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Castanho FM, Costa BLCD, Abe VY, Yokoyama A, Darben LM, Oliveira LS, Ferreira EGC, Lopes IDON, Carvalho MCDCGD, Balbi-Peña MI, Marcelino-Guimarães FC. Variability and functional characterization of the Phakopsora pachyrhizi Egh16-like effectors. Genet Mol Biol 2024; 47:e20230192. [PMID: 39239924 PMCID: PMC11378017 DOI: 10.1590/1678-4685-gmb-2023-0192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 06/05/2024] [Indexed: 09/07/2024] Open
Abstract
Effector proteins in Phakopsora pachyrhizi (Pp), the causative agent of Asian Soybean rust, are involved in the infection process. A previous study identified a rust effector Egh16-like family based expression profile during the interaction with soybean. Herein, we scrutinized available the Pp genomes to validate the predicted Egh16-like family of Pp and identify new family members. We described 22 members of the Egh16-like gene family in the Pp MT2006 genome and 18 in the UFV02 and K8108 genomes, highlighting a family expansion. Family members have a small signal peptide, conserved cysteine-rich R/Y/FxC motifs in the C-terminal region, and a virulence-related Egh16-like domain and were able to suppress PTI related responses in Benthamiana. Phylogenetic analysis placed the family members into eight clusters, with members induced during the early stages of rust infection. Members of clusters VI and VII are present in different copy numbers in Pp genomes and suppressed PAMP-related responses.
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Affiliation(s)
- Fernanda Machado Castanho
- Centro de Ciências Biológicas, Programa de Pós-Graduação em Genética e Biologia Molecular, Londrina, PR, Brazil
| | | | - Valéria Yukari Abe
- Empresa Brasileira de Pesquisa e Agropecuária (Embrapa Soja), Laboratório de Biotecnologia Vegetal e Bioinformática, Londrina, PR, Brazil
| | - Alessandra Yokoyama
- Departamento de Bioquímica e Biotecnologia, Programa de Pós-Graduação em Biotecnologia, Londrina, PR, Brazil
| | | | - Liliane Santana Oliveira
- Empresa Brasileira de Pesquisa e Agropecuária (Embrapa Soja), Laboratório de Biotecnologia Vegetal e Bioinformática, Londrina, PR, Brazil
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2
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Yeh SM, Yoon M, Scott S, Chatterjee A, Hemara LM, Chen RKY, Wang T, Templeton K, Rikkerink EHA, Jayaraman J, Brendolise C. NbPTR1 confers resistance against Pseudomonas syringae pv. actinidiae in kiwifruit. PLANT, CELL & ENVIRONMENT 2024. [PMID: 38899426 DOI: 10.1111/pce.15002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Accepted: 06/04/2024] [Indexed: 06/21/2024]
Abstract
Pseudomonas syringae pv. actinidiae biovar 3 (Psa3) causes a devastating canker disease in yellow-fleshed kiwifruit (Actinidia chinensis). The effector HopZ5, which is present in all isolates of Psa3 causing global outbreaks of pandemic kiwifruit canker disease, triggers immunity in Nicotiana benthamiana and is not recognised in susceptible A. chinensis cultivars. In a search for N. benthamiana nonhost resistance genes against HopZ5, we found that the nucleotide-binding leucine-rich repeat receptor NbPTR1 recognised HopZ5. RPM1-interacting protein 4 orthologues from N. benthamiana and A. chinensis formed a complex with NbPTR1 and HopZ5 activity was able to disrupt this interaction. No functional orthologues of NbPTR1 were found in A. chinensis. NbPTR1 transformed into Psa3-susceptible A. chinensis var. chinensis 'Hort16A' plants introduced HopZ5-specific resistance against Psa3. Altogether, this study suggested that expressing NbPTR1 in Psa3-susceptible kiwifruit is a viable approach to acquiring resistance to Psa3 and it provides valuable information for engineering resistance in otherwise susceptible kiwifruit genotypes.
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Affiliation(s)
- Shin-Mei Yeh
- New Cultivar Innovation, The New Zealand Institute for Plant & Food Research Limited (PFR), Mt Albert Research Centre, Auckland, New Zealand
| | - Minsoo Yoon
- Bioprotection, The New Zealand Institute for Plant & Food Research Limited (PFR), Mt Albert Research Centre, Auckland, New Zealand
| | - Sidney Scott
- New Cultivar Innovation, The New Zealand Institute for Plant & Food Research Limited (PFR), Mt Albert Research Centre, Auckland, New Zealand
| | - Abhishek Chatterjee
- New Cultivar Innovation, The New Zealand Institute for Plant & Food Research Limited (PFR), Mt Albert Research Centre, Auckland, New Zealand
| | - Lauren M Hemara
- Bioprotection, The New Zealand Institute for Plant & Food Research Limited (PFR), Mt Albert Research Centre, Auckland, New Zealand
- School of Biological Sciences, University of Auckland, Auckland, New Zealand
| | - Ronan K Y Chen
- Food Innovation, The New Zealand Institute for Plant and Food Research Limited (PFR), Palmerston North, New Zealand
| | - Tianchi Wang
- New Cultivar Innovation, The New Zealand Institute for Plant & Food Research Limited (PFR), Mt Albert Research Centre, Auckland, New Zealand
| | - Kerry Templeton
- New Cultivar Innovation, The New Zealand Institute for Plant and Food Research Limited (PFR), Motueka, New Zealand
| | - Erik H A Rikkerink
- Bioprotection, The New Zealand Institute for Plant & Food Research Limited (PFR), Mt Albert Research Centre, Auckland, New Zealand
| | - Jay Jayaraman
- Bioprotection, The New Zealand Institute for Plant & Food Research Limited (PFR), Mt Albert Research Centre, Auckland, New Zealand
| | - Cyril Brendolise
- New Cultivar Innovation, The New Zealand Institute for Plant & Food Research Limited (PFR), Mt Albert Research Centre, Auckland, New Zealand
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Li Z, Velásquez‐Zapata V, Elmore JM, Li X, Xie W, Deb S, Tian X, Banerjee S, Jørgensen HJL, Pedersen C, Wise RP, Thordal‐Christensen H. Powdery mildew effectors AVR A1 and BEC1016 target the ER J-domain protein HvERdj3B required for immunity in barley. MOLECULAR PLANT PATHOLOGY 2024; 25:e13463. [PMID: 38695677 PMCID: PMC11064805 DOI: 10.1111/mpp.13463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Revised: 03/06/2024] [Accepted: 04/11/2024] [Indexed: 05/05/2024]
Abstract
The barley powdery mildew fungus, Blumeria hordei (Bh), secretes hundreds of candidate secreted effector proteins (CSEPs) to facilitate pathogen infection and colonization. One of these, CSEP0008, is directly recognized by the barley nucleotide-binding leucine-rich-repeat (NLR) receptor MLA1 and therefore is designated AVRA1. Here, we show that AVRA1 and the sequence-unrelated Bh effector BEC1016 (CSEP0491) suppress immunity in barley. We used yeast two-hybrid next-generation interaction screens (Y2H-NGIS), followed by binary Y2H and in planta protein-protein interactions studies, and identified a common barley target of AVRA1 and BEC1016, the endoplasmic reticulum (ER)-localized J-domain protein HvERdj3B. Silencing of this ER quality control (ERQC) protein increased Bh penetration. HvERdj3B is ER luminal, and we showed using split GFP that AVRA1 and BEC1016 translocate into the ER signal peptide-independently. Overexpression of the two effectors impeded trafficking of a vacuolar marker through the ER; silencing of HvERdj3B also exhibited this same cellular phenotype, coinciding with the effectors targeting this ERQC component. Together, these results suggest that the barley innate immunity, preventing Bh entry into epidermal cells, requires ERQC. Here, the J-domain protein HvERdj3B appears to be essential and can be regulated by AVRA1 and BEC1016. Plant disease resistance often occurs upon direct or indirect recognition of pathogen effectors by host NLR receptors. Previous work has shown that AVRA1 is directly recognized in the cytosol by the immune receptor MLA1. We speculate that the AVRA1 J-domain target being inside the ER, where it is inapproachable by NLRs, has forced the plant to evolve this challenging direct recognition.
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Affiliation(s)
- Zizhang Li
- Department of Plant and Environmental SciencesUniversity of CopenhagenFrederiksberg CDenmark
- Present address:
Institute for Bioscience and Biotechnology Research & Department of Plant Sciences and Landscape ArchitectureUniversity of MarylandRockvilleMarylandUSA
| | - Valeria Velásquez‐Zapata
- Program in Bioinformatics & Computational BiologyIowa State UniversityAmesIowaUSA
- Department of Plant Pathology, Entomology and MicrobiologyIowa State UniversityAmesIowaUSA
- Present address:
GreenLight Biosciences, IncResearch Triangle ParkNorth CarolinaUSA
| | - J. Mitch Elmore
- Department of Plant Pathology, Entomology and MicrobiologyIowa State UniversityAmesIowaUSA
- USDA‐Agricultural Research Service, Corn Insects and Crop Genetics Research UnitAmesIowaUSA
- Present address:
USDA‐Agricultural Research Service, Cereal Disease LaboratorySt. PaulMinnesotaUSA
| | - Xuan Li
- Department of Plant and Environmental SciencesUniversity of CopenhagenFrederiksberg CDenmark
| | - Wenjun Xie
- Department of Plant and Environmental SciencesUniversity of CopenhagenFrederiksberg CDenmark
| | - Sohini Deb
- Department of Plant and Environmental SciencesUniversity of CopenhagenFrederiksberg CDenmark
| | - Xiao Tian
- Department of Plant and Environmental SciencesUniversity of CopenhagenFrederiksberg CDenmark
| | - Sagnik Banerjee
- Program in Bioinformatics & Computational BiologyIowa State UniversityAmesIowaUSA
- Department of StatisticsIowa State UniversityAmesIowaUSA
- Present address:
Bristol Myers SquibbSan DiegoCaliforniaUSA
| | - Hans J. L. Jørgensen
- Department of Plant and Environmental SciencesUniversity of CopenhagenFrederiksberg CDenmark
| | - Carsten Pedersen
- Department of Plant and Environmental SciencesUniversity of CopenhagenFrederiksberg CDenmark
| | - Roger P. Wise
- Program in Bioinformatics & Computational BiologyIowa State UniversityAmesIowaUSA
- Department of Plant Pathology, Entomology and MicrobiologyIowa State UniversityAmesIowaUSA
- USDA‐Agricultural Research Service, Corn Insects and Crop Genetics Research UnitAmesIowaUSA
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4
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Zheng P, Liu M, Pang L, Sun R, Yao M, Wang X, Kang Z, Liu J. Stripe rust effector Pst21674 compromises wheat resistance by targeting transcription factor TaASR3. PLANT PHYSIOLOGY 2023; 193:2806-2824. [PMID: 37706535 DOI: 10.1093/plphys/kiad497] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 08/17/2023] [Accepted: 08/18/2023] [Indexed: 09/15/2023]
Abstract
Pathogens compromise host defense responses by strategically secreting effector proteins. However, the molecular mechanisms by which effectors manipulate disease-resistance factors to evade host surveillance remain poorly understood. In this study, we characterized a Puccinia striiformis f. sp. tritici (Pst) effector Pst21674 with a signal peptide. Pst21674 was significantly upregulated during Pst infections in wheat (Triticum aestivum L.) and knocking down Pst21674 by host-induced gene silencing led to reduced Pst pathogenicity and restricted hyphal spread in wheat. Pst21674 interaction with the abscisic acid-, stress-, and ripening-induced protein TaASR3 was validated mainly in the nucleus. Size exclusion chromatography, bimolecular fluorescence complementation, and luciferase complementation imaging assays confirmed that TaASR3 could form a functional tetramer. Virus-induced gene silencing and overexpression demonstrated that TaASR3 contributes to wheat resistance to stripe rust by promoting accumulation of reactive oxygen species and cell death. Additionally, transcriptome analysis revealed that the expression of defense-related genes was regulated in transgenic wheat plants overexpressing TaASR3. Interaction between Pst21674 and TaASR3 interfered with the polymerization of TaASR3 and suppressed TaASR3-mediated transcriptional activation of defense-related genes. These results indicate that Pst21674 serves as an important virulence factor secreted into the host nucleus to impede wheat resistance to Pst, possibly by targeting and preventing polymerization of TaASR3.
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Affiliation(s)
- Peijing Zheng
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Mengxue Liu
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Lijing Pang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Ruyi Sun
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Mohan Yao
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Xiaojie Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Zhensheng Kang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Jie Liu
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling 712100, Shaanxi, China
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5
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Jayaraman J, Yoon M, Hemara LM, Bohne D, Tahir J, Chen RKY, Brendolise C, Rikkerink EHA, Templeton MD. Contrasting effector profiles between bacterial colonisers of kiwifruit reveal redundant roles converging on PTI-suppression and RIN4. THE NEW PHYTOLOGIST 2023; 238:1605-1619. [PMID: 36856342 DOI: 10.1111/nph.18848] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Accepted: 02/14/2023] [Indexed: 06/18/2023]
Abstract
Testing effector knockout strains of the Pseudomonas syringae pv. actinidiae biovar 3 (Psa3) for reduced in planta growth in their native kiwifruit host revealed a number of nonredundant effectors that contribute to Psa3 virulence. Conversely, complementation in the weak kiwifruit pathogen P. syringae pv. actinidifoliorum (Pfm) for increased growth identified redundant Psa3 effectors. Psa3 effectors hopAZ1a and HopS2b and the entire exchangeable effector locus (ΔEEL; 10 effectors) were significant contributors to bacterial colonisation of the host and were additive in their effects on virulence. Four of the EEL effectors (HopD1a, AvrB2b, HopAW1a and HopD2a) redundantly contribute to virulence through suppression of pattern-triggered immunity (PTI). Important Psa3 effectors include several redundantly required effectors early in the infection process (HopZ5a, HopH1a, AvrPto1b, AvrRpm1a and HopF1e). These largely target the plant immunity hub, RIN4. This comprehensive effector profiling revealed that Psa3 carries robust effector redundancy for a large portion of its effectors, covering a few functions critical to disease.
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Affiliation(s)
- Jay Jayaraman
- The New Zealand Institute for Plant and Food Research Ltd, Mt. Albert Research Centre, Auckland, 1025, New Zealand
| | - Minsoo Yoon
- The New Zealand Institute for Plant and Food Research Ltd, Mt. Albert Research Centre, Auckland, 1025, New Zealand
| | - Lauren M Hemara
- The New Zealand Institute for Plant and Food Research Ltd, Mt. Albert Research Centre, Auckland, 1025, New Zealand
- School of Biological Sciences, University of Auckland, Auckland, 1010, New Zealand
| | - Deborah Bohne
- The New Zealand Institute for Plant and Food Research Ltd, Mt. Albert Research Centre, Auckland, 1025, New Zealand
| | - Jibran Tahir
- The New Zealand Institute for Plant and Food Research Ltd, Mt. Albert Research Centre, Auckland, 1025, New Zealand
| | - Ronan K Y Chen
- The New Zealand Institute for Plant and Food Research Ltd, Food Industry Science Centre, Palmerston North, 4472, New Zealand
| | - Cyril Brendolise
- The New Zealand Institute for Plant and Food Research Ltd, Mt. Albert Research Centre, Auckland, 1025, New Zealand
| | - Erik H A Rikkerink
- The New Zealand Institute for Plant and Food Research Ltd, Mt. Albert Research Centre, Auckland, 1025, New Zealand
| | - Matthew D Templeton
- The New Zealand Institute for Plant and Food Research Ltd, Mt. Albert Research Centre, Auckland, 1025, New Zealand
- School of Biological Sciences, University of Auckland, Auckland, 1010, New Zealand
- Bioprotection Aotearoa, Lincoln, 7647, New Zealand
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6
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Kvitko BH, Collmer A. Discovery of the Hrp Type III Secretion System in Phytopathogenic Bacteria: How Investigation of Hypersensitive Cell Death in Plants Led to a Novel Protein Injector System and a World of Inter-Organismal Molecular Interactions Within Plant Cells. PHYTOPATHOLOGY 2023; 113:626-636. [PMID: 37099273 DOI: 10.1094/phyto-08-22-0292-kd] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
In the early 1960s, Pseudomonas syringae and other host-specific phytopathogenic proteobacteria were discovered to elicit a rapid, resistance-associated death when infiltrated at high inoculum levels into nonhost tobacco leaves. This hypersensitive reaction (or response; HR) was a useful indicator of basic pathogenic ability. Research over the next 20 years failed to identify an elicitor of the HR but revealed that its elicitation required contact between metabolically active bacterial and plant cells. Beginning in the early 1980s, molecular genetic tools were applied to the HR puzzle, revealing the presence in P. syringae of clusters of hrp genes, so named because they are required for the HR and pathogenicity, and of avr genes, so named because their presence confers HR-associated avirulence in resistant cultivars of a host plant species. A series of breakthroughs over the next two decades revealed that (i) hrp gene clusters encode a type III secretion system (T3SS), which injects Avr (now "effector") proteins into plant cells, where their recognition triggers the HR; (ii) T3SSs, which are typically present in pathogenicity islands acquired by horizontal gene transfers, are found in many bacterial pathogens of plants and animals and inject many effector proteins, which are collectively essential for pathogenicity; and (iii) a primary function of phytopathogen effectors is to subvert non-HR defenses resulting from recognition of conserved microbial features presented outside of plant cells. In the 2000s, Hrp system research shifted to extracellular components enabling effector delivery across plant cell walls and plasma membranes, regulation, and tools for studying effectors. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
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Affiliation(s)
- Brian H Kvitko
- Department of Plant Pathology, University of Georgia, 120 Carlton St., Athens, GA 30602
| | - Alan Collmer
- Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, 334 Plant Science Bldg., Ithaca, NY 14853
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7
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Fu Y, Liu X, Wang Q, Liu H, Cheng Y, Li H, Zhang Y, Chen J. Two salivary proteins Sm10 and SmC002 from grain aphid Sitobion miscanthi modulate wheat defense and enhance aphid performance. FRONTIERS IN PLANT SCIENCE 2023; 14:1104275. [PMID: 37056510 PMCID: PMC10086322 DOI: 10.3389/fpls.2023.1104275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Accepted: 03/13/2023] [Indexed: 06/19/2023]
Abstract
The grain aphid Sitobion miscanthi is a serious pest of wheat that causes severe economic damage by sucking phloem sap and transmitting plant viruses. Here, two putative salivary effector homologs from S. miscanthi (Sm10 and SmC002) were selected based on sequence similarity to other characterized aphid candidate effectors. These effectors were then delivered into wheat cells separately via the type III secretion system of Pseudomonas fluorescens to elucidate their functions in the regulation of plant defenses and host fitness. The results showed that the delivery of either Sm10 or SmC002 into wheat plants significantly suppressed callose deposition and affected the transcript levels of callose synthase genes. The expression levels of salicylic acid (SA)-associated defense genes were upregulated significantly in wheat leaves carrying either Sm10 or SmC002. Moreover, LC-MS/MS analysis revealed that wheat SA levels significantly increased after the delivery of the two effectors. The results of aphid bioassays conducted on the wheat plants carrying Sm10 or SmC002 showed significant increases in the survival and fecundity of S. miscanthi. This study demonstrated that the Sm10 and SmC002 salivary effectors of S. miscanthi enhanced host plant susceptibility and benefited S. miscanthi performance by regulating wheat defense signaling pathways.
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Affiliation(s)
- Yu Fu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Xiaobei Liu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Qian Wang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Huan Liu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Yumeng Cheng
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Hongmei Li
- Ministry of Agricultural and Rural Affairs-Centre for Agriculture and Bioscience International (MARA-CABI) Joint Laboratory for Bio-Safety, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Yong Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Julian Chen
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
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8
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Cooperative virulence via the collective action of secreted pathogen effectors. Nat Microbiol 2023; 8:640-650. [PMID: 36782026 DOI: 10.1038/s41564-023-01328-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Accepted: 01/13/2023] [Indexed: 02/15/2023]
Abstract
Although virulence is typically attributed to single pathogenic strains, here we investigated whether effectors secreted by a population of non-virulent strains could function as public goods to enable the emergence of collective virulence. We disaggregated the 36 type III effectors of the phytopathogenic bacterium Pseudomonas syringae strain PtoDC3000 into a 'metaclone' of 36 coisogenic strains, each carrying a single effector in an effectorless background. Each coisogenic strain was individually unfit, but the metaclone was collectively as virulent as the wild-type strain on Arabidopsis thaliana, suggesting that effectors can drive the emergence of cooperation-based virulence through their public action. We show that independently evolved effector suits can equally drive this cooperative behaviour by transferring the effector alleles native to the strain PmaES4326 into the conspecific but divergent strain PtoDC3000. Finally, we transferred the disaggregated PtoDC3000 effector arsenal into Pseudomonas fluorescens and show that their cooperative action was sufficient to convert this rhizosphere-inhabiting beneficial bacterium into a phyllosphere pathogen. These results emphasize the importance of microbial community interactions and expand the ecological scale at which disease may be attributed.
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9
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Jensen C, Korolev A, Corredor-Moreno P, Minter F, Dodds PN, Saunders DGO. Caveats of Using Bacterial Type Three Secretion Assays for Validating Fungal Avirulence Effectors in Wheat. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2022; 35:1061-1066. [PMID: 36445162 DOI: 10.1094/mpmi-08-22-0167-sc] [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: 06/16/2023]
Abstract
Functional characterization of effector proteins of fungal obligate biotrophic pathogens, especially confirmation of avirulence (Avr) properties, has been notoriously difficult, due to the experimental intractability of many of these organisms. Previous studies in wheat have shown promising data suggesting the type III secretion system (T3SS) of bacteria may be a suitable surrogate for delivery and detection of Avr properties of fungal effectors. However, these delivery systems were tested in the absence of confirmed Avr effectors. Here, we tested two previously described T3SS-mediated delivery systems for their suitability when delivering two confirmed Avr effectors from two fungal pathogens of wheat, Puccinia graminis f. sp. tritici and Magnaporthe oryzae pathotype tritici. We showed that both effectors (AvrSr50 and AvrRmg8) were unable to elicit a hypersensitive response on wheat seedlings with the corresponding resistance gene when expressed by the Pseudomonas fluorescens "Effector to Host Analyser" (EtHAn) system. Furthermore, we found the utility of Burkholderia glumae for screening Avr phenotypes is severely limited, as the wild-type strain elicits nonhost cell death in multiple wheat accessions. These results provide valuable insight into the suitability of these systems for screening fungal effectors for Avr properties that may help guide further development of surrogate bacterial delivery systems in wheat. [Formula: see text] Copyright © 2022 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
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Affiliation(s)
- Cassandra Jensen
- John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, United Kingdom
| | - Andrey Korolev
- John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, United Kingdom
| | | | - Francesca Minter
- John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, United Kingdom
| | - Peter N Dodds
- CSIRO Agriculture and Food Australia, GPO Box 1700, Clunies Ross Street, Canberra ACT 2601, Australia
| | - Diane G O Saunders
- John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, United Kingdom
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10
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Wu N, Ozketen AC, Cheng Y, Jiang W, Zhou X, Zhao X, Guan Y, Xiang Z, Akkaya MS. Puccinia striiformis f. sp. tritici effectors in wheat immune responses. FRONTIERS IN PLANT SCIENCE 2022; 13:1012216. [PMID: 36420019 PMCID: PMC9677129 DOI: 10.3389/fpls.2022.1012216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Accepted: 10/10/2022] [Indexed: 06/16/2023]
Abstract
The obligate biotrophic fungus Puccinia striiformis f. sp. tritici, which causes yellow (stripe) rust disease, is among the leading biological agents resulting in tremendous yield losses on global wheat productions per annum. The combatting strategies include, but are not limited to, fungicide applications and the development of resistant cultivars. However, evolutionary pressure drives rapid changes, especially in its "effectorome" repertoire, thus allowing pathogens to evade and breach resistance. The extracellular and intracellular effectors, predominantly secreted proteins, are tactical arsenals aiming for many defense processes of plants. Hence, the identity of the effectors and the molecular mechanisms of the interactions between the effectors and the plant immune system have long been targeted in research. The obligate biotrophic nature of P. striiformis f. sp. tritici and the challenging nature of its host, the wheat, impede research on this topic. Next-generation sequencing and novel prediction algorithms in bioinformatics, which are accompanied by in vitro and in vivo validation approaches, offer a speedy pace for the discovery of new effectors and investigations of their biological functions. Here, we briefly review recent findings exploring the roles of P. striiformis f. sp. tritici effectors together with their cellular/subcellular localizations, host responses, and interactors. The current status and the challenges will be discussed. We hope that the overall work will provide a broader view of where we stand and a reference point to compare and evaluate new findings.
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Affiliation(s)
- Nan Wu
- School of Bioengineering, Dalian University of Technology, Dalian, China
| | | | - Yu Cheng
- School of Bioengineering, Dalian University of Technology, Dalian, China
| | - Wanqing Jiang
- School of Bioengineering, Dalian University of Technology, Dalian, China
| | - Xuan Zhou
- School of Bioengineering, Dalian University of Technology, Dalian, China
| | - Xinran Zhao
- School of Bioengineering, Dalian University of Technology, Dalian, China
| | - Yaorong Guan
- School of Bioengineering, Dalian University of Technology, Dalian, China
| | - Zhaoxia Xiang
- School of Bioengineering, Dalian University of Technology, Dalian, China
| | - Mahinur S. Akkaya
- School of Bioengineering, Dalian University of Technology, Dalian, China
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11
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Olawole OI, Gleason ML, Beattie GA. Expression and Functional Analysis of the Type III Secretion System Effector Repertoire of the Xylem Pathogen Erwinia tracheiphila on Cucurbits. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2022; 35:768-778. [PMID: 35471035 DOI: 10.1094/mpmi-01-22-0002-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: 06/14/2023]
Abstract
The predicted repertoire of type III secretion system effectors (T3SEs) in Erwinia tracheiphila, causal agent of cucurbit bacterial wilt, is much larger than in xylem pathogens in the closely related genera Erwinia and Pantoea. The genomes of strains BHKY and SCR3, which represent distinct E. tracheiphila clades, encode at least 6 clade-specific and 12 shared T3SEs. The strains expressed the majority of the T3SE genes examined in planta. Among the shared T3SE genes, eop1 was expressed most highly in both strains in squash (Cucurbita pepo) and muskmelon (Cucumis melo) but the clade-specific gene avrRpm2 was expressed 40- to 900-fold more than eop1 in BHKY. The T3SEs AvrRpm2, Eop1, SrfC, and DspE contributed to BHKY virulence on squash and muskmelon, as shown using combinatorial mutants involving six T3SEs, whereas OspG and AvrB4 contributed to BHKY virulence only on muskmelon, demonstrating host-specific virulence functions. Moreover, Eop1 was functionally redundant with AvrRpm2, SrfC, OspG, and AvrB4 in BHKY, and BHKY mutants lacking up to five effector genes showed similar virulence to mutants lacking only two genes. The T3SEs OspG, AvrB4, and DspE contributed additively to SCR3 virulence on muskmelon and were not functionally redundant with Eop1. Rather, loss of eop1 and avrB4 restored wild-type virulence to the avrB4 mutant, suggesting that Eop1 suppresses a functionally redundant effector in SCR3. These results highlight functional differences in effector inventories between two E. tracheiphila clades, provide the first evidence of OspG as a phytopathogen effector, and suggest that Eop1 may be a metaeffector influencing virulence. [Formula: see text] Copyright © 2022 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, 50011-1101, U.S.A
| | - Mark L Gleason
- Department of Plant Pathology and Microbiology, Iowa State University, Ames, IA, 50011-1101, U.S.A
| | - Gwyn A Beattie
- Department of Plant Pathology and Microbiology, Iowa State University, Ames, IA, 50011-1101, U.S.A
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12
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Michalopoulou VA, Mermigka G, Kotsaridis K, Mentzelopoulou A, Celie PHN, Moschou PN, Jones JDG, Sarris PF. The host exocyst complex is targeted by a conserved bacterial type-III effector that promotes virulence. THE PLANT CELL 2022; 34:3400-3424. [PMID: 35640532 PMCID: PMC9421483 DOI: 10.1093/plcell/koac162] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 05/23/2022] [Indexed: 05/30/2023]
Abstract
For most Gram-negative bacteria, pathogenicity largely depends on the type-III secretion system that delivers virulence effectors into eukaryotic host cells. The subcellular targets for the majority of these effectors remain unknown. Xanthomonas campestris, the causal agent of black rot disease of crucifers such as Brassica spp., radish, and turnip, delivers XopP, a highly conserved core-effector protein produced by X. campestris, which is essential for virulence. Here, we show that XopP inhibits the function of the host-plant exocyst complex by direct targeting of Exo70B, a subunit of the exocyst complex, which plays a significant role in plant immunity. XopP interferes with exocyst-dependent exocytosis and can do this without activating a plant NOD-like receptor that guards Exo70B in Arabidopsis. In this way, Xanthomonas efficiently inhibits the host's pathogen-associated molecular pattern (PAMP)-triggered immunity by blocking exocytosis of pathogenesis-related protein-1A, callose deposition, and localization of the FLAGELLIN SENSITIVE2 (FLS2) immune receptor to the plasma membrane, thus promoting successful infection. Inhibition of exocyst function without activating the related defenses represents an effective virulence strategy, indicating the ability of pathogens to adapt to host defenses by avoiding host immunity responses.
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Affiliation(s)
- Vassiliki A Michalopoulou
- Department of Biology, University of Crete, Heraklion, Crete 714 09, Greece
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Heraklion, Crete 70013, Greece
| | - Glykeria Mermigka
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Heraklion, Crete 70013, Greece
| | - Konstantinos Kotsaridis
- Department of Biology, University of Crete, Heraklion, Crete 714 09, Greece
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Heraklion, Crete 70013, Greece
| | | | - Patrick H N Celie
- Division of Biochemistry, the Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Panagiotis N Moschou
- Department of Biology, University of Crete, Heraklion, Crete 714 09, Greece
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Heraklion, Crete 70013, Greece
- Department of Plant Biology, Swedish University of Agricultural Sciences, Uppsala BioCenter, Linnean Center for Plant Biology, Uppsala S-75007, Sweden
| | | | - Panagiotis F Sarris
- Department of Biology, University of Crete, Heraklion, Crete 714 09, Greece
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Heraklion, Crete 70013, Greece
- Biosciences, University of Exeter, Exeter, UK
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13
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Maia T, Rody HVS, Bombardelli RGH, Souto TG, Camargo LEA, Monteiro-Vitorello CB. A Bacterial Type Three Secretion-Based Delivery System for Functional Characterization of Sporisorium scitamineum Plant Immune Suppressing Effector Proteins. PHYTOPATHOLOGY 2022; 112:1513-1523. [PMID: 35050679 DOI: 10.1094/phyto-08-21-0326-r] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The facultative biotrophic basidiomycete Sporisorium scitamineum causes smut disease in sugarcane. This study applied an assay to identify S. scitamineum candidate effectors (CEs) with plant immunity suppression activities by delivering them into Nicotiana benthamiana cells via the type-three secretion system of Pseudomonas fluorescens EtHAn. Six CEs were individually cloned into the pEDV6 vector and expressed by P. fluorescens EtHAn for translocation into the plant cells. Three CEs (g1052, g3890, and g5159) could suppress pattern-triggered immunity (PTI) responses with high reproducibility in different coinfiltration experiments with P. syringae pv. tomato DC3000. In addition, three CEs (g1052, g4549, and g5159) were also found to be AvrB-induced suppressors of effector-triggered immunity (ETI), demonstrating for the first time that S. scitamineum can defeat both PTI and ETI responses. A transcriptomic analysis at different stages of infection by the smut fungus of three sugarcane cultivars with contrasting responses to the pathogen revealed that suppressors g1052, g3890, g4549, and g5159 were induced at the early stage of infection. By contrast, the two CEs (g2666 and g6610) that did not exhibit suppression activities expressed only at the late stage of infection. Moreover, genomic structures of the CEs and searches for orthologs in other smut species suggested duplication events and further divergence in CEs evolution of S. scitamineum. Thus, the transient assay applied here demonstrated the potential of pEDV6 and P. fluorescens EtHAn as biological tools for identifying plant immune suppressors from S. scitamineum.
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Affiliation(s)
- Thiago Maia
- Departamento de Fitopatologia e Nematologia, Universidade de São Paulo (USP), Escola Superior de Agricultura Luiz de Queiroz (ESALQ), Piracicaba, SP, Brazil
- Departamento de Genética, USP, ESALQ, Piracicaba, SP, Brazil
| | - Hugo V S Rody
- Departamento de Genética, USP, ESALQ, Piracicaba, SP, Brazil
| | | | - Tiarla Graciane Souto
- Departamento de Fitopatologia e Nematologia, Universidade de São Paulo (USP), Escola Superior de Agricultura Luiz de Queiroz (ESALQ), Piracicaba, SP, Brazil
- Departamento de Genética, USP, ESALQ, Piracicaba, SP, Brazil
| | - Luis Eduardo Aranha Camargo
- Departamento de Fitopatologia e Nematologia, Universidade de São Paulo (USP), Escola Superior de Agricultura Luiz de Queiroz (ESALQ), Piracicaba, SP, Brazil
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14
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Dongus JA, Bhandari DD, Penner E, Lapin D, Stolze SC, Harzen A, Patel M, Archer L, Dijkgraaf L, Shah J, Nakagami H, Parker JE. Cavity surface residues of PAD4 and SAG101 contribute to EDS1 dimer signaling specificity in plant immunity. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2022; 110:1415-1432. [PMID: 35324052 DOI: 10.1111/tpj.15747] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 03/09/2022] [Accepted: 03/17/2022] [Indexed: 06/14/2023]
Abstract
Arabidopsis pathogen effector-triggered immunity (ETI) is controlled by a family of three lipase-like proteins (EDS1, PAD4, and SAG101) and two subfamilies of HET-S/LOB-B (HeLo)-domain "helper" nucleotide-binding/leucine-rich repeats (ADR1s and NRG1s). EDS1-PAD4 dimers cooperate with ADR1s, and EDS1-SAG101 dimers with NRG1s, in two separate defense-promoting modules. EDS1-PAD4-ADR1 and EDS1-SAG101-NRG1 complexes were detected in immune-activated leaf extracts but the molecular determinants for specific complex formation and function remain unknown. EDS1 signaling is mediated by a C-terminal EP domain (EPD) surface surrounding a cavity formed by the heterodimer. Here we investigated whether the EPDs of PAD4 and SAG101 contribute to EDS1 dimer functions. Using a structure-guided approach, we undertook a comprehensive mutational analysis of Arabidopsis PAD4. We identify two conserved residues (Arg314 and Lys380) lining the PAD4 EPD cavity that are essential for EDS1-PAD4-mediated pathogen resistance, but are dispensable for the PAD4-mediated restriction of green peach aphid infestation. Positionally equivalent Met304 and Arg373 at the SAG101 EPD cavity are required for EDS1-SAG101 promotion of ETI-related cell death. In a PAD4 and SAG101 interactome analysis of ETI-activated tissues, PAD4R314A and SAG101M304R EPD variants maintain interaction with EDS1 but lose association, respectively, with helper nucleotide-binding/leucine-rich repeats ADR1-L1 and NRG1.1, and other immune-related proteins. Our data reveal a fundamental contribution of similar but non-identical PAD4 and SAG101 EPD surfaces to specific EDS1 dimer protein interactions and pathogen immunity.
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Affiliation(s)
- Joram A Dongus
- Department of Plant-Microbe Interactions, Max Planck Institute for Plant Breeding Research, Carl-von-Linné-Weg 10, 50829, Cologne, Germany
- Laboratory of Plant Physiology, Wageningen University, Droevendaalsesteeg 1, 6700, AA Wageningen, The Netherlands
| | - Deepak D Bhandari
- Department of Plant-Microbe Interactions, Max Planck Institute for Plant Breeding Research, Carl-von-Linné-Weg 10, 50829, Cologne, Germany
- Plant Research Laboratory, Michigan State University, 612, Wilson Road, East Lansing, Michigan, 48824, USA
| | - Eva Penner
- Department of Plant-Microbe Interactions, Max Planck Institute for Plant Breeding Research, Carl-von-Linné-Weg 10, 50829, Cologne, Germany
| | - Dmitry Lapin
- Department of Plant-Microbe Interactions, Max Planck Institute for Plant Breeding Research, Carl-von-Linné-Weg 10, 50829, Cologne, Germany
- Plant-Microbe Interactions, Utrecht University, Padualaan 8, 3584, CH Utrecht, The Netherlands
| | - Sara C Stolze
- Protein Mass Spectrometry, Max Planck Institute for Plant Breeding Research, Carl-von-Linné-Weg 10, 50829, Cologne, Germany
| | - Anne Harzen
- Protein Mass Spectrometry, Max Planck Institute for Plant Breeding Research, Carl-von-Linné-Weg 10, 50829, Cologne, Germany
| | - Monika Patel
- Department of Biological Sciences and BioDiscovery Institute, University of North Texas, 1511 West Sycamore, Denton, 76201, Texas, USA
| | - Lani Archer
- Department of Biological Sciences and BioDiscovery Institute, University of North Texas, 1511 West Sycamore, Denton, 76201, Texas, USA
| | - Lucas Dijkgraaf
- Department of Plant-Microbe Interactions, Max Planck Institute for Plant Breeding Research, Carl-von-Linné-Weg 10, 50829, Cologne, Germany
- Plant-Microbe Interactions, Utrecht University, Padualaan 8, 3584, CH Utrecht, The Netherlands
| | - Jyoti Shah
- Department of Biological Sciences and BioDiscovery Institute, University of North Texas, 1511 West Sycamore, Denton, 76201, Texas, USA
| | - Hirofumi Nakagami
- Protein Mass Spectrometry, Max Planck Institute for Plant Breeding Research, Carl-von-Linné-Weg 10, 50829, Cologne, Germany
| | - Jane E Parker
- Department of Plant-Microbe Interactions, Max Planck Institute for Plant Breeding Research, Carl-von-Linné-Weg 10, 50829, Cologne, Germany
- Cologne-Düsseldorf Cluster of Excellence on Plant Sciences (CEPLAS), 40225, Düsseldorf, Germany
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15
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Zhang N, He J, Muhammad A, Shao Y. CRISPR/Cas9–Mediated Genome Editing for Pseudomonas fulva, a Novel Pseudomonas Species with Clinical, Animal, and Plant–Associated Isolates. Int J Mol Sci 2022; 23:ijms23105443. [PMID: 35628253 PMCID: PMC9145825 DOI: 10.3390/ijms23105443] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 05/08/2022] [Accepted: 05/09/2022] [Indexed: 12/23/2022] Open
Abstract
As one of the most widespread groups of Gram–negative bacteria, Pseudomonas bacteria are prevalent in almost all natural environments, where they have developed intimate associations with plants and animals. Pseudomonas fulva is a novel species of Pseudomonas with clinical, animal, and plant–associated isolates, closely related to human and animal health, plant growth, and bioremediation. Although genetic manipulations have been proven as powerful tools for understanding bacterial biological and biochemical characteristics and the evolutionary origins, native isolates are often difficult to genetically manipulate, thereby making it a time–consuming and laborious endeavor. Here, by using the CRISPR–Cas system, a versatile gene–editing tool with a two–plasmid strategy was developed for a native P. fulva strain isolated from the model organism silkworm (Bombyx mori) gut. We harmonized and detailed the experimental setup and clarified the optimal conditions for bacteria transformation, competent cell preparation, and higher editing efficiency. Furthermore, we provided some case studies, testing and validating this approach. An antibiotic–related gene, oqxB, was knocked out, resulting in the slow growth of the P. fulva deletion mutant in LB containing chloramphenicol. Fusion constructs with knocked–in gfp exhibited intense fluorescence. Altogether, the successful construction and application of new genetic editing approaches gave us more powerful tools to investigate the functionalities of the novel Pseudomonas species.
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Affiliation(s)
- Nan Zhang
- Max Planck Partner Group, Faculty of Agriculture, Life and Environmental Sciences, Institute of Sericulture and Apiculture, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China (A.M.)
| | - Jintao He
- Max Planck Partner Group, Faculty of Agriculture, Life and Environmental Sciences, Institute of Sericulture and Apiculture, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China (A.M.)
| | - Abrar Muhammad
- Max Planck Partner Group, Faculty of Agriculture, Life and Environmental Sciences, Institute of Sericulture and Apiculture, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China (A.M.)
| | - Yongqi Shao
- Max Planck Partner Group, Faculty of Agriculture, Life and Environmental Sciences, Institute of Sericulture and Apiculture, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China (A.M.)
- Key Laboratory for Molecular Animal Nutrition, Ministry of Education, Hangzhou 310058, China
- Correspondence: ; Fax: +86-571-88982757
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16
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Wu Z, Tian L, Liu X, Huang W, Zhang Y, Li X. The N-terminally truncated helper NLR NRG1C antagonizes immunity mediated by its full-length neighbors NRG1A and NRG1B. THE PLANT CELL 2022; 34:1621-1640. [PMID: 34871452 PMCID: PMC9048947 DOI: 10.1093/plcell/koab285] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Accepted: 11/11/2021] [Indexed: 05/19/2023]
Abstract
Both plants and animals utilize nucleotide-binding leucine-rich repeat immune receptors (NLRs) to perceive the presence of pathogen-derived molecules and induce immune responses. NLR genes are far more abundant and diverse in vascular plants than in animals. Truncated NLRs, which lack one or more of the canonical domains, are also commonly encoded in plant genomes. However, little is known about their functions, especially the N-terminally truncated ones. Here, we show that the Arabidopsis thaliana N-terminally truncated helper NLR (hNLR) gene N REQUIREMENT GENE1 (NRG1C) is highly induced upon pathogen infection and in autoimmune mutants. The immune response and cell death conferred by some Toll/interleukin-1 receptor-type NLRs (TNLs) were compromised in Arabidopsis NRG1C overexpression lines. Detailed genetic analysis revealed that NRG1C antagonizes the immunity mediated by its full-length neighbors NRG1A and NRG1B. Biochemical tests suggested that NRG1C might interfere with the EDS1-SAG101 complex, which functions in immunity signaling together with NRG1A/1B. Interestingly, Brassicaceae NRG1Cs are functionally exchangeable and that the Nicotiana benthamiana N-terminally truncated hNLR NRG2 also antagonizes NRG1 activity. Together, our study uncovers an unexpected negative role of N-terminally truncated hNLRs in immunity in different plant species.
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Affiliation(s)
- Zhongshou Wu
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
- Department of Botany, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Lei Tian
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
- Department of Botany, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Xueru Liu
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
- Department of Botany, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Weijie Huang
- Department of Botany, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Yuelin Zhang
- Department of Botany, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Xin Li
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
- Department of Botany, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
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17
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Bai X, Peng H, Goher F, Islam MA, Xu S, Guo J, Kang Z, Guo J. A candidate effector protein PstCFEM1 contributes to virulence of stripe rust fungus and impairs wheat immunity. STRESS BIOLOGY 2022; 2:21. [PMID: 37676523 PMCID: PMC10441960 DOI: 10.1007/s44154-022-00042-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2021] [Accepted: 02/28/2022] [Indexed: 09/08/2023]
Abstract
Common in Fungal Extracellular Membrane (CFEM) domain proteins are considered to be unique to fungi and closely related to pathogenicity. However, the Puccinia striiformis f. sp. tritici (Pst) effector containing the CFEM domain has not been reported. Here, we obtained an effector, PstCFEM1, containing a functional N-terminal signal peptide sequence and the CFEM domain from Pst race CYR31. qRT-PCR assay indicated that the transcript levels of PstCFEM1 were highly induced during the early stages of infection. Overexpression of PstCFEM1 suppressed Pst322 (an elicitor-like protein of Pst)-trigged cell death, reactive oxygen species (ROS) accumulation and callose deposition. Host-induced gene silencing (HIGS) experiments showed that knockdown of PstCFEM1 decreased the virulence of Pst, while ROS accumulation in silenced plants increased near the infection site. In addition, wheat containing the PstCFEM1-silenced construct increased resistance to multiple races of Pst. Our data suggest that PstCFEM1 suppresses wheat defense by inhibiting ROS accumulation and contributes to increased virulence of Pst.
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Affiliation(s)
- Xingxuan Bai
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Huan Peng
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Farhan Goher
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Md Ashraful Islam
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Sanding Xu
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Jia Guo
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Zhensheng Kang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Jun Guo
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, 712100, Shaanxi, China.
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18
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Link TI. Host-Induced Gene Silencing Using BPMV on Soybean to Study Genes in the Soybean Rust Fungus Phakopsora pachyrhizi. Methods Mol Biol 2022; 2523:79-91. [PMID: 35759192 DOI: 10.1007/978-1-0716-2449-4_6] [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] [Indexed: 06/15/2023]
Abstract
To obtain direct evidence for the influence of an effector on the virulence or pathogenicity of a pathogen, it is necessary to knock out, knock down, or silence the respective gene. Since genetic transformation is not yet possible for rust fungi, silencing the gene is the only option. Posttranscriptional gene silencing uses RNAi. RNAi in plant pathogens can be accomplished by introducing dsRNA either by direct application of in vitro synthesized dsRNA or through positive-strand or double-strand RNA plant viruses. For studying effectors in Phakopsora pachyrhizi, we have implemented a host-induced silencing procedure based on virus-induced gene silencing using the bean pod mottle virus system. Here, procedures and interpretations of results are described and limitations of the system are discussed.
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Affiliation(s)
- Tobias I Link
- Department of Phytopathology, University of Hohenheim, Stuttgart, Germany.
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19
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Song GC, Jeon J, Choi HK, Sim H, Kim S, Ryu C. Bacterial type III effector-induced plant C8 volatiles elicit antibacterial immunity in heterospecific neighbouring plants via airborne signalling. PLANT, CELL & ENVIRONMENT 2022; 45:236-247. [PMID: 34708407 PMCID: PMC9298316 DOI: 10.1111/pce.14209] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 10/08/2021] [Accepted: 10/15/2021] [Indexed: 05/10/2023]
Abstract
Upon sensing attack by pathogens and insect herbivores, plants release complex mixtures of volatile compounds. Here, we show that the infection of lima bean (Phaseolus lunatus L.) plants with the non-host bacterial pathogen Pseudomonas syringae pv. tomato led to the production of microbe-induced plant volatiles (MIPVs). Surprisingly, the bacterial type III secretion system, which injects effector proteins directly into the plant cytosol to subvert host functions, was found to prime both intra- and inter-specific defense responses in neighbouring wild tobacco (Nicotiana benthamiana) plants. Screening of each of 16 effectors using the Pseudomonas fluorescens effector-to-host analyser revealed that an effector, HopP1, was responsible for immune activation in receiver tobacco plants. Further study demonstrated that 1-octen-3-ol, 3-octanone and 3-octanol are novel MIPVs emitted by the lima bean plant in a HopP1-dependent manner. Exposure to synthetic 1-octen-3-ol activated immunity in tobacco plants against a virulent pathogen Pseudomonas syringae pv. tabaci. Our results show for the first time that a bacterial type III effector can trigger the emission of C8 plant volatiles that mediate defense priming via plant-plant interactions. These results provide novel insights into the role of airborne chemicals in bacterial pathogen-induced inter-specific plant-plant interactions.
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Affiliation(s)
- Geun Cheol Song
- Molecular Phytobacteriology LaboratoryInfectious Disease Research Center, KRIBBDaejeonSouth Korea
| | - Je‐Seung Jeon
- Molecular Phytobacteriology LaboratoryInfectious Disease Research Center, KRIBBDaejeonSouth Korea
| | - Hye Kyung Choi
- Molecular Phytobacteriology LaboratoryInfectious Disease Research Center, KRIBBDaejeonSouth Korea
| | - Hee‐Jung Sim
- Environmental Chemistry Research GroupKorea Institute of Toxicology (KIT)JinjuSouth Korea
| | - Sang‐Gyu Kim
- Department of Biological SciencesKorea Advanced Institute of Science and TechnologyDaejeonSouth Korea
| | - Choong‐Min Ryu
- Molecular Phytobacteriology LaboratoryInfectious Disease Research Center, KRIBBDaejeonSouth Korea
- Biosystems and Bioengineering ProgramUniversity of Science and Technology (UST)DaejeonSouth Korea
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20
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Mukhi N, Brown H, Gorenkin D, Ding P, Bentham AR, Stevenson CEM, Jones JDG, Banfield MJ. Perception of structurally distinct effectors by the integrated WRKY domain of a plant immune receptor. Proc Natl Acad Sci U S A 2021; 118:e2113996118. [PMID: 34880132 PMCID: PMC8685902 DOI: 10.1073/pnas.2113996118] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/08/2021] [Indexed: 01/11/2023] Open
Abstract
Plants use intracellular nucleotide-binding domain (NBD) and leucine-rich repeat (LRR)-containing immune receptors (NLRs) to detect pathogen-derived effector proteins. The Arabidopsis NLR pair RRS1-R/RPS4 confers disease resistance to different bacterial pathogens by perceiving the structurally distinct effectors AvrRps4 from Pseudomonas syringae pv. pisi and PopP2 from Ralstonia solanacearum via an integrated WRKY domain in RRS1-R. How the WRKY domain of RRS1 (RRS1WRKY) perceives distinct classes of effector to initiate an immune response is unknown. Here, we report the crystal structure of the in planta processed C-terminal domain of AvrRps4 (AvrRps4C) in complex with RRS1WRKY Perception of AvrRps4C by RRS1WRKY is mediated by the β2-β3 segment of RRS1WRKY that binds an electronegative patch on the surface of AvrRps4C Structure-based mutations that disrupt AvrRps4C-RRS1WRKY interactions in vitro compromise RRS1/RPS4-dependent immune responses. We also show that AvrRps4C can associate with the WRKY domain of the related but distinct RRS1B/RPS4B NLR pair, and the DNA-binding domain of AtWRKY41, with similar binding affinities and how effector binding interferes with WRKY-W-box DNA interactions. This work demonstrates how integrated domains in plant NLRs can directly bind structurally distinct effectors to initiate immunity.
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Affiliation(s)
- Nitika Mukhi
- Department of Biochemistry and Metabolism, John Innes Centre, Norwich NR4 7UH, United Kingdom
| | - Hannah Brown
- The Sainsbury Laboratory, University of East Anglia, Norwich NR4 7UH, United Kingdom
| | - Danylo Gorenkin
- Department of Biochemistry and Metabolism, John Innes Centre, Norwich NR4 7UH, United Kingdom
| | - Pingtao Ding
- The Sainsbury Laboratory, University of East Anglia, Norwich NR4 7UH, United Kingdom
- The Sainsbury Laboratory, University of East Anglia, Norwich NR4 7UH, United Kingdom
| | - Adam R Bentham
- Department of Biochemistry and Metabolism, John Innes Centre, Norwich NR4 7UH, United Kingdom
| | - Clare E M Stevenson
- Department of Biochemistry and Metabolism, John Innes Centre, Norwich NR4 7UH, United Kingdom
| | - Jonathan D G Jones
- The Sainsbury Laboratory, University of East Anglia, Norwich NR4 7UH, United Kingdom
| | - Mark J Banfield
- Department of Biochemistry and Metabolism, John Innes Centre, Norwich NR4 7UH, United Kingdom;
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21
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Ding P, Sakai T, Krishna Shrestha R, Manosalva Perez N, Guo W, Ngou BPM, He S, Liu C, Feng X, Zhang R, Vandepoele K, MacLean D, Jones JDG. Chromatin accessibility landscapes activated by cell-surface and intracellular immune receptors. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:7927-7941. [PMID: 34387350 DOI: 10.1093/jxb/erab373] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Accepted: 08/12/2021] [Indexed: 06/13/2023]
Abstract
Activation of cell-surface and intracellular receptor-mediated immunity results in rapid transcriptional reprogramming that underpins disease resistance. However, the mechanisms by which co-activation of both immune systems lead to transcriptional changes are not clear. Here, we combine RNA-seq and ATAC-seq to define changes in gene expression and chromatin accessibility. Activation of cell-surface or intracellular receptor-mediated immunity, or both, increases chromatin accessibility at induced defence genes. Analysis of ATAC-seq and RNA-seq data combined with publicly available information on transcription factor DNA-binding motifs enabled comparison of individual gene regulatory networks activated by cell-surface or intracellular receptor-mediated immunity, or by both. These results and analyses reveal overlapping and conserved transcriptional regulatory mechanisms between the two immune systems.
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Affiliation(s)
- Pingtao Ding
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
- Institute of Biology Leiden, Leiden University, Sylviusweg 72, Leiden 2333 BE, The Netherlands
| | - Toshiyuki Sakai
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
| | - Ram Krishna Shrestha
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
| | - Nicolas Manosalva Perez
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 71, 9052 Ghent, Belgium
- VIB Center for Plant Systems Biology, Technologiepark 71, 9052 Ghent, Belgium
| | - Wenbin Guo
- Information and Computational Sciences, The James Hutton Institute, Dundee DD2 5DA, UK
| | - Bruno Pok Man Ngou
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
| | - Shengbo He
- John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Chang Liu
- Institute of Biology, University of Hohenheim, Garbenstrasse 30, 70599 Stuttgart, Germany
| | - Xiaoqi Feng
- John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Runxuan Zhang
- Information and Computational Sciences, The James Hutton Institute, Dundee DD2 5DA, UK
| | - Klaas Vandepoele
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 71, 9052 Ghent, Belgium
- VIB Center for Plant Systems Biology, Technologiepark 71, 9052 Ghent, Belgium
| | - Dan MacLean
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
| | - Jonathan D G Jones
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
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22
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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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23
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Xia Y, Zou R, Escouboué M, Zhong L, Zhu C, Pouzet C, Wu X, Wang Y, Lv G, Zhou H, Sun P, Ding K, Deslandes L, Yuan S, Zhang ZM. Secondary-structure switch regulates the substrate binding of a YopJ family acetyltransferase. Nat Commun 2021; 12:5969. [PMID: 34645811 PMCID: PMC8514532 DOI: 10.1038/s41467-021-26183-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2021] [Accepted: 09/21/2021] [Indexed: 11/11/2022] Open
Abstract
The Yersinia outer protein J (YopJ) family effectors are widely deployed through the type III secretion system by both plant and animal pathogens. As non-canonical acetyltransferases, the enzymatic activities of YopJ family effectors are allosterically activated by the eukaryote-specific ligand inositol hexaphosphate (InsP6). However, the underpinning molecular mechanism remains undefined. Here we present the crystal structure of apo-PopP2, a YopJ family member secreted by the plant pathogen Ralstonia solanacearum. Structural comparison of apo-PopP2 with the InsP6-bound PopP2 reveals a substantial conformational readjustment centered in the substrate-binding site. Combining biochemical and computational analyses, we further identify a mechanism by which the association of InsP6 with PopP2 induces an α-helix-to-β-strand transition in the catalytic core, resulting in stabilization of the substrate recognition helix in the target protein binding site. Together, our study uncovers the molecular basis governing InsP6-mediated allosteric regulation of YopJ family acetyltransferases and further expands the paradigm of fold-switching proteins.
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Affiliation(s)
- Yao Xia
- International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Development of Chinese Ministry of Education (MOE), College of Pharmacy, Jinan University, 510632, Guangzhou, China
- Guangdong Province Key Laboratory of Pharmacodynamic Constituents of TCM and New Drugs Research, College of Pharmacy, Jinan University, 510632, Guangzhou, China
| | - Rongfeng Zou
- Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, 518005, Shenzhen, China
| | - Maxime Escouboué
- Laboratoire des Interactions Plantes-Microbes-Environnement (LIPME), INRAE, CNRS, Université de Toulouse, 31326, Castanet-Tolosan, France
| | - Liang Zhong
- International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Development of Chinese Ministry of Education (MOE), College of Pharmacy, Jinan University, 510632, Guangzhou, China
- Guangdong Province Key Laboratory of Pharmacodynamic Constituents of TCM and New Drugs Research, College of Pharmacy, Jinan University, 510632, Guangzhou, China
| | - Chengjun Zhu
- International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Development of Chinese Ministry of Education (MOE), College of Pharmacy, Jinan University, 510632, Guangzhou, China
- Guangdong Province Key Laboratory of Pharmacodynamic Constituents of TCM and New Drugs Research, College of Pharmacy, Jinan University, 510632, Guangzhou, China
| | - Cécile Pouzet
- FRAIB-TRI Imaging Platform Facilities, FR AIB, Université de Toulouse, CNRS, 31320, Castanet-Tolosan, France
| | - Xueqiang Wu
- Institute for Pharmaceutical Analysis, College of Pharmacy, Jinan University, 510632, Guangzhou, China
| | - Yongjin Wang
- International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Development of Chinese Ministry of Education (MOE), College of Pharmacy, Jinan University, 510632, Guangzhou, China
- Guangdong Province Key Laboratory of Pharmacodynamic Constituents of TCM and New Drugs Research, College of Pharmacy, Jinan University, 510632, Guangzhou, China
| | - Guohua Lv
- Division of Histology & Embryology, Medical College, Jinan University, 510632, Guangzhou, China
| | - Haibo Zhou
- Institute for Pharmaceutical Analysis, College of Pharmacy, Jinan University, 510632, Guangzhou, China
| | - Pinghua Sun
- International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Development of Chinese Ministry of Education (MOE), College of Pharmacy, Jinan University, 510632, Guangzhou, China.
- Guangdong Province Key Laboratory of Pharmacodynamic Constituents of TCM and New Drugs Research, College of Pharmacy, Jinan University, 510632, Guangzhou, China.
| | - Ke Ding
- International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Development of Chinese Ministry of Education (MOE), College of Pharmacy, Jinan University, 510632, Guangzhou, China.
- Guangdong Province Key Laboratory of Pharmacodynamic Constituents of TCM and New Drugs Research, College of Pharmacy, Jinan University, 510632, Guangzhou, China.
| | - Laurent Deslandes
- Laboratoire des Interactions Plantes-Microbes-Environnement (LIPME), INRAE, CNRS, Université de Toulouse, 31326, Castanet-Tolosan, France.
| | - Shuguang Yuan
- Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, 518005, Shenzhen, China.
| | - 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, 510632, Guangzhou, China.
- Guangdong Province Key Laboratory of Pharmacodynamic Constituents of TCM and New Drugs Research, College of Pharmacy, Jinan University, 510632, Guangzhou, China.
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24
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Jayaraman J, Chatterjee A, Hunter S, Chen R, Stroud EA, Saei H, Hoyte S, Deroles S, Tahir J, Templeton MD, Brendolise C. Rapid Methodologies for Assessing Pseudomonas syringae pv. actinidiae Colonization and Effector-Mediated Hypersensitive Response in Kiwifruit. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2021; 34:880-890. [PMID: 33834857 DOI: 10.1094/mpmi-02-21-0043-r] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The infection of Pseudomonas syringae pv. actinidiae in kiwifruit is currently assessed by numerous methodologies, each with their own limitations. Most studies are based on either a laborious method of growth quantification of the pathogen or qualitative assessments by visual scoring following stem or cutting inoculation. Additionally, when assessing for resistance against specific pathogen effectors, confounding interactions between multiple genes in the pathogen can make mapping resistance phenotypes nearly impossible. Here, we present robust alternative methods to quantify pathogen load based on rapid bacterial DNA quantification by PCR, the use of Pseudomonas fluorescens, and a transient reporter eclipse assay for assessing resistance conferred by isolated bacterial avirulence genes. These assays compare well with bacterial plate counts to assess bacterial colonization as a result of plant resistance activation. The DNA-based quantification, when coupled with the P. fluorescens and reporter eclipse assays to independently identify bacterial avirulence genes, is rapid, highly reproducible, and scalable for high-throughput screens of multiple cultivars or genotypes. Application of these methodologies will allow rapid and high-throughput identification of resistant cultivars and the bacterial avirulence genes they recognize, facilitating resistance gene discovery for plant breeding programs.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
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Affiliation(s)
- Jay Jayaraman
- The New Zealand Institute for Plant and Food Research Limited, Auckland, New Zealand
- Bio-Protection Research Centre, Lincoln, New Zealand
| | - Abhishek Chatterjee
- The New Zealand Institute for Plant and Food Research Limited, Auckland, New Zealand
| | - Shannon Hunter
- The New Zealand Institute for Plant and Food Research Limited, Auckland, New Zealand
| | - Ronan Chen
- The New Zealand Institute for Plant and Food Research Limited, Palmerston North, New Zealand
| | - Erin A Stroud
- The New Zealand Institute for Plant and Food Research Limited, Auckland, New Zealand
- School of Biological Sciences, University of Auckland, Auckland, New Zealand
| | - Hassan Saei
- The New Zealand Institute for Plant and Food Research Limited, Palmerston North, New Zealand
| | - Stephen Hoyte
- The New Zealand Institute for Plant and Food Research Limited, Ruakura Research Centre, Hamilton, New Zealand
| | - Simon Deroles
- The New Zealand Institute for Plant and Food Research Limited, Palmerston North, New Zealand
| | - Jibran Tahir
- The New Zealand Institute for Plant and Food Research Limited, Auckland, New Zealand
| | - Matthew D Templeton
- The New Zealand Institute for Plant and Food Research Limited, Auckland, New Zealand
- Bio-Protection Research Centre, Lincoln, New Zealand
- School of Biological Sciences, University of Auckland, Auckland, New Zealand
| | - Cyril Brendolise
- The New Zealand Institute for Plant and Food Research Limited, Auckland, New Zealand
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25
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Jacob P, Kim NH, Wu F, El-Kasmi F, Chi Y, Walton WG, Furzer OJ, Lietzan AD, Sunil S, Kempthorn K, Redinbo MR, Pei ZM, Wan L, Dangl JL. Plant "helper" immune receptors are Ca 2+-permeable nonselective cation channels. Science 2021; 373:420-425. [PMID: 34140391 PMCID: PMC8939002 DOI: 10.1126/science.abg7917] [Citation(s) in RCA: 185] [Impact Index Per Article: 61.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 06/07/2021] [Indexed: 12/15/2022]
Abstract
Plant nucleotide-binding leucine-rich repeat receptors (NLRs) regulate immunity and cell death. In Arabidopsis, a subfamily of "helper" NLRs is required by many "sensor" NLRs. Active NRG1.1 oligomerized, was enriched in plasma membrane puncta, and conferred cytoplasmic calcium ion (Ca2+) influx in plant and human cells. NRG1.1-dependent Ca2+ influx and cell death were sensitive to Ca2+ channel blockers and were suppressed by mutations affecting oligomerization or plasma membrane enrichment. Ca2+ influx and cell death mediated by NRG1.1 and ACTIVATED DISEASE RESISTANCE 1 (ADR1), another helper NLR, required conserved negatively charged N-terminal residues. Whole-cell voltage-clamp recordings demonstrated that Arabidopsis helper NLRs form Ca2+-permeable cation channels to directly regulate cytoplasmic Ca2+ levels and consequent cell death. Thus, helper NLRs transduce cell death signals directly.
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Affiliation(s)
- Pierre Jacob
- Department of Biology and Howard Hughes Medical Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Nak Hyun Kim
- Department of Biology and Howard Hughes Medical Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Feihua Wu
- Department of Biology, Duke University, Durham, NC 27708, USA
- Department of Horticulture, Foshan University, Foshan, China
| | - Farid El-Kasmi
- Department of Plant Physiology, Centre of Plant Molecular Biology (ZMBP), University of Tübingen, Tübingen, Germany
| | - Yuan Chi
- Department of Biology, Duke University, Durham, NC 27708, USA
| | - William G Walton
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Oliver J Furzer
- Department of Biology and Howard Hughes Medical Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Adam D Lietzan
- Division of Oral and Craniofacial Health Sciences, Adams School of Dentistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Sruthi Sunil
- Department of Plant Physiology, Centre of Plant Molecular Biology (ZMBP), University of Tübingen, Tübingen, Germany
| | - Korina Kempthorn
- Department of Biology and Howard Hughes Medical Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Matthew R Redinbo
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Zhen-Ming Pei
- Department of Biology, Duke University, Durham, NC 27708, USA.
| | - Li Wan
- Department of Biology and Howard Hughes Medical Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Jeffery L Dangl
- Department of Biology and Howard Hughes Medical Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
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26
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Sun X, Lapin D, Feehan JM, Stolze SC, Kramer K, Dongus JA, Rzemieniewski J, Blanvillain-Baufumé S, Harzen A, Bautor J, Derbyshire P, Menke FLH, Finkemeier I, Nakagami H, Jones JDG, Parker JE. Pathogen effector recognition-dependent association of NRG1 with EDS1 and SAG101 in TNL receptor immunity. Nat Commun 2021; 12:3335. [PMID: 34099661 PMCID: PMC8185089 DOI: 10.1038/s41467-021-23614-x] [Citation(s) in RCA: 81] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 04/30/2021] [Indexed: 02/05/2023] Open
Abstract
Plants utilise intracellular nucleotide-binding, leucine-rich repeat (NLR) immune receptors to detect pathogen effectors and activate local and systemic defence. NRG1 and ADR1 "helper" NLRs (RNLs) cooperate with enhanced disease susceptibility 1 (EDS1), senescence-associated gene 101 (SAG101) and phytoalexin-deficient 4 (PAD4) lipase-like proteins to mediate signalling from TIR domain NLR receptors (TNLs). The mechanism of RNL/EDS1 family protein cooperation is not understood. Here, we present genetic and molecular evidence for exclusive EDS1/SAG101/NRG1 and EDS1/PAD4/ADR1 co-functions in TNL immunity. Using immunoprecipitation and mass spectrometry, we show effector recognition-dependent interaction of NRG1 with EDS1 and SAG101, but not PAD4. An EDS1-SAG101 complex interacts with NRG1, and EDS1-PAD4 with ADR1, in an immune-activated state. NRG1 requires an intact nucleotide-binding P-loop motif, and EDS1 a functional EP domain and its partner SAG101, for induced association and immunity. Thus, two distinct modules (NRG1/EDS1/SAG101 and ADR1/EDS1/PAD4) mediate TNL receptor defence signalling.
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Affiliation(s)
- Xinhua Sun
- Department of Plant-Microbe Interactions, Max Planck Institute for Plant Breeding Research, Cologne, Germany
| | - Dmitry Lapin
- Department of Plant-Microbe Interactions, Max Planck Institute for Plant Breeding Research, Cologne, Germany
- Plant-Microbe Interactions, Department of Biology, Utrecht University, Utrecht, The Netherlands
| | - Joanna M Feehan
- The Sainsbury Laboratory, University of East Anglia, Norwich, UK
| | - Sara C Stolze
- Proteomics group, Max Planck Institute for Plant Breeding Research, Cologne, Germany
| | - Katharina Kramer
- Proteomics group, Max Planck Institute for Plant Breeding Research, Cologne, Germany
| | - Joram A Dongus
- Department of Plant-Microbe Interactions, Max Planck Institute for Plant Breeding Research, Cologne, Germany
| | - Jakub Rzemieniewski
- Department of Plant-Microbe Interactions, Max Planck Institute for Plant Breeding Research, Cologne, Germany
- Department of Phytopathology, TUM School of Life Sciences Weihenstephan, Technical University of Munich, Freising, Germany
| | - Servane Blanvillain-Baufumé
- Department of Plant-Microbe Interactions, Max Planck Institute for Plant Breeding Research, Cologne, Germany
| | - Anne Harzen
- Proteomics group, Max Planck Institute for Plant Breeding Research, Cologne, Germany
| | - Jaqueline Bautor
- Department of Plant-Microbe Interactions, Max Planck Institute for Plant Breeding Research, Cologne, Germany
| | - Paul Derbyshire
- The Sainsbury Laboratory, University of East Anglia, Norwich, UK
| | - Frank L H Menke
- The Sainsbury Laboratory, University of East Anglia, Norwich, UK
| | - Iris Finkemeier
- Proteomics group, Max Planck Institute for Plant Breeding Research, Cologne, Germany
- Institute of Biology and Biotechnology of Plants, University of Muenster, Muenster, Germany
| | - Hirofumi Nakagami
- Department of Plant-Microbe Interactions, Max Planck Institute for Plant Breeding Research, Cologne, Germany
- Proteomics group, Max Planck Institute for Plant Breeding Research, Cologne, Germany
| | | | - Jane E Parker
- Department of Plant-Microbe Interactions, Max Planck Institute for Plant Breeding Research, Cologne, Germany.
- Cologne-Düsseldorf Cluster of Excellence on Plant Sciences (CEPLAS), Düsseldorf, Germany.
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27
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Sun X, Lapin D, Feehan JM, Stolze SC, Kramer K, Dongus JA, Rzemieniewski J, Blanvillain-Baufumé S, Harzen A, Bautor J, Derbyshire P, Menke FLH, Finkemeier I, Nakagami H, Jones JDG, Parker JE. Pathogen effector recognition-dependent association of NRG1 with EDS1 and SAG101 in TNL receptor immunity. Nat Commun 2021; 12:3335. [PMID: 34099661 DOI: 10.1101/2020.12.21.423810] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 04/30/2021] [Indexed: 05/21/2023] Open
Abstract
Plants utilise intracellular nucleotide-binding, leucine-rich repeat (NLR) immune receptors to detect pathogen effectors and activate local and systemic defence. NRG1 and ADR1 "helper" NLRs (RNLs) cooperate with enhanced disease susceptibility 1 (EDS1), senescence-associated gene 101 (SAG101) and phytoalexin-deficient 4 (PAD4) lipase-like proteins to mediate signalling from TIR domain NLR receptors (TNLs). The mechanism of RNL/EDS1 family protein cooperation is not understood. Here, we present genetic and molecular evidence for exclusive EDS1/SAG101/NRG1 and EDS1/PAD4/ADR1 co-functions in TNL immunity. Using immunoprecipitation and mass spectrometry, we show effector recognition-dependent interaction of NRG1 with EDS1 and SAG101, but not PAD4. An EDS1-SAG101 complex interacts with NRG1, and EDS1-PAD4 with ADR1, in an immune-activated state. NRG1 requires an intact nucleotide-binding P-loop motif, and EDS1 a functional EP domain and its partner SAG101, for induced association and immunity. Thus, two distinct modules (NRG1/EDS1/SAG101 and ADR1/EDS1/PAD4) mediate TNL receptor defence signalling.
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Affiliation(s)
- Xinhua Sun
- Department of Plant-Microbe Interactions, Max Planck Institute for Plant Breeding Research, Cologne, Germany
| | - Dmitry Lapin
- Department of Plant-Microbe Interactions, Max Planck Institute for Plant Breeding Research, Cologne, Germany
- Plant-Microbe Interactions, Department of Biology, Utrecht University, Utrecht, The Netherlands
| | - Joanna M Feehan
- The Sainsbury Laboratory, University of East Anglia, Norwich, UK
| | - Sara C Stolze
- Proteomics group, Max Planck Institute for Plant Breeding Research, Cologne, Germany
| | - Katharina Kramer
- Proteomics group, Max Planck Institute for Plant Breeding Research, Cologne, Germany
| | - Joram A Dongus
- Department of Plant-Microbe Interactions, Max Planck Institute for Plant Breeding Research, Cologne, Germany
| | - Jakub Rzemieniewski
- Department of Plant-Microbe Interactions, Max Planck Institute for Plant Breeding Research, Cologne, Germany
- Department of Phytopathology, TUM School of Life Sciences Weihenstephan, Technical University of Munich, Freising, Germany
| | - Servane Blanvillain-Baufumé
- Department of Plant-Microbe Interactions, Max Planck Institute for Plant Breeding Research, Cologne, Germany
| | - Anne Harzen
- Proteomics group, Max Planck Institute for Plant Breeding Research, Cologne, Germany
| | - Jaqueline Bautor
- Department of Plant-Microbe Interactions, Max Planck Institute for Plant Breeding Research, Cologne, Germany
| | - Paul Derbyshire
- The Sainsbury Laboratory, University of East Anglia, Norwich, UK
| | - Frank L H Menke
- The Sainsbury Laboratory, University of East Anglia, Norwich, UK
| | - Iris Finkemeier
- Proteomics group, Max Planck Institute for Plant Breeding Research, Cologne, Germany
- Institute of Biology and Biotechnology of Plants, University of Muenster, Muenster, Germany
| | - Hirofumi Nakagami
- Department of Plant-Microbe Interactions, Max Planck Institute for Plant Breeding Research, Cologne, Germany
- Proteomics group, Max Planck Institute for Plant Breeding Research, Cologne, Germany
| | | | - Jane E Parker
- Department of Plant-Microbe Interactions, Max Planck Institute for Plant Breeding Research, Cologne, Germany.
- Cologne-Düsseldorf Cluster of Excellence on Plant Sciences (CEPLAS), Düsseldorf, Germany.
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28
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Ngou BPM, Ahn HK, Ding P, Jones JDG. Mutual potentiation of plant immunity by cell-surface and intracellular receptors. Nature 2021; 592:110-115. [PMID: 33692545 DOI: 10.1101/2020.04.10.034173] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Accepted: 02/01/2021] [Indexed: 05/25/2023]
Abstract
The plant immune system involves cell-surface receptors that detect intercellular pathogen-derived molecules, and intracellular receptors that activate immunity upon detection of pathogen-secreted effector proteins that act inside the plant cell. Immunity mediated by surface receptors has been extensively studied1, but that mediated by intracellular receptors has rarely been investigated in the absence of surface-receptor-mediated immunity. Furthermore, interactions between these two immune pathways are poorly understood. Here, by activating intracellular receptors without inducing surface-receptor-mediated immunity, we analyse interactions between these two distinct immune systems in Arabidopsis. Pathogen recognition by surface receptors activates multiple protein kinases and NADPH oxidases, and we find that intracellular receptors primarily potentiate the activation of these proteins by increasing their abundance through several mechanisms. Likewise, the hypersensitive response that depends on intracellular receptors is strongly enhanced by the activation of surface receptors. Activation of either immune system alone is insufficient to provide effective resistance against the bacterial pathogen Pseudomonas syringae. Thus, immune pathways activated by cell-surface and intracellular receptors in plants mutually potentiate to activate strong defences against pathogens. These findings reshape our understanding of plant immunity and have broad implications for crop improvement.
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Affiliation(s)
| | - Hee-Kyung Ahn
- The Sainsbury Laboratory, University of East Anglia, Norwich, UK
| | - Pingtao Ding
- The Sainsbury Laboratory, University of East Anglia, Norwich, UK.
- Institute of Biology Leiden, Leiden University, Leiden, The Netherlands.
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29
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Stuttmann J, Barthel K, Martin P, Ordon J, Erickson JL, Herr R, Ferik F, Kretschmer C, Berner T, Keilwagen J, Marillonnet S, Bonas U. Highly efficient multiplex editing: one-shot generation of 8× Nicotiana benthamiana and 12× Arabidopsis mutants. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 106:8-22. [PMID: 33577114 DOI: 10.1111/tpj.15197] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 02/07/2021] [Accepted: 02/09/2021] [Indexed: 06/12/2023]
Abstract
Genome editing by RNA-guided nucleases, such as SpCas9, has been used in numerous different plant species. However, to what extent multiple independent loci can be targeted simultaneously by multiplexing has not been well documented. Here, we developed a toolkit, based on a highly intron-optimized zCas9i gene, which allows assembly of nuclease constructs expressing up to 32 single guide RNAs (sgRNAs). We used this toolkit to explore the limits of multiplexing in two major model species, and report on the isolation of transgene-free octuple (8×) Nicotiana benthamiana and duodecuple (12×) Arabidopsis thaliana mutant lines in a single generation (T1 and T2 , respectively). We developed novel counter-selection markers for N. benthamiana, most importantly Sl-FAST2, comparable to the well-established Arabidopsis seed fluorescence marker, and FCY-UPP, based on the production of toxic 5-fluorouracil in the presence of a precursor. Targeting eight genes with an array of nine different sgRNAs and relying on FCY-UPP for selection of non-transgenic T1 , we identified N. benthamiana mutant lines with astonishingly high efficiencies: All analyzed plants carried mutations in all genes (approximately 112/116 target sites edited). Furthermore, we targeted 12 genes by an array of 24 sgRNAs in A. thaliana. Efficiency was significantly lower in A. thaliana, and our results indicate Cas9 availability is the limiting factor in such higher-order multiplexing applications. We identified a duodecuple mutant line by a combination of phenotypic screening and amplicon sequencing. The resources and results presented provide new perspectives for how multiplexing can be used to generate complex genotypes or to functionally interrogate groups of candidate genes.
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Affiliation(s)
- Johannes Stuttmann
- Department of Plant Genetics, Institute for Biology, Martin Luther University Halle-Wittenberg, Weinbergweg 10, Halle (Saale), 06120, Germany
| | - Karen Barthel
- Department of Plant Genetics, Institute for Biology, Martin Luther University Halle-Wittenberg, Weinbergweg 10, Halle (Saale), 06120, Germany
| | - Patrick Martin
- Department of Plant Genetics, Institute for Biology, Martin Luther University Halle-Wittenberg, Weinbergweg 10, Halle (Saale), 06120, Germany
| | - Jana Ordon
- Department of Plant Genetics, Institute for Biology, Martin Luther University Halle-Wittenberg, Weinbergweg 10, Halle (Saale), 06120, Germany
| | - Jessica L Erickson
- Department of Plant Genetics, Institute for Biology, Martin Luther University Halle-Wittenberg, Weinbergweg 10, Halle (Saale), 06120, Germany
| | - Rosalie Herr
- Department of Plant Genetics, Institute for Biology, Martin Luther University Halle-Wittenberg, Weinbergweg 10, Halle (Saale), 06120, Germany
| | - Filiz Ferik
- Department of Plant Genetics, Institute for Biology, Martin Luther University Halle-Wittenberg, Weinbergweg 10, Halle (Saale), 06120, Germany
| | - Carola Kretschmer
- Department of Plant Genetics, Institute for Biology, Martin Luther University Halle-Wittenberg, Weinbergweg 10, Halle (Saale), 06120, Germany
| | - Thomas Berner
- Institute for Biosafety in Plant Biotechnology, Federal Research Centre for Cultivated Plants, Julius Kühn-Institute (JKI), Quedlinburg, Germany
| | - Jens Keilwagen
- Institute for Biosafety in Plant Biotechnology, Federal Research Centre for Cultivated Plants, Julius Kühn-Institute (JKI), Quedlinburg, Germany
| | - Sylvestre Marillonnet
- Department of Cell and Metabolic Biology, Leibniz Institute of Plant Biochemistry, Weinberg 3, Halle (Saale), 06120, Germany
| | - Ulla Bonas
- Department of Plant Genetics, Institute for Biology, Martin Luther University Halle-Wittenberg, Weinbergweg 10, Halle (Saale), 06120, Germany
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30
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Ngou BPM, Ahn HK, Ding P, Jones JDG. Mutual potentiation of plant immunity by cell-surface and intracellular receptors. Nature 2021; 592:110-115. [PMID: 33692545 DOI: 10.1038/s41586-021-03315-7] [Citation(s) in RCA: 443] [Impact Index Per Article: 147.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Accepted: 02/01/2021] [Indexed: 02/03/2023]
Abstract
The plant immune system involves cell-surface receptors that detect intercellular pathogen-derived molecules, and intracellular receptors that activate immunity upon detection of pathogen-secreted effector proteins that act inside the plant cell. Immunity mediated by surface receptors has been extensively studied1, but that mediated by intracellular receptors has rarely been investigated in the absence of surface-receptor-mediated immunity. Furthermore, interactions between these two immune pathways are poorly understood. Here, by activating intracellular receptors without inducing surface-receptor-mediated immunity, we analyse interactions between these two distinct immune systems in Arabidopsis. Pathogen recognition by surface receptors activates multiple protein kinases and NADPH oxidases, and we find that intracellular receptors primarily potentiate the activation of these proteins by increasing their abundance through several mechanisms. Likewise, the hypersensitive response that depends on intracellular receptors is strongly enhanced by the activation of surface receptors. Activation of either immune system alone is insufficient to provide effective resistance against the bacterial pathogen Pseudomonas syringae. Thus, immune pathways activated by cell-surface and intracellular receptors in plants mutually potentiate to activate strong defences against pathogens. These findings reshape our understanding of plant immunity and have broad implications for crop improvement.
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Affiliation(s)
| | - Hee-Kyung Ahn
- The Sainsbury Laboratory, University of East Anglia, Norwich, UK
| | - Pingtao Ding
- The Sainsbury Laboratory, University of East Anglia, Norwich, UK. .,Institute of Biology Leiden, Leiden University, Leiden, The Netherlands.
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Baltrus DA, Smith C, Derrick M, Leligdon C, Rosenthal Z, Mollico M, Moore A, Clark M. Genomic Background Governs Opposing Responses to Nalidixic Acid upon Megaplasmid Acquisition in Pseudomonas. mSphere 2021; 6:e00008-21. [PMID: 33597171 PMCID: PMC8544880 DOI: 10.1128/msphere.00008-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Accepted: 01/21/2021] [Indexed: 11/20/2022] Open
Abstract
Horizontal gene transfer is a significant driver of evolutionary dynamics across microbial populations. Although the benefits of the acquisition of new genetic material are often quite clear, experiments across systems have demonstrated that gene transfer events can cause significant phenotypic changes and entail fitness costs in a way that is dependent on the genomic and environmental context. Here, we test for the generality of one previously identified cost, sensitization of cells to the antibiotic nalidixic acid after acquisition of an ∼1-Mb megaplasmid, across Pseudomonas strains and species. Overall, we find that the presence of this megaplasmid sensitizes many different Pseudomonas strains to nalidixic acid but that this same horizontal gene transfer event increases resistance of Pseudomonas putida KT2440 to nalidixic acid across assays as well as to ciprofloxacin under competitive conditions. These phenotypic results are not easily explained away as secondary consequences of overall fitness effects and appear to occur independently of another cost associated with this megaplasmid, sensitization to higher temperatures. Lastly, we draw parallels between these reported results and the phenomenon of sign epistasis for de novo mutations and explore how context dependence of effects of plasmid acquisition could impact overall evolutionary dynamics and the evolution of antimicrobial resistance.IMPORTANCE Numerous studies have demonstrated that gene transfer events (e.g., plasmid acquisition) can entail a variety of costs that arise as by-products of the incorporation of foreign DNA into established physiological and genetic systems. These costs can be ameliorated through evolutionary time by the occurrence of compensatory mutations, which stabilize the presence of a horizontally transferred region within the genome but which also may skew future adaptive possibilities for these lineages. Here, we demonstrate another possible outcome, that phenotypic changes arising as a consequence of the same horizontal gene transfer (HGT) event are costly to some strains but may actually be beneficial in other genomic backgrounds under the right conditions. These results provide a new viewpoint for considering conditions that promote plasmid maintenance and highlight the influence of genomic and environmental contexts when considering amelioration of fitness costs after HGT events.
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Affiliation(s)
- David A Baltrus
- School of Plant Sciences, University of Arizona, Tucson, Arizona, USA
- School of Animal and Comparative Biomedical Sciences, University of Arizona, Tucson, Arizona, USA
| | - Caitlin Smith
- School of Plant Sciences, University of Arizona, Tucson, Arizona, USA
| | - MacKenzie Derrick
- School of Plant Sciences, University of Arizona, Tucson, Arizona, USA
| | - Courtney Leligdon
- School of Plant Sciences, University of Arizona, Tucson, Arizona, USA
| | - Zoe Rosenthal
- School of Plant Sciences, University of Arizona, Tucson, Arizona, USA
| | - Madison Mollico
- School of Plant Sciences, University of Arizona, Tucson, Arizona, USA
| | - Andrew Moore
- School of Plant Sciences, University of Arizona, Tucson, Arizona, USA
| | - Meara Clark
- School of Plant Sciences, University of Arizona, Tucson, Arizona, USA
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32
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Jayaraman J, Yoon M, Applegate ER, Stroud EA, Templeton MD. AvrE1 and HopR1 from Pseudomonas syringae pv. actinidiae are additively required for full virulence on kiwifruit. MOLECULAR PLANT PATHOLOGY 2020; 21:1467-1480. [PMID: 32969167 PMCID: PMC7548996 DOI: 10.1111/mpp.12989] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 08/14/2020] [Accepted: 08/14/2020] [Indexed: 06/01/2023]
Abstract
Pseudomonas syringae pv. actinidiae ICMP 18884 biovar 3 (Psa3) produces necrotic lesions during infection of its kiwifruit host. Bacterial growth in planta and lesion formation are dependent upon a functional type III secretion system (T3S), which translocates multiple effector proteins into host cells. Associated with the T3S locus is the conserved effector locus (CEL), which has been characterized and shown to be essential for the full virulence in other P. syringae pathovars. Two effectors at the CEL, hopM1 and avrE1, as well as an avrE1-related non-CEL effector, hopR1, have been shown to be redundant in the model pathogen P. syringae pv. tomato DC3000 (Pto), a close relative of Psa. However, it is not known whether CEL-related effectors are required for Psa pathogenicity. The Psa3 allele of hopM1, and its associated chaperone, shcM, have diverged significantly from their orthologs in Pto. Furthermore, the CEL effector hopAA1-1, as well as a related non-CEL effector, hopAA1-2, have both been pseudogenized. We have shown that HopM1 does not contribute to Psa3 virulence due to a truncation in shcM, a truncation conserved in the Psa lineage, probably due to the need to evade HopM1-triggered immunity in kiwifruit. We characterized the virulence contribution of CEL and related effectors in Psa3 and found that only avrE1 and hopR1, additively, are required for in planta growth and lesion production. This is unlike the redundancy described for these effectors in Pto and indicates that these two Psa3 genes are key determinants essential for kiwifruit bacterial canker disease.
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Affiliation(s)
- Jay Jayaraman
- The New Zealand Institute for Plant and Food Research LimitedAucklandNew Zealand
- Bio‐Protection Research CentreLincolnNew Zealand
| | - Minsoo Yoon
- The New Zealand Institute for Plant and Food Research LimitedAucklandNew Zealand
| | - Emma R. Applegate
- The New Zealand Institute for Plant and Food Research LimitedAucklandNew Zealand
- School of Biological SciencesUniversity of AucklandAucklandNew Zealand
- Present address:
AgResearch Ltd., Grasslands Research CentrePalmerston NorthNew Zealand
| | - Erin A. Stroud
- The New Zealand Institute for Plant and Food Research LimitedAucklandNew Zealand
- School of Biological SciencesUniversity of AucklandAucklandNew Zealand
| | - Matthew D. Templeton
- The New Zealand Institute for Plant and Food Research LimitedAucklandNew Zealand
- Bio‐Protection Research CentreLincolnNew Zealand
- School of Biological SciencesUniversity of AucklandAucklandNew Zealand
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33
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Jaswal R, Rajarammohan S, Dubey H, Sharma TR. Smut fungi as a stratagem to characterize rust effectors: opportunities and challenges. World J Microbiol Biotechnol 2020; 36:150. [PMID: 32924088 DOI: 10.1007/s11274-020-02927-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Accepted: 09/05/2020] [Indexed: 11/30/2022]
Abstract
The rust pathogens are one of the most complex fungi in the Basidiomycetes. The development of genomic resources for rust and other plant pathogens has opened the opportunities for functional genomics of fungal genes. Despite significant progress in the field of fungal genomics, functional characterization of the genome components has lacked, especially for the rust pathogens. Their obligate nature and lack of standard stable transformation protocol are the primary reasons for rusts to be one of the least explored genera despite its significance. In the recently sequenced rust genomes, a vast catalogue of predicted effectors and pathogenicity genes have been reported. However, most of these candidate genes remained unexplored due to the lack of suitable characterization methods. The heterologous expression of putative effectors in Nicotiana benthamiana and Arabidopsis thaliana has proved to be a rapid screening method for identifying the role of these effectors in virulence. However, no fungal system has been used for the functional validation of these candidate genes. The smuts, from the evolutionary point of view, are closely related to the rust pathogens. Moreover, they have been widely studied and hence could be a suitable model system for expressing rust fungal genes heterologously. The genetic manipulation methods for smuts are also well standardized. Complementation assays can be used for functional validation of the homologous genes present in rust and smut fungal pathogens, while the species-specific proteins can be expressed in the mutant strains of smut pathogens having reduced or no virulence for virulence analysis. We propose that smuts, especially Ustilago maydis, may prove to be a good model system to characterize rust effector proteins in the absence of methods to manipulate the rust genomes directly.
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Affiliation(s)
- Rajdeep Jaswal
- National Agri-Food Biotechnology Institute (NABI), Sector-81 (Knowledge City), PO Manauli, S.A.S. Nagar, Mohali, Punjab, 140306, India
| | - Sivasubramanian Rajarammohan
- National Agri-Food Biotechnology Institute (NABI), Sector-81 (Knowledge City), PO Manauli, S.A.S. Nagar, Mohali, Punjab, 140306, India
| | - Himanshu Dubey
- ICAR-National Institute for Plant Biotechnology, Pusa Campus, New Delhi, 110012, India
| | - T R Sharma
- National Agri-Food Biotechnology Institute (NABI), Sector-81 (Knowledge City), PO Manauli, S.A.S. Nagar, Mohali, Punjab, 140306, India.
- Crop Science Division, Indian Council of Agricultural Research, New Delhi, 110001, India.
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34
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Saile SC, Jacob P, Castel B, Jubic LM, Salas-Gonzáles I, Bäcker M, Jones JDG, Dangl JL, El Kasmi F. Two unequally redundant "helper" immune receptor families mediate Arabidopsis thaliana intracellular "sensor" immune receptor functions. PLoS Biol 2020; 18:e3000783. [PMID: 32925907 PMCID: PMC7514072 DOI: 10.1371/journal.pbio.3000783] [Citation(s) in RCA: 88] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 09/24/2020] [Accepted: 08/17/2020] [Indexed: 01/08/2023] Open
Abstract
Plant nucleotide-binding (NB) leucine-rich repeat (LRR) receptor (NLR) proteins function as intracellular immune receptors that perceive the presence of pathogen-derived virulence proteins (effectors) to induce immune responses. The 2 major types of plant NLRs that “sense” pathogen effectors differ in their N-terminal domains: these are Toll/interleukin-1 receptor resistance (TIR) domain-containing NLRs (TNLs) and coiled-coil (CC) domain-containing NLRs (CNLs). In many angiosperms, the RESISTANCE TO POWDERY MILDEW 8 (RPW8)-CC domain containing NLR (RNL) subclass of CNLs is encoded by 2 gene families, ACTIVATED DISEASE RESISTANCE 1 (ADR1) and N REQUIREMENT GENE 1 (NRG1), that act as “helper” NLRs during multiple sensor NLR-mediated immune responses. Despite their important role in sensor NLR-mediated immunity, knowledge of the specific, redundant, and synergistic functions of helper RNLs is limited. We demonstrate that the ADR1 and NRG1 families act in an unequally redundant manner in basal resistance, effector-triggered immunity (ETI) and regulation of defense gene expression. We define RNL redundancy in ETI conferred by some TNLs and in basal resistance against virulent pathogens. We demonstrate that, in Arabidopsis thaliana, the 2 RNL families contribute specific functions in ETI initiated by specific CNLs and TNLs. Time-resolved whole genome expression profiling revealed that RNLs and “classical” CNLs trigger similar transcriptome changes, suggesting that RNLs act like other CNLs to mediate ETI downstream of sensor NLR activation. Together, our genetic data confirm that RNLs contribute to basal resistance, are fully required for TNL signaling, and can also support defense activation during CNL-mediated ETI. This study shows that two intracellular plant Nod-like immune receptor (NLR-) subfamilies act with unequal redundancy in their roles in plant disease resistance to virulent and avirulent pathogens, in effector-triggered immunity induced gene expression and in immunity-associated cell death. This function is most likely in parallel with, and not downstream of, other canonical intracellular plant immune receptors.
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Affiliation(s)
- Svenja C. Saile
- Center for Plant Molecular Biology, Eberhard Karls University of Tübingen, Tübingen, Germany
| | - Pierre Jacob
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- Howard Hughes Medical Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Baptiste Castel
- The Sainsbury Laboratory, Norwich Research Park, Norwich, United Kingdom
| | - Lance M. Jubic
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- Howard Hughes Medical Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Isai Salas-Gonzáles
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- Howard Hughes Medical Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- Curriculum in Bioinformatics and Computational Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Marcel Bäcker
- Center for Plant Molecular Biology, Eberhard Karls University of Tübingen, Tübingen, Germany
| | | | - Jeffery L. Dangl
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- Howard Hughes Medical Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- Curriculum in Bioinformatics and Computational Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- Carolina Center for Genome Sciences, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Farid El Kasmi
- Center for Plant Molecular Biology, Eberhard Karls University of Tübingen, Tübingen, Germany
- * E-mail:
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Jaswal R, Kiran K, Rajarammohan S, Dubey H, Singh PK, Sharma Y, Deshmukh R, Sonah H, Gupta N, Sharma TR. Effector Biology of Biotrophic Plant Fungal Pathogens: Current Advances and Future Prospects. Microbiol Res 2020; 241:126567. [PMID: 33080488 DOI: 10.1016/j.micres.2020.126567] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 07/21/2020] [Accepted: 07/25/2020] [Indexed: 12/13/2022]
Abstract
The interaction of fungal pathogens with their host requires a novel invading mechanism and the presence of various virulence-associated components responsible for promoting the infection. The small secretory proteins, explicitly known as effector proteins, are one of the prime mechanisms of host manipulation utilized by the pathogen to disarm the host. Several effector proteins are known to translocate from fungus to the plant cell for host manipulation. Many fungal effectors have been identified using genomic, transcriptomic, and bioinformatics approaches. Most of the effector proteins are devoid of any conserved signatures, and their prediction based on sequence homology is very challenging, therefore by combining the sequence consensus based upon machine learning features, multiple tools have also been developed for predicting apoplastic and cytoplasmic effectors. Various post-genomics approaches like transcriptomics of virulent isolates have also been utilized for identifying active consortia of effectors. Significant progress has been made in understanding biotrophic effectors; however, most of it is underway due to their complex interaction with host and complicated recognition and signaling networks. This review discusses advances, and challenges in effector identification and highlighted various features of the potential effector proteins and approaches for understanding their genetics and strategies for regulation.
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Affiliation(s)
- Rajdeep Jaswal
- National Agri-Food Biotechnology Institute (NABI), Mohali, Punjab, 140306, India; Department of Microbiology, Panjab University, Chandigarh, Punjab, 160014, India
| | - Kanti Kiran
- ICAR-National Institute for Plant Biotechnology, Pusa Campus New Delhi, 110012, India
| | | | - Himanshu Dubey
- ICAR-National Institute for Plant Biotechnology, Pusa Campus New Delhi, 110012, India
| | - Pankaj Kumar Singh
- National Agri-Food Biotechnology Institute (NABI), Mohali, Punjab, 140306, India
| | - Yogesh Sharma
- National Agri-Food Biotechnology Institute (NABI), Mohali, Punjab, 140306, India
| | - Rupesh Deshmukh
- National Agri-Food Biotechnology Institute (NABI), Mohali, Punjab, 140306, India
| | - Humira Sonah
- National Agri-Food Biotechnology Institute (NABI), Mohali, Punjab, 140306, India
| | - Naveen Gupta
- Department of Microbiology, Panjab University, Chandigarh, Punjab, 160014, India.
| | - T R Sharma
- National Agri-Food Biotechnology Institute (NABI), Mohali, Punjab, 140306, India.
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36
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Revealing Differentially Expressed Genes and Identifying Effector Proteins of Puccinia striiformis f. sp.
tritici
in Response to High-Temperature Seedling Plant Resistance of Wheat Based on Transcriptome Sequencing. mSphere 2020. [PMCID: PMC7316484 DOI: 10.1128/msphere.00096-20] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In the present study, we performed transcriptomic analysis to identify differentially expressed genes and effector proteins of
Puccinia striiformis
f. sp.
tritici
(
Pst
) in response to the high-temperature seedling-plant (HTSP) resistance in wheat. Experimental validation confirmed the function of the highest upregulated effector protein, PstCEP1. This study provides a key resource for understanding the biology and molecular basis of
Pst
responses to wheat HTSP resistance, and PstCEP1 may be used in future studies to understand pathogen-associated molecular pattern-triggered immunity and effector-triggered immunity processes in the
Pst
-wheat interaction system.
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37
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Ngou BPM, Ahn HK, Ding P, Redkar A, Brown H, Ma Y, Youles M, Tomlinson L, Jones JDG. Estradiol-inducible AvrRps4 expression reveals distinct properties of TIR-NLR-mediated effector-triggered immunity. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:2186-2197. [PMID: 32050020 PMCID: PMC7242080 DOI: 10.1093/jxb/erz571] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 01/14/2020] [Indexed: 05/18/2023]
Abstract
Plant nucleotide-binding domain, leucine-rich repeat receptor (NLR) proteins play important roles in recognition of pathogen-derived effectors. However, the mechanism by which plant NLRs activate immunity is still largely unknown. The paired Arabidopsis NLRs RRS1-R and RPS4, that confer recognition of bacterial effectors AvrRps4 and PopP2, are well studied, but how the RRS1/RPS4 complex activates early immediate downstream responses upon effector detection is still poorly understood. To study RRS1/RPS4 responses without the influence of cell surface receptor immune pathways, we generated an Arabidopsis line with inducible expression of the effector AvrRps4. Induction does not lead to hypersensitive cell death response (HR) but can induce electrolyte leakage, which often correlates with plant cell death. Activation of RRS1 and RPS4 without pathogens cannot activate mitogen-associated protein kinase cascades, but still activates up-regulation of defence genes, and therefore resistance against bacteria.
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Affiliation(s)
- Bruno Pok Man Ngou
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich, UK
| | - Hee-Kyung Ahn
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich, UK
| | - Pingtao Ding
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich, UK
| | - Amey Redkar
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich, UK
- Department of Genetics, University of Córdoba, Córdoba, Spain
| | - Hannah Brown
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich, UK
| | - Yan Ma
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich, UK
| | - Mark Youles
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich, UK
| | - Laurence Tomlinson
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich, UK
| | - Jonathan D G Jones
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich, UK
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38
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Prokchorchik M, Choi S, Chung EH, Won K, Dangl JL, Sohn KH. A host target of a bacterial cysteine protease virulence effector plays a key role in convergent evolution of plant innate immune system receptors. THE NEW PHYTOLOGIST 2020; 225:1327-1342. [PMID: 31550400 DOI: 10.1111/nph.16218] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Accepted: 09/17/2019] [Indexed: 06/10/2023]
Abstract
Some virulence effectors secreted from pathogens target host proteins and induce biochemical modifications that are monitored by nucleotide-binding and leucine-rich repeat (NLR) immune receptors. Arabidopsis RIN4 protein (AtRIN4: RPM1-interacting protein 4) homologs are present in diverse plant species and targeted by several bacterial type III effector proteins including the cysteine protease AvrRpt2. RIN4 is 'guarded' by several independently evolved NLRs from various plant species, including Arabidopsis RPS2. Recently, it was shown that the MR5 NLR from a wild apple relative can recognize the AvrRpt2 effector from Erwinia amylovora, but the details of this recognition remained unclear. The present contribution reports the mechanism of AvrRpt2 recognition by independently evolved NLRs, MR5 from apple and RPS2, both of which require proteolytically processed RIN4 for activation. It shows that the C-terminal cleaved product of apple RIN4 (MdRIN4) but not AtRIN4 is necessary and sufficient for MR5 activation. Additionally, two polymorphic residues in AtRIN4 and MdRIN4 are identified that are crucial in the regulation of and physical association with NLRs. It is proposed that polymorphisms in RIN4 from distantly related plant species allow it to remain an effector target while maintaining compatibility with multiple NLRs.
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Affiliation(s)
- Maxim Prokchorchik
- 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
| | - Sera Choi
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, 37673, Korea
| | - Eui-Hwan Chung
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599-3280, USA
- Howard Hughes Medical Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599-3280, USA
| | - Kyungho Won
- National Institute of Horticultural and Herbal Science (NIHHS), Rural Development Administration (RDA), Naju, 54875, Korea
| | - Jeffery L Dangl
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599-3280, USA
- Howard Hughes Medical Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599-3280, USA
| | - Kee Hoon Sohn
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, 37673, Korea
- School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, Pohang, 37673, Korea
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Lonjon F, Rengel D, Roux F, Henry C, Turner M, Le Ru A, Razavi N, Sabbagh CRR, Genin S, Vailleau F. HpaP Sequesters HrpJ, an Essential Component of Ralstonia solanacearum Virulence That Triggers Necrosis in Arabidopsis. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2020; 33:200-211. [PMID: 31567040 DOI: 10.1094/mpmi-05-19-0139-r] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The Gram-negative bacterium Ralstonia solanacearum, the causal agent of bacterial wilt, is a worldwide major crop pathogen whose virulence strongly relies on a type III secretion system (T3SS). This extracellular apparatus allows the translocation of proteins, called type III effectors (T3Es), directly into the host cells. To date, very few data are available in plant-pathogenic bacteria concerning the role played by type III secretion (T3S) regulators at the posttranslational level. We have demonstrated that HpaP, a putative T3S substrate specificity switch protein of R. solanacearum, controls T3E secretion. To better understand the role of HpaP on T3S control, we analyzed the secretomes of the GMI1000 wild-type strain as well as the hpaP mutant using a mass spectrometry experiment (liquid chromatography tandem mass spectrometry). The secretomes of both strains appeared to be very similar and highlighted the modulation of the secretion of few type III substrates. Interestingly, only one type III-associated protein, HrpJ, was identified as specifically secreted by the hpaP mutant. HrpJ appeared to be an essential component of the T3SS, essential for T3S and pathogenicity. We further showed that HrpJ is specifically translocated in planta by the hpaP mutant and that HrpJ can physically interact with HpaP. Moreover, confocal microscopy experiments demonstrated a cytoplasmic localization for HrpJ once in planta. When injected into Arabidopsis thaliana leaves, HrpJ is able to trigger a necrosis on 16 natural accessions. A genome-wide association mapping revealed a major association peak with 12 highly significant single-nucleotide polymorphisms located on a plant acyl-transferase.
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Affiliation(s)
- Fabien Lonjon
- LIPM, Université de Toulouse, INRA, CNRS, Castanet-Tolosan, France
| | - David Rengel
- LIPM, Université de Toulouse, INRA, CNRS, Castanet-Tolosan, France
| | - Fabrice Roux
- LIPM, Université de Toulouse, INRA, CNRS, Castanet-Tolosan, France
| | - Céline Henry
- Micalis Institute, PAPPSO, INRA, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France
| | - Marie Turner
- LIPM, Université de Toulouse, INRA, CNRS, Castanet-Tolosan, France
| | - Aurélie Le Ru
- Research Federation "Agrobiosciences, Interactions et Biodiversité" Castanet-Tolosan, France
| | - Narjes Razavi
- LIPM, Université de Toulouse, INRA, CNRS, Castanet-Tolosan, France
| | | | - Stéphane Genin
- LIPM, Université de Toulouse, INRA, CNRS, Castanet-Tolosan, France
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Xu Q, Tang C, Wang L, Zhao C, Kang Z, Wang X. Haustoria - arsenals during the interaction between wheat and Puccinia striiformis f. sp. tritici. MOLECULAR PLANT PATHOLOGY 2020; 21:83-94. [PMID: 31774224 PMCID: PMC6913192 DOI: 10.1111/mpp.12882] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
As an obligate parasite, Puccinia striiformis f. sp. tritici (Pst) forms haustoria to obtain nutrients from plant cells for development, and these structures are essential for pathogen survival. To better understand the contribution of haustoria to the interactions with the host plants, we isolated haustoria from susceptible wheat leaves infected with Pst race CYR31 and sequenced their transcriptome as well as those of urediospores and germ tubes, and compared the three transcriptomes. A total of 3524 up-regulated genes were obtained from haustoria, of which 73 genes were related to thiamine biosynthesis, glycolysis and lipid metabolic processes. Silencing seven of the genes reduced the growth and development of Pst in wheat. More interestingly, 1197 haustorial secreted proteins (HASPs) were detected in haustoria, accounting for 34% of the total proteins, indicating that these HASPs play important roles in haustorium-mediated pathogenic progression. Furthermore, 69 HASPs were able to suppress Bax-triggered programmed cell death in tobacco. Additionally, 46 HASPs significantly reduced callose deposition in wheat using the type III secretion system. This study identified a large number of effectors through transcriptome sequencing, and the results revealed components of metabolic pathways that impact the growth and colonization of the pathogen and indicate essential functions of haustoria in the growth and pathogenicity of Pst.
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Affiliation(s)
- Qiang Xu
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant ProtectionNorthwest A&F UniversityYanglingShaanxi712100China
| | - Chunlei Tang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant ProtectionNorthwest A&F UniversityYanglingShaanxi712100China
| | - Likun Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant ProtectionNorthwest A&F UniversityYanglingShaanxi712100China
| | - Congcong Zhao
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant ProtectionNorthwest A&F UniversityYanglingShaanxi712100China
| | - Zhensheng Kang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant ProtectionNorthwest A&F UniversityYanglingShaanxi712100China
| | - Xiaojie Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant ProtectionNorthwest A&F UniversityYanglingShaanxi712100China
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Prasad P, Savadi S, Bhardwaj SC, Gangwar OP, Kumar S. Rust pathogen effectors: perspectives in resistance breeding. PLANTA 2019; 250:1-22. [PMID: 30980247 DOI: 10.1007/s00425-019-03167-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Accepted: 04/09/2019] [Indexed: 06/09/2023]
Abstract
Identification and functional characterization of plant pathogen effectors promise to ameliorate future research and develop effective and sustainable strategies for controlling or containing crop diseases. Wheat is the second most important food crop of the world after rice. Rust pathogens, one of the major biotic stresses in wheat production, are capable of threatening the world food security. Understanding the molecular basis of plant-pathogen interactions is essential for devising novel strategies for resistance breeding and disease management. Now, it has been established that effectors, the proteins secreted by pathogens, play a key role in plant-pathogen interactions. Therefore, effector biology has emerged as one of the most important research fields in plant biology. Recent advances in genomics and bioinformatics have allowed identification of a large repertoire of candidate effectors, while the evolving high-throughput tools have continued to assist in their functional characterization. The repertoires of effectors have become an important resource for better understanding of effector biology of pathosystems and resistance breeding of crop plants. In recent years, a significant progress has been made in the field of rust effector biology. This review describes the recent advances in effector biology of obligate fungal pathogens, identification and functional analysis of wheat rust pathogens effectors and the potential applications of effectors in molecular plant biology and rust resistance breeding in wheat.
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Affiliation(s)
- Pramod Prasad
- ICAR-Indian Institute of Wheat and Barley Research, Regional Station, Shimla, Himachal Pradesh, 171002, India
| | - Siddanna Savadi
- ICAR-Directorate of Cashew Research, Puttur, Karnataka, 574202, India
| | - S C Bhardwaj
- ICAR-Indian Institute of Wheat and Barley Research, Regional Station, Shimla, Himachal Pradesh, 171002, India.
| | - O P Gangwar
- ICAR-Indian Institute of Wheat and Barley Research, Regional Station, Shimla, Himachal Pradesh, 171002, India
| | - Subodh Kumar
- ICAR-Indian Institute of Wheat and Barley Research, Regional Station, Shimla, Himachal Pradesh, 171002, India
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Yin C, Ramachandran SR, Zhai Y, Bu C, Pappu HR, Hulbert SH. A novel fungal effector from Puccinia graminis suppressing RNA silencing and plant defense responses. THE NEW PHYTOLOGIST 2019; 222:1561-1572. [PMID: 30623449 DOI: 10.1111/nph.15676] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Accepted: 01/03/2019] [Indexed: 05/11/2023]
Abstract
Fungal plant pathogens, like rust-causing biotrophic fungi, secrete hundreds of effectors into plant cells to subvert host immunity and promote pathogenicity on their host plants by manipulating specific physiological processes or signal pathways, but the actual function has been demonstrated for very few of these proteins. Here, we show that the PgtSR1 effector proteins, encoded by two allelic genes (PgtSR1-a and PgtSR1-b), from the wheat stem rust pathogen Puccinia graminis f. sp. tritici (Pgt), suppress RNA silencing in plants and impede plant defenses by altering the abundance of small RNAs that serve as defense regulators. Expression of the PgtSR1s in plants revealed that the PgtSR1s promote susceptibility to multiple pathogens and partially suppress cell death triggered by multiple R proteins. Overall, our study provides the first evidence that the filamentous fungus P. graminis has evolved to produce fungal suppressors of RNA silencing and indicates that PgtSR1s suppress both basal defenses and effector triggered immunity.
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Affiliation(s)
- Chuntao Yin
- Department of Plant Pathology, Washington State University, Pullman, WA, 99164-6430, USA
| | - Sowmya R Ramachandran
- Department of Plant Pathology, Washington State University, Pullman, WA, 99164-6430, USA
| | - Ying Zhai
- Department of Plant Pathology, Washington State University, Pullman, WA, 99164-6430, USA
| | - Chunya Bu
- College of Biological Science and Engineering, Beijing University of Agriculture, Beijing, 102206, China
| | - Hanu R Pappu
- Department of Plant Pathology, Washington State University, Pullman, WA, 99164-6430, USA
| | - Scot H Hulbert
- Department of Plant Pathology, Washington State University, Pullman, WA, 99164-6430, USA
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Newman TE, Lee J, Williams SJ, Choi S, Halane MK, Zhou J, Solomon P, Kobe B, Jones JDG, Segonzac C, Sohn KH. Autoimmunity and effector recognition in Arabidopsis thaliana can be uncoupled by mutations in the RRS1-R immune receptor. THE NEW PHYTOLOGIST 2019; 222:954-965. [PMID: 30500990 DOI: 10.1111/nph.15617] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 11/23/2018] [Indexed: 05/13/2023]
Abstract
Plant nucleotide-binding leucine-rich repeat (NLR) disease resistance proteins recognize specific pathogen effectors and activate a cellular defense program. In Arabidopsis thaliana (Arabidopsis), Resistance to Ralstonia solanacearum 1 (RRS1-R) and Resistance to Pseudomonas syringae 4 (RPS4) function together to recognize the unrelated bacterial effectors PopP2 and AvrRps4. In the plant cell nucleus, the RRS1-R/RPS4 complex binds to and signals the presence of AvrRps4 or PopP2. The exact mechanism underlying NLR signaling and immunity activation remains to be elucidated. Using genetic and biochemical approaches, we characterized the intragenic suppressors of sensitive to low humidity 1 (slh1), a temperature-sensitive autoimmune allele of RRS1-R. Our analyses identified five amino acid residues that contribute to RRS1-RSLH1 autoactivity. We investigated the role of these residues in the RRS1-R allele by genetic complementation, and found that C15 in the Toll/interleukin-1 receptor (TIR) domain and L816 in the LRR domain were also important for effector recognition. Further characterization of the intragenic suppressive mutations located in the RRS1-R TIR domain revealed differing requirements for RRS1-R/RPS4-dependent autoimmunity and effector-triggered immunity. Our results provide novel information about the mechanisms which, in turn, hold an NLR protein complex inactive and allow adequate activation in the presence of pathogens.
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Affiliation(s)
- Toby E Newman
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, 37673, Republic of Korea
- Bioprotection Centre of Research Excellence, Institute of Agriculture and Environment, Massey University, Palmerston North, 4442, New Zealand
| | - Jungmin Lee
- School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, Pohang, 37673, Republic of Korea
| | - Simon J Williams
- Division of Plant Sciences, Research School of Biology, Australian National University, Acton, ACT, 2601, Australia
| | - Sera Choi
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, 37673, Republic of Korea
| | - Morgan K Halane
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, 37673, Republic of Korea
| | - Jun Zhou
- Bioprotection Centre of Research Excellence, Institute of Agriculture and Environment, Massey University, Palmerston North, 4442, New Zealand
| | - Peter Solomon
- Division of Plant Sciences, Research School of Biology, Australian National University, Acton, ACT, 2601, Australia
| | - Bostjan Kobe
- School of Chemistry and Molecular Biosciences, Institute for Molecular Bioscience and Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, Qld, 4072, Australia
| | | | - Cécile Segonzac
- Department of Plant Science, Plant Genomics and Breeding Institute and Research Institute of Agriculture and Life Sciences, College of Agriculture and Life Sciences, Seoul National University, Seoul, 08826, Republic of Korea
- Plant Immunity Research Center, College of Agriculture and Life Sciences, Seoul National University, Seoul, 08826, 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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Castel B, Ngou PM, Cevik V, Redkar A, Kim DS, Yang Y, Ding P, Jones JDG. Diverse NLR immune receptors activate defence via the RPW8-NLR NRG1. THE NEW PHYTOLOGIST 2019; 222:966-980. [PMID: 30582759 DOI: 10.1111/nph.15659] [Citation(s) in RCA: 153] [Impact Index Per Article: 30.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 12/13/2018] [Indexed: 05/09/2023]
Abstract
Most land plant genomes carry genes that encode RPW8-NLR Resistance (R) proteins. Angiosperms carry two RPW8-NLR subclasses: ADR1 and NRG1. ADR1s act as 'helper' NLRs for multiple TIR- and CC-NLR R proteins in Arabidopsis. In angiosperm families, NRG1 co-occurs with TIR-NLR Resistance (R) genes. We tested whether NRG1 is required for signalling of multiple TIR-NLRs. Using CRISPR mutagenesis, we obtained an nrg1a-nrg1b double mutant in two Arabidopsis accessions, and an nrg1 mutant in Nicotiana benthamiana. These mutants are compromised in signalling of all TIR-NLRs tested, including WRR4A, WRR4B, RPP1, RPP2, RPP4 and the pairs RRS1/RPS4, RRS1B/RPS4B, CHS1/SOC3 and CHS3/CSA1. In Arabidopsis, NRG1 is required for the hypersensitive cell death response (HR) and full oomycete resistance, but not for salicylic acid induction or bacterial resistance. By contrast, nrg1 loss of function does not compromise the CC-NLR R proteins RPS5 and MLA. RPM1 and RPS2 (CC-NLRs) function is slightly compromised in an nrg1 mutant. Thus, NRG1 is required for full TIR-NLR function and contributes to the signalling of some CC-NLRs. Some NRG1-dependent R proteins also signal partially via the NRG1 sister clade, ADR1. We propose that some NLRs signal via NRG1 only, some via ADR1 only and some via both or neither.
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Affiliation(s)
- Baptiste Castel
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Colney Lane, Norwich, NR4 7UH, UK
| | - Pok-Man Ngou
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Colney Lane, Norwich, NR4 7UH, UK
| | - Volkan Cevik
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Colney Lane, Norwich, NR4 7UH, UK
- The Milner Centre for Evolution, Department of Biology and Biochemistry, University of Bath, Bath, BA2 7AY, UK
| | - Amey Redkar
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Colney Lane, Norwich, NR4 7UH, UK
- Department of Genetics, University of Córdoba, Córdoba, 14071, Spain
| | - Dae-Sung Kim
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Colney Lane, Norwich, NR4 7UH, UK
- Department of Plant Sciences, College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Ying Yang
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Colney Lane, Norwich, NR4 7UH, UK
- Center for Plant Science Innovation, Beadle Center, University of Lincoln-Nebraska, Lincoln, NE, 68588, USA
| | - Pingtao Ding
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Colney Lane, Norwich, NR4 7UH, UK
| | - Jonathan D G Jones
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Colney Lane, Norwich, NR4 7UH, UK
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Hausner J, Jordan M, Otten C, Marillonnet S, Büttner D. Modular Cloning of the Type III Secretion Gene Cluster from the Plant-Pathogenic Bacterium Xanthomonas euvesicatoria. ACS Synth Biol 2019; 8:532-547. [PMID: 30694661 DOI: 10.1021/acssynbio.8b00434] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Type III secretion (T3S) systems are essential pathogenicity factors of most Gram-negative bacteria and translocate effector proteins into plant or animal cells. T3S systems can, therefore, be used as tools for protein delivery into eukaryotic cells, for instance after transfer of the T3S gene cluster into nonpathogenic recipient strains. Here, we report the modular cloning of the T3S gene cluster from the plant-pathogenic bacterium Xanthomonas euvesicatoria. The resulting multigene construct encoded a functional T3S system and delivered effector proteins into plant cells. The modular design of the T3S gene cluster allowed the efficient replacement and rearrangement of single genes or operons and the insertion of reporter genes for functional studies. In the present study, we used the modular T3S system to analyze the assembly of a fluorescent fusion of the predicted cytoplasmic ring protein HrcQ. Our studies demonstrate the use of the modular T3S gene cluster for functional analyses and mutant approaches in X. euvesicatoria. A potential application of the modular T3S system as protein delivery tool is discussed.
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Affiliation(s)
- Jens Hausner
- Institute of Biology, Department of Genetics, Martin Luther University Halle-Wittenberg, Weinbergweg 10, 06120 Halle, Saale, Germany
| | - Michael Jordan
- Institute of Biology, Department of Genetics, Martin Luther University Halle-Wittenberg, Weinbergweg 10, 06120 Halle, Saale, Germany
| | - Christian Otten
- Institute of Biology, Department of Genetics, Martin Luther University Halle-Wittenberg, Weinbergweg 10, 06120 Halle, Saale, Germany
| | | | - Daniela Büttner
- Institute of Biology, Department of Genetics, Martin Luther University Halle-Wittenberg, Weinbergweg 10, 06120 Halle, Saale, Germany
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Saur IML, Bauer S, Lu X, Schulze-Lefert P. A cell death assay in barley and wheat protoplasts for identification and validation of matching pathogen AVR effector and plant NLR immune receptors. PLANT METHODS 2019; 15:118. [PMID: 31666804 PMCID: PMC6813131 DOI: 10.1186/s13007-019-0502-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Accepted: 10/14/2019] [Indexed: 05/08/2023]
Abstract
BACKGROUND Plant disease resistance to host-adapted pathogens is often mediated by host nucleotide-binding and leucine-rich repeat (NLR) receptors that detect matching pathogen avirulence effectors (AVR) inside plant cells. AVR-triggered NLR activation is typically associated with a rapid host cell death at sites of attempted infection and this response constitutes a widely used surrogate for NLR activation. However, it is challenging to assess this cell death in cereal hosts. RESULTS Here we quantify cell death upon NLR-mediated recognition of fungal pathogen AVRs in mesophyll leaf protoplasts of barley and wheat. We provide measurements for the recognition of the fungal AVRs AvrSr50 and AVR a1 by their respective cereal NLRs Sr50 and Mla1 upon overexpression of the AVR and NLR pairs in mesophyll protoplast of both, wheat and barley. CONCLUSIONS Our data demonstrate that the here described approach can be effectively used to detect and quantify death of wheat and barley cells induced by overexpression of NLR and AVR effectors or AVR effector candidate genes from diverse fungal pathogens within 24 h.
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Affiliation(s)
- Isabel M. L. Saur
- Department of Plant-Microbe Interactions, Max Planck Institute for Plant Breeding Research, 50829 Cologne, Germany
| | - Saskia Bauer
- Department of Plant-Microbe Interactions, Max Planck Institute for Plant Breeding Research, 50829 Cologne, Germany
| | - Xunli Lu
- Department of Plant-Microbe Interactions, Max Planck Institute for Plant Breeding Research, 50829 Cologne, Germany
- Present Address: Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing, 100193 China
| | - Paul Schulze-Lefert
- Department of Plant-Microbe Interactions, Max Planck Institute for Plant Breeding Research, 50829 Cologne, Germany
- Cluster of Excellence on Plant Sciences, 40225 Düsseldorf, Germany
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Qi M, Mei Y, Grayczyk JP, Darben LM, Rieker MEG, Seitz JM, Voegele RT, Whitham SA, Link TI. Candidate Effectors From Uromyces appendiculatus, the Causal Agent of Rust on Common Bean, Can Be Discriminated Based on Suppression of Immune Responses. FRONTIERS IN PLANT SCIENCE 2019; 10:1182. [PMID: 31636645 PMCID: PMC6787271 DOI: 10.3389/fpls.2019.01182] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Accepted: 08/29/2019] [Indexed: 05/07/2023]
Abstract
Rust fungi are devastating pathogens for several important crop plants. The biotrophic lifestyle of rust fungi requires that they influence their host plants to create a favorable environment for growth and reproduction. Rust fungi secrete a variety of effector proteins that manipulate host target proteins to alter plant metabolism and suppress defense responses. Because of the obligate biotrophic lifestyle of rust fungi, direct evidence for effector function is difficult to obtain, and so suites of experiments utilizing expression in heterologous systems are necessary. Here, we present results from a yeast cell death suppression assay and assays for suppression of PAMP-triggered immunity (PTI) and effector triggered immunity (ETI) based on delivery of effectors through the bacterial type III secretion system. In addition, subcellular localization was tested using transient expression of GFP fusion proteins in Nicotiana benthamiana through Agrobacterium infiltration. We tested 31 representative effector candidates from the devastating common bean rust pathogen Uromyces appendiculatus. These effector candidates were selected based on features of their gene families, most important lineage specificity. We show that several of our effector candidates suppress plant defense. Some of them also belong to families of effector candidates that are present in multiple rust species where their homologs probably also have effector functions. In our analysis of candidate effector mRNA expression, some of those effector candidates that gave positive results in the other assays were not up-regulated during plant infection, indicating that either these proteins have functions at multiple life stages or that strong up-regulation of RNA level in planta may not be as important a criterion for identifying effectors as previously thought. Overall, our pipeline for selecting effector candidates based on sequence features followed by screening assays using heterologous expression systems was successful in discriminating effector candidates. This work lays the foundation for functional characterization of U. appendiculatus effectors, the identification of effector targets, and identification of novel sources for resistance in common bean.
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Affiliation(s)
- Mingsheng Qi
- Department of Plant Pathology and Microbiology, Iowa State University, Ames, IA, United States
| | - Yu Mei
- Department of Plant Pathology and Microbiology, Iowa State University, Ames, IA, United States
| | - James P. Grayczyk
- Department of Plant Pathology and Microbiology, Iowa State University, Ames, IA, United States
| | | | | | - Janina M. Seitz
- Institut für Phytomedizin, Universität Hohenheim, Stuttgart, Germany
| | - Ralf T. Voegele
- Institut für Phytomedizin, Universität Hohenheim, Stuttgart, Germany
| | - Steven A. Whitham
- Department of Plant Pathology and Microbiology, Iowa State University, Ames, IA, United States
| | - Tobias I. Link
- Institut für Phytomedizin, Universität Hohenheim, Stuttgart, Germany
- *Correspondence: Tobias Link,
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Jayaraman J, Halane MK, Choi S, McCann HC, Sohn KH. Using Bioinformatics and Molecular Biology to Streamline Construction of Effector Libraries for Phytopathogenic Pseudomonas syringae Strains. Methods Mol Biol 2019; 1991:1-12. [PMID: 31041757 DOI: 10.1007/978-1-4939-9458-8_1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The war between plants and their pathogens is endless, with plant resistance genes offering protection against pathogens until the pathogen evolves a way to overcome this resistance. Given how quickly new pathogen strains can arise and defeat plant defenses, it is critical to more rapidly identify and examine the specific genomic characteristics new virulent strains have gained which give them the upper hand. An indispensable tool is bioinformatics. Genome sequencing has advanced rapidly in the last decade, and labs are frequently uploading high-quality genomes of various organisms, including plant pathogenic bacteria such as Pseudomonas syringae. Pseudomonas syringae strains inject several effector proteins into host cells which often overcome host defenses. Probing online genomes provides a way to quickly and accurately predict effector repertoires of Pseudomonas, enabling the cloning of complete effector libraries of newly emerged strains. Here, we describe detailed protocols to rapidly clone bioinformatically predicted P. syringae effectors for various screening applications.
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Affiliation(s)
- Jay Jayaraman
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Republic of Korea
- The New Zealand Institute for Plant & Food Research Ltd, Auckland, New Zealand
| | - Morgan K Halane
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Republic of Korea
| | - Sera Choi
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Republic of Korea
| | - Honour C McCann
- New Zealand Institute for Advanced Study, Massey University, Auckland, New Zealand
| | - Kee Hoon Sohn
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Republic of Korea.
- School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, Pohang, Republic of Korea.
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Abstract
Bacterial pathogens cause plant diseases that threaten the global food supply. To control diseases, it is important to understand how pathogenic bacteria evade plant defense and promote infection. We identify from the phytopathogen Pseudomonas syringae a small-molecule virulence factor—phevamine A. Both the chemical structure and mode of action of phevamine A are different from known bacterial phytotoxins. Phevamine A promotes bacterial growth by suppressing plant immune responses, including both early (the generation of reactive oxygen species) and late (the deposition of cell wall reinforcing callose in leaves and leaf cell death) markers. This work uncovers a widely distributed, small-molecule virulence factor and shows the power of a multidisciplinary approach to identify small molecules important for plant infection. Bacterial plant pathogens cause significant crop damage worldwide. They invade plant cells by producing a variety of virulence factors, including small-molecule toxins and phytohormone mimics. Virulence of the model pathogen Pseudomonas syringae pv. tomato DC3000 (Pto) is regulated in part by the sigma factor HrpL. Our study of the HrpL regulon identified an uncharacterized, three-gene operon in Pto that is controlled by HrpL and related to the Erwinia hrp-associated systemic virulence (hsv) operon. Here, we demonstrate that the hsv operon contributes to the virulence of Pto on Arabidopsis thaliana and suppresses bacteria-induced immune responses. We show that the hsv-encoded enzymes in Pto synthesize a small molecule, phevamine A. This molecule consists of l-phenylalanine, l-valine, and a modified spermidine, and is different from known small molecules produced by phytopathogens. We show that phevamine A suppresses a potentiation effect of spermidine and l-arginine on the reactive oxygen species burst generated upon recognition of bacterial flagellin. The hsv operon is found in the genomes of divergent bacterial genera, including ∼37% of P. syringae genomes, suggesting that phevamine A is a widely distributed virulence factor in phytopathogens. Our work identifies a small-molecule virulence factor and reveals a mechanism by which bacterial pathogens overcome plant defense. This work highlights the power of omics approaches in identifying important small molecules in bacteria–host interactions.
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Chen W, Zhang Y, Zhang Y, Pi Y, Gu T, Song L, Wang Y, Ji Q. CRISPR/Cas9-based Genome Editing in Pseudomonas aeruginosa and Cytidine Deaminase-Mediated Base Editing in Pseudomonas Species. iScience 2018; 6:222-231. [PMID: 30240613 PMCID: PMC6137401 DOI: 10.1016/j.isci.2018.07.024] [Citation(s) in RCA: 107] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Revised: 07/17/2018] [Accepted: 07/26/2018] [Indexed: 12/13/2022] Open
Abstract
Pseudomonas species are a large class of gram-negative bacteria that exhibit significant biomedical, ecological, and industrial importance. Despite the extensive research and wide applications, genetic manipulation in Pseudomonas species, in particular in the major human pathogen Pseudomonas aeruginosa, remains a laborious endeavor. Here we report the development of a genome editing method pCasPA/pACRISPR by harnessing the CRISPR/Cas9 and the phage λ-Red recombination systems. The method allows for efficient and scarless genetic manipulation in P. aeruginosa. By engineering the fusion of the cytidine deaminase APOBEC1 and the Cas9 nickase, we further develop a base editing system pnCasPA-BEC, which enables highly efficient gene inactivation and point mutations in a variety of Pseudomonas species, such as P. aeruginosa, Pseudomonas putida, Pseudomonas fluorescens, and Pseudomonas syringae. Application of the two genome editing methods will dramatically accelerate a wide variety of investigations, such as bacterial physiology study, drug target exploration, and metabolic engineering.
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Affiliation(s)
- Weizhong Chen
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Ya Zhang
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Yifei Zhang
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Yishuang Pi
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Tongnian Gu
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Liqiang Song
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Yu Wang
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Quanjiang Ji
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China.
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