| | - Martial Briand
- Univ Angers, Institut Agro, INRAE, IRHS, SFR QUASAV, F‐49000 Angers, France
| | - Joana Costa
- University of Coimbra, Centre for Functional Ecology ‐ Science for People & the Planet, Department of Life SciencesCoimbraPortugal
| | - David J. Studholme
- Biosciences, College of Life and Environmental SciencesUniversity of ExeterExeterUK
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12
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Tang D, Chen X, Jia Y, Liang Y, He Y, Lu T, Zhu C, Han B, An S, Tang J. Genome-wide screen and functional analysis in Xanthomonas reveal a large number of mRNA-derived sRNAs, including the novel RsmA-sequester RsmU. Mol Plant Pathol 2020; 21:1573-1590. [PMID: 32969159 PMCID: PMC7694677 DOI: 10.1111/mpp.12997] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 08/02/2020] [Accepted: 08/26/2020] [Indexed: 05/07/2023]
Abstract
Although bacterial small noncoding RNAs (sRNAs) are known to play a critical role in various cellular processes, including pathogenesis, the identity and action of such sRNAs are still poorly understood in many organisms. Here we have performed a genome-wide screen and functional analysis of the sRNAs in Xanthomonas campestris pv. campestris (Xcc), an important phytopathogen. The 50-500-nt RNA fragments isolated from the wild-type strain grown in a virulence gene-inducing condition were sequenced and a total of 612 sRNA candidates (SRCs) were identified. The majority (82%) of the SRCs were derived from mRNA, rather than specific sRNA genes. A representative panel of 121 SRCs were analysed by northern blotting; 117 SRCs were detected, supporting the contention that the overwhelming majority of the 612 SRCs identified are indeed sRNAs. Phenotypic analysis of strains overexpressing different candidates showed that a particular sRNA, RsmU, acts as a negative regulator of virulence, the hypersensitive response, and cell motility in Xcc. In vitro electrophoretic mobility shift assay and in vivo coimmunoprecipitation analyses indicated that RsmU interacted with the global posttranscriptional regulator RsmA, although sequence analysis displayed that RsmU is not a member of the sRNAs families known to antagonize RsmA. Northern blotting analyses demonstrated that RsmU has two isoforms that are processed from the 3'-untranslated region of the mRNA of XC1332 predicted to encode ComEA, a periplasmic protein required for DNA uptake in bacteria. This work uncovers an unexpected major sRNA biogenesis strategy in bacteria and a hidden layer of sRNA-mediated virulence regulation in Xcc.
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Affiliation(s)
- Dong‐Jie Tang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐bioresourcesCollege of Life Science and TechnologyGuangxi UniversityNanningChina
| | - Xiao‐Lin Chen
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐bioresourcesCollege of Life Science and TechnologyGuangxi UniversityNanningChina
- Present address:
Plant Protection Research InstituteGuangxi Academy of Agricultural Science174 Daxue RoadNanningGuangxi530007China
| | - Yu Jia
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐bioresourcesCollege of Life Science and TechnologyGuangxi UniversityNanningChina
| | - Yu‐Wei Liang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐bioresourcesCollege of Life Science and TechnologyGuangxi UniversityNanningChina
| | - Yuan‐Ping He
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐bioresourcesCollege of Life Science and TechnologyGuangxi UniversityNanningChina
| | - Ting‐Ting Lu
- National Center for Gene Research & Institute of Plant Physiology and EcologyShanghai Institutes of Biological SciencesChinese Academy of SciencesShanghaiChina
| | - Chuan‐Rang Zhu
- National Center for Gene Research & Institute of Plant Physiology and EcologyShanghai Institutes of Biological SciencesChinese Academy of SciencesShanghaiChina
| | - Bin Han
- National Center for Gene Research & Institute of Plant Physiology and EcologyShanghai Institutes of Biological SciencesChinese Academy of SciencesShanghaiChina
| | - Shi‐Qi An
- National Biofilms Innovation CentreBiological SciencesUniversity of SouthamptonSouthamptonUK
| | - Ji‐Liang Tang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐bioresourcesCollege of Life Science and TechnologyGuangxi UniversityNanningChina
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13
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Jia H, Wang N. Generation of homozygous canker-resistant citrus in the T0 generation using CRISPR-SpCas9p. Plant Biotechnol J 2020; 18:1990-1992. [PMID: 32167662 PMCID: PMC7540605 DOI: 10.1111/pbi.13375] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2020] [Revised: 02/21/2020] [Accepted: 02/28/2020] [Indexed: 05/09/2023]
Affiliation(s)
- Hongge Jia
- Citrus Research and Education CenterDepartment of Microbiology and Cell ScienceInstitute of Food and Agricultural Sciences (IFAS)University of FloridaLake AlfredFlUSA
| | - Nian Wang
- Citrus Research and Education CenterDepartment of Microbiology and Cell ScienceInstitute of Food and Agricultural Sciences (IFAS)University of FloridaLake AlfredFlUSA
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14
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Li R, Wang X, Wu L, Huang L, Qin Q, Yao J, Lu G, Tang J. Xanthomonas campestris sensor kinase HpaS co-opts the orphan response regulator VemR to form a branched two-component system that regulates motility. Mol Plant Pathol 2020; 21:360-375. [PMID: 31919999 PMCID: PMC7036368 DOI: 10.1111/mpp.12901] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 11/26/2019] [Accepted: 12/04/2019] [Indexed: 05/07/2023]
Abstract
Xanthomonas campestris pv. campestris (Xcc) controls virulence and plant infection mechanisms via the activity of the sensor kinase and response regulator pair HpaS/hypersensitive response and pathogenicity G (HrpG). Detailed analysis of the regulatory role of HpaS has suggested the occurrence of further regulators besides HrpG. Here we used in vitro and in vivo approaches to identify the orphan response regulator VemR as another partner of HpaS and to characterize relevant interactions between components of this signalling system. Bacterial two-hybrid and protein pull-down assays revealed that HpaS physically interacts with VemR. Phos-tag SDS-PAGE analysis showed that mutation in hpaS reduced markedly the phosphorylation of VemR in vivo. Mutation analysis reveals that HpaS and VemR contribute to the regulation of motility and this relationship appears to be epistatic. Additionally, we show that VemR control of Xcc motility is due in part to its ability to interact and bind to the flagellum rotor protein FliM. Taken together, the findings describe the unrecognized regulatory role of sensor kinase HpaS and orphan response regulator VemR in the control of motility in Xcc and contribute to the understanding of the complex regulatory mechanisms used by Xcc during plant infection.
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Affiliation(s)
- Rui‐Fang Li
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐bioresourcesCollege of Life Science and TechnologyGuangxi UniversityNanningChina
- Guangxi Key Laboratory of Biology for Crop Diseases and Insect PestsPlant Protection Research InstituteGuangxi Academy of Agricultural SciencesNanningChina
| | - Xin‐Xin Wang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐bioresourcesCollege of Life Science and TechnologyGuangxi UniversityNanningChina
| | - Liu Wu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐bioresourcesCollege of Life Science and TechnologyGuangxi UniversityNanningChina
| | - Li Huang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐bioresourcesCollege of Life Science and TechnologyGuangxi UniversityNanningChina
| | - Qi‐Jian Qin
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐bioresourcesCollege of Life Science and TechnologyGuangxi UniversityNanningChina
| | - Jia‐Li Yao
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐bioresourcesCollege of Life Science and TechnologyGuangxi UniversityNanningChina
| | - Guang‐Tao Lu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐bioresourcesCollege of Life Science and TechnologyGuangxi UniversityNanningChina
| | - Ji‐Liang Tang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐bioresourcesCollege of Life Science and TechnologyGuangxi UniversityNanningChina
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15
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Sapkota S, Mergoum M, Liu Z. The translucens group of Xanthomonas translucens: Complicated and important pathogens causing bacterial leaf streak on cereals. Mol Plant Pathol 2020; 21:291-302. [PMID: 31967397 PMCID: PMC7036361 DOI: 10.1111/mpp.12909] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 11/14/2019] [Accepted: 12/21/2019] [Indexed: 05/31/2023]
Abstract
UNLABELLED Xanthomonas translucens is a group of gram-negative bacteria that can cause important diseases in cereal crops and forage grasses. Different pathovars have been defined according to their host ranges, and molecular and biochemical characteristics. Pathovars have been placed into two major groups: translucens and graminis. The translucens group contains the pathovars causing bacterial leaf streak (BLS) on cereal crops such as wheat, barley, triticale, rye, and oat. In recent years, BLS has re-emerged as a major problem for many wheat- and barley-producing areas worldwide. The biology of the pathogens and the host-pathogen interactions in cereal BLS diseases were poorly understood. However, recent genome sequence data have provided an insight into the bacterial phylogeny and identification and pathogenicity/virulence. Furthermore, identification of sources of resistance to BLS and mapping of the resistance genes have been initiated. TAXONOMY Kingdom Bacteria; Phylum Proteobacteria; Class Gammaproteobacteria; Order Xanthomonadales; Family Xanthomonadaceae; Genus Xanthomonas; Species X. translucens; translucens group pathovars: undulosa, translucens, cerealis, hordei, and secalis; graminis group pathovars: arrhenatheri, graminis, poae, phlei; newly established pathovar: pistaciae. HOST RANGE X. translucens mainly infects plant species in the Poaceae with the translucens group on cereal crop species and the graminis group on forage grass species. However, some strains have been isolated from, and are able to infect, ornamental asparagus and pistachio trees. Most pathovars have a narrow host range, while a few can infect a broad range of hosts. GENOME The complete genome sequence is available for two X. translucens pv. undulosa strains and one pv. translucens strain. A draft genome sequence is also available for at least one strain from each pathovar. The X. translucens pv. undulosa strain Xt4699 was the first to have its complete genome sequenced, which consists of 4,561,137 bp with total GC content approximately at 68% and 3,528 predicted genes. VIRULENCE MECHANISMS Like most xanthomonads, X. translucens utilizes a type III secretion system (T3SS) to deliver a suite of T3SS effectors (T3Es) inside plant cells. Transcription activator-like effectors, a special group of T3Es, have been identified in most of the X. translucens genomes, some of which have been implicated in virulence. Genetic factors determining host range virulence have also been identified.
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Affiliation(s)
- Suraj Sapkota
- Institute of Plant Breeding, Genetics, and GenomicsUniversity of GeorgiaGriffin Campus, GriffinGAUSA
| | - Mohamed Mergoum
- Institute of Plant Breeding, Genetics, and GenomicsUniversity of GeorgiaGriffin Campus, GriffinGAUSA
- Department of Crop and Soil SciencesUniversity of GeorgiaGriffin Campus, GriffinGAUSA
| | - Zhaohui Liu
- Department of Plant PathologyNorth Dakota State UniversityFargoNDUSA
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16
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Li C, Ji C, Huguet‐Tapia JC, White FF, Dong H, Yang B. An efficient method to clone TAL effector genes from Xanthomonas oryzae using Gibson assembly. Mol Plant Pathol 2019; 20:1453-1462. [PMID: 31414714 PMCID: PMC6792135 DOI: 10.1111/mpp.12820] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Transcription Activator-Like effectors (TALes) represent the largest family of type III effectors among pathogenic bacteria and play a critical role in the process of infection. Strains of Xanthomonas oryzae pv. oryzae (Xoo) and some strains of other Xanthomonas pathogens contain large numbers of TALe genes. Previous techniques to clone individual or a complement of TALe genes through conventional strategies are inefficient and time-consuming due to multiple genes (up to 29 copies) in a given genome, and technically challenging due to the repetitive sequences (up to 33 nearly identical 102-nucleotide repeats) of individual TALe genes. Thus, only a limited number of TALe genes have been molecularly cloned and characterized, and the functions of most TALe genes remain unknown. Here, we present an easy and efficient cloning technique to clone TALe genes selectively through in vitro homologous recombination and single-strand annealing, and demonstrate the feasibility of this approach with four different Xoo strains. Based on the Gibson assembly strategy, two complementary vectors with scaffolds that can preferentially capture all TALe genes from a pool of genomic fragments were designed. Both vector systems enabled cloning of a full complement of TALe genes from each of four Xoo strains and functional analysis of individual TALes in rice in approximately 1 month compared to 3 months by previously used methods. The results demonstrate a robust tool to advance TALe biology and a potential for broad usage of this approach to clone multiple copies of highly competitive DNA elements in any genome of interest.
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Affiliation(s)
- Chenhao Li
- Department of Plant PathologyNanjing Agricultural UniversityNanjing210095Jiangsu ProvidenceP.R. China
- Division of Plant SciencesUniversity of MissouriColumbiaMO65211USA
| | - Chonghui Ji
- Division of Plant SciencesUniversity of MissouriColumbiaMO65211USA
| | | | - Frank F. White
- Department of Plant PathologyUniversity of FloridaGainesvilleFL32611USA
| | - Hansong Dong
- Department of Plant PathologyNanjing Agricultural UniversityNanjing210095Jiangsu ProvidenceP.R. China
| | - Bing Yang
- Division of Plant SciencesUniversity of MissouriColumbiaMO65211USA
- Donald Danforth Plant Science CenterSt. LouisMO63132USA
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17
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Leng M, Lu Z, Qin Z, Qi Y, Lu G, Tang J. Flp, a Fis-like protein, contributes to the regulation of type III secretion and virulence processes in the phytopathogen Xanthomonas campestris pv. campestris. Mol Plant Pathol 2019; 20:1119-1133. [PMID: 31090173 PMCID: PMC6640185 DOI: 10.1111/mpp.12818] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The ability of the plant pathogen Xanthomonas campestris pv. campestris (Xcc) to cause disease is dependent on its ability to adapt quickly to the host environment during infection. Like most bacterial pathogens, Xcc has evolved complex regulatory networks that ensure expression and regulation of their virulence genes. Here, we describe the identification and characterization of a Fis-like protein (named Flp), which plays an important role in virulence and type III secretion system (T3SS) gene expression in Xcc. Deletion of flp caused reduced virulence and hypersensitive response (HR) induction of Xcc and alterations in stress tolerance. Global transcriptome analyses revealed the Flp had a broad regulatory role and that most T3SS HR and pathogenicity (hrp) genes were down-regulated in the flp mutant. β-glucuronidase activity assays implied that Flp regulates the expression of hrp genes via controlling the expression of hrpX. More assays confirmed that Flp binds to the promoter of hrpX and affected the transcription of hrpX directly. Interestingly, the constitutive expression of hrpX in the flp mutant restored the HR phenotype but not full virulence. Taken together, the findings describe the unrecognized regulatory role of Flp protein that controls hrp gene expression and pathogenesis in Xcc.
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Affiliation(s)
- Ming Leng
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐bioresources, College of Life Science and TechnologyGuangxi University100 Daxue RoadNanningGuangxi530004China
| | - Zhuo‐Jian Lu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐bioresources, College of Life Science and TechnologyGuangxi University100 Daxue RoadNanningGuangxi530004China
| | - Zuo‐Shu Qin
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐bioresources, College of Life Science and TechnologyGuangxi University100 Daxue RoadNanningGuangxi530004China
| | - Yan‐Hua Qi
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐bioresources, College of Life Science and TechnologyGuangxi University100 Daxue RoadNanningGuangxi530004China
| | - Guang‐Tao Lu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐bioresources, College of Life Science and TechnologyGuangxi University100 Daxue RoadNanningGuangxi530004China
| | - Ji‐Liang Tang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐bioresources, College of Life Science and TechnologyGuangxi University100 Daxue RoadNanningGuangxi530004China
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18
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Conforte VP, Malamud F, Yaryura PM, Toum Terrones L, Torres PS, De Pino V, Chazarreta CN, Gudesblat GE, Castagnaro AP, R. Marano M, Vojnov AA. The histone-like protein HupB influences biofilm formation and virulence in Xanthomonas citri ssp. citri through the regulation of flagellar biosynthesis. Mol Plant Pathol 2019; 20:589-598. [PMID: 30537413 PMCID: PMC6637892 DOI: 10.1111/mpp.12777] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Citrus canker is an important disease of citrus, whose causal agent is the bacterium Xanthomonas citri ssp. citri (Xcc). In previous studies, we found a group of Xcc mutants, generated by the insertion of the Tn5 transposon, which showed impaired ability to attach to an abiotic substrate. One of these mutants carries the Tn5 insertion in hupB, a gene encoding a bacterial histone-like protein, homologue to the β-subunit of the Heat-Unstable (HU) nucleoid protein of Escherichia coli. These types of protein are necessary to maintain the bacterial nucleoid organization and the global regulation of gene expression. Here, we characterized the influence of the mutation in hupB regarding Xcc biofilm formation and virulence. The mutant strain hupB was incapable of swimming in soft agar, whereas its complemented strain partially recovered this phenotype. Electron microscope imaging revealed that impaired motility of hupB was a consequence of the absence of the flagellum. Comparison of the expression of flagellar genes between the wild-type strain and hupB showed that the mutant exhibited decreased expression of fliC (encoding flagellin). The hupB mutant also displayed reduced virulence compared with the wild-type strain when they were used to infect Citrus lemon plants using different infection methods. Our results therefore show that the histone-like protein HupB plays an essential role in the pathogenesis of Xcc through the regulation of biofilm formation and biosynthesis of the flagellum.
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Affiliation(s)
- Valeria P. Conforte
- Instituto de Ciencia y Tecnología Dr. César Milstein, Fundación Pablo Cassará, CONICETSaladillo 2468Ciudad de Buenos AiresC1440FFXArgentina
| | - Florencia Malamud
- Instituto de Investigaciones Biotecnológicas, Universidad Nacional de San MartínCampus Migueletes, 25 de Mayo y FranciaGeneral San MartínB1650HMN Provincia de Buenos AiresArgentina
| | - Pablo M. Yaryura
- Centro de Investigaciones y Transferencia de Villa María CONICETUniversidad de Villa MaríaCarlos Pellegrini 211Villa María, X5900FSECórdobaArgentina
| | - Laila Toum Terrones
- Departamento de FisiologíaBiología Molecular y Celular, Instituto de Biodiversidad y Biología Experimental y Aplicada, CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos AiresIntendente Güiraldes 2160Buenos AiresC1428EGAArgentina
| | - Pablo S. Torres
- Instituto de Ciencia y Tecnología Dr. César Milstein, Fundación Pablo Cassará, CONICETSaladillo 2468Ciudad de Buenos AiresC1440FFXArgentina
| | - Verónica De Pino
- Instituto de Ciencia y Tecnología Dr. César Milstein, Fundación Pablo Cassará, CONICETSaladillo 2468Ciudad de Buenos AiresC1440FFXArgentina
| | - Cristian N. Chazarreta
- Instituto de Ciencia y Tecnología Dr. César Milstein, Fundación Pablo Cassará, CONICETSaladillo 2468Ciudad de Buenos AiresC1440FFXArgentina
| | - Gustavo E. Gudesblat
- Instituto de Tecnología Agroindustrial del Noroeste Argentino (ITANOA), Estación Experimental Agroindustrial Obispo Colombres (EEAOC), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)Av. William Cross 3150Las TalitasC.P. T4101XACTucumánArgentina
| | - Atilio P. Castagnaro
- Departamento de FisiologíaBiología Molecular y Celular, Instituto de Biodiversidad y Biología Experimental y Aplicada, CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos AiresIntendente Güiraldes 2160Buenos AiresC1428EGAArgentina
| | - María R. Marano
- Instituto de Biología Molecular y Celular de Rosario, Departamento de Microbiología, Facultad de Ciencias, Bioquímicas y FarmacéuticasUniversidad Nacional de RosarioSuipacha 531RosarioS2002LRKSanta FéArgentina
| | - Adrian A. Vojnov
- Instituto de Ciencia y Tecnología Dr. César Milstein, Fundación Pablo Cassará, CONICETSaladillo 2468Ciudad de Buenos AiresC1440FFXArgentina
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19
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Hui S, Shi Y, Tian J, Wang L, Li Y, Wang S, Yuan M. TALE-carrying bacterial pathogens trap host nuclear import receptors for facilitation of infection of rice. Mol Plant Pathol 2019; 20:519-532. [PMID: 30499169 PMCID: PMC6637887 DOI: 10.1111/mpp.12772] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Many plant-pathogenic Xanthomonas rely on the secretion of virulence transcription activator-like effector (TALE) proteins into plant cells to activate plant susceptibility genes to cause disease. The process is dependent on the binding of TALEs to specific elements of host target gene promoters in the plant nucleus. However, it is unclear how TALEs, after injection into host cells, are transferred from the plant cytoplasm into the plant nucleus, which is the key step of successful pathogen infection. Here, we show that the host plant cytoplasm/nuclear shuttle proteins OsImpα1a and OsImpα1b are key components for infection by the TALE-carrying bacterial pathogens Xanthomonas oryzae pv. oryzae (Xoo) and Xanthomonas oryzae pv. oryzicola (Xoc), the causal agents of bacterial leaf blight and bacterial leaf streak, respectively, in rice. Direct interaction between the second nuclear localization signal of TALEs of Xoo or Xoc and OsImpα1a or OsImpα1b is required for the transportation of TALEs into the nucleus. Conversely, suppression of the expression of OsImpα1a and OsImpα1b genes attenuates the shuttling of TALEs from the cytoplasm into the nucleus and the induction of susceptibility genes, thus improving the broad-spectrum disease resistance of rice to Xoo and Xoc. These results provide an applicable strategy for the improvement of resistance to TALE-carrying pathogens in rice by moderate suppression of the expression of plant nuclear import receptor proteins.
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Affiliation(s)
- Shugang Hui
- National Key Laboratory of Crop Genetic ImprovementNational Center of Plant Gene Research (Wuhan), Huazhong Agricultural UniversityWuhan430070China
| | - Yarui Shi
- National Key Laboratory of Crop Genetic ImprovementNational Center of Plant Gene Research (Wuhan), Huazhong Agricultural UniversityWuhan430070China
| | - Jingjing Tian
- National Key Laboratory of Crop Genetic ImprovementNational Center of Plant Gene Research (Wuhan), Huazhong Agricultural UniversityWuhan430070China
| | - Li Wang
- National Key Laboratory of Crop Genetic ImprovementNational Center of Plant Gene Research (Wuhan), Huazhong Agricultural UniversityWuhan430070China
| | - Yueyue Li
- National Key Laboratory of Crop Genetic ImprovementNational Center of Plant Gene Research (Wuhan), Huazhong Agricultural UniversityWuhan430070China
| | - Shiping Wang
- National Key Laboratory of Crop Genetic ImprovementNational Center of Plant Gene Research (Wuhan), Huazhong Agricultural UniversityWuhan430070China
| | - Meng Yuan
- National Key Laboratory of Crop Genetic ImprovementNational Center of Plant Gene Research (Wuhan), Huazhong Agricultural UniversityWuhan430070China
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20
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Abstract
Xanthomonas oryzae pv. oryzae (Xoo) causes a damaging bacterial leaf blight disease in rice. Cold shock proteins (Csps) are highly conserved nucleic acid-binding proteins present in various bacterial genera, but relatively little is known about their functions in Xanthomonas. Herein, we identified four Csps (CspA-CspD) in the Xoo PXO99A strain. Deletion of cspA decreased cold adaptation and a few known pathogenic factors, including bacterial pathogenicity, biofilm formation and polysaccharide production. Furthermore, we performed transcriptomic and chromosome immunoprecipitation (ChIP) experiments to identify direct targets of CspA and to determine its DNA-binding sequence. Integrative data analysis revealed that CspA directly regulates two genes, PXO_RS11830 and PXO_RS01060, by binding to a conserved CCAAT sequence in the promoter region. We generated single-deletion mutants of each gene and the results indicate that both are responsible for Xanthomonas pathogenicity. In addition, quantitative real-time polymerase chain reaction and western blotting showed that CspA suppressed the expression of its direct targets. In summary, our study clarifies the characteristics of Csps in Xanthomonas and greatly advances our understanding of the mechanisms underlying the contribution of CspA to bacterial virulence.
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Affiliation(s)
- Liming Wu
- College of Plant ProtectionNanjing Agricultural University, Key Laboratory of Monitoring and Management of Crop Disease and Pest Insects, Ministry of EducationNanjing210095China
| | - Liumin Ma
- College of Plant ProtectionNanjing Agricultural University, Key Laboratory of Monitoring and Management of Crop Disease and Pest Insects, Ministry of EducationNanjing210095China
| | - Xi Li
- College of Plant ProtectionNanjing Agricultural University, Key Laboratory of Monitoring and Management of Crop Disease and Pest Insects, Ministry of EducationNanjing210095China
| | - Ziyang Huang
- College of Plant ProtectionNanjing Agricultural University, Key Laboratory of Monitoring and Management of Crop Disease and Pest Insects, Ministry of EducationNanjing210095China
| | - Xuewen Gao
- College of Plant ProtectionNanjing Agricultural University, Key Laboratory of Monitoring and Management of Crop Disease and Pest Insects, Ministry of EducationNanjing210095China
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21
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Meline V, Delage W, Brin C, Li‐Marchetti C, Sochard D, Arlat M, Rousseau C, Darrasse A, Briand M, Lebreton G, Portier P, Fischer‐Le Saux M, Durand K, Jacques M, Belin E, Boureau T. Role of the acquisition of a type 3 secretion system in the emergence of novel pathogenic strains of Xanthomonas. Mol Plant Pathol 2019; 20:33-50. [PMID: 30076773 PMCID: PMC6430459 DOI: 10.1111/mpp.12737] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Cases of emergence of novel plant-pathogenic strains are regularly reported that reduce the yields of crops and trees. However, the molecular mechanisms underlying such emergence are still poorly understood. The acquisition by environmental non-pathogenic strains of novel virulence genes by horizontal gene transfer has been suggested as a driver for the emergence of novel pathogenic strains. In this study, we tested such an hypothesis by transferring a plasmid encoding the type 3 secretion system (T3SS) and four associated type 3 secreted proteins (T3SPs) to the non-pathogenic strains of Xanthomonas CFBP 7698 and CFBP 7700, which lack genes encoding T3SS and any previously known T3SPs. The resulting strains were phenotyped on Nicotiana benthamiana using chlorophyll fluorescence imaging and image analysis. Wild-type, non-pathogenic strains induced a hypersensitive response (HR)-like necrosis, whereas strains complemented with T3SS and T3SPs suppressed this response. Such suppression depends on a functional T3SS. Amongst the T3SPs encoded on the plasmid, Hpa2, Hpa1 and, to a lesser extent, XopF1 collectively participate in suppression. Monitoring of the population sizes in planta showed that the sole acquisition of a functional T3SS by non-pathogenic strains impairs growth inside leaf tissues. These results provide functional evidence that the acquisition via horizontal gene transfer of a T3SS and four T3SPs by environmental non-pathogenic strains is not sufficient to make strains pathogenic. In the absence of a canonical effector, the sole acquisition of a T3SS seems to be counter-selective, and further acquisition of type 3 effectors is probably needed to allow the emergence of novel pathogenic strains.
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Affiliation(s)
- Valérian Meline
- IRHSINRA, Université d’AngersAgrocampus‐OuestSFR 4207 QuaSav49071BeaucouzéFrance
| | - Wesley Delage
- IRHSINRA, Université d’AngersAgrocampus‐OuestSFR 4207 QuaSav49071BeaucouzéFrance
| | - Chrystelle Brin
- IRHSINRA, Université d’AngersAgrocampus‐OuestSFR 4207 QuaSav49071BeaucouzéFrance
| | - Camille Li‐Marchetti
- IRHSINRA, Université d’AngersAgrocampus‐OuestSFR 4207 QuaSav49071BeaucouzéFrance
| | - Daniel Sochard
- Platform PHENOTICIRHSINRA, Université d’AngersAgrocampus‐OuestSFR 4207 QuaSav49071BeaucouzéFrance
| | - Matthieu Arlat
- INRAUMR 441, Laboratoire des Interactions Plantes Micro‐organismes (LIPM)F‐31326Castanet‐TolosanFrance
| | - Céline Rousseau
- Platform PHENOTICIRHSINRA, Université d’AngersAgrocampus‐OuestSFR 4207 QuaSav49071BeaucouzéFrance
| | - Armelle Darrasse
- IRHSINRA, Université d’AngersAgrocampus‐OuestSFR 4207 QuaSav49071BeaucouzéFrance
| | - Martial Briand
- IRHSINRA, Université d’AngersAgrocampus‐OuestSFR 4207 QuaSav49071BeaucouzéFrance
| | - Guillaume Lebreton
- Platform PHENOTICIRHSINRA, Université d’AngersAgrocampus‐OuestSFR 4207 QuaSav49071BeaucouzéFrance
| | - Perrine Portier
- IRHSINRA, Université d’AngersAgrocampus‐OuestSFR 4207 QuaSav49071BeaucouzéFrance
- CIRM‐CFBP French Collection for Plant‐associated BacteriaIRHSUMR 1345INRA‐ACO‐UA42 rue Georges Morel49070Beaucouzé CedexFrance
| | - Marion Fischer‐Le Saux
- IRHSINRA, Université d’AngersAgrocampus‐OuestSFR 4207 QuaSav49071BeaucouzéFrance
- CIRM‐CFBP French Collection for Plant‐associated BacteriaIRHSUMR 1345INRA‐ACO‐UA42 rue Georges Morel49070Beaucouzé CedexFrance
| | - Karine Durand
- IRHSINRA, Université d’AngersAgrocampus‐OuestSFR 4207 QuaSav49071BeaucouzéFrance
| | - Marie‐Agnès Jacques
- IRHSINRA, Université d’AngersAgrocampus‐OuestSFR 4207 QuaSav49071BeaucouzéFrance
| | - Etienne Belin
- Platform PHENOTICIRHSINRA, Université d’AngersAgrocampus‐OuestSFR 4207 QuaSav49071BeaucouzéFrance
- Laboratoire Angevin de Recherche en Ingénierie des Systèmes (LARIS)Université d’AngersF‐49000AngersFrance
| | - Tristan Boureau
- IRHSINRA, Université d’AngersAgrocampus‐OuestSFR 4207 QuaSav49071BeaucouzéFrance
- Platform PHENOTICIRHSINRA, Université d’AngersAgrocampus‐OuestSFR 4207 QuaSav49071BeaucouzéFrance
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22
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Qin J, Zhou X, Sun L, Wang K, Yang F, Liao H, Rong W, Yin J, Chen H, Chen X, Zhang J. The Xanthomonas effector XopK harbours E3 ubiquitin-ligase activity that is required for virulence. New Phytol 2018; 220:219-231. [PMID: 29949665 DOI: 10.1111/nph.15287] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Accepted: 05/22/2018] [Indexed: 05/26/2023]
Abstract
Xanthomonas oryzae pv. oryzae is the causative agent of rice bacterial leaf blight. While the type III secretion system of X. oryzae pv. oryzae is essential for virulence, the biochemical activities and virulence mechanisms of non-transcription activator-like (non-TAL) effectors delivered by this system are largely unknown. Here, by screening for non-TAL effectors that contribute to X. oryzae pv. oryzae virulence, we revealed that Xanthomonas outer protein K (XopK) inhibits pathogen-associated molecular pattern-triggered immunity upstream of mitogen-activated protein kinase cascades. Specifically, XopK interacted with and directly ubiquitinated rice somatic embryogenic receptor kinase 2 (OsSERK2), resulting in its degradation. Accordingly, mutation of a putative ubiquitin-conjugation enzyme (E2) binding site abolished XopK-induced degradation of OsSERK2 and compromised XopK-dependent virulence. As crucial immune regulators associated with a multitude of immune receptors, SERKs have been shown to be perturbed by Pseudomonas effectors via different mechanisms. Our study revealed a distinct perturbation mechanism of SERK activity via ubiquitination achieved by Xanthomonas non-TAL effector.
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Affiliation(s)
- Jun Qin
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Xiaogang Zhou
- State Key Laboratory of Hybrid Rice, Key Laboratory of Major Crop Diseases and Collaborative Innovation Center for Hybrid Rice in Yangtze River Basin, Rice Research Institute, Sichuan Agricultural University at Wenjiang, Chengdu, Sichuan, 611130, China
- Key Laboratory for Aging and Regenerative Medicine, Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, Sichuan, 646000, China
| | - Lifan Sun
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Kailun Wang
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Fan Yang
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Haicheng Liao
- State Key Laboratory of Hybrid Rice, Key Laboratory of Major Crop Diseases and Collaborative Innovation Center for Hybrid Rice in Yangtze River Basin, Rice Research Institute, Sichuan Agricultural University at Wenjiang, Chengdu, Sichuan, 611130, China
| | - Wei Rong
- College of Tropical Agriculture and Forestry, Hainan University, Haikou, 570228, China
| | - Junjie Yin
- State Key Laboratory of Hybrid Rice, Key Laboratory of Major Crop Diseases and Collaborative Innovation Center for Hybrid Rice in Yangtze River Basin, Rice Research Institute, Sichuan Agricultural University at Wenjiang, Chengdu, Sichuan, 611130, China
| | - Huamin Chen
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Xuewei Chen
- State Key Laboratory of Hybrid Rice, Key Laboratory of Major Crop Diseases and Collaborative Innovation Center for Hybrid Rice in Yangtze River Basin, Rice Research Institute, Sichuan Agricultural University at Wenjiang, Chengdu, Sichuan, 611130, China
| | - Jie Zhang
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
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23
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Khan M, Seto D, Subramaniam R, Desveaux D. Oh, the places they'll go! A survey of phytopathogen effectors and their host targets. Plant J 2018; 93:651-663. [PMID: 29160935 DOI: 10.1111/tpj.13780] [Citation(s) in RCA: 87] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 11/03/2017] [Accepted: 11/07/2017] [Indexed: 05/09/2023]
Abstract
Phytopathogens translocate effector proteins into plant cells where they sabotage the host cellular machinery to promote infection. An individual pathogen can translocate numerous distinct effectors during the infection process to target an array of host macromolecules (proteins, metabolites, DNA, etc.) and manipulate them using a variety of enzymatic activities. In this review, we have surveyed the literature for effector targets and curated them to convey the range of functions carried out by phytopathogenic proteins inside host cells. In particular, we have curated the locations of effector targets, as well as their biological and molecular functions and compared these properties across diverse phytopathogens. This analysis validates previous observations about effector functions (e.g. immunosuppression), and also highlights some interesting features regarding effector specificity as well as functional diversification of phytopathogen virulence strategies.
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Affiliation(s)
- Madiha Khan
- Department of Cell and Systems Biology, University of Toronto, 25 Willcocks Street, Toronto, ON, M5S 3B2, Canada
| | - Derek Seto
- Department of Cell and Systems Biology, University of Toronto, 25 Willcocks Street, Toronto, ON, M5S 3B2, Canada
| | - Rajagopal Subramaniam
- Department of Cell and Systems Biology, University of Toronto, 25 Willcocks Street, Toronto, ON, M5S 3B2, Canada
- Agriculture and Agri-Food Canada/Agriculture et Agroalimentaire Canada, KW Neatby bldg, 960 Carling Ave., Ottawa, ON, K1A 0C6, Canada
| | - Darrell Desveaux
- Department of Cell and Systems Biology, University of Toronto, 25 Willcocks Street, Toronto, ON, M5S 3B2, Canada
- Centre for the Analysis of Genome Function and Evolution, University of Toronto, 25 Willcocks Street, Toronto, ON, M5S 3B2, Canada
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24
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Adlung N, Bonas U. Dissecting virulence function from recognition: cell death suppression in Nicotiana benthamiana by XopQ/HopQ1-family effectors relies on EDS1-dependent immunity. Plant J 2017; 91:430-442. [PMID: 28423458 DOI: 10.1111/tpj.13578] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Revised: 04/07/2017] [Accepted: 04/11/2017] [Indexed: 05/27/2023]
Abstract
Many Gram-negative plant pathogenic bacteria express effector proteins of the XopQ/HopQ1 family which are translocated into plant cells via the type III secretion system during infection. In Nicotiana benthamiana, recognition of XopQ/HopQ1 proteins induces an effector-triggered immunity (ETI) reaction which is not associated with strong cell death but renders plants immune against Pseudomonas syringae and Xanthomonas campestris pv. vesicatoria strains. Additionally, XopQ suppresses cell death in N. benthamiana when transiently co-expressed with cell death inducers. Here, we show that representative XopQ/HopQ1 proteins are recognized similarly, likely by a single resistance protein of the TIR-NB-LRR class. Extensive analysis of XopQ derivatives indicates the recognition of structural features. We performed Agrobacterium-mediated protein expression experiments in wild-type and EDS1-deficient (eds1) N. benthamiana leaves, not recognizing XopQ/HopQ1. XopQ recognition limits multiplication of Agrobacterium and attenuates levels of transiently expressed proteins. Remarkably, XopQ fails to suppress cell death reactions induced by different effectors in eds1 plants. We conclude that XopQ-mediated cell death suppression in N. benthamiana is due to the attenuation of Agrobacterium-mediated protein expression rather than the cause of the genuine XopQ virulence activity. Thus, our study expands our understanding of XopQ recognition and function, and also challenges the commonly used co-expression assays for elucidation of in planta effector activities, at least under conditions of ETI induction.
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Affiliation(s)
- Norman Adlung
- Institute for Biology, Department of Genetics, Martin Luther University Halle-Wittenberg, 06099, Halle (Saale), Germany
| | - Ulla Bonas
- Institute for Biology, Department of Genetics, Martin Luther University Halle-Wittenberg, 06099, Halle (Saale), Germany
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