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Bhandari DD, Brandizzi F. Logistics of defense: The contribution of endomembranes to plant innate immunity. J Cell Biol 2024; 223:e202307066. [PMID: 38551496 PMCID: PMC10982075 DOI: 10.1083/jcb.202307066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 03/15/2024] [Accepted: 03/18/2024] [Indexed: 04/02/2024] Open
Abstract
Phytopathogens cause plant diseases that threaten food security. Unlike mammals, plants lack an adaptive immune system and rely on their innate immune system to recognize and respond to pathogens. Plant response to a pathogen attack requires precise coordination of intracellular traffic and signaling. Spatial and/or temporal defects in coordinating signals and cargo can lead to detrimental effects on cell development. The role of intracellular traffic comes into a critical focus when the cell sustains biotic stress. In this review, we discuss the current understanding of the post-immune activation logistics of plant defense. Specifically, we focus on packaging and shipping of defense-related cargo, rerouting of intracellular traffic, the players enabling defense-related traffic, and pathogen-mediated subversion of these pathways. We highlight the roles of the cytoskeleton, cytoskeleton-organelle bridging proteins, and secretory vesicles in maintaining pathways of exocytic defense, acting as sentinels during pathogen attack, and the necessary elements for building the cell wall as a barrier to pathogens. We also identify points of convergence between mammalian and plant trafficking pathways during defense and highlight plant unique responses to illustrate evolutionary adaptations that plants have undergone to resist biotic stress.
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Affiliation(s)
- Deepak D. Bhandari
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, USA
- Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI, USA
| | - Federica Brandizzi
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, USA
- Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI, USA
- Department of Plant Biology, Michigan State University, East Lansing, MI, USA
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2
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Naveed ZA, Jamil M, Asif N, Waqas M, Ajaz S, Khan SH. Cross-regulation of cytoskeleton and calcium signaling at plant-pathogen interface. Cell Signal 2024; 117:111100. [PMID: 38360248 DOI: 10.1016/j.cellsig.2024.111100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 02/06/2024] [Accepted: 02/12/2024] [Indexed: 02/17/2024]
Abstract
During plant-pathogen interactions, cytoskeleton and calcium signaling work independently as well as in coordination with each other for developing preformed and induced defense responses. A cell wall (CW) - plasma membrane (PM) - cytoskeleton (CS) continuum is maintained by coordination of cytoskeleton and calcium signaling. The current review is focused on the current knowledge of cytoskeleton‑calcium cross-regulation during plant-pathogen interactions. Implications of recent technological developments in the existing toolkit that can address the outstanding questions of cytoskeleton‑calcium coordination plant immunity are also discussed.
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Affiliation(s)
- Zunaira Afzal Naveed
- Center for Advanced Studies in Agriculture and Food Security, University of Agriculture Faisalabad, Pakistan; Center of Agricultural Biochemistry and Biotechnology, University of Agriculture Faisalabad, Pakistan
| | - Mahnoor Jamil
- Center for Advanced Studies in Agriculture and Food Security, University of Agriculture Faisalabad, Pakistan
| | - Nouman Asif
- Center for Advanced Studies in Agriculture and Food Security, University of Agriculture Faisalabad, Pakistan
| | - Muhammad Waqas
- Center for Advanced Studies in Agriculture and Food Security, University of Agriculture Faisalabad, Pakistan
| | - Sobia Ajaz
- Center for Advanced Studies in Agriculture and Food Security, University of Agriculture Faisalabad, Pakistan
| | - Sultan Habibullah Khan
- Center for Advanced Studies in Agriculture and Food Security, University of Agriculture Faisalabad, Pakistan; Center of Agricultural Biochemistry and Biotechnology, University of Agriculture Faisalabad, Pakistan.
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3
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Lauber E, González-Fuente M, Escouboué M, Vicédo C, Luneau JS, Pouzet C, Jauneau A, Gris C, Zhang ZM, Pichereaux C, Carrère S, Deslandes L, Noël LD. Bacterial host adaptation through sequence and structural variations of a single type III effector gene. iScience 2024; 27:109224. [PMID: 38439954 PMCID: PMC10909901 DOI: 10.1016/j.isci.2024.109224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 12/02/2023] [Accepted: 02/08/2024] [Indexed: 03/06/2024] Open
Abstract
Molecular mechanisms underlying quantitative variations of pathogenicity remain elusive. Here, we identified the Xanthomonas campestris XopJ6 effector that triggers disease resistance in cauliflower and Arabidopsis thaliana. XopJ6 is a close homolog of the Ralstoniapseudosolanacearum PopP2 YopJ family acetyltransferase. XopJ6 is recognized by the RRS1-R/RPS4 NLR pair that integrates a WRKY decoy domain mimicking effector targets. We identified a XopJ6 natural variant carrying a single residue substitution in XopJ6 WRKY-binding site that disrupts interaction with WRKY proteins. This mutation allows XopJ6 to evade immune perception while retaining some XopJ6 virulence functions. Interestingly, xopJ6 resides in a Tn3-family transposon likely contributing to xopJ6 copy number variation (CNV). Using synthetic biology, we demonstrate that xopJ6 CNV tunes pathogen virulence on Arabidopsis through gene dosage-mediated modulation of xopJ6 expression. Together, our findings highlight how sequence and structural genetic variations restricted at a particular effector gene contribute to bacterial host adaptation.
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Affiliation(s)
- Emmanuelle Lauber
- Laboratoire des Interactions Plantes-Microbes-Environnement (LIPME), Université de Toulouse, INRAE, CNRS, F-31326 Castanet-Tolosan, France
| | - Manuel González-Fuente
- Laboratoire des Interactions Plantes-Microbes-Environnement (LIPME), Université de Toulouse, INRAE, CNRS, F-31326 Castanet-Tolosan, France
| | - Maxime Escouboué
- Laboratoire des Interactions Plantes-Microbes-Environnement (LIPME), Université de Toulouse, INRAE, CNRS, F-31326 Castanet-Tolosan, France
| | - Céline Vicédo
- Laboratoire des Interactions Plantes-Microbes-Environnement (LIPME), Université de Toulouse, INRAE, CNRS, F-31326 Castanet-Tolosan, France
| | - Julien S. Luneau
- Laboratoire des Interactions Plantes-Microbes-Environnement (LIPME), Université de Toulouse, INRAE, CNRS, F-31326 Castanet-Tolosan, France
| | - Cécile Pouzet
- TRI-FRAIB Imaging Platform Facilities, FRAIB, Université de Toulouse, CNRS, UPS, 31320 Castanet-Tolosan, France
| | - Alain Jauneau
- TRI-FRAIB Imaging Platform Facilities, FRAIB, Université de Toulouse, CNRS, UPS, 31320 Castanet-Tolosan, France
| | - Carine Gris
- Laboratoire des Interactions Plantes-Microbes-Environnement (LIPME), Université de Toulouse, INRAE, CNRS, F-31326 Castanet-Tolosan, France
| | - Zhi-Min Zhang
- International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Development of Chinese Ministry of Education (MOE), College of Pharmacy, Jinan University, Guangzhou 510632, China
| | - Carole Pichereaux
- Fédération de Recherche Agrobiosciences, Interactions et Biodiversité (FRAIB), Université de Toulouse, CNRS, Université de Toulouse III - Paul Sabatier (UT3), Auzeville-Tolosane, France
- Institut de Pharmacologie et de Biologie Structurale (IPBS), Université de Toulouse, CNRS, Université de Toulouse III - Paul Sabatier (UT3), Toulouse, France
- Infrastructure nationale de protéomique, ProFI, FR 2048, Toulouse, France
| | - Sébastien Carrère
- Laboratoire des Interactions Plantes-Microbes-Environnement (LIPME), Université de Toulouse, INRAE, CNRS, F-31326 Castanet-Tolosan, France
| | - Laurent Deslandes
- Laboratoire des Interactions Plantes-Microbes-Environnement (LIPME), Université de Toulouse, INRAE, CNRS, F-31326 Castanet-Tolosan, France
| | - Laurent D. Noël
- Laboratoire des Interactions Plantes-Microbes-Environnement (LIPME), Université de Toulouse, INRAE, CNRS, F-31326 Castanet-Tolosan, France
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4
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Jacott CN, Schoonbeek HJ, Sidhu GS, Steuernagel B, Kirby R, Zheng X, von Tiedermann A, Macioszek VK, Kononowicz AK, Fell H, Fitt BDL, Mitrousia GK, Stotz HU, Ridout CJ, Wells R. Pathogen lifestyle determines host genetic signature of quantitative disease resistance loci in oilseed rape (Brassica napus). TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2024; 137:65. [PMID: 38430276 PMCID: PMC10908622 DOI: 10.1007/s00122-024-04569-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2023] [Accepted: 01/30/2024] [Indexed: 03/03/2024]
Abstract
KEY MESSAGE Using associative transcriptomics, our study identifies genes conferring resistance to four diverse fungal pathogens in crops, emphasizing key genetic determinants of multi-pathogen resistance. Crops are affected by several pathogens, but these are rarely studied in parallel to identify common and unique genetic factors controlling diseases. Broad-spectrum quantitative disease resistance (QDR) is desirable for crop breeding as it confers resistance to several pathogen species. Here, we use associative transcriptomics (AT) to identify candidate gene loci associated with Brassica napus constitutive QDR to four contrasting fungal pathogens: Alternaria brassicicola, Botrytis cinerea, Pyrenopeziza brassicae, and Verticillium longisporum. We did not identify any shared loci associated with broad-spectrum QDR to fungal pathogens with contrasting lifestyles. Instead, we observed QDR dependent on the lifestyle of the pathogen-hemibiotrophic and necrotrophic pathogens had distinct QDR responses and associated loci, including some loci associated with early immunity. Furthermore, we identify a genomic deletion associated with resistance to V. longisporum and potentially broad-spectrum QDR. This is the first time AT has been used for several pathosystems simultaneously to identify host genetic loci involved in broad-spectrum QDR. We highlight constitutive expressed candidate loci for broad-spectrum QDR with no antagonistic effects on susceptibility to the other pathogens studies as candidates for crop breeding. In conclusion, this study represents an advancement in our understanding of broad-spectrum QDR in B. napus and is a significant resource for the scientific community.
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Affiliation(s)
- Catherine N Jacott
- Crop Genetics Department, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Henk-Jan Schoonbeek
- Crop Genetics Department, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Gurpinder Singh Sidhu
- Computational and Systems Biology Department, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Burkhard Steuernagel
- Computational and Systems Biology Department, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Rachel Kirby
- Crop Genetics Department, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Xiaorong Zheng
- Department of Crop Sciences, Georg August University, 37077, Göttingen, Germany
| | | | - Violetta K Macioszek
- Department of Biology and Plant Ecology, Faculty of Biology, University of Bialystok, 15-245, Białystok, Poland
| | - Andrzej K Kononowicz
- Department of Plant Ecophysiology, Faculty of Biology and Environmental Protection, University of Lodz, 90-237, Lodz, Poland
| | - Heather Fell
- Centre for Agriculture, Food and Environmental Management Research, School of Life and Medical Sciences, University of Hertfordshire, Hatfield, Hertfordshire, AL10 9AB, UK
| | - Bruce D L Fitt
- Centre for Agriculture, Food and Environmental Management Research, School of Life and Medical Sciences, University of Hertfordshire, Hatfield, Hertfordshire, AL10 9AB, UK
| | - Georgia K Mitrousia
- Centre for Agriculture, Food and Environmental Management Research, School of Life and Medical Sciences, University of Hertfordshire, Hatfield, Hertfordshire, AL10 9AB, UK
- Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ, UK
| | - Henrik U Stotz
- Centre for Agriculture, Food and Environmental Management Research, School of Life and Medical Sciences, University of Hertfordshire, Hatfield, Hertfordshire, AL10 9AB, UK
| | - Christopher J Ridout
- Crop Genetics Department, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Rachel Wells
- Crop Genetics Department, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK.
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5
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Yang N, Ren J, Dai S, Wang K, Leung M, Lu Y, An Y, Burlingame A, Xu S, Wang Z, Yu W, Li N. The Quantitative Biotinylproteomics Studies Reveal a WInd-Related Kinase 1 (Raf-Like Kinase 36) Functioning as an Early Signaling Component in Wind-Induced Thigmomorphogenesis and Gravitropism. Mol Cell Proteomics 2024; 23:100738. [PMID: 38364992 PMCID: PMC10951710 DOI: 10.1016/j.mcpro.2024.100738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Revised: 01/31/2024] [Accepted: 02/08/2024] [Indexed: 02/18/2024] Open
Abstract
Wind is one of the most prevalent environmental forces entraining plants to develop various mechano-responses, collectively called thigmomorphogenesis. Largely unknown is how plants transduce these versatile wind force signals downstream to nuclear events and to the development of thigmomorphogenic phenotype or anemotropic response. To identify molecular components at the early steps of the wind force signaling, two mechanical signaling-related phosphoproteins, identified from our previous phosphoproteomic study of Arabidopsis touch response, mitogen-activated protein kinase kinase 1 (MKK1) and 2 (MKK2), were selected for performing in planta TurboID (ID)-based quantitative proximity-labeling (PL) proteomics. This quantitative biotinylproteomics was separately performed on MKK1-ID and MKK2-ID transgenic plants, respectively, using the genetically engineered TurboID biotin ligase expression transgenics as a universal control. This unique PTM proteomics successfully identified 11 and 71 MKK1 and MKK2 putative interactors, respectively. Biotin occupancy ratio (BOR) was found to be an alternative parameter to measure the extent of proximity and specificity between the proximal target proteins and the bait fusion protein. Bioinformatics analysis of these biotinylprotein data also found that TurboID biotin ligase favorably labels the loop region of target proteins. A WInd-Related Kinase 1 (WIRK1), previously known as rapidly accelerated fibrosarcoma (Raf)-like kinase 36 (RAF36), was found to be a putative common interactor for both MKK1 and MKK2 and preferentially interacts with MKK2. Further molecular biology studies of the Arabidopsis RAF36 kinase found that it plays a role in wind regulation of the touch-responsive TCH3 and CML38 gene expression and the phosphorylation of a touch-regulated PATL3 phosphoprotein. Measurement of leaf morphology and shoot gravitropic response of wirk1 (raf36) mutant revealed that the WIRK1 gene is involved in both wind-triggered rosette thigmomorphogenesis and gravitropism of Arabidopsis stems, suggesting that the WIRK1 (RAF36) protein probably functioning upstream of both MKK1 and MKK2 and that it may serve as the crosstalk point among multiple mechano-signal transduction pathways mediating both wind mechano-response and gravitropism.
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Affiliation(s)
- Nan Yang
- Division of Life Science, The Hong Kong University of Science and Technology, Hong Kong SAR, China
| | - Jia Ren
- Division of Life Science, The Hong Kong University of Science and Technology, Hong Kong SAR, China
| | - Shuaijian Dai
- Division of Life Science, The Hong Kong University of Science and Technology, Hong Kong SAR, China
| | - Kai Wang
- Division of Life Science, The Hong Kong University of Science and Technology, Hong Kong SAR, China
| | - Manhin Leung
- Division of Life Science, The Hong Kong University of Science and Technology, Hong Kong SAR, China
| | - Yinglin Lu
- Institute of Nanfan and Seed Industry, Guangdong Academy of Sciences, Guangzhou, Guangdong, China
| | - Yuxing An
- Institute of Nanfan and Seed Industry, Guangdong Academy of Sciences, Guangzhou, Guangdong, China
| | - Al Burlingame
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, California, USA
| | - Shouling Xu
- Department of Plant Biology, Carnegie Institution for Science, Stanford, California, USA
| | - Zhiyong Wang
- Department of Plant Biology, Carnegie Institution for Science, Stanford, California, USA
| | - Weichuan Yu
- Department of Electronic and Computer Engineering, The Hong Kong University of Science and Technology, Hong Kong SAR, China.
| | - Ning Li
- Division of Life Science, The Hong Kong University of Science and Technology, Hong Kong SAR, China; Shenzhen Research Institute, The Hong Kong University of Science and Technology, Shenzhen, Guangdong, China.
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6
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Jiménez-Guerrero I, Sonawane M, Eckshtain-Levi N, Tuang ZK, da Silva GM, Pérez-Montaño F, Leibman-Markus M, Gupta R, Noda-Garcia L, Bar M, Burdman S. Natural variation in a short region of the Acidovorax citrulli type III-secreted effector AopW1 is associated with differences in cytotoxicity and host adaptation. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2024; 117:516-540. [PMID: 37864805 DOI: 10.1111/tpj.16507] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 10/03/2023] [Accepted: 10/04/2023] [Indexed: 10/23/2023]
Abstract
Bacterial fruit blotch, caused by Acidovorax citrulli, is a serious disease of melon and watermelon. The strains of the pathogen belong to two major genetic groups: group I strains are strongly associated with melon, while group II strains are more aggressive on watermelon. A. citrulli secretes many protein effectors to the host cell via the type III secretion system. Here we characterized AopW1, an effector that shares similarity to the actin cytoskeleton-disrupting effector HopW1 of Pseudomonas syringae and with effectors from other plant-pathogenic bacterial species. AopW1 has a highly variable region (HVR) within amino acid positions 147 to 192, showing 14 amino acid differences between group I and II variants. We show that group I AopW1 is more toxic to yeast and Nicotiana benthamiana cells than group II AopW1, having stronger actin filament disruption activity, and increased ability to induce cell death and reduce callose deposition. We further demonstrated the importance of some amino acid positions within the HVR for AopW1 cytotoxicity. Cellular analyses revealed that AopW1 also localizes to the endoplasmic reticulum, chloroplasts, and plant endosomes. We also show that overexpression of the endosome-associated protein EHD1 attenuates AopW1-induced cell death and increases defense responses. Finally, we show that sequence variation in AopW1 plays a significant role in the adaptation of group I and II strains to their preferred hosts, melon and watermelon, respectively. This study provides new insights into the HopW1 family of bacterial effectors and provides first evidence on the involvement of EHD1 in response to biotic stress.
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Affiliation(s)
- Irene Jiménez-Guerrero
- Department of Plant Pathology and Microbiology, The Robert H. Smith Faculty of Agriculture, Food and Environment, Institute of Environmental Sciences, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Monica Sonawane
- Department of Plant Pathology and Microbiology, The Robert H. Smith Faculty of Agriculture, Food and Environment, Institute of Environmental Sciences, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Noam Eckshtain-Levi
- Department of Plant Pathology and Microbiology, The Robert H. Smith Faculty of Agriculture, Food and Environment, Institute of Environmental Sciences, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Za Khai Tuang
- Department of Plant Pathology and Microbiology, The Robert H. Smith Faculty of Agriculture, Food and Environment, Institute of Environmental Sciences, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Gustavo Mateus da Silva
- Department of Plant Pathology and Microbiology, The Robert H. Smith Faculty of Agriculture, Food and Environment, Institute of Environmental Sciences, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Francisco Pérez-Montaño
- Department of Plant Pathology and Microbiology, The Robert H. Smith Faculty of Agriculture, Food and Environment, Institute of Environmental Sciences, The Hebrew University of Jerusalem, Rehovot, Israel
- Department of Microbiology, University of Seville, Seville, Spain
| | - Meirav Leibman-Markus
- Department of Plant Pathology and Weed Research, Agricultural Research Organization, The Volcani Institute, Bet Dagan, Israel
| | - Rupali Gupta
- Department of Plant Pathology and Weed Research, Agricultural Research Organization, The Volcani Institute, Bet Dagan, Israel
| | - Lianet Noda-Garcia
- Department of Plant Pathology and Microbiology, The Robert H. Smith Faculty of Agriculture, Food and Environment, Institute of Environmental Sciences, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Maya Bar
- Department of Plant Pathology and Weed Research, Agricultural Research Organization, The Volcani Institute, Bet Dagan, Israel
| | - Saul Burdman
- Department of Plant Pathology and Microbiology, The Robert H. Smith Faculty of Agriculture, Food and Environment, Institute of Environmental Sciences, The Hebrew University of Jerusalem, Rehovot, Israel
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7
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Bhandari DD, Ko DK, Kim SJ, Nomura K, He SY, Brandizzi F. Defense against phytopathogens relies on efficient antimicrobial protein secretion mediated by the microtubule-binding protein TGNap1. Nat Commun 2023; 14:6357. [PMID: 37821453 PMCID: PMC10567756 DOI: 10.1038/s41467-023-41807-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Accepted: 09/19/2023] [Indexed: 10/13/2023] Open
Abstract
Plant immunity depends on the secretion of antimicrobial proteins, which occurs through yet-largely unknown mechanisms. The trans-Golgi network (TGN), a hub for intracellular and extracellular trafficking pathways, and the cytoskeleton, which is required for antimicrobial protein secretion, are emerging as pathogen targets to dampen plant immunity. In this work, we demonstrate that tgnap1-2, a loss-of-function mutant of Arabidopsis TGNap1, a TGN-associated and microtubule (MT)-binding protein, is susceptible to Pseudomonas syringae (Pst DC3000). Pst DC3000 infected tgnap1-2 is capable of mobilizing defense pathways, accumulating salicylic acid (SA), and expressing antimicrobial proteins. The susceptibility of tgnap1-2 is due to a failure to efficiently transport antimicrobial proteins to the apoplast in a partially MT-dependent pathway but independent from SA and is additive to the pathogen-antagonizing MIN7, a TGN-associated ARF-GEF protein. Therefore, our data demonstrate that plant immunity relies on TGNap1 for secretion of antimicrobial proteins, and that TGNap1 is a key immunity element that functionally links secretion and cytoskeleton in SA-independent pathogen responses.
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Affiliation(s)
- Deepak D Bhandari
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, 48824, USA
- Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI, 48824, USA
| | - Dae Kwan Ko
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, 48824, USA
- Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI, 48824, USA
| | - Sang-Jin Kim
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, 48824, USA
- Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI, 48824, USA
- Department of Plant Biology, Michigan State University, East Lansing, MI, 48824, USA
| | - Kinya Nomura
- Department of Biology, Duke University, Durham, NC, 27708, USA
- Howard Hughes Medical Institute, Duke University, Durham, NC, 27708, USA
| | - Sheng Yang He
- Department of Biology, Duke University, Durham, NC, 27708, USA
- Howard Hughes Medical Institute, Duke University, Durham, NC, 27708, USA
| | - Federica Brandizzi
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, 48824, USA.
- Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI, 48824, USA.
- Department of Plant Biology, Michigan State University, East Lansing, MI, 48824, USA.
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8
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Tomar V, Rikkerink EHA, Song J, Sofkova-Bobcheva S, Bus VGM. Structure-Function Characterisation of Eop1 Effectors from the Erwinia-Pantoea Clade Reveals They May Acetylate Their Defence Target through a Catalytic Dyad. Int J Mol Sci 2023; 24:14664. [PMID: 37834112 PMCID: PMC10572645 DOI: 10.3390/ijms241914664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Revised: 09/21/2023] [Accepted: 09/25/2023] [Indexed: 10/15/2023] Open
Abstract
The YopJ group of acetylating effectors from phytopathogens of the genera Pseudomonas and Ralstonia have been widely studied to understand how they modify and suppress their host defence targets. In contrast, studies on a related group of effectors, the Eop1 group, lag far behind. Members of the Eop1 group are widely present in the Erwinia-Pantoea clade of Gram-negative bacteria, which contains phytopathogens, non-pathogens and potential biocontrol agents, implying that they may play an important role in agroecological or pathological adaptations. The lack of research in this group of YopJ effectors has left a significant knowledge gap in their functioning and role. For the first time, we perform a comparative analysis combining AlphaFold modelling, in planta transient expressions and targeted mutational analyses of the Eop1 group effectors from the Erwinia-Pantoea clade, to help elucidate their likely activity and mechanism(s). This integrated study revealed several new findings, including putative binding sites for inositol hexakisphosphate and acetyl coenzyme A and newly postulated target-binding domains, and raises questions about whether these effectors function through a catalytic triad mechanism. The results imply that some Eop1s may use a catalytic dyad acetylation mechanism that we found could be promoted by the electronegative environment around the active site.
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Affiliation(s)
- Vishant Tomar
- Mt Albert Research Centre, The New Zealand Institute for Plant and Food Research Limited, Auckland 1025, New Zealand
- School of Agriculture and Environment, Massey University, Private Bag 11222, Palmerston North 4442, New Zealand;
| | - Erik H. A. Rikkerink
- Mt Albert Research Centre, The New Zealand Institute for Plant and Food Research Limited, Auckland 1025, New Zealand
| | - Janghoon Song
- Pear Research Institute, National Institute of Horticultural & Herbal Science, Rural Development Administration, Naju 58216, Republic of Korea
| | - Svetla Sofkova-Bobcheva
- School of Agriculture and Environment, Massey University, Private Bag 11222, Palmerston North 4442, New Zealand;
| | - Vincent G. M. Bus
- Hawkes Bay Research Centre, The New Zealand Institute for Plant and Food Research Limited, Havelock North 4130, New Zealand;
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9
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Ahn YJ, Kim H, Choi S, Mazo-Molina C, Prokchorchik M, Zhang N, Kim B, Mang H, Koehler N, Kim J, Lee S, Yoon H, Choi D, Kim MS, Segonzac C, Martin GB, Schultink A, Sohn KH. Ptr1 and ZAR1 immune receptors confer overlapping and distinct bacterial pathogen effector specificities. THE NEW PHYTOLOGIST 2023; 239:1935-1953. [PMID: 37334551 DOI: 10.1111/nph.19073] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2023] [Accepted: 05/22/2023] [Indexed: 06/20/2023]
Abstract
Some nucleotide-binding and leucine-rich repeat receptors (NLRs) indirectly detect pathogen effectors by monitoring their host targets. In Arabidopsis thaliana, RIN4 is targeted by multiple sequence-unrelated effectors and activates immune responses mediated by RPM1 and RPS2. These effectors trigger cell death in Nicotiana benthamiana, but the corresponding NLRs have yet not been identified. To identify N. benthamiana NLRs (NbNLRs) that recognize Arabidopsis RIN4-targeting effectors, we conducted a rapid reverse genetic screen using an NbNLR VIGS library. We identified that the N. benthamiana homolog of Ptr1 (Pseudomonas tomato race 1) recognizes the Pseudomonas effectors AvrRpt2, AvrRpm1, and AvrB. We demonstrated that recognition of the Xanthomonas effector AvrBsT and the Pseudomonas effector HopZ5 is conferred independently by the N. benthamiana homolog of Ptr1 and ZAR1. Interestingly, the recognition of HopZ5 and AvrBsT is contributed unequally by Ptr1 and ZAR1 in N. benthamiana and Capsicum annuum. In addition, we showed that the RLCK XII family protein JIM2 is required for the NbZAR1-dependent recognition of AvrBsT and HopZ5. The recognition of sequence-unrelated effectors by NbPtr1 and NbZAR1 provides an additional example of convergently evolved effector recognition. Identification of key components involved in Ptr1 and ZAR1-mediated immunity could reveal unique mechanisms of expanded effector recognition.
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Affiliation(s)
- Ye Jin Ahn
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, 37673, Korea
| | - Haseong Kim
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, 37673, Korea
- Plant Immunity Research Center, Seoul National University, Seoul, 08826, Korea
| | - Sera Choi
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, 37673, Korea
| | - Carolina Mazo-Molina
- Boyce Thompson Institute for Plant Research, Ithaca, NY, 14853, USA
- Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, 14853, USA
| | - Maxim Prokchorchik
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, 37673, Korea
| | - Ning Zhang
- Boyce Thompson Institute for Plant Research, Ithaca, NY, 14853, USA
- Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, 14853, USA
| | - Boyoung Kim
- Plant Immunity Research Center, Seoul National University, Seoul, 08826, Korea
- Department of Agriculture, Forestry and Bioresources, Seoul National University, Seoul, 08826, Korea
| | - Hyunggon Mang
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, 37673, Korea
| | - Naio Koehler
- Fortiphyte Inc., 3071 Research Drive, Richmond, CA, 94806, USA
| | - Jieun Kim
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, 37673, Korea
| | - Soeui Lee
- Plant Immunity Research Center, Seoul National University, Seoul, 08826, Korea
- Department of Agriculture, Forestry and Bioresources, Seoul National University, Seoul, 08826, Korea
| | - Hayeon Yoon
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, 37673, Korea
| | - Doil Choi
- Plant Immunity Research Center, Seoul National University, Seoul, 08826, Korea
- Department of Agriculture, Forestry and Bioresources, Seoul National University, Seoul, 08826, Korea
| | - Min-Sung Kim
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, 37673, Korea
| | - Cécile Segonzac
- Plant Immunity Research Center, Seoul National University, Seoul, 08826, Korea
- Department of Agriculture, Forestry and Bioresources, Seoul National University, Seoul, 08826, Korea
- Plant Genomics and Breeding Institute, Seoul National University, Seoul, 08826, Korea
- Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, 08826, Korea
| | - Gregory B Martin
- Boyce Thompson Institute for Plant Research, Ithaca, NY, 14853, USA
- Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, 14853, USA
| | - Alex Schultink
- Fortiphyte Inc., 3071 Research Drive, Richmond, CA, 94806, USA
| | - Kee Hoon Sohn
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, 37673, Korea
- Plant Immunity Research Center, Seoul National University, Seoul, 08826, Korea
- Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, 08826, Korea
- Department of Agricultural Biotechnology, Seoul National University, Seoul, 08826, Korea
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10
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Wang H, Yu J, Zhu B, Gu L, Wang H, Du X, Zeng T, Tang H. The SbbHLH041- SbEXPA11 Module Enhances Cadmium Accumulation and Rescues Biomass by Increasing Photosynthetic Efficiency in Sorghum. Int J Mol Sci 2023; 24:13061. [PMID: 37685867 PMCID: PMC10487693 DOI: 10.3390/ijms241713061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 08/18/2023] [Accepted: 08/21/2023] [Indexed: 09/10/2023] Open
Abstract
In plants, expansin genes are responsive to heavy metal exposure. To study the bioremediary potential of this important gene family, we discovered a root-expressed expansin gene in sorghum, SbEXPA11, which is notably upregulated following cadmium (Cd) exposure. However, the mechanism underlying the Cd detoxification and accumulation mediated by SbEXPA11 in sorghum remains unclear. We overexpressed SbEXPA11 in sorghum and compared wild-type (WT) and SbEXPA11-overexpressing transgenic sorghum in terms of Cd accumulation and physiological indices following Cd. Compared with the WT, we found that SbEXPA11 mediates Cd tolerance by exerting reactive oxygen species (ROS)-scavenging effects through upregulating the expression of antioxidant enzymes. Moreover, the overexpression of SbEXPA11 rescued biomass production by increasing the photosynthetic efficiency of transgenic plants. In the pot experiment with a dosage of 10 mg/kg Cd, transgenic sorghum plants demonstrated higher efficacy in reducing the Cd content of the soil (8.62 mg/kg) compared to WT sorghum plants (9.51 mg/kg). Subsequent analysis revealed that the SbbHLH041 transcription factor has the ability to induce SbEXPA11 expression through interacting with the E-box located within the SbEXPA11 promoter. These findings suggest that the SbbHLH041-SbEXPA11 cascade module may be beneficial for the development of phytoremediary sorghum varieties.
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Affiliation(s)
- Huinan Wang
- School of Life Sciences, Guizhou Normal University, Guiyang 550025, China; (H.W.); (J.Y.); (B.Z.); (L.G.); (H.W.); (X.D.)
| | - Junxing Yu
- School of Life Sciences, Guizhou Normal University, Guiyang 550025, China; (H.W.); (J.Y.); (B.Z.); (L.G.); (H.W.); (X.D.)
| | - Bin Zhu
- School of Life Sciences, Guizhou Normal University, Guiyang 550025, China; (H.W.); (J.Y.); (B.Z.); (L.G.); (H.W.); (X.D.)
| | - Lei Gu
- School of Life Sciences, Guizhou Normal University, Guiyang 550025, China; (H.W.); (J.Y.); (B.Z.); (L.G.); (H.W.); (X.D.)
| | - Hongcheng Wang
- School of Life Sciences, Guizhou Normal University, Guiyang 550025, China; (H.W.); (J.Y.); (B.Z.); (L.G.); (H.W.); (X.D.)
| | - Xuye Du
- School of Life Sciences, Guizhou Normal University, Guiyang 550025, China; (H.W.); (J.Y.); (B.Z.); (L.G.); (H.W.); (X.D.)
| | - Tuo Zeng
- School of Life Sciences, Guizhou Normal University, Guiyang 550025, China; (H.W.); (J.Y.); (B.Z.); (L.G.); (H.W.); (X.D.)
| | - Heng Tang
- National Key Laboratory of Wheat Breeding, Agronomy College, Shandong Agricultural University, Tai’an 271002, China
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11
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Ortmann S, Marx J, Lampe C, Handrick V, Ehnert TM, Zinecker S, Reimers M, Bonas U, Erickson JL. A conserved microtubule-binding region in Xanthomonas XopL is indispensable for induced plant cell death reactions. PLoS Pathog 2023; 19:e1011263. [PMID: 37578981 PMCID: PMC10449215 DOI: 10.1371/journal.ppat.1011263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 08/24/2023] [Accepted: 07/17/2023] [Indexed: 08/16/2023] Open
Abstract
Pathogenic Xanthomonas bacteria cause disease on more than 400 plant species. These Gram-negative bacteria utilize the type III secretion system to inject type III effector proteins (T3Es) directly into the plant cell cytosol where they can manipulate plant pathways to promote virulence. The host range of a given Xanthomonas species is limited, and T3E repertoires are specialized during interactions with specific plant species. Some effectors, however, are retained across most strains, such as Xanthomonas Outer Protein L (XopL). As an 'ancestral' effector, XopL contributes to the virulence of multiple xanthomonads, infecting diverse plant species. XopL homologs harbor a combination of a leucine-rich-repeat (LRR) domain and an XL-box which has E3 ligase activity. Despite similar domain structure there is evidence to suggest that XopL function has diverged, exemplified by the finding that XopLs expressed in plants often display bacterial species-dependent differences in their sub-cellular localization and plant cell death reactions. We found that XopL from X. euvesicatoria (XopLXe) directly associates with plant microtubules (MTs) and causes strong cell death in agroinfection assays in N. benthamiana. Localization of XopLXe homologs from three additional Xanthomonas species, of diverse infection strategy and plant host, revealed that the distantly related X. campestris pv. campestris harbors a XopL (XopLXcc) that fails to localize to MTs and to cause plant cell death. Comparative sequence analyses of MT-binding XopLs and XopLXcc identified a proline-rich-region (PRR)/α-helical region important for MT localization. Functional analyses of XopLXe truncations and amino acid exchanges within the PRR suggest that MT-localized XopL activity is required for plant cell death reactions. This study exemplifies how the study of a T3E within the context of a genus rather than a single species can shed light on how effector localization is linked to biochemical activity.
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Affiliation(s)
- Simon Ortmann
- Department of Genetics, Institute for Biology, Martin Luther University Halle-Wittenberg, Halle, Germany
- Department of Biochemistry of Plant Interactions, Leibniz Institute for Plant Biochemistry, Halle, Germany
| | - Jolina Marx
- Department of Genetics, Institute for Biology, Martin Luther University Halle-Wittenberg, Halle, Germany
| | - Christina Lampe
- Department of Genetics, Institute for Biology, Martin Luther University Halle-Wittenberg, Halle, Germany
| | - Vinzenz Handrick
- Department of Biochemistry of Plant Interactions, Leibniz Institute for Plant Biochemistry, Halle, Germany
| | - Tim-Martin Ehnert
- Department of Biochemistry of Plant Interactions, Leibniz Institute for Plant Biochemistry, Halle, Germany
| | - Sarah Zinecker
- Department of Plant Physiology, Institute for Biology, Martin Luther University Halle-Wittenberg, Halle, Germany
| | - Matthias Reimers
- Department of Plant Physiology, Institute for Biology, Martin Luther University Halle-Wittenberg, Halle, Germany
| | - Ulla Bonas
- Department of Genetics, Institute for Biology, Martin Luther University Halle-Wittenberg, Halle, Germany
| | - Jessica Lee Erickson
- Department of Genetics, Institute for Biology, Martin Luther University Halle-Wittenberg, Halle, Germany
- Department of Biochemistry of Plant Interactions, Leibniz Institute for Plant Biochemistry, Halle, Germany
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12
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The Cytoskeleton in Plant Immunity: Dynamics, Regulation, and Function. Int J Mol Sci 2022; 23:ijms232415553. [PMID: 36555194 PMCID: PMC9779068 DOI: 10.3390/ijms232415553] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 12/04/2022] [Accepted: 12/06/2022] [Indexed: 12/13/2022] Open
Abstract
The plant cytoskeleton, consisting of actin filaments and microtubules, is a highly dynamic filamentous framework involved in plant growth, development, and stress responses. Recently, research has demonstrated that the plant cytoskeleton undergoes rapid remodeling upon sensing pathogen attacks, coordinating the formation of microdomain immune complexes, the dynamic and turnover of pattern-recognizing receptors (PRRs), the movement and aggregation of organelles, and the transportation of defense compounds, thus serving as an important platform for responding to pathogen infections. Meanwhile, pathogens produce effectors targeting the cytoskeleton to achieve pathogenicity. Recent findings have uncovered several cytoskeleton-associated proteins mediating cytoskeletal remodeling and defense signaling. Furthermore, the reorganization of the actin cytoskeleton is revealed to further feedback-regulate reactive oxygen species (ROS) production and trigger salicylic acid (SA) signaling, suggesting an extremely complex role of the cytoskeleton in plant immunity. Here, we describe recent advances in understanding the host cytoskeleton dynamics upon sensing pathogens and summarize the effectors that target the cytoskeleton. We highlight advances in the regulation of cytoskeletal remodeling associated with the defense response and assess the important function of the rearrangement of the cytoskeleton in the immune response. Finally, we propose suggestions for future research in this area.
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13
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Cheng SS, Ku YS, Cheung MY, Lam HM. Identification of stably expressed reference genes for expression studies in Arabidopsis thaliana using mass spectrometry-based label-free quantification. FRONTIERS IN PLANT SCIENCE 2022; 13:1001920. [PMID: 36247637 PMCID: PMC9557097 DOI: 10.3389/fpls.2022.1001920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/24/2022] [Accepted: 08/29/2022] [Indexed: 06/16/2023]
Abstract
Arabidopsis thaliana has been used regularly as a model plant in gene expression studies on transcriptional reprogramming upon pathogen infection, such as that by Pseudomonas syringae pv. tomato DC3000 (Pst DC3000), or when subjected to stress hormone treatments including jasmonic acid (JA), salicylic acid (SA), and abscisic acid (ABA). Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) has been extensively employed to quantitate these gene expression changes. However, the accuracy of the quantitation is largely dependent on the stability of the expressions of reference genes used for normalization. Recently, RNA sequencing (RNA-seq) has been widely used to mine stably expressed genes for use as references in RT-qPCR. However, the amplification step in RNA-seq creates an intrinsic bias against those genes with relatively low expression levels, and therefore does not provide an accurate quantification of all expressed genes. In this study, we employed mass spectrometry-based label-free quantification (LFQ) in proteomic analyses to identify those proteins with abundances unaffected by Pst DC3000 infection. We verified, using RT-qPCR, that the levels of their corresponding mRNAs were also unaffected by Pst DC3000 infection. Compared to commonly used reference genes for expression studies in A. thaliana upon Pst DC3000 infection, the candidate reference genes reported in this study generally have a higher expression stability. In addition, using RT-qPCR, we verified that the mRNAs of the candidate reference genes were stably expressed upon stress hormone treatments including JA, SA, and ABA. Results indicated that the candidate genes identified here had stable expressions upon these stresses and are suitable to be used as reference genes for RT-qPCR. Among the 18 candidate reference genes reported in this study, many of them had greater expression stability than the commonly used reference genes, such as ACT7, in previous studies. Here, besides proposing more appropriate reference genes for Arabidopsis expression studies, we also demonstrated the capacity of mass spectrometry-based LFQ to quantify protein abundance and the possibility to extend protein expression studies to the transcript level.
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14
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Olawole OI, Liu Q, Chen C, Gleason ML, Beattie GA. The Contributions to Virulence of the Effectors Eop1 and DspE Differ Between Two Clades of Erwinia tracheiphila Strains. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2021; 34:1399-1408. [PMID: 34505816 DOI: 10.1094/mpmi-06-21-0149-r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Strains of Erwinia tracheiphila, causal agent of bacterial wilt of cucurbits, are divided into distinct clades. Et-melo clade strains wilt Cucumis spp. but not Cucurbita spp., thus exhibiting host specificity, whereas Et-C1 clade strains wilt Cucurbita spp. more rapidly than Cucumis melo, thus exhibiting a host preference. This study investigated the contribution of the effector proteins Eop1 and DspE to E. tracheiphila pathogenicity and host adaptation. Loss of eop1 did not enable Et-melo strains to infect squash (Cucurbita pepo) or an Et-C1 strain to induce a more rapid wilt of muskmelon (Cucumis melo), indicating that Eop1 did not function in host specificity or preference as in the related pathogen E. amylovora. However, overexpression of eop1 from Et-melo strain MDCuke but not from Et-C1 strain BHKY increased the virulence of a BHKY eop1 deletion mutant on muskmelon, demonstrating that the Eop1 variants in the two clades are distinct in their virulence functions. Loss of dspE from Et-melo strains reduced but did not eliminate virulence on hosts muskmelon and cucumber, whereas loss of dspE from an Et-C1 strain eliminated pathogenicity on hosts squash, muskmelon, and cucumber. Thus, the centrality of DspE to virulence differs in the two clades. Et-melo mutants lacking the chaperone DspF exhibited similar virulence to mutants lacking DspE, indicating that DspF is the sole chaperone for DspE in E. tracheiphila, unlike in E. amylovora. Collectively, these results provide the first functional evaluation of effectors in E. tracheiphila and demonstrate clade-specific differences in the roles of Eop1 and DspE.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY 4.0 International license.
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Affiliation(s)
- Olakunle I Olawole
- Department of Plant Pathology and Microbiology, Iowa State University, Ames, IA, U.S.A
| | - Qian Liu
- Department of Plant Pathology and Microbiology, Iowa State University, Ames, IA, U.S.A
| | - Chiliang Chen
- Department of Plant Pathology and Microbiology, Iowa State University, Ames, IA, U.S.A
| | - Mark L Gleason
- Department of Plant Pathology and Microbiology, Iowa State University, Ames, IA, U.S.A
| | - Gwyn A Beattie
- Department of Plant Pathology and Microbiology, Iowa State University, Ames, IA, U.S.A
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15
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Choi S, Prokchorchik M, Lee H, Gupta R, Lee Y, Chung EH, Cho B, Kim MS, Kim ST, Sohn KH. Direct acetylation of a conserved threonine of RIN4 by the bacterial effector HopZ5 or AvrBsT activates RPM1-dependent immunity in Arabidopsis. MOLECULAR PLANT 2021; 14:1951-1960. [PMID: 34329778 DOI: 10.1016/j.molp.2021.07.017] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 06/28/2021] [Accepted: 07/23/2021] [Indexed: 06/13/2023]
Abstract
Plant pathogenic bacteria deliver effectors into plant cells to suppress immunity and promote pathogen survival; however, these effectors can be recognized by plant disease resistance proteins to activate innate immunity. The bacterial acetyltransferase effectors HopZ5 and AvrBsT trigger immunity in Arabidopsis thaliana genotypes lacking SUPPRESSOR OF AVRBST-ELICITED RESISTANCE 1 (SOBER1). Using an Arabidopsis accession, Tscha-1, that naturally lacks functional SOBER1 but is unable to recognize HopZ5, we demonstrated that RESISTANCE TO P. SYRINGAE PV MACULICOLA 1 (RPM1) and RPM1-INTERACTING PROTEIN 4 (RIN4) are indispensable for HopZ5- or AvrBsT-triggered immunity. Remarkably, T166 of RIN4, the phosphorylation of which is induced by AvrB and AvrRpm1, is directly acetylated by HopZ5 and AvrBsT. Furthermore, we demonstrated that the acetylation of RIN4 T166 is required and sufficient for HopZ5- or AvrBsT-triggered RPM1-dependent defense activation. Finally, we showed that SOBER1 interferes with HopZ5- or AvrBsT-triggered immunity by deacetylating RIN4 T166. Collectively, our study elucidates detailed molecular mechanisms underlying the activation and suppression of plant innate immunity triggered by two bacterial acetyltransferases, HopZ5 and AvrBsT, from different bacterial pathogens.
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Affiliation(s)
- Sera Choi
- Department of Life Sciences, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
| | - Maxim Prokchorchik
- Department of Life Sciences, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
| | - Hyeonjung Lee
- Department of Life Sciences, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
| | - Ravi Gupta
- Department of Plant Bioscience, Life and Industry Convergence Research Institute, Pusan National University, Miryang 50463, Republic of Korea; Department of Botany, School of Chemical and Life Sciences, Jamia Hamdard, Hamdard Nagar, New Delhi 110062, India
| | - Yoonyoung Lee
- Department of Life Sciences, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
| | - Eui-Hwan Chung
- Division of Biotechnology, Korea University, Seoul 02841, Republic of Korea
| | - Buhyeon Cho
- Department of Life Sciences, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
| | - Min-Sung Kim
- Department of Life Sciences, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
| | - Sun Tae Kim
- Department of Plant Bioscience, Life and Industry Convergence Research Institute, Pusan National University, Miryang 50463, Republic of Korea
| | - Kee Hoon Sohn
- Department of Life Sciences, Pohang University of Science and Technology, Pohang 37673, Republic of Korea; School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, Pohang 37673, Republic of Korea.
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16
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Sharma A, Timilsina S, Abrahamian P, Minsavage GV, Colee J, Ojiambo PS, Goss EM, Vallad GE, Jones JB. Need for speed: bacterial effector XopJ2 is associated with increased dispersal velocity of Xanthomonas perforans. Environ Microbiol 2021; 23:5850-5865. [PMID: 33891376 PMCID: PMC8597037 DOI: 10.1111/1462-2920.15541] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 04/20/2021] [Indexed: 11/28/2022]
Abstract
Bacterial spot caused by Xanthomonas perforans (Xp) is an economically important disease in tomato. Previous studies have shown that the recently isolated Xp strains have acquired and retained the effector gene, xopJ2, which has been reported to increase fitness of the pathogen in the field. To elucidate the fitness benefit of xopJ2, we quantified the effect of xopJ2 on the dispersal and evolution of Xp populations on tomato. We compared movement of two wild-type Xp strains expressing xopJ2 to their respective xopJ2 mutants when co-inoculated in the field. We developed a binary logistic model to predict the presence of Xp over spatial and temporal dimensions with or without xopJ2. Based on the model, wild-type bacteria were dispersed approximately three times faster than the xopJ2 mutants. In a simulation experiment, the selective advantage due to increased dispersal velocity led to an increase in the frequency of xopJ2 gene in the Xp population and its apparent fixation within 10 to 12 cropping seasons of the tomato crop. Our results show that the presence of a single gene can affect the dispersal of a bacterial pathogen and significantly alter its population dynamics.
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Affiliation(s)
- Anuj Sharma
- Department of Plant PathologyUniversity of FloridaGainesvilleFloridaUSA
| | - Sujan Timilsina
- Department of Plant PathologyUniversity of FloridaGainesvilleFloridaUSA
| | - Peter Abrahamian
- Gulf Coast Research and Education CenterUniversity of FloridaWimaumaFloridaUSA
| | | | - James Colee
- Statistics Consulting Unit, Institute of Food and Agricultural SciencesUniversity of FloridaGainesvilleFloridaUSA
| | - Peter S. Ojiambo
- Department of Entomology and Plant PathologyNorth Carolina State UniversityRaleighNorth CarolinaUSA
| | - Erica M. Goss
- Department of Plant PathologyUniversity of FloridaGainesvilleFloridaUSA
- Emerging Pathogens InstituteUniversity of FloridaGainesvilleFloridaUSA
| | - Gary E. Vallad
- Gulf Coast Research and Education CenterUniversity of FloridaWimaumaFloridaUSA
| | - Jeffrey B. Jones
- Department of Plant PathologyUniversity of FloridaGainesvilleFloridaUSA
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17
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Wang J, Liu C, Chen Y, Zhao Y, Ma Z. Protein acetylation and deacetylation in plant-pathogen interactions. Environ Microbiol 2021; 23:4841-4855. [PMID: 34398483 DOI: 10.1111/1462-2920.15725] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 08/12/2021] [Accepted: 08/13/2021] [Indexed: 12/12/2022]
Abstract
Protein acetylation and deacetylation catalysed by lysine acetyltransferases (KATs) and deacetylases (KDACs), respectively, are major mechanisms regulating various cellular processes. During the fight between microbial pathogens and host plants, both apply a set of measures, including acetylation interference, to strengthen themselves while suppressing the other. In this review, we first summarize KATs and KDACs in plants and their pathogens. Next, we introduce diverse acetylation and deacetylation mechanisms affecting protein functions, including the regulation of enzyme activity and specificity, protein-protein or protein-DNA interactions, subcellular localization and protein stability. We then focus on the current understanding of acetylation and deacetylation in plant-pathogen interactions. Additionally, we also discuss potential acetylation-related approaches for controlling plant diseases.
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Affiliation(s)
- Jing Wang
- State Key Laboratory of Rice Biology, and Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, Hangzhou, China
| | - Chao Liu
- State Key Laboratory of Rice Biology, and Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, Hangzhou, China
| | - Yun Chen
- State Key Laboratory of Rice Biology, and Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, Hangzhou, China
| | - Youfu Zhao
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Zhonghua Ma
- State Key Laboratory of Rice Biology, and Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, Hangzhou, China
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18
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Gough C, Sadanandom A. Understanding and Exploiting Post-Translational Modifications for Plant Disease Resistance. Biomolecules 2021; 11:1122. [PMID: 34439788 PMCID: PMC8392720 DOI: 10.3390/biom11081122] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 07/23/2021] [Accepted: 07/26/2021] [Indexed: 12/27/2022] Open
Abstract
Plants are constantly threatened by pathogens, so have evolved complex defence signalling networks to overcome pathogen attacks. Post-translational modifications (PTMs) are fundamental to plant immunity, allowing rapid and dynamic responses at the appropriate time. PTM regulation is essential; pathogen effectors often disrupt PTMs in an attempt to evade immune responses. Here, we cover the mechanisms of disease resistance to pathogens, and how growth is balanced with defence, with a focus on the essential roles of PTMs. Alteration of defence-related PTMs has the potential to fine-tune molecular interactions to produce disease-resistant crops, without trade-offs in growth and fitness.
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Affiliation(s)
| | - Ari Sadanandom
- Department of Biosciences, Durham University, Stockton Road, Durham DH1 3LE, UK;
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19
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Schreiber KJ, Chau-Ly IJ, Lewis JD. What the Wild Things Do: Mechanisms of Plant Host Manipulation by Bacterial Type III-Secreted Effector Proteins. Microorganisms 2021; 9:1029. [PMID: 34064647 PMCID: PMC8150971 DOI: 10.3390/microorganisms9051029] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 05/03/2021] [Accepted: 05/04/2021] [Indexed: 01/05/2023] Open
Abstract
Phytopathogenic bacteria possess an arsenal of effector proteins that enable them to subvert host recognition and manipulate the host to promote pathogen fitness. The type III secretion system (T3SS) delivers type III-secreted effector proteins (T3SEs) from bacterial pathogens such as Pseudomonas syringae, Ralstonia solanacearum, and various Xanthomonas species. These T3SEs interact with and modify a range of intracellular host targets to alter their activity and thereby attenuate host immune signaling. Pathogens have evolved T3SEs with diverse biochemical activities, which can be difficult to predict in the absence of structural data. Interestingly, several T3SEs are activated following injection into the host cell. Here, we review T3SEs with documented enzymatic activities, as well as T3SEs that facilitate virulence-promoting processes either indirectly or through non-enzymatic mechanisms. We discuss the mechanisms by which T3SEs are activated in the cell, as well as how T3SEs modify host targets to promote virulence or trigger immunity. These mechanisms may suggest common enzymatic activities and convergent targets that could be manipulated to protect crop plants from infection.
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Affiliation(s)
- Karl J. Schreiber
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94710, USA; (K.J.S.); (I.J.C.-L.)
| | - Ilea J. Chau-Ly
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94710, USA; (K.J.S.); (I.J.C.-L.)
| | - Jennifer D. Lewis
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94710, USA; (K.J.S.); (I.J.C.-L.)
- Plant Gene Expression Center, United States Department of Agriculture, University of California, Berkeley, CA 94710, USA
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20
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Takáč T, Křenek P, Komis G, Vadovič P, Ovečka M, Ohnoutková L, Pechan T, Kašpárek P, Tichá T, Basheer J, Arick M, Šamaj J. TALEN-Based HvMPK3 Knock-Out Attenuates Proteome and Root Hair Phenotypic Responses to flg22 in Barley. FRONTIERS IN PLANT SCIENCE 2021; 12:666229. [PMID: 33995462 PMCID: PMC8117018 DOI: 10.3389/fpls.2021.666229] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Accepted: 03/31/2021] [Indexed: 05/26/2023]
Abstract
Mitogen activated protein kinases (MAPKs) integrate elicitor perception with both early and late responses associated with plant defense and innate immunity. Much of the existing knowledge on the role of plant MAPKs in defense mechanisms against microbes stems from extensive research in the model plant Arabidopsis thaliana. In the present study, we investigated the involvement of barley (Hordeum vulgare) MPK3 in response to flagellin peptide flg22, a well-known bacterial elicitor. Using differential proteomic analysis we show that TALEN-induced MPK3 knock-out lines of barley (HvMPK3 KO) exhibit constitutive downregulation of defense related proteins such as PR proteins belonging to thaumatin family and chitinases. Further analyses showed that the same protein families were less prone to flg22 elicitation in HvMPK3 KO plants compared to wild types. These results were supported and validated by chitinase activity analyses and immunoblotting for HSP70. In addition, differential proteomes correlated with root hair phenotypes and suggested tolerance of HvMPK3 KO lines to flg22. In conclusion, our study points to the specific role of HvMPK3 in molecular and root hair phenotypic responses of barley to flg22.
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Affiliation(s)
- Tomáš Takáč
- Department of Cell Biology, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University Olomouc, Olomouc, Czechia
| | - Pavel Křenek
- Department of Cell Biology, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University Olomouc, Olomouc, Czechia
| | - George Komis
- Department of Cell Biology, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University Olomouc, Olomouc, Czechia
| | - Pavol Vadovič
- Department of Cell Biology, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University Olomouc, Olomouc, Czechia
| | - Miroslav Ovečka
- Department of Cell Biology, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University Olomouc, Olomouc, Czechia
| | - Ludmila Ohnoutková
- Laboratory of Growth Regulators, Palacký University and Institute of Experimental Botany, Czech Academy of Sciences, Olomouc, Czechia
| | - Tibor Pechan
- Institute for Genomics, Biocomputing and Biotechnology, Mississippi Agricultural and Forestry Experiment Station, Mississippi State University, Starkville, MS, United States
| | - Petr Kašpárek
- Laboratory of Transgenic Models of Diseases, Institute of Molecular Genetics of the CAS, Vestec, Czechia
| | - Tereza Tichá
- Department of Cell Biology, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University Olomouc, Olomouc, Czechia
| | - Jasim Basheer
- Department of Cell Biology, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University Olomouc, Olomouc, Czechia
| | - Mark Arick
- Institute for Genomics, Biocomputing and Biotechnology, Mississippi Agricultural and Forestry Experiment Station, Mississippi State University, Starkville, MS, United States
| | - Jozef Šamaj
- Department of Cell Biology, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University Olomouc, Olomouc, Czechia
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21
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Bhandari DD, Brandizzi F. Plant endomembranes and cytoskeleton: moving targets in immunity. CURRENT OPINION IN PLANT BIOLOGY 2020; 58:8-16. [PMID: 33099211 DOI: 10.1016/j.pbi.2020.09.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 08/28/2020] [Accepted: 09/11/2020] [Indexed: 06/11/2023]
Abstract
Pathogens attack plant cells to divert resources toward pathogen proliferation. To resist pathogens, plant cells rely on multilayered signaling pathways that hinge upon the secretory pathway for the synthesis and trafficking of pathogen sensors and defense molecules. In recent years, significant strides have been made in the understanding of the functional relationship between pathogen response and membrane traffic. Here we discuss how the plant cytoskeleton and endomembranes are targeted by pathogen effectors and highlight an emerging role of membrane contact sites in biotic stress responses.
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Affiliation(s)
- Deepak D Bhandari
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA
| | - Federica Brandizzi
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA; Department of Plant Biology, Michigan State University, East Lansing, MI 48824, USA; Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI 48824, USA.
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22
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Leontovyčová H, Kalachova T, Janda M. Disrupted actin: a novel player in pathogen attack sensing? THE NEW PHYTOLOGIST 2020; 227:1605-1609. [PMID: 32259281 DOI: 10.1111/nph.16584] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Accepted: 03/26/2020] [Indexed: 06/11/2023]
Abstract
The actin cytoskeleton is widely involved in plant immune responses. The majority of studies show that chemical disruption of the actin cytoskeleton increases plant susceptibility to pathogen infection. Similarly, several pathogens have adopted this as a virulence strategy and produce effectors that affect cytoskeleton integrity. Such effectors either exhibit actin-depolymerizing activity themselves or prevent actin polymerization. Is it thus possible for plants to recognize the actin's status and launch a counterattack? Recently we showed that chemical depolymerization of actin filaments can trigger resistance to further infection via the specific activation of salicylic acid (SA) signalling. This is accompanied by several defence-related, but SA-independent, effects (e.g. callose deposition, gene expression), relying on vesicular trafficking and phospholipid metabolism. These data suggest that the role of actin in plant-pathogen interactions is more complex than previously believed. It raises the question of whether plants have evolved a mechanism of sensing pathological actin disruption that eventually triggers defence responses. If so, what is the molecular basis of it? Otherwise, why does actin depolymerization specifically influence SA content but not any other phytohormone? Here we propose an updated model of actin's role in plant-microbe interactions and suggest some future directions of research to be conducted in this area.
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Affiliation(s)
- Hana Leontovyčová
- Laboratory of Pathological Plant Physiology, Institute of Experimental Botany, The Czech Academy of Sciences, Rozvojova 263, 165 02, Prague 6, Czech Republic
- Laboratory of Plant Biochemistry, Department of Biochemistry and Microbiology, University of Chemistry and Technology Prague, Technicka 5, 166 28, Prague 6, Czech Republic
- Department of Biochemistry, Faculty of Science, Faculty of Science, Charles University in Prague, Hlavova 2030/8, 128 44, Prague 2, Czech Republic
| | - Tetiana Kalachova
- Laboratory of Pathological Plant Physiology, Institute of Experimental Botany, The Czech Academy of Sciences, Rozvojova 263, 165 02, Prague 6, Czech Republic
| | - Martin Janda
- Laboratory of Pathological Plant Physiology, Institute of Experimental Botany, The Czech Academy of Sciences, Rozvojova 263, 165 02, Prague 6, Czech Republic
- Laboratory of Plant Biochemistry, Department of Biochemistry and Microbiology, University of Chemistry and Technology Prague, Technicka 5, 166 28, Prague 6, Czech Republic
- Faculty of Biology, Biocenter, Department Genetics, Ludwig-Maximilians-University of Munich (LMU), Grosshaderner Str. 2-4, D-82152, Martinsried, Germany
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23
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Maurya R, Srivastava D, Singh M, Sawant SV. Envisioning the immune interactome in Arabidopsis. FUNCTIONAL PLANT BIOLOGY : FPB 2020; 47:486-507. [PMID: 32345431 DOI: 10.1071/fp19188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Accepted: 01/13/2020] [Indexed: 06/11/2023]
Abstract
During plant-pathogen interaction, immune targets were regulated by protein-protein interaction events such as ligand-receptor/co-receptor, kinase-substrate, protein sequestration, activation or repression via post-translational modification and homo/oligo/hetro-dimerisation of proteins. A judicious use of molecular machinery requires coordinated protein interaction among defence components. Immune signalling in Arabidopsis can be broadly represented in successive or simultaneous steps; pathogen recognition at cell surface, Ca2+ and reactive oxygen species signalling, MAPK signalling, post-translational modification, transcriptional regulation and phyto-hormone signalling. Proteome wide interaction studies have shown the existence of interaction hubs associated with physiological function. So far, a number of protein interaction events regulating immune targets have been identified, but their understanding in an interactome view is lacking. We focussed specifically on the integration of protein interaction signalling in context to plant-pathogenesis and identified the key targets. The present review focuses towards a comprehensive view of the plant immune interactome including signal perception, progression, integration and physiological response during plant pathogen interaction.
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Affiliation(s)
- Rashmi Maurya
- Plant Molecular Biology Lab, National Botanical Research Institute, Lucknow. 226001; and Department of Botany, Lucknow University, Lucknow. 226007
| | - Deepti Srivastava
- Integral Institute of Agricultural Science and Technology (IIAST) Integral University, Kursi Road, Dashauli, Uttar Pradesh. 226026
| | - Munna Singh
- Department of Botany, Lucknow University, Lucknow. 226007
| | - Samir V Sawant
- Plant Molecular Biology Lab, National Botanical Research Institute, Lucknow. 226001; and Corresponding author.
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24
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Schreiber KJ, Lewis JD. Protein Acetylation in Pathogen Virulence and Host Defense: In Vitro Detection of Protein Acetylation by Radiolabeled Acetyl Coenzyme A. Methods Mol Biol 2020; 1991:23-32. [PMID: 31041759 DOI: 10.1007/978-1-4939-9458-8_3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Protein acetylation has emerged as a common modification that modulates multiple aspects of protein function, including localization, stability, and protein-protein interactions. It is increasingly evident that protein acetylation significantly impacts the outcome of host-microbe interactions. In order to characterize novel putative acetyltransferase enzymes and their substrates, we describe a simple protocol for the detection of acetyltransferase activity in vitro. Purified proteins are incubated with 14C-acetyl CoA and separated electrophoretically, and acetylated proteins are detected by phosphorimaging or autoradiography.
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Affiliation(s)
- Karl J Schreiber
- Department of Plant and Microbial Biology, University of California-Berkeley, Berkeley, CA, USA
| | - Jennifer D Lewis
- Department of Plant and Microbial Biology, University of California-Berkeley, Berkeley, CA, USA. .,Plant Gene Expression Center, United States Department of Agriculture, Albany, CA, USA.
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25
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Song YR, Hwang IS, Oh CS. Natural Variation in Virulence of Acidovorax citrulli Isolates That Cause Bacterial Fruit Blotch in Watermelon, Depending on Infection Routes. THE PLANT PATHOLOGY JOURNAL 2020; 36:29-42. [PMID: 32089659 PMCID: PMC7012574 DOI: 10.5423/ppj.oa.10.2019.0254] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 11/13/2019] [Accepted: 12/02/2019] [Indexed: 05/21/2023]
Abstract
Acidovorax citrulli causes bacterial fruit blotch in Cucurbitaceae, including watermelon. Although A. citrulli is a seed-borne pathogen, it can cause diverse symptoms in other plant organs like leaves, stems and fruits. To determine the infection routes of A. citrulli, we examined the virulence of six isolates (Ac0, Ac1, Ac2, Ac4, Ac8, and Ac11) on watermelon using several inoculation methods. Among six isolates, DNA polymorphism reveals that three isolates Ac0, Ac1, and Ac4 belong to Clonal Complex (CC) group II and the others do CC group I. Ac0, Ac4, and Ac8 isolates efficiently infected seeds during germination in soil, and Ac0 and Ac4 also infected the roots of watermelon seedlings wounded prior to inoculation. Infection through leaves was successful only by three isolates belonging to CC group II, and two of these also infected the mature watermelon fruits. Ac2 did not cause the disease in all assays. Interestingly, three putative type III effectors (Aave_2166, Aave_2708, and Aave_3062) with intact forms were only found in CC group II. Overall, our results indicate that A. citrulli can infect watermelons through diverse routes, and the CC grouping of A. citrulli was only correlated with virulence in leaf infection assays.
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Affiliation(s)
| | | | - Chang-Sik Oh
- Corresponding author: Phone) +82-31-201-2678, FAX) +82-31-204-8116, E-mail)
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26
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Lopes Fischer N, Naseer N, Shin S, Brodsky IE. Effector-triggered immunity and pathogen sensing in metazoans. Nat Microbiol 2019; 5:14-26. [DOI: 10.1038/s41564-019-0623-2] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 10/29/2019] [Indexed: 01/06/2023]
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27
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Wang X, Mao T. Understanding the functions and mechanisms of plant cytoskeleton in response to environmental signals. CURRENT OPINION IN PLANT BIOLOGY 2019; 52:86-96. [PMID: 31542697 DOI: 10.1016/j.pbi.2019.08.002] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 07/12/2019] [Accepted: 08/08/2019] [Indexed: 06/10/2023]
Abstract
Plants perceive multiple physiological and environmental signals in order to fine-tune their growth and development. The highly dynamic plant cytoskeleton, including actin and microtubule networks, can rapidly alter their organization, stability and dynamics in response to internal and external stimuli, which is considered vital for plant growth and adaptation to the environment. The cytoskeleton-associated proteins have been shown to be key regulatory molecules in mediating cytoskeleton reorganization in response to multiple environmental signals, such as light, salt, drought and biotic stimuli. Recent findings, including our studies, have expanded knowledge about the functions and underlying mechanisms of the plant cytoskeleton in environmental adaptation.
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Affiliation(s)
- Xiangfeng Wang
- State Key Laboratory of Plant Physiology and Biochemistry, Department of Plant Sciences, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Tonglin Mao
- State Key Laboratory of Plant Physiology and Biochemistry, Department of Plant Sciences, College of Biological Sciences, China Agricultural University, Beijing 100193, China.
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28
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Traore SM, Eckshtain‐Levi N, Miao J, Castro Sparks A, Wang Z, Wang K, Li Q, Burdman S, Walcott R, Welbaum GE, Zhao B. Nicotiana species as surrogate host for studying the pathogenicity of Acidovorax citrulli, the causal agent of bacterial fruit blotch of cucurbits. MOLECULAR PLANT PATHOLOGY 2019; 20:800-814. [PMID: 30938096 PMCID: PMC6637898 DOI: 10.1111/mpp.12792] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Bacterial fruit blotch (BFB) caused by Acidovorax citrulli is one of the most important bacterial diseases of cucurbits worldwide. However, the mechanisms associated with A. citrulli pathogenicity and genetics of host resistance have not been extensively investigated. We idenitfied Nicotiana benthamiana and Nicotiana tabacum as surrogate hosts for studying A. citrulli pathogenicity and non-host resistance triggered by type III secreted (T3S) effectors. Two A. citrulli strains, M6 and AAC00-1, that represent the two major groups amongst A. citrulli populations, induced disease symptoms on N. benthamiana, but triggered a hypersensitive response (HR) on N. tabacum plants. Transient expression of 19 T3S effectors from A. citrulli in N. benthamiana leaves revealed that three effectors, Aave_1548, Aave_2708, and Aave_2166, trigger water-soaking-like cell death in N. benthamiana. Aave_1548 knockout mutants of M6 and AAC00-1 displayed reduced virulence on N. benthamiana and melon (Cucumis melo L.). Transient expression of Aave_1548 and Aave_2166 effectors triggered a non-host HR in N. tabacum, which was dependent on the functionality of the immune signalling component, NtSGT1. Hence, employing Nicotiana species as surrogate hosts for studying A. citrulli pathogenicity may help characterize the function of A. citrulli T3S effectors and facilitate the development of new strategies for BFB management.
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Affiliation(s)
- Sy M. Traore
- School of Plant and Environmental SciencesVirginia TechBlacksburgVAUSA
| | - Noam Eckshtain‐Levi
- Department of Plant Pathology and MicrobiologyThe Hebrew University of JerusalemRehovotIsrael
| | - Jiamin Miao
- School of Plant and Environmental SciencesVirginia TechBlacksburgVAUSA
| | | | - Zhibo Wang
- School of Plant and Environmental SciencesVirginia TechBlacksburgVAUSA
| | - Kunru Wang
- School of Plant and Environmental SciencesVirginia TechBlacksburgVAUSA
| | - Qi Li
- School of Plant and Environmental SciencesVirginia TechBlacksburgVAUSA
| | - Saul Burdman
- Department of Plant Pathology and MicrobiologyThe Hebrew University of JerusalemRehovotIsrael
| | - Ron Walcott
- Department of Plant PathologyUniversity of GeorgiaAthensGAUSA
| | | | - Bingyu Zhao
- School of Plant and Environmental SciencesVirginia TechBlacksburgVAUSA
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29
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Cao Y, Fan G, Wang Z, Gu Z. Phytoplasma-induced Changes in the Acetylome and Succinylome of Paulownia tomentosa Provide Evidence for Involvement of Acetylated Proteins in Witches' Broom Disease. Mol Cell Proteomics 2019; 18:1210-1226. [PMID: 30936209 PMCID: PMC6553929 DOI: 10.1074/mcp.ra118.001104] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 02/20/2019] [Indexed: 12/16/2022] Open
Abstract
Lysine acetylation and succinylation are post-translational modifications of proteins that have been shown to play roles in plants response to pathogen infection. Phytoplasma infection can directly alter multiple metabolic processes in the deciduous plant Paulownia and lead to Paulownia witches' broom (PaWB) disease, the major cause of Paulownia mortality worldwide. However, the extent and function of lysine aceylation and succinylation during phytoplasma infection have yet to be explored. Here, we investigated the changes in the proteome, acetylome, and succinylome of phytoplasma-infected Paulownia tomentosa seedlings using quantitative mass spectrometry. In total, we identified 8963 proteins, 2893 acetylated proteins (5558 acetylation sites), and 1271 succinylated proteins (1970 succinylation sites), with 425 (533 sites) simultaneously acetylated and succinylated. Comparative analysis revealed that 276 proteins, 546 acetylated proteins (741 acetylation sites) and 5 succinylated proteins (5 succinylation sites) were regulated in response to phytoplasma infection, suggesting that acetylation may be more important than succinylation in PaWB. Enzymatic assays showed that acetylation of specific sites in protochlorophyllide reductase and RuBisCO, key enzymes in chlorophyll and starch biosynthesis, respectively, modifies their activity in phytoplasma-infected seedlings. On the basis of these results, we propose a model to elucidate the molecular mechanism of responses to PaWB and offer a resource for functional studies on the effects of acetylation on protein function.
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Affiliation(s)
| | - Guoqiang Fan
- From the ‡Institute of Paulownia and
- §College of Forestry, Henan Agricultural University, Zhengzhou, Henan, 450002, P. R. China
| | - Zhe Wang
- From the ‡Institute of Paulownia and
| | - Zhibin Gu
- From the ‡Institute of Paulownia and
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30
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Li P, Day B. Battlefield Cytoskeleton: Turning the Tide on Plant Immunity. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2019; 32:25-34. [PMID: 30355064 PMCID: PMC6326859 DOI: 10.1094/mpmi-07-18-0195-fi] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
The plant immune system comprises a complex network of signaling processes, regulated not only by classically defined immune components (e.g., resistance genes) but also by a suite of developmental, environmental, abiotic, and biotic-associated factors. In total, it is the sum of these interactions-the connectivity to a seemingly endless array of environments-that ensures proper activation, and control, of a system that is responsible for cell surveillance and response to threats presented by invading pests and pathogens. Over the past decade, the field of plant pathology has witnessed the discovery of numerous points of convergence between immunity, growth, and development, as well as overlap with seemingly disparate processes such as those that underpin plant response to changes in the environment. Toward defining how immune signaling is regulated, recent studies have focused on dissecting the mechanisms that underpin receptor-ligand interactions, phospho-regulation of signaling cascades, and the modulation of host gene expression during infection. As one of the major regulators of these immune signaling cascades, the plant cytoskeleton is the stage from which immune-associated processes are mobilized and oriented and, in this role, it controls the movement of the organelles, proteins, and chemical signals that support plant defense signaling. In short, the cytoskeleton is the battlefield from which pathogens and plants volley virulence and resistance, transforming resistance to susceptibility. Herein, we discuss the role of the eukaryotic cytoskeleton as a platform for the function of the plant immune system.
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Affiliation(s)
- Pai Li
- Department of Plant Biology, Michigan State University, East Lansing, MI 48824, USA
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI 48824, USA
| | - Brad Day
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI 48824, USA
- Michigan State University Plant Resilience Institute, East Lansing, MI 48824, USA
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31
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Abrahamian P, Timilsina S, Minsavage GV, Kc S, Goss EM, Jones JB, Vallad GE. The Type III Effector AvrBsT Enhances Xanthomonas perforans Fitness in Field-Grown Tomato. PHYTOPATHOLOGY 2018; 108:1355-1362. [PMID: 29905507 DOI: 10.1094/phyto-02-18-0052-r] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Type III secretion system effectors contribute to pathogenicity through various mechanisms. Recent surveys showed an increasing prevalence of the type III secretion effector avrBsT among Xanthomonas perforans strains. We hypothesized that the acquisition of avrBsT has a fitness advantage for the pathogen. The contribution of avrBsT to fitness on tomato was evaluated based on disease severity, in planta growth, competition, and recovery rates of wild-type (WT) and avrBsT mutant strains in greenhouse and field plants. GEV872 and GEV1001, representative strains of two phylogenomic groups of X. perforans, were selected for generating avrBsT mutants. Disease severity was higher for WT strains compared with the avrBsT mutant strains. X. perforans WT and avrBsT mutant strains did not differ following leaf infiltration of greenhouse plants in direct competition and in planta growth assays. The effect of avrBsT on pathogen fitness was noticeable under field conditions. Differences in strain recovery were significant, with WT being recovered two to eight times more than avrBsT mutant strains in the case of both strains GEV872 and GEV1001. WT strains were capable of spreading longer distances across field plots compared with avrBsT mutant strains. Findings suggest that the functional AvrBsT affects the fitness of X. perforans under field conditions, making it an ideal candidate for bacterial spot resistance breeding efforts in tomato.
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Affiliation(s)
- Peter Abrahamian
- First, second, fourth, and seventh authors; Gulf Coast and Research Education Center, Wimauma, FL; first, second, third, fifth, sixth, and seventh authors: Department of Plant Pathology, University of Florida, Gainesville; and fifth author: Emerging Pathogens Institute, University of Florida, Gainesville
| | - Sujan Timilsina
- First, second, fourth, and seventh authors; Gulf Coast and Research Education Center, Wimauma, FL; first, second, third, fifth, sixth, and seventh authors: Department of Plant Pathology, University of Florida, Gainesville; and fifth author: Emerging Pathogens Institute, University of Florida, Gainesville
| | - Gerald V Minsavage
- First, second, fourth, and seventh authors; Gulf Coast and Research Education Center, Wimauma, FL; first, second, third, fifth, sixth, and seventh authors: Department of Plant Pathology, University of Florida, Gainesville; and fifth author: Emerging Pathogens Institute, University of Florida, Gainesville
| | - Sushmita Kc
- First, second, fourth, and seventh authors; Gulf Coast and Research Education Center, Wimauma, FL; first, second, third, fifth, sixth, and seventh authors: Department of Plant Pathology, University of Florida, Gainesville; and fifth author: Emerging Pathogens Institute, University of Florida, Gainesville
| | - Erica M Goss
- First, second, fourth, and seventh authors; Gulf Coast and Research Education Center, Wimauma, FL; first, second, third, fifth, sixth, and seventh authors: Department of Plant Pathology, University of Florida, Gainesville; and fifth author: Emerging Pathogens Institute, University of Florida, Gainesville
| | - Jeffrey B Jones
- First, second, fourth, and seventh authors; Gulf Coast and Research Education Center, Wimauma, FL; first, second, third, fifth, sixth, and seventh authors: Department of Plant Pathology, University of Florida, Gainesville; and fifth author: Emerging Pathogens Institute, University of Florida, Gainesville
| | - Gary E Vallad
- First, second, fourth, and seventh authors; Gulf Coast and Research Education Center, Wimauma, FL; first, second, third, fifth, sixth, and seventh authors: Department of Plant Pathology, University of Florida, Gainesville; and fifth author: Emerging Pathogens Institute, University of Florida, Gainesville
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Prochaska H, Thieme S, Daum S, Grau J, Schmidtke C, Hallensleben M, John P, Bacia K, Bonas U. A conserved motif promotes HpaB-regulated export of type III effectors from Xanthomonas. MOLECULAR PLANT PATHOLOGY 2018; 19:2473-2487. [PMID: 30073738 PMCID: PMC6638074 DOI: 10.1111/mpp.12725] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Revised: 06/07/2018] [Accepted: 06/29/2018] [Indexed: 06/08/2023]
Abstract
The type III secretion (T3S) system, an essential pathogenicity factor in most Gram-negative plant-pathogenic bacteria, injects bacterial effector proteins directly into the plant cell cytosol. Here, the type III effectors (T3Es) manipulate host cell processes to suppress defence and establish appropriate conditions for bacterial multiplication in the intercellular spaces of the plant tissue. T3E export depends on a secretion signal which is also present in 'non-effectors'. The latter are secreted extracellular components of the T3S apparatus, but are not translocated into the plant cell. How the T3S system discriminates between T3Es and non-effectors is still enigmatic. Previously, we have identified a putative translocation motif (TrM) in several T3Es from Xanthomonas campestris pv. vesicatoria (Xcv). Here, we analysed the TrM of the Xcv effector XopB in detail. Mutation studies showed that the proline/arginine-rich motif is required for efficient type III-dependent secretion and translocation of XopB and determines the dependence of XopB transport on the general T3S chaperone HpaB. Similar results were obtained for other effectors from Xcv. As the arginine residues of the TrM mediate specific binding of XopB to cardiolipin, one of the major lipid components in Xanthomonas membranes, we assume that the association of T3Es to the bacterial membrane prior to secretion supports type III-dependent export.
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Affiliation(s)
- Heike Prochaska
- Institute for Biology, Department of GeneticsMartin Luther University Halle‐WittenbergHalle (Saale)06120Germany
| | - Sabine Thieme
- Institute for Biology, Department of GeneticsMartin Luther University Halle‐WittenbergHalle (Saale)06120Germany
| | - Sebastian Daum
- Institute for Chemistry, Department of Biophysical ChemistryMartin Luther University Halle‐WittenbergHalle (Saale)06120Germany
| | - Jan Grau
- Institute for Informatics, Department of BioinformaticsMartin Luther University Halle‐WittenbergHalle (Saale)06120Germany
| | - Cornelius Schmidtke
- Institute for Biology, Department of GeneticsMartin Luther University Halle‐WittenbergHalle (Saale)06120Germany
| | - Magnus Hallensleben
- Institute for Biology, Department of GeneticsMartin Luther University Halle‐WittenbergHalle (Saale)06120Germany
| | - Peter John
- Institute for Biology, Department of GeneticsMartin Luther University Halle‐WittenbergHalle (Saale)06120Germany
| | - Kirsten Bacia
- Institute for Chemistry, Department of Biophysical ChemistryMartin Luther University Halle‐WittenbergHalle (Saale)06120Germany
| | - Ulla Bonas
- Institute for Biology, Department of GeneticsMartin Luther University Halle‐WittenbergHalle (Saale)06120Germany
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33
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Li J, Staiger CJ. Understanding Cytoskeletal Dynamics During the Plant Immune Response. ANNUAL REVIEW OF PHYTOPATHOLOGY 2018; 56:513-533. [PMID: 29975609 DOI: 10.1146/annurev-phyto-080516-035632] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The plant cytoskeleton is a dynamic framework of cytoplasmic filaments that rearranges as the needs of the cell change during growth and development. Incessant turnover mechanisms allow these networks to be rapidly redeployed in defense of host cytoplasm against microbial invaders. Both chemical and mechanical stimuli are recognized as danger signals to the plant, and these are perceived and transduced into cytoskeletal dynamics and architecture changes through a collection of well-recognized, previously characterized players. Recent advances in quantitative cell biology approaches, along with the powerful molecular genetics techniques associated with Arabidopsis, have uncovered two actin-binding proteins as key intermediaries in the immune response to phytopathogens and defense signaling. Certain bacterial phytopathogens have adapted to the cytoskeletal-based defense mechanism during the basal immune response and have evolved effector proteins that target actin filaments and microtubules to subvert transcriptional reprogramming, secretion of defense-related proteins, and cell wall-based defenses. In this review, we describe current knowledge about host cytoskeletal dynamics operating at the crossroads of the molecular and cellular arms race between microbes and plants.
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Affiliation(s)
- Jiejie Li
- Department of Biological Sciences and Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana 47907, USA;
- Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Science, Beijing Normal University, Beijing 100875, China
| | - Christopher J Staiger
- Department of Biological Sciences and Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana 47907, USA;
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34
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Labriola JM, Zhou Y, Nagar B. Structural Analysis of the Bacterial Effector AvrA Identifies a Critical Helix Involved in Substrate Recognition. Biochemistry 2018; 57:4985-4996. [PMID: 30025209 DOI: 10.1021/acs.biochem.8b00512] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Bacterial effector proteins are essential for the infection and proliferation of pathogenic bacteria through manipulation of host immune response pathways. AvrA is a Salmonella effector that belongs to the YopJ family of acetyltransferases, which suppresses c-JUN N-terminal kinase (JNK) signaling in mammals through acetylation of mitogen-activated receptor kinase kinases 4 and 7 (MKK4/7). Interestingly, there are two paralogues of AvrA that differ by only a single internal leucine residue, which when absent (AvrAΔL140) abrogates the ability to suppress JNK signaling. Here, we present the first crystal structure of a bacterial effector from an animal pathogen, AvrAΔL140, accompanied by a thorough biophysical characterization of both AvrA variants. The structure in complex with inositol hexaphosphate and coenzyme A reveals two closely associated domains consisting of a catalytic core that resembles the CE clan peptidases and a wedge-shaped regulatory region that mediates cofactor and substrate binding. The loss of the putative function of AvrAΔL140 is due to its inability to interact with MKK4/7, which ultimately arises from an altered conformation of a critical helix adjacent to the active site that harbors L140. These results provide general insights into substrate recognition across the YopJ family of acetyltransferases.
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Affiliation(s)
- Jonathan M Labriola
- Department of Biochemistry and Groupe de Recherche Axé sur la Structure des Protéines , McGill University , Montreal , QC H3G 0B1 , Canada
| | - Yifan Zhou
- Department of Biochemistry and Groupe de Recherche Axé sur la Structure des Protéines , McGill University , Montreal , QC H3G 0B1 , Canada
| | - Bhushan Nagar
- Department of Biochemistry and Groupe de Recherche Axé sur la Structure des Protéines , McGill University , Montreal , QC H3G 0B1 , Canada
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35
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Choi S, Jayaraman J, Sohn KH. Arabidopsis thaliana SOBER1 (SUPPRESSOR OF AVRBST-ELICITED RESISTANCE 1) suppresses plant immunity triggered by multiple bacterial acetyltransferase effectors. THE NEW PHYTOLOGIST 2018; 219:324-335. [PMID: 29577317 DOI: 10.1111/nph.15125] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Accepted: 02/19/2018] [Indexed: 05/21/2023]
Abstract
Plants evolved disease resistance (R) proteins that recognize corresponding pathogen effectors and activate effector-triggered immunity (ETI). However, it is largely unknown why, in some cases, a suppressor of ETI exists in plants. Arabidopsis SOBER1 (Suppressor of AvrBsT-elicited Resistance 1) was identified previously as a suppressor of Xanthomonas acetyltransferase effector AvrBsT-triggered immunity. Nevertheless, the extent to which SOBER1 suppresses ETI is unclear. Here, we identified SOBER1 as a suppressor of Pseudomonas acetyltransferase effector HopZ5-triggered immunity in Arabidopsis using recombinant inbred lines. Further analysis showed that SOBER1 suppresses immunity triggered by multiple bacterial acetyltransferases. Interestingly, SOBER1 interferes with the immunity signalling activated by some but not all tested acetyltransferase effectors, indicating that SOBER1 might target components that are shared between several ETI pathways.
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Affiliation(s)
- Sera Choi
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, 37673, Korea
- Bioprotection Research Centre, Institute of Agriculture and Environment, Massey University, Palmerston North, 4474, New Zealand
| | - Jay Jayaraman
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, 37673, Korea
- Bioprotection Research Centre, Institute of Agriculture and Environment, Massey University, Palmerston North, 4474, New Zealand
- New Zealand Institute for Plant & Food Research Limited (PFR), Mt Albert, Auckland, 1025, New Zealand
| | - Kee Hoon Sohn
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, 37673, Korea
- Bioprotection Research Centre, Institute of Agriculture and Environment, Massey University, Palmerston North, 4474, New Zealand
- School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, Pohang, 37673, Korea
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36
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Verma V, Croley F, Sadanandom A. Fifty shades of SUMO: its role in immunity and at the fulcrum of the growth-defence balance. MOLECULAR PLANT PATHOLOGY 2018; 19:1537-1544. [PMID: 29024335 PMCID: PMC6637990 DOI: 10.1111/mpp.12625] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Revised: 10/05/2017] [Accepted: 10/06/2017] [Indexed: 05/10/2023]
Abstract
The sessile nature of plants requires them to cope with an ever-changing environment. Effective adaptive responses require sophisticated cellular mechanisms at the post-transcriptional and post-translational levels. Post-translational modification by small ubiquitin-like modifier (SUMO) proteins is emerging as a key player in these adaptive responses. SUMO conjugation can rapidly change the overall fate of target proteins by altering their stability or interaction with partner proteins or DNA. SUMOylation entails an enzyme cascade that leads to the activation, conjugation and ligation of SUMO to lysine residues of target proteins. In addition to their SUMO processing activities, SUMO proteases also possess de-conjugative activity capable of cleaving SUMO from target proteins, providing reversibility and buffering to the pathway. These proteases play critical roles in the maintenance of the SUMO machinery in equilibrium. We hypothesize that SUMO proteases provide the all-important substrate specificity within the SUMO system. Furthermore, we provide an overview of the role of SUMO in plant innate immunity. SUMOylation also overlaps with multiple growth-promoting and defence-related hormone signalling pathways, and hence is pivotal for the maintenance of the growth-defence balance. This review aims to highlight the intricate molecular mechanisms utilized by SUMO to regulate plant defence and to stabilize the growth-defence equilibrium.
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Affiliation(s)
- Vivek Verma
- Department of BiosciencesDurham UniversityDurham DH1 3LEUK
| | - Fenella Croley
- Department of BiosciencesDurham UniversityDurham DH1 3LEUK
| | - Ari Sadanandom
- Department of BiosciencesDurham UniversityDurham DH1 3LEUK
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N-hydroxy-pipecolic acid is a mobile metabolite that induces systemic disease resistance in Arabidopsis. Proc Natl Acad Sci U S A 2018; 115:E4920-E4929. [PMID: 29735713 DOI: 10.1073/pnas.1805291115] [Citation(s) in RCA: 148] [Impact Index Per Article: 24.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Systemic acquired resistance (SAR) is a global response in plants induced at the site of infection that leads to long-lasting and broad-spectrum disease resistance at distal, uninfected tissues. Despite the importance of this priming mechanism, the identity and complexity of defense signals that are required to initiate SAR signaling is not well understood. In this paper, we describe a metabolite, N-hydroxy-pipecolic acid (N-OH-Pip) and provide evidence that this mobile molecule plays a role in initiating SAR signal transduction in Arabidopsis thaliana We demonstrate that FLAVIN-DEPENDENT MONOOXYGENASE 1 (FMO1), a key regulator of SAR-associated defense priming, can synthesize N-OH-Pip from pipecolic acid in planta, and exogenously applied N-OH-Pip moves systemically in Arabidopsis and can rescue the SAR-deficiency of fmo1 mutants. We also demonstrate that N-OH-Pip treatment causes systemic changes in the expression of pathogenesis-related genes and metabolic pathways throughout the plant and enhances resistance to a bacterial pathogen. This work provides insight into the chemical nature of a signal for SAR and also suggests that the N-OH-Pip pathway is a promising target for metabolic engineering to enhance disease resistance.
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38
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Park E, Nedo A, Caplan JL, Dinesh-Kumar SP. Plant-microbe interactions: organelles and the cytoskeleton in action. THE NEW PHYTOLOGIST 2018; 217:1012-1028. [PMID: 29250789 DOI: 10.1111/nph.14959] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Accepted: 11/10/2017] [Indexed: 05/06/2023]
Abstract
Contents Summary 1012 I. Introduction 1012 II. The endomembrane system in plant-microbe interactions 1013 III. The cytoskeleton in plant-microbe interactions 1017 IV. Organelles in plant-microbe interactions 1019 V. Inter-organellar communication in plant-microbe interactions 1022 VI. Conclusions and prospects 1023 Acknowledgements 1024 References 1024 SUMMARY: Plants have evolved a multilayered immune system with well-orchestrated defense strategies against pathogen attack. Multiple immune signaling pathways, coordinated by several subcellular compartments and interactions between these compartments, play important roles in a successful immune response. Pathogens use various strategies to either directly attack the plant's immune system or to indirectly manipulate the physiological status of the plant to inhibit an immune response. Microscopy-based approaches have allowed the direct visualization of membrane trafficking events, cytoskeleton reorganization, subcellular dynamics and inter-organellar communication during the immune response. Here, we discuss the contributions of organelles and the cytoskeleton to the plant's defense response against microbial pathogens, as well as the mechanisms used by pathogens to target these compartments to overcome the plant's defense barrier.
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Affiliation(s)
- Eunsook Park
- Department of Plant Biology and The Genome Center, College of Biological Sciences, University of California, Davis, CA, 95616, USA
| | - Alexander Nedo
- Department of Biological Sciences, Delaware Biotechnology Institute, University of Delaware, Newark, DE, 19711, USA
| | - Jeffrey L Caplan
- Department of Biological Sciences, Delaware Biotechnology Institute, University of Delaware, Newark, DE, 19711, USA
- Department of Plant and Soil Sciences, University of Delaware, Newark, DE, 19711, USA
| | - Savithramma P Dinesh-Kumar
- Department of Plant Biology and The Genome Center, College of Biological Sciences, University of California, Davis, CA, 95616, USA
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39
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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. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2018; 93:651-663. [PMID: 29160935 DOI: 10.1111/tpj.13780] [Citation(s) in RCA: 96] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [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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40
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Büttner D. Behind the lines-actions of bacterial type III effector proteins in plant cells. FEMS Microbiol Rev 2018; 40:894-937. [PMID: 28201715 PMCID: PMC5091034 DOI: 10.1093/femsre/fuw026] [Citation(s) in RCA: 181] [Impact Index Per Article: 30.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Revised: 03/31/2016] [Accepted: 07/03/2016] [Indexed: 01/30/2023] Open
Abstract
Pathogenicity of most Gram-negative plant-pathogenic bacteria depends on the type III secretion (T3S) system, which translocates bacterial effector proteins into plant cells. Type III effectors modulate plant cellular pathways to the benefit of the pathogen and promote bacterial multiplication. One major virulence function of type III effectors is the suppression of plant innate immunity, which is triggered upon recognition of pathogen-derived molecular patterns by plant receptor proteins. Type III effectors also interfere with additional plant cellular processes including proteasome-dependent protein degradation, phytohormone signaling, the formation of the cytoskeleton, vesicle transport and gene expression. This review summarizes our current knowledge on the molecular functions of type III effector proteins with known plant target molecules. Furthermore, plant defense strategies for the detection of effector protein activities or effector-triggered alterations in plant targets are discussed.
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Affiliation(s)
- Daniela Büttner
- Genetics Department, Institute of Biology, Martin-Luther University Halle-Wittenberg, Halle (Saale), Germany
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41
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Bürger M, Willige BC, Chory J. A hydrophobic anchor mechanism defines a deacetylase family that suppresses host response against YopJ effectors. Nat Commun 2017; 8:2201. [PMID: 29259199 PMCID: PMC5736716 DOI: 10.1038/s41467-017-02347-w] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Accepted: 11/20/2017] [Indexed: 01/09/2023] Open
Abstract
Several Pseudomonas and Xanthomonas species are plant pathogens that infect the model organism Arabidopsis thaliana and important crops such as Brassica. Resistant plants contain the infection by rapid cell death of the infected area through the hypersensitive response (HR). A family of highly related α/β hydrolases is involved in diverse processes in all domains of life. Functional details of their catalytic machinery, however, remained unclear. We report the crystal structures of α/β hydrolases representing two different clades of the family, including the protein SOBER1, which suppresses AvrBsT-incited HR in Arabidopsis. Our results reveal a unique hydrophobic anchor mechanism that defines a previously unknown family of protein deacetylases. Furthermore, this study identifies a lid-loop as general feature for substrate turnover in acyl-protein thioesterases and the described family of deacetylases. Furthermore, we found that SOBER1's biological function is not restricted to Arabidopsis thaliana and not limited to suppress HR induced by AvrBsT.
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Affiliation(s)
- Marco Bürger
- Plant Biology Laboratory, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Björn C Willige
- Plant Biology Laboratory, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Joanne Chory
- Plant Biology Laboratory, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA, 92037, USA.
- Howard Hughes Medical Institute, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA, 92037, USA.
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42
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Abstract
Lysine acetylation is a key posttranslational modification that regulates diverse proteins involved in a range of biological processes. The role of histone acetylation in plant defense is well established, and it is known that pathogen effector proteins encoding acetyltransferases can directly acetylate host proteins to alter immunity. However, it is unclear whether endogenous plant enzymes can modulate protein acetylation during an immune response. Here, we investigate how the effector molecule HC-toxin (HCT), a histone deacetylase inhibitor produced by the fungal pathogen Cochliobolus carbonum race 1, promotes virulence in maize through altering protein acetylation. Using mass spectrometry, we globally quantified the abundance of 3,636 proteins and the levels of acetylation at 2,791 sites in maize plants treated with HCT as well as HCT-deficient or HCT-producing strains of C. carbonum Analyses of these data demonstrate that acetylation is a widespread posttranslational modification impacting proteins encoded by many intensively studied maize genes. Furthermore, the application of exogenous HCT enabled us to show that the activity of plant-encoded enzymes (histone deacetylases) can be modulated to alter acetylation of nonhistone proteins during an immune response. Collectively, these results provide a resource for further mechanistic studies examining the regulation of protein function by reversible acetylation and offer insight into the complex immune response triggered by virulent C. carbonum.
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43
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Blüher D, Laha D, Thieme S, Hofer A, Eschen-Lippold L, Masch A, Balcke G, Pavlovic I, Nagel O, Schonsky A, Hinkelmann R, Wörner J, Parvin N, Greiner R, Weber S, Tissier A, Schutkowski M, Lee J, Jessen H, Schaaf G, Bonas U. A 1-phytase type III effector interferes with plant hormone signaling. Nat Commun 2017; 8:2159. [PMID: 29255246 PMCID: PMC5735085 DOI: 10.1038/s41467-017-02195-8] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Accepted: 11/13/2017] [Indexed: 11/16/2022] Open
Abstract
Most Gram-negative phytopathogenic bacteria inject type III effector (T3E) proteins into plant cells to manipulate signaling pathways to the pathogen's benefit. In resistant plants, specialized immune receptors recognize single T3Es or their biochemical activities, thus halting pathogen ingress. However, molecular function and mode of recognition for most T3Es remains elusive. Here, we show that the Xanthomonas T3E XopH possesses phytase activity, i.e., dephosphorylates phytate (myo-inositol-hexakisphosphate, InsP6), the major phosphate storage compound in plants, which is also involved in pathogen defense. A combination of biochemical approaches, including a new NMR-based method to discriminate inositol polyphosphate enantiomers, identifies XopH as a naturally occurring 1-phytase that dephosphorylates InsP6 at C1. Infection of Nicotiana benthamiana and pepper by Xanthomonas results in a XopH-dependent conversion of InsP6 to InsP5. 1-phytase activity is required for XopH-mediated immunity of plants carrying the Bs7 resistance gene, and for induction of jasmonate- and ethylene-responsive genes in N. benthamiana.
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Affiliation(s)
- Doreen Blüher
- Institute for Biology, Department of Genetics, Martin-Luther University Halle-Wittenberg, Weinbergweg 10, 06120, Halle (Saale), Germany
| | - Debabrata Laha
- Institute of Crop Science and Resource Conservation, Department of Plant Nutrition, University of Bonn, Karlrobert-Kreiten-Strasse 13, 53115, Bonn, Germany
- Center for Plant Molecular Biology, Department of Plant Physiology, Eberhard Karls University Tübingen, Auf der Morgenstelle 32, 72076, Tübingen, Germany
| | - Sabine Thieme
- Institute for Biology, Department of Genetics, Martin-Luther University Halle-Wittenberg, Weinbergweg 10, 06120, Halle (Saale), Germany
| | - Alexandre Hofer
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Lennart Eschen-Lippold
- Department of Stress and Developmental Biology, Leibniz Institute of Plant Biochemistry, Weinberg 3, 06120, Halle (Saale), Germany
| | - Antonia Masch
- Institute for Biochemistry and Biotechnology, Department of Enzymology, Martin-Luther University Halle-Wittenberg, Kurt-Mothes-Strasse 3, 06120, Halle (Saale), Germany
| | - Gerd Balcke
- Department of Cell and Metabolic Biology, Leibniz Institute of Plant Biochemistry, Weinberg 3, 06120, Halle (Saale), Germany
| | - Igor Pavlovic
- Institute of Organic Chemistry, Albert-Ludwigs University Freiburg, Albertstrasse 21, 79104, Freiburg, Germany
| | - Oliver Nagel
- Institute for Biology, Department of Genetics, Martin-Luther University Halle-Wittenberg, Weinbergweg 10, 06120, Halle (Saale), Germany
| | - Antje Schonsky
- Institute for Biology, Department of Genetics, Martin-Luther University Halle-Wittenberg, Weinbergweg 10, 06120, Halle (Saale), Germany
| | - Rahel Hinkelmann
- Institute of Organic Chemistry, Albert-Ludwigs University Freiburg, Albertstrasse 21, 79104, Freiburg, Germany
| | - Jakob Wörner
- Institute of Physical Chemistry, Albert-Ludwigs University Freiburg, Albertstrasse 21, 79104, Freiburg, Germany
| | - Nargis Parvin
- Center for Plant Molecular Biology, Department of Plant Physiology, Eberhard Karls University Tübingen, Auf der Morgenstelle 32, 72076, Tübingen, Germany
| | - Ralf Greiner
- Department of Food Technology and Bioprocess Engineering, Max-Rubner-Institut, Federal Research Institute of Nutrition and Food, Haid-und-Neu-Straße 9, 76131, Karlsruhe, Germany
| | - Stefan Weber
- Institute of Physical Chemistry, Albert-Ludwigs University Freiburg, Albertstrasse 21, 79104, Freiburg, Germany
| | - Alain Tissier
- Department of Cell and Metabolic Biology, Leibniz Institute of Plant Biochemistry, Weinberg 3, 06120, Halle (Saale), Germany
| | - Mike Schutkowski
- Institute for Biochemistry and Biotechnology, Department of Enzymology, Martin-Luther University Halle-Wittenberg, Kurt-Mothes-Strasse 3, 06120, Halle (Saale), Germany
| | - Justin Lee
- Department of Stress and Developmental Biology, Leibniz Institute of Plant Biochemistry, Weinberg 3, 06120, Halle (Saale), Germany
| | - Henning Jessen
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland.
- Institute of Organic Chemistry, Albert-Ludwigs University Freiburg, Albertstrasse 21, 79104, Freiburg, Germany.
| | - Gabriel Schaaf
- Institute of Crop Science and Resource Conservation, Department of Plant Nutrition, University of Bonn, Karlrobert-Kreiten-Strasse 13, 53115, Bonn, Germany.
- Center for Plant Molecular Biology, Department of Plant Physiology, Eberhard Karls University Tübingen, Auf der Morgenstelle 32, 72076, Tübingen, Germany.
| | - Ulla Bonas
- Institute for Biology, Department of Genetics, Martin-Luther University Halle-Wittenberg, Weinbergweg 10, 06120, Halle (Saale), Germany.
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44
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Peterson LW, Philip NH, DeLaney A, Wynosky-Dolfi MA, Asklof K, Gray F, Choa R, Bjanes E, Buza EL, Hu B, Dillon CP, Green DR, Berger SB, Gough PJ, Bertin J, Brodsky IE. RIPK1-dependent apoptosis bypasses pathogen blockade of innate signaling to promote immune defense. J Exp Med 2017; 214:3171-3182. [PMID: 28855241 PMCID: PMC5679171 DOI: 10.1084/jem.20170347] [Citation(s) in RCA: 90] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Revised: 07/19/2017] [Accepted: 08/17/2017] [Indexed: 12/11/2022] Open
Abstract
RIPK1 regulates cytokine signaling and cell death during infection and inflammation. Peterson et al. show that RIPK1 kinase activity triggers apoptosis in response to bacterial pathogen blockade of innate immune signaling and that this pathway of effector-triggered immunity is critical for a successful antibacterial response. Many pathogens deliver virulence factors or effectors into host cells in order to evade host defenses and establish infection. Although such effector proteins disrupt critical cellular signaling pathways, they also trigger specific antipathogen responses, a process termed “effector-triggered immunity.” The Gram-negative bacterial pathogen Yersinia inactivates critical proteins of the NF-κB and MAPK signaling cascade, thereby blocking inflammatory cytokine production but also inducing apoptosis. Yersinia-induced apoptosis requires the kinase activity of receptor-interacting protein kinase 1 (RIPK1), a key regulator of cell death, NF-κB, and MAPK signaling. Through the targeted disruption of RIPK1 kinase activity, which selectively disrupts RIPK1-dependent cell death, we now reveal that Yersinia-induced apoptosis is critical for host survival, containment of bacteria in granulomas, and control of bacterial burdens in vivo. We demonstrate that this apoptotic response provides a cell-extrinsic signal that promotes optimal innate immune cytokine production and antibacterial defense, demonstrating a novel role for RIPK1 kinase–induced apoptosis in mediating effector-triggered immunity to circumvent pathogen inhibition of immune signaling.
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Affiliation(s)
- Lance W Peterson
- Department of Pathobiology, University of Pennsylvania School of Veterinary Medicine, Philadelphia, PA.,Institue for Immunology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
| | - Naomi H Philip
- Department of Pathobiology, University of Pennsylvania School of Veterinary Medicine, Philadelphia, PA.,Institue for Immunology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
| | - Alexandra DeLaney
- Department of Pathobiology, University of Pennsylvania School of Veterinary Medicine, Philadelphia, PA.,Institue for Immunology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
| | - Meghan A Wynosky-Dolfi
- Department of Pathobiology, University of Pennsylvania School of Veterinary Medicine, Philadelphia, PA.,Institue for Immunology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
| | - Kendra Asklof
- Department of Pathobiology, University of Pennsylvania School of Veterinary Medicine, Philadelphia, PA
| | - Falon Gray
- Department of Pathobiology, University of Pennsylvania School of Veterinary Medicine, Philadelphia, PA
| | - Ruth Choa
- Department of Pathobiology, University of Pennsylvania School of Veterinary Medicine, Philadelphia, PA.,Institue for Immunology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
| | - Elisabet Bjanes
- Department of Pathobiology, University of Pennsylvania School of Veterinary Medicine, Philadelphia, PA.,Institue for Immunology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
| | - Elisabeth L Buza
- Department of Pathobiology, University of Pennsylvania School of Veterinary Medicine, Philadelphia, PA
| | - Baofeng Hu
- Department of Pathobiology, University of Pennsylvania School of Veterinary Medicine, Philadelphia, PA
| | | | - Douglas R Green
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN
| | - Scott B Berger
- Host Defense Discovery Performance Unit, Infectious Disease Therapy Area Unit, GlaxoSmithKline, Collegeville, PA
| | - Peter J Gough
- Host Defense Discovery Performance Unit, Infectious Disease Therapy Area Unit, GlaxoSmithKline, Collegeville, PA
| | - John Bertin
- Pattern Recognition Receptor Discovery Performance Unit, Immuno-Inflammation Therapeutic Area, GlaxoSmithKline, Collegeville, PA
| | - Igor E Brodsky
- Department of Pathobiology, University of Pennsylvania School of Veterinary Medicine, Philadelphia, PA .,Institue for Immunology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
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Liu L, Wang Y, Cui F, Fang A, Wang S, Wang J, Wei C, Li S, Sun W. The type III effector AvrXccB in Xanthomonas campestris pv. campestris targets putative methyltransferases and suppresses innate immunity in Arabidopsis. MOLECULAR PLANT PATHOLOGY 2017; 18:768-782. [PMID: 27241588 PMCID: PMC6638230 DOI: 10.1111/mpp.12435] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Revised: 05/17/2016] [Accepted: 05/23/2016] [Indexed: 05/04/2023]
Abstract
Xanthomonas campestris pv. campestris (Xcc) causes black rot, one of the most important diseases of brassica crops worldwide. The type III effector inventory plays important roles in the virulence and pathogenicity of the pathogen. However, little is known about the virulence function(s) of the putative type III effector AvrXccB in Xcc. Here, we investigated the immune suppression ability of AvrXccB and the possible underlying mechanisms. AvrXccB was demonstrated to be secreted in a type III secretion system-dependent manner. AvrXccB tagged with green fluorescent protein is localized to the plasma membrane in Arabidopsis, and the putative N-myristoylation motif is essential for its localization. Chemical-induced expression of AvrXccB suppresses flg22-triggered callose deposition and the oxidative burst, and promotes the in planta growth of Xcc and Pseudomonas syringae pv. tomato in transgenic Arabidopsis plants. The putative catalytic triad and plasma membrane localization of AvrXccB are required for its immunosuppressive activity. Furthermore, it was demonstrated that AvrXccB interacts with the Arabidopsis S-adenosyl-l-methionine-dependent methyltransferases SAM-MT1 and SAM-MT2. Interestingly, SAM-MT1 is not only self-associated, but also associated with SAM-MT2 in vivo. SAM-MT1 and SAM-MT2 expression is significantly induced upon stimulation of microbe-associated molecular patterns and bacterial infection. Collectively, these findings indicate that AvrXccB targets a putative methyltransferase complex and suppresses plant immunity.
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Affiliation(s)
- Lijuan Liu
- Department of Plant Pathology, Key Laboratory of Plant Pathology, Ministry of AgricultureChina Agricultural UniversityBeijing100193China
| | - Yanping Wang
- Department of Plant Pathology, Key Laboratory of Plant Pathology, Ministry of AgricultureChina Agricultural UniversityBeijing100193China
| | - Fuhao Cui
- Department of Plant Pathology, Key Laboratory of Plant Pathology, Ministry of AgricultureChina Agricultural UniversityBeijing100193China
| | - Anfei Fang
- Department of Plant Pathology, Key Laboratory of Plant Pathology, Ministry of AgricultureChina Agricultural UniversityBeijing100193China
| | - Shanzhi Wang
- Department of Plant Pathology, Key Laboratory of Plant Pathology, Ministry of AgricultureChina Agricultural UniversityBeijing100193China
| | - Jiyang Wang
- Department of Plant Pathology, Key Laboratory of Plant Pathology, Ministry of AgricultureChina Agricultural UniversityBeijing100193China
| | - Chao Wei
- Department of Plant Pathology, Key Laboratory of Plant Pathology, Ministry of AgricultureChina Agricultural UniversityBeijing100193China
| | - Shuai Li
- Department of Plant Pathology, Key Laboratory of Plant Pathology, Ministry of AgricultureChina Agricultural UniversityBeijing100193China
| | - Wenxian Sun
- Department of Plant Pathology, Key Laboratory of Plant Pathology, Ministry of AgricultureChina Agricultural UniversityBeijing100193China
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Zhang ZM, Ma KW, Gao L, Hu Z, Schwizer S, Ma W, Song J. Mechanism of host substrate acetylation by a YopJ family effector. NATURE PLANTS 2017; 3:17115. [PMID: 28737762 PMCID: PMC5546152 DOI: 10.1038/nplants.2017.115] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Accepted: 06/26/2017] [Indexed: 05/22/2023]
Abstract
The Yersinia outer protein J (YopJ) family of bacterial effectors depends on a novel acetyltransferase domain to acetylate signalling proteins from plant and animal hosts. However, the underlying mechanism is unclear. Here, we report the crystal structures of PopP2, a YopJ effector produced by the plant pathogen Ralstonia solanacearum, in complex with inositol hexaphosphate (InsP6), acetyl-coenzyme A (AcCoA) and/or substrate Resistance to Ralstonia solanacearum 1 (RRS1-R)WRKY. PopP2 recognizes the WRKYGQK motif of RRS1-RWRKY to position a targeted lysine in the active site for acetylation. Importantly, the PopP2-RRS1-RWRKY association is allosterically regulated by InsP6 binding, suggesting a previously unidentified role of the eukaryote-specific cofactor in substrate interaction. Furthermore, we provide evidence for the reaction intermediate of PopP2-mediated acetylation, an acetyl-cysteine covalent adduct, lending direct support to the 'ping-pong'-like catalytic mechanism proposed for YopJ effectors. Our study provides critical mechanistic insights into the virulence activity of YopJ class of acetyltransferases.
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Affiliation(s)
- Zhi-Min Zhang
- Department of Biochemistry, University of California, Riverside, California 92521, USA
| | - Ka-Wai Ma
- Department of Plant Pathology and Microbiology, University of California, Riverside, California 92521, USA
| | - Linfeng Gao
- Environmental Toxicology Program, University of California, Riverside, California 92521, USA
| | - Zhenquan Hu
- High Magnetic Field Laboratory, Chinese Academy of Sciences, Anhui 230031, China
| | - Simon Schwizer
- Department of Plant Pathology and Microbiology, University of California, Riverside, California 92521, USA
| | - Wenbo Ma
- Department of Plant Pathology and Microbiology, University of California, Riverside, California 92521, USA
- Center for Plant Cell Biology, University of California, Riverside, California 92521, USA
- Institute of Integrative Genome Biology, University of California, Riverside, California 92521, USA
| | - Jikui Song
- Department of Biochemistry, University of California, Riverside, California 92521, USA
- Environmental Toxicology Program, University of California, Riverside, California 92521, USA
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A bacterial acetyltransferase triggers immunity in Arabidopsis thaliana independent of hypersensitive response. Sci Rep 2017; 7:3557. [PMID: 28620210 PMCID: PMC5472582 DOI: 10.1038/s41598-017-03704-x] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Accepted: 05/08/2017] [Indexed: 12/14/2022] Open
Abstract
Type-III secreted effectors (T3Es) play critical roles during bacterial pathogenesis in plants. Plant recognition of certain T3Es can trigger defence, often accompanied by macroscopic cell death, termed the hypersensitive response (HR). Economically important species of kiwifruit are susceptible to Pseudomonas syringae pv. actinidiae (Psa), the causal agent of kiwifruit bacterial canker. Although Psa is non-pathogenic in Arabidopsis thaliana, we observed that a T3E, HopZ5 that is unique to a global outbreak clade of Psa, triggers HR and defence in Arabidopsis accession Ct-1. Ws-2 and Col-0 accessions are unable to produce an HR in response to Pseudomonas-delivered HopZ5. While Ws-2 is susceptible to virulent bacterial strain Pseudomonas syringae pv. tomato DC3000 carrying HopZ5, Col-0 is resistant despite the lack of an HR. We show that HopZ5, like other members of the YopJ superfamily of acetyltransferases that it belongs to, autoacetylates lysine residues. Through comparisons to other family members, we identified an acetyltransferase catalytic activity and demonstrate its requirement for triggering defence in Arabidopsis and Nicotiana species. Collectively, data herein indicate that HopZ5 is a plasma membrane-localized acetyltransferase with autoacetylation activity required for avirulence.
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48
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Han SW, Hwang BK. Molecular functions of Xanthomonas type III effector AvrBsT and its plant interactors in cell death and defense signaling. PLANTA 2017; 245:237-253. [PMID: 27928637 DOI: 10.1007/s00425-016-2628-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2016] [Accepted: 11/30/2016] [Indexed: 05/20/2023]
Abstract
Xanthomonas effector AvrBsT interacts with plant defense proteins and triggers cell death and defense response. This review highlights our current understanding of the molecular functions of AvrBsT and its host interactor proteins. The AvrBsT protein is a member of a growing family of effector proteins in both plant and animal pathogens. Xanthomonas type III effector AvrBsT, a member of the YopJ/AvrRxv family, suppresses plant defense responses in susceptible hosts, but triggers cell death signaling leading to hypersensitive response (HR) and defense responses in resistant plants. AvrBsT interacts with host defense-related proteins to trigger the HR cell death and defense responses in plants. Here, we review and discuss recent progress in understanding the molecular functions of AvrBsT and its host interactor proteins in pepper (Capsicum annuum). Pepper arginine decarboxylase1 (CaADC1), pepper aldehyde dehydrogenase1 (CaALDH1), pepper heat shock protein 70a (CaHSP70a), pepper suppressor of the G2 allele of skp1 (CaSGT1), pepper SNF1-related kinase1 (SnRK1), and Arabidopsis acetylated interacting protein1 (ACIP1) have been identified as AvrBsT interactors in pepper and Arabidopsis. Gene expression profiling, virus-induced gene silencing, and transient transgenic overexpression approaches have advanced the functional characterization of AvrBsT-interacting proteins in plants. AvrBsT is localized in the cytoplasm and forms protein-protein complexes with host interactors. All identified AvrBsT interactors regulate HR cell death and defense responses in plants. Notably, CaSGT1 physically binds to both AvrBsT and pepper receptor-like cytoplasmic kinase1 (CaPIK1) in the cytoplasm. During infection with Xanthomonas campestris pv. vesicatoria strain Ds1 (avrBsT), AvrBsT is phosphorylated by CaPIK1 and forms the active AvrBsT-CaSGT1-CaPIK1 complex, which ultimately triggers HR cell death and defense responses. Collectively, the AvrBsT interactor proteins are involved in plant cell death and immunity signaling.
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Affiliation(s)
- Sang Wook Han
- Department of Integrative Plant Science, Chung-Ang University, Anseong, 17546, Republic of Korea
| | - Byung Kook Hwang
- Laboratory of Molecular Plant Pathology, College of Life Sciences and Biotechnology, Korea University, Anam-dong, Sungbuk-ku, Seoul, 02841, Republic of Korea.
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49
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YopJ Family Effectors Promote Bacterial Infection through a Unique Acetyltransferase Activity. Microbiol Mol Biol Rev 2016; 80:1011-1027. [PMID: 27784797 DOI: 10.1128/mmbr.00032-16] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Gram-negative bacterial pathogens rely on the type III secretion system to inject virulence proteins into host cells. These type III secreted "effector" proteins directly manipulate cellular processes to cause disease. Although the effector repertoires in different bacterial species are highly variable, the Yersinia outer protein J (YopJ) effector family is unique in that its members are produced by diverse animal and plant pathogens as well as a nonpathogenic microsymbiont. All YopJ family effectors share a conserved catalytic triad that is identical to that of the C55 family of cysteine proteases. However, an accumulating body of evidence demonstrates that many YopJ effectors modify their target proteins in hosts by acetylating specific serine, threonine, and/or lysine residues. This unique acetyltransferase activity allows the YopJ family effectors to affect the function and/or stability of their targets, thereby dampening innate immunity. Here, we summarize the current understanding of this prevalent and evolutionarily conserved type III effector family by describing their enzymatic activities and virulence functions in animals and plants. In particular, the molecular mechanisms by which representative YopJ family effectors subvert host immunity through posttranslational modification of their target proteins are discussed.
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50
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Abstract
Pseudomonas syringae secretes effectors from its type III secretion system to infect plants. In this issue of Cell Host & Microbe, Guo et al. (2016) determine that the T3SS effector, HopE1, targets calmodulin and the microtubule-associated protein MAP65-1 to subvert plant immunity.
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Affiliation(s)
- Christopher J Staiger
- Department of Biological Sciences and The Bindley Bioscience Center, Purdue University, 201 South University Street, West Lafayette, IN 47907-2064, USA.
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