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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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Rogers A, Jaiswal N, Roggenkamp E, Kim HS, MacCready JS, Chilvers MI, Scofield SR, Iyer-Pascuzzi AS, Helm M. Genome-Informed Trophic Classification and Functional Characterization of Virulence Proteins from the Maize Tar Spot Pathogen Phyllachora maydis. PHYTOPATHOLOGY 2024; 114:1940-1949. [PMID: 38717940 DOI: 10.1094/phyto-01-24-0037-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: 08/22/2024]
Abstract
Phyllachora maydis is an ascomycete foliar fungal pathogen and the causal agent of tar spot in maize. Although P. maydis is considered an economically important foliar pathogen of maize, our general knowledge of the trophic lifestyle and functional role of effector proteins from this fungal pathogen remains limited. Here, we utilized a genome-informed approach to predict the trophic lifestyle of P. maydis and functionally characterized a subset of candidate effectors from this fungal pathogen. Leveraging the most recent P. maydis genome annotation and the CATAStrophy pipeline, we show that this fungal pathogen encodes a predicted carbohydrate-active enzymes (CAZymes) repertoire consistent with that of biotrophs. To investigate fungal pathogenicity, we selected 18 candidate effector proteins that were previously shown to be expressed during primary disease development. We assessed whether these putative effectors share predicted structural similarity with other characterized fungal effectors and determined whether any suppress plant immune responses. Using AlphaFold2 and Foldseek, we showed that one candidate effector, PM02_g1115, adopts a predicted protein structure similar to that of an effector from Verticillium dahlia. Furthermore, transient expression of candidate effector-fluorescent protein fusions in Nicotiana benthamiana revealed two putative effectors, PM02_g378 and PM02_g2610, accumulated predominantly in the cytosol, and three candidate effectors, PM02_g1115, PM02_g7882, and PM02_g8240, consistently attenuated chitin-mediated reactive oxygen species production. Collectively, the results presented herein provide insights into the predicted trophic lifestyle and putative functions of effectors from P. maydis and will likely stimulate continued research to elucidate the molecular mechanisms used by P. maydis to induce tar spot.
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Affiliation(s)
- Abigail Rogers
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907
| | - Namrata Jaiswal
- Crop Production and Pest Control Research Unit, U.S. Department of Agriculture-Agricultural Research Service, West Lafayette, IN 47907
| | - Emily Roggenkamp
- Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, MI 48824
| | - Hye-Seon Kim
- U.S. Department of Agriculture-Agricultural Research Service, National Center for Agricultural Utilization Research, Mycotoxin Prevention and Applied Microbiology Research Unit, Peoria, IL 61604
| | - Joshua S MacCready
- Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, MI 48824
| | - Martin I Chilvers
- Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, MI 48824
| | - Steven R Scofield
- Crop Production and Pest Control Research Unit, U.S. Department of Agriculture-Agricultural Research Service, West Lafayette, IN 47907
| | | | - Matthew Helm
- Crop Production and Pest Control Research Unit, U.S. Department of Agriculture-Agricultural Research Service, West Lafayette, IN 47907
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Kim DS, Li Y, Ahn HK, Woods-Tör A, Cevik V, Furzer OJ, Ma W, Tör M, Jones JDG. ATR2 C ala2 from Arabidopsis-infecting downy mildew requires 4 TIR-NLR immune receptors for full recognition. THE NEW PHYTOLOGIST 2024; 243:330-344. [PMID: 38742296 DOI: 10.1111/nph.19790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Accepted: 04/17/2024] [Indexed: 05/16/2024]
Abstract
Arabidopsis Col-0 RPP2A and RPP2B confer recognition of Arabidopsis downy mildew (Hyaloperonospora arabidopsidis [Hpa]) isolate Cala2, but the identity of the recognized ATR2Cala2 effector was unknown. To reveal ATR2Cala2, an F2 population was generated from a cross between Hpa-Cala2 and Hpa-Noks1. We identified ATR2Cala2 as a non-canonical RxLR-type effector that carries a signal peptide, a dEER motif, and WY domains but no RxLR motif. Recognition of ATR2Cala2 and its effector function were verified by biolistic bombardment, ectopic expression and Hpa infection. ATR2Cala2 is recognized in accession Col-0 but not in Ler-0 in which RPP2A and RPP2B are absent. In ATR2Emoy2 and ATR2Noks1 alleles, a frameshift results in an early stop codon. RPP2A and RPP2B are essential for the recognition of ATR2Cala2. Stable and transient expression of ATR2Cala2 under 35S promoter in Arabidopsis and Nicotiana benthamiana enhances disease susceptibility. Two additional Col-0 TIR-NLR (TNL) genes (RPP2C and RPP2D) adjacent to RPP2A and RPP2B are quantitatively required for full resistance to Hpa-Cala2. We compared RPP2 haplotypes in multiple Arabidopsis accessions and showed that all four genes are present in all ATR2Cala2-recognizing accessions.
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Affiliation(s)
- Dae Sung Kim
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei University, Wuhan, 430062, China
- The Sainsbury Laboratory, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Yufei Li
- The Sainsbury Laboratory, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Hee-Kyung Ahn
- The Sainsbury Laboratory, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Alison Woods-Tör
- Department of Biological Sciences, School of Science and the Environment, University of Worcester, Worcester, WR2 6AJ, UK
| | - Volkan Cevik
- Department of Life Sciences, The Milner Centre for Evolution, University of Bath, Bath, BA2 7AY, UK
| | - Oliver J Furzer
- The Sainsbury Laboratory, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Wenbo Ma
- The Sainsbury Laboratory, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Mahmut Tör
- Department of Biological Sciences, School of Science and the Environment, University of Worcester, Worcester, WR2 6AJ, UK
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Horton KN, Gassmann W. Greater than the sum of their parts: an overview of the AvrRps4 effector family. FRONTIERS IN PLANT SCIENCE 2024; 15:1400659. [PMID: 38799092 PMCID: PMC11116571 DOI: 10.3389/fpls.2024.1400659] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/14/2024] [Accepted: 04/26/2024] [Indexed: 05/29/2024]
Abstract
Phytopathogenic microbes use secreted effector proteins to increase their virulence in planta. If these effectors or the results of their activity are detected by the plant cell, the plant will mount an immune response which applies evolutionary pressure by reducing growth and success of the pathogen. Bacterial effector proteins in the AvrRps4 family (AvrRps4, HopK1, and XopO) have commonly been used as tools to investigate plant immune components. At the same time, the in planta functions of this family of effectors have yet to be fully characterized. In this minireview we summarize current knowledge about the AvrRps4 effector family with emphasis on properties of the proteins themselves. We hypothesize that the HopK1 C-terminus and the AvrRps4 C-terminus, though unrelated in sequence and structure, are broadly related in functions that counteract plant defense responses.
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Affiliation(s)
| | - Walter Gassmann
- Division of Plant Science and Technology, Bond Life Sciences Center, and Interdisciplinary Plant Group, University of Missouri, Columbia, MO, United States
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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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Liu C, Wang Y, Du Y, Kang Z, Guo J, Guo J. Glycine-serine-rich effector PstGSRE4 in Puccinia striiformis f. sp. tritici targets and stabilizes TaGAPDH2 that promotes stripe rust disease. PLANT, CELL & ENVIRONMENT 2024; 47:947-960. [PMID: 38105492 DOI: 10.1111/pce.14786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Revised: 12/01/2023] [Accepted: 12/04/2023] [Indexed: 12/19/2023]
Abstract
Puccinia striiformis f. sp. tritici (Pst) secretes effector proteins that enter plant cells and manipulate host processes. In a previous study, we identified a glycine-serine-rich effector PstGSRE4, which was proven to regulate the reactive oxygen species (ROS) pathway by interacting with TaCZSOD2. In this study, we further demonstrated that PstGSRE4 interacts with wheat glyceraldehyde-3-phosphate dehydrogenase TaGAPDH2, which is related to ROS signalling. In wheat, silencing of TaGAPDH2 by virus-induced gene silencing increased the accumulation of ROS induced by the Pst virulent race CYR31. Overexpression of TaGAPDH2 decreased the accumulation of ROS induced by the avirulent Pst race CYR23. In addition, TaGAPDH2 suppressed Pst candidate elicitor Pst322-triggered cell death by decreasing ROS accumulation in Nicotiana benthamiana. Knocking down TaGAPDH2 expression attenuated Pst infection, whereas overexpression of TaGAPDH2 promoted Pst infection, indicating that TaGAPDH2 is a negative regulator of plant defence. In N. benthamiana, PstGSRE4 stabilized TaGAPDH2 through inhibition of the 26S proteasome-mediated destabilization. Overall, these results suggest that TaGAPDH2 is hijacked by the Pst effector as a negative regulator of plant immunity to promote Pst infection in wheat.
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Affiliation(s)
- Cong Liu
- State Key Laboratory of Crop Stress Biology for Arid Areas, Key Laboratory of Plant Protection Resources and Pest Management of Ministry of Education, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China
| | - Yanfeng Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas, Key Laboratory of Plant Protection Resources and Pest Management of Ministry of Education, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China
| | - Yuanyuan Du
- State Key Laboratory of Crop Stress Biology for Arid Areas, Key Laboratory of Plant Protection Resources and Pest Management of Ministry of Education, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China
| | - Zhensheng Kang
- State Key Laboratory of Crop Stress Biology for Arid Areas, Key Laboratory of Plant Protection Resources and Pest Management of Ministry of Education, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China
| | - Jia Guo
- State Key Laboratory of Crop Stress Biology for Arid Areas, Key Laboratory of Plant Protection Resources and Pest Management of Ministry of Education, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China
| | - Jun Guo
- State Key Laboratory of Crop Stress Biology for Arid Areas, Key Laboratory of Plant Protection Resources and Pest Management of Ministry of Education, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China
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Kim W, Jeon H, Lee H, Sohn KH, Segonzac C. The Ralstonia pseudosolanacearum Type III Effector RipL Delays Flowering and Promotes Susceptibility to Pseudomonas syringae in Arabidopsis thaliana. Mol Cells 2023; 46:710-724. [PMID: 37968984 PMCID: PMC10654456 DOI: 10.14348/molcells.2023.0127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 09/20/2023] [Accepted: 09/24/2023] [Indexed: 11/17/2023] Open
Abstract
The plant defense responses to microbial infection are tightly regulated and integrated with the developmental program for optimal resources allocation. Notably, the defense- associated hormone salicylic acid (SA) acts as a promoter of flowering while several plant pathogens actively target the flowering signaling pathway to promote their virulence or dissemination. Ralstonia pseudosolanacearum inject tens of effectors in the host cells that collectively promote bacterial proliferation in plant tissues. Here, we characterized the function of the broadly conserved R. pseudosolanacearum effector RipL, through heterologous expression in Arabidopsis thaliana . RipL-expressing transgenic lines presented a delayed flowering, which correlated with a low expression of flowering regulator genes. Delayed flowering was also observed in Nicotiana benthamiana plants transiently expressing RipL. In parallel, RipL promoted plant susceptibility to virulent strains of Pseudomonas syringae in the effector-expressing lines or when delivered by the type III secretion system. Unexpectedly, SA accumulation and SA-dependent immune signaling were not significantly affected by RipL expression. Rather, the RNA-seq analysis of infected RipL-expressing lines revealed that the overall amplitude of the transcriptional response was dampened, suggesting that RipL could promote plant susceptibility in an SA-independent manner. Further elucidation of the molecular mechanisms underpinning RipL effect on flowering and immunity may reveal novel effector functions in host cells.
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Affiliation(s)
- Wanhui Kim
- Plant Immunity Research Center, Seoul National University, Seoul 08826, Korea
| | - Hyelim Jeon
- Plant Immunity Research Center, Seoul National University, Seoul 08826, Korea
- Department of Agriculture, Forestry and Bioresources, Seoul National University, Seoul 08826, Korea
| | - Hyeonjung Lee
- School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, Pohang 37673, Korea
| | - Kee Hoon Sohn
- Plant Immunity Research Center, Seoul National University, Seoul 08826, Korea
- School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, Pohang 37673, Korea
- Department of Agricultural Biotechnology, Seoul National University, Seoul 08826, Korea
- Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 08826, Korea
- Plant Genomics and Breeding Institute, Seoul National University, Seoul 08826, Korea
| | - Cécile Segonzac
- Plant Immunity Research Center, Seoul National University, Seoul 08826, Korea
- Department of Agriculture, Forestry and Bioresources, Seoul National University, Seoul 08826, Korea
- Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 08826, Korea
- Plant Genomics and Breeding Institute, Seoul National University, Seoul 08826, Korea
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8
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Kim B, Yu W, Kim H, Dong Q, Choi S, Prokchorchick M, Macho AP, Sohn KH, Segonzac C. A plasma membrane nucleotide-binding leucine-rich repeat receptor mediates the recognition of the Ralstonia pseudosolanacearum effector RipY in Nicotiana benthamiana. PLANT COMMUNICATIONS 2023; 4:100640. [PMID: 37349986 PMCID: PMC10721487 DOI: 10.1016/j.xplc.2023.100640] [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: 12/06/2022] [Revised: 06/01/2023] [Accepted: 06/18/2023] [Indexed: 06/24/2023]
Abstract
Bacterial wilt disease caused by several Ralstonia species is one of the most destructive diseases in Solanaceae crops. Only a few functional resistance genes against bacterial wilt have been cloned to date. Here, we show that the broadly conserved type III secreted effector RipY is recognized by the Nicotiana benthamiana immune system, leading to cell death induction, induction of defense-related gene expression, and restriction of bacterial pathogen growth. Using a multiplexed virus-induced gene-silencing-based N. benthamiana nucleotide-binding and leucine-rich repeat receptor (NbNLR) library, we identified a coiled-coil (CC) nucleotide-binding and leucine-rich repeat receptor (CNL) required for recognition of RipY, which we named RESISTANCE TO RALSTONIA SOLANACEARUM RIPY (RRS-Y). Genetic complementation assays in RRS-Y-silenced plants and stable rrs-y knockout mutants demonstrated that RRS-Y is sufficient to activate RipY-induced cell death and RipY-induced immunity to Ralstonia pseudosolanacearum. RRS-Y function is dependent on the phosphate-binding loop motif of the nucleotide-binding domain but independent of the characterized signaling components ENHANCED DISEASE SUSCEPTIBILITY 1, ACTIVATED DISEASE RESISTANCE 1, and N REQUIREMENT GENE 1 and the NLR helpers NB-LRR REQUIRED FOR HR-ASSOCIATED CELL DEATH-2, -3, and -4 in N. benthamiana. We further show that RRS-Y localization at the plasma membrane is mediated by two cysteine residues in the CC domain and is required for RipY recognition. RRS-Y also broadly recognizes RipY homologs across Ralstonia species. Lastly, we show that the C-terminal region of RipY is indispensable for RRS-Y activation. Together, our findings provide an additional effector/receptor pair system to deepen our understanding of CNL activation in plants.
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Affiliation(s)
- Boyoung Kim
- Department of Agriculture, Forestry and Bioresources, Seoul National University, Seoul 08826, Republic of Korea; Plant Immunity Research Center, Seoul National University, Seoul 08826, Republic of Korea
| | - Wenjia Yu
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 201602, China
| | - Haseong Kim
- Plant Immunity Research Center, Seoul National University, Seoul 08826, Republic of Korea; Department of Life Sciences, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
| | - Qian Dong
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 201602, China
| | - Sera Choi
- Department of Life Sciences, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
| | - Maxim Prokchorchick
- Department of Life Sciences, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
| | - Alberto P Macho
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 201602, China
| | - Kee Hoon Sohn
- Plant Immunity Research Center, Seoul National University, Seoul 08826, Republic of Korea; Department of Agricultural Biotechnology, Seoul National University, Seoul 08826, Republic of Korea
| | - Cécile Segonzac
- Department of Agriculture, Forestry and Bioresources, Seoul National University, Seoul 08826, Republic of Korea; Plant Immunity Research Center, Seoul National University, Seoul 08826, Republic of Korea; Plant Genomics and Breeding Institute, Seoul National University, Seoul 08826, Republic of Korea; Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 08826, Republic of Korea.
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Chen Y, Miao L, Li X, Liu Y, Xi D, Zhang D, Gao L, Zhu Y, Dai S, Zhu H. Comparative Transcriptome Analysis between Resistant and Susceptible Pakchoi Cultivars in Response to Downy Mildew. Int J Mol Sci 2023; 24:15710. [PMID: 37958694 PMCID: PMC10649052 DOI: 10.3390/ijms242115710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 10/09/2023] [Accepted: 10/27/2023] [Indexed: 11/15/2023] Open
Abstract
Downy mildew caused by the obligate parasite Hyaloperonospora brassicae is a devastating disease for Brassica species. Infection of Hyaloperonospora brassicae often leads to yellow spots on leaves, which significantly impacts quality and yield of pakchoi. In the present study, we conducted a comparative transcriptome between the resistant and susceptible pakchoi cultivars in response to Hyaloperonospora brassicae infection. A total of 1073 disease-resistance-related differentially expressed genes were identified using a Venn diagram. The Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses revealed that these genes were mainly involved in plant-pathogen interaction, plant hormone signal transduction, and other photosynthesis-related metabolic processes. Analysis of the phytohormone content revealed that salicylic acid increased significantly in the resistant material after inoculation with Hyaloperonospora brassicae, whereas the contents of jasmonic acid, abscisic acid, and 1-aminocyclopropane-1-carboxylic acid decreased. Exogenous salicylic acid treatment also significantly upregulated Hyaloperonospora brassicae-induced genes, which further confirmed a crucial role of salicylic acid during pakchoi defense against Hyaloperonospora brassicae. Based on these findings, we suggest that the salicylic-acid-mediated signal transduction contributes to the resistance of pakchoi to downy mildew, and PAL1, ICS1, NPR1, PR1, PR5, WRKY70, WRKY33, CML43, CNGC9, and CDPK15 were involved in this responsive process. Our findings evidently contribute to revealing the molecular mechanism of pakchoi defense against Hyaloperonospora brassicae.
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Affiliation(s)
- Yaosong Chen
- Shanghai Key Laboratory of Protected Horticultural Technology, Horticulture Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai 201403, China; (Y.C.)
- Development Center of Plant Germplasm Resources, College of Life Sciences, Shanghai Normal University, Shanghai 201418, China
| | - Liming Miao
- Shanghai Key Laboratory of Protected Horticultural Technology, Horticulture Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai 201403, China; (Y.C.)
| | - Xiaofeng Li
- Shanghai Key Laboratory of Protected Horticultural Technology, Horticulture Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai 201403, China; (Y.C.)
| | - Yiwen Liu
- Institute of Agricultural Science and Technology Information, Shanghai Academy of Agricultural Sciences, Shanghai 201403, China
| | - Dandan Xi
- Shanghai Key Laboratory of Protected Horticultural Technology, Horticulture Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai 201403, China; (Y.C.)
| | - Dingyu Zhang
- Shanghai Key Laboratory of Protected Horticultural Technology, Horticulture Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai 201403, China; (Y.C.)
| | - Lu Gao
- Shanghai Key Laboratory of Protected Horticultural Technology, Horticulture Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai 201403, China; (Y.C.)
| | - Yuying Zhu
- Shanghai Key Laboratory of Protected Horticultural Technology, Horticulture Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai 201403, China; (Y.C.)
| | - Shaojun Dai
- Development Center of Plant Germplasm Resources, College of Life Sciences, Shanghai Normal University, Shanghai 201418, China
| | - Hongfang Zhu
- Shanghai Key Laboratory of Protected Horticultural Technology, Horticulture Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai 201403, China; (Y.C.)
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10
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Fernandez J. The Phantom Menace: latest findings on effector biology in the rice blast fungus. ABIOTECH 2023; 4:140-154. [PMID: 37581025 PMCID: PMC10423181 DOI: 10.1007/s42994-023-00099-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Accepted: 02/11/2023] [Indexed: 08/16/2023]
Abstract
Magnaporthe oryzae is a hemibiotrophic fungus responsible for the economically devastating and recalcitrant rice blast disease. However, the blast fungus is not only restricted to rice plants as it can also infect wheat, millet, and other crops. Despite previous outstanding discoveries aimed to understand and control the disease, the fungus remains one of the most important pathogens that threatens global food security. To cause disease, M. oryzae initiates morphological changes to attach, penetrate, and colonize rice cells, all while suppressing plant immune defenses that would otherwise hinder its proliferation. As such, M. oryzae actively secretes a battery of small proteins called "effectors" to manipulate host machinery. In this review, we summarize the latest findings in effector identification, expression, regulation, and functionality. We review the most studied effectors and their roles in pathogenesis. Additionally, we discern the current methodologies to structurally catalog effectors, and we highlight the importance of climate change and its impact on the future of rice blast disease.
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Affiliation(s)
- Jessie Fernandez
- Department of Microbiology and Cell Science at University of Florida-Institute of Food and Agricultural Science, Gainesville, FL 32611 USA
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11
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Padilla-Roji I, Ruiz-Jiménez L, Bakhat N, Vielba-Fernández A, Pérez-García A, Fernández-Ortuño D. RNAi Technology: A New Path for the Research and Management of Obligate Biotrophic Phytopathogenic Fungi. Int J Mol Sci 2023; 24:ijms24109082. [PMID: 37240427 DOI: 10.3390/ijms24109082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 05/05/2023] [Accepted: 05/10/2023] [Indexed: 05/28/2023] Open
Abstract
Powdery mildew and rust fungi are major agricultural problems affecting many economically important crops and causing significant yield losses. These fungi are obligate biotrophic parasites that are completely dependent on their hosts for growth and reproduction. Biotrophy in these fungi is determined by the presence of haustoria, specialized fungal cells that are responsible for nutrient uptake and molecular dialogue with the host, a fact that undoubtedly complicates their study under laboratory conditions, especially in terms of genetic manipulation. RNA interference (RNAi) is the biological process of suppressing the expression of a target gene through double-stranded RNA that induces mRNA degradation. RNAi technology has revolutionized the study of these obligate biotrophic fungi by enabling the analysis of gene function in these fungal. More importantly, RNAi technology has opened new perspectives for the management of powdery mildew and rust diseases, first through the stable expression of RNAi constructs in transgenic plants and, more recently, through the non-transgenic approach called spray-induced gene silencing (SIGS). In this review, the impact of RNAi technology on the research and management of powdery mildew and rust fungi will be addressed.
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Affiliation(s)
- Isabel Padilla-Roji
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, 29071 Málaga, Spain
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Universidad de Málaga, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), 29071 Málaga, Spain
| | - Laura Ruiz-Jiménez
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, 29071 Málaga, Spain
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Universidad de Málaga, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), 29071 Málaga, Spain
| | - Nisrine Bakhat
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, 29071 Málaga, Spain
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Universidad de Málaga, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), 29071 Málaga, Spain
| | - Alejandra Vielba-Fernández
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, 29071 Málaga, Spain
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Universidad de Málaga, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), 29071 Málaga, Spain
| | - Alejandro Pérez-García
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, 29071 Málaga, Spain
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Universidad de Málaga, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), 29071 Málaga, Spain
| | - Dolores Fernández-Ortuño
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, 29071 Málaga, Spain
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Universidad de Málaga, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), 29071 Málaga, Spain
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12
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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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13
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Qi Y, Li J, Mapuranga J, Zhang N, Chang J, Shen Q, Zhang Y, Wei J, Cui L, Liu D, Yang W. Wheat leaf rust fungus effector Pt13024 is avirulent to TcLr30. FRONTIERS IN PLANT SCIENCE 2023; 13:1098549. [PMID: 36726676 PMCID: PMC9885084 DOI: 10.3389/fpls.2022.1098549] [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: 11/15/2022] [Accepted: 12/16/2022] [Indexed: 06/18/2023]
Abstract
Wheat leaf rust, caused by Puccinia triticina Eriks. (Pt), is a global wheat disease threatening wheat production. Dissecting how Pt effector proteins interact with wheat has great significance in understanding the pathogenicity mechanisms of Pt. In the study, the cDNA of Pt 13-5-72 interacting with susceptible cultivar Thatcher was used as template to amplify Pt13024 gene. The expression pattern and structure of Pt13024 were analyzed by qRT-PCR and online softwares. The secretion function of Pt13024 signal peptide was verified by the yeast system. Subcellular localization of Pt13024 was analyzed using transient expression on Nicotiana benthamiana. The verification that Pt13024 inhibited programmed cell death (PCD) was conducted on N. benthamiana and wheat. The deletion mutation of Pt13024 was used to identify the virulence function motif. The transient transformation of wheat mediated by the type III secretion system (TTSS) was used to analyze the activity of regulating the host defense response of Pt13024. Pt13024 gene silencing was performed by host-induced gene silencing (HIGS). The results showed that Pt13024 was identified as an effector and localized in the cytoplasm and nucleus on the N. benthamiana. It can inhibit PCD induced by the Bcl-2-associated X protein (BAX) from mice and infestans 1 (INF1) from Phytophthora infestans on N. benthamiana, and it can also inhibit PCD induced by DC3000 on wheat. The amino acids 22 to 41 at N-terminal of the Pt13024 are essential for the inhibition of programmed cell death (PCD) induced by BAX. The accumulation of reactive oxygen species and deposition of callose in near-isogenic line TcLr30, which is in Thatcher background with Lr30, induced by Pt13024 was higher than that in 41 wheat leaf rust-resistant near-isogenic lines (monogenic lines) with different resistance genes and Thatcher. Silencing of Pt13024 reduced the leaf rust resistance of Lr30 during the interaction between Pt and TcLr30. We can conclude that Pt13024 is avirulent to TcLr30 when Pt interacts with TcLr30. These findings lay the foundation for further investigations into the role of Pt effector proteins in pathogenesis and their regulatory mechanisms.
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Affiliation(s)
- Yue Qi
- Department of Plant Pathology, Agricultural University of Hebei/Technological Innovation Center for Biological Control of Plant Diseases and Insect Pests of Hebei Province/National Engineering Research Center for Agriculture in Northern Mountainous Areas, Baoding, China
- Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Jianyuan Li
- Department of Plant Pathology, Agricultural University of Hebei/Technological Innovation Center for Biological Control of Plant Diseases and Insect Pests of Hebei Province/National Engineering Research Center for Agriculture in Northern Mountainous Areas, Baoding, China
- College of Biological Sciences and Engineering, Xingtai University, Xingtai, China
| | - Johannes Mapuranga
- Department of Plant Pathology, Agricultural University of Hebei/Technological Innovation Center for Biological Control of Plant Diseases and Insect Pests of Hebei Province/National Engineering Research Center for Agriculture in Northern Mountainous Areas, Baoding, China
| | - Na Zhang
- Department of Plant Pathology, Agricultural University of Hebei/Technological Innovation Center for Biological Control of Plant Diseases and Insect Pests of Hebei Province/National Engineering Research Center for Agriculture in Northern Mountainous Areas, Baoding, China
| | - Jiaying Chang
- Department of Plant Pathology, Agricultural University of Hebei/Technological Innovation Center for Biological Control of Plant Diseases and Insect Pests of Hebei Province/National Engineering Research Center for Agriculture in Northern Mountainous Areas, Baoding, China
| | - Qianhua Shen
- Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Yue Zhang
- Department of Plant Pathology, Agricultural University of Hebei/Technological Innovation Center for Biological Control of Plant Diseases and Insect Pests of Hebei Province/National Engineering Research Center for Agriculture in Northern Mountainous Areas, Baoding, China
- Dryland Farming Institute, Hebei Academy of Agricultural and Forestry Science, Hengshui, China
| | - Jie Wei
- Department of Plant Pathology, Agricultural University of Hebei/Technological Innovation Center for Biological Control of Plant Diseases and Insect Pests of Hebei Province/National Engineering Research Center for Agriculture in Northern Mountainous Areas, Baoding, China
- Department of Agriculture and Animal Husbandry Engineering, Cangzhou Technical College, Cangzhou, China
| | - Liping Cui
- Department of Plant Pathology, Agricultural University of Hebei/Technological Innovation Center for Biological Control of Plant Diseases and Insect Pests of Hebei Province/National Engineering Research Center for Agriculture in Northern Mountainous Areas, Baoding, China
| | - Daqun Liu
- Department of Plant Pathology, Agricultural University of Hebei/Technological Innovation Center for Biological Control of Plant Diseases and Insect Pests of Hebei Province/National Engineering Research Center for Agriculture in Northern Mountainous Areas, Baoding, China
| | - Wenxiang Yang
- Department of Plant Pathology, Agricultural University of Hebei/Technological Innovation Center for Biological Control of Plant Diseases and Insect Pests of Hebei Province/National Engineering Research Center for Agriculture in Northern Mountainous Areas, Baoding, China
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14
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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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15
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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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16
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Transcriptome analysis of mulberry (Morus alba L.) leaves to identify differentially expressed genes associated with post-harvest shelf-life elongation. Sci Rep 2022; 12:18195. [PMID: 36307466 PMCID: PMC9616847 DOI: 10.1038/s41598-022-21828-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 10/04/2022] [Indexed: 12/31/2022] Open
Abstract
Present study deals with molecular expression patterns responsible for post-harvest shelf-life extension of mulberry leaves. Quantitative profiling showed retention of primary metabolite and accumulation of stress markers in NS7 and CO7 respectively. The leaf mRNA profiles was sequenced using the Illumina platform to identify DEGs. A total of 3413 DEGs were identified between the treatments. Annotation with Arabidopsis database has identified 1022 DEGs unigenes. STRING generated protein-protein interaction, identified 1013 DEGs nodes with p < 1.0e-16. KEGG classifier has identified genes and their participating biological processes. MCODE and BiNGO detected sub-networking and ontological enrichment, respectively at p ≤ 0.05. Genes associated with chloroplast architecture, photosynthesis, detoxifying ROS and RCS, and innate-immune response were significantly up-regulated, responsible for extending shelf-life in NS7. Loss of storage sucrose, enhanced activity of senescence-related hormones, accumulation of xenobiotics, and development of osmotic stress inside tissue system was the probable reason for tissue deterioration in CO7. qPCR validation of DEGs was in good agreement with RNA sequencing results, indicating the reliability of the sequencing platform. Present outcome provides a molecular insight regarding involvement of genes in self-life extension, which might help the sericulture industry to overcome their pre-existing problems related to landless farmers and larval feeding during monsoon.
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17
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The molecular dialog between oomycete effectors and their plant and animal hosts. FUNGAL BIOL REV 2022. [DOI: 10.1016/j.fbr.2022.10.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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18
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Bueno TV, Fontes PP, Abe VY, Utiyama AS, Senra RL, Oliveira LS, Brombini Dos Santos A, Ferreira EGC, Darben LM, de Oliveira AB, Abdelnoor RV, Whitham SA, Fietto LG, Marcelino-Guimarães FC. A Phakopsora pachyrhizi Effector Suppresses PAMP-Triggered Immunity and Interacts with a Soybean Glucan Endo-1,3-β-Glucosidase to Promote Virulence. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2022; 35:779-790. [PMID: 35617509 DOI: 10.1094/mpmi-12-21-0301-r] [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] [Indexed: 06/15/2023]
Abstract
Asian soybean rust, caused by the fungus Phakopsora pachyrhizi, is one of the most important diseases affecting soybean production in tropical areas. During infection, P. pachyrhizi secretes proteins from haustoria that are transferred into plant cells to promote virulence. To date, only one candidate P. pachyrhizi effector protein has been characterized in detail to understand the mechanism by which it suppresses plant defenses to enhance infection. Here, we aimed to extend understanding of the pathogenic mechanisms of P. pachyrhizi based on the discovery of host proteins that interact with the effector candidate Phapa-7431740. We demonstrated that Phapa-7431740 suppresses pathogen-associated molecular pattern-triggered immunity (PTI) and that it interacts with a soybean glucan endo-1,3-β-glucosidase (GmβGLU), a pathogenesis-related (PR) protein belonging to the PR-2 family. Structural and phylogenetic characterization of the PR-2 protein family predicted in the soybean genome and comparison to PR-2 family members in Arabidopsis thaliana and cotton, demonstrated that GmβGLU is a type IV β-1,3-glucanase. Transcriptional profiling during an infection time course showed that the GmβGLU mRNA is highly induced during the initial hours after infection, coinciding with peak of expression of Phapa-7431740. The effector was able to interfere with the activity of GmβGLU in vitro, with a dose-dependent inhibition. Our results suggest that Phapa-7431740 may suppress PTI by interfering with glucan endo-1,3-β-glucosidase activity. [Formula: see text] The author(s) have dedicated the work to the public domain under the Creative Commons CC0 "No Rights Reserved" license by waiving all of his or her rights to the work worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law, 2022.
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Affiliation(s)
- Thays V Bueno
- Department of Agronomy, Federal University of Viçosa, Viçosa, Minas Gerais, CEP 36570-900, Brazil
| | - Patrícia P Fontes
- Department of Biochemistry and Molecular Biology, Federal University of Viçosa, Viçosa, Minas Gerais, CEP 36570-900, Brazil
| | - Valeria Y Abe
- Embrapa soja, Plant Biotechnology, Londrina, Paraná, CEP 70770-901, Brazil
| | - Alice Satiko Utiyama
- Department of Agronomy, Federal University of Viçosa, Viçosa, Minas Gerais, CEP 36570-900, Brazil
| | - Renato L Senra
- Department of Biochemistry and Molecular Biology, Federal University of Viçosa, Viçosa, Minas Gerais, CEP 36570-900, Brazil
| | - Liliane S Oliveira
- Embrapa soja, Plant Biotechnology, Londrina, Paraná, CEP 70770-901, Brazil
- Department of Computer Science, Federal University of Technology - Paraná (UTFPR), Cornélio Procópio, Paraná 86300-000, Brazil
| | | | | | | | | | | | - Steven A Whitham
- Department of Plant Pathology and Microbiology, Iowa State University, Ames, IA 50011, U.S.A
| | - Luciano G Fietto
- Department of Biochemistry and Molecular Biology, Federal University of Viçosa, Viçosa, Minas Gerais, CEP 36570-900, Brazil
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19
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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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20
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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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21
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Iswanto ABB, Vu MH, Pike S, Lee J, Kang H, Son GH, Kim J, Kim SH. Pathogen effectors: What do they do at plasmodesmata? MOLECULAR PLANT PATHOLOGY 2022; 23:795-804. [PMID: 34569687 PMCID: PMC9104267 DOI: 10.1111/mpp.13142] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 09/10/2021] [Accepted: 09/10/2021] [Indexed: 06/13/2023]
Abstract
Plants perceive an assortment of external cues during their life cycle, including abiotic and biotic stressors. Biotic stress from a variety of pathogens, including viruses, oomycetes, fungi, and bacteria, is considered to be a substantial factor hindering plant growth and development. To hijack the host cell's defence machinery, plant pathogens have evolved sophisticated attack strategies mediated by numerous effector proteins. Several studies have indicated that plasmodesmata (PD), symplasmic pores that facilitate cell-to-cell communication between a cell and neighbouring cells, are one of the targets of pathogen effectors. However, in contrast to plant-pathogenic viruses, reports of fungal- and bacterial-encoded effectors that localize to and exploit PD are limited. Surprisingly, a recent study of PD-associated bacterial effectors has shown that a number of bacterial effectors undergo cell-to-cell movement via PD. Here we summarize and highlight recent advances in the study of PD-associated fungal/oomycete/bacterial effectors. We also discuss how pathogen effectors interfere with host defence mechanisms in the context of PD regulation.
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Affiliation(s)
- Arya Bagus Boedi Iswanto
- Division of Applied Life Science (BK21 Four Program)Plant Molecular Biology and Biotechnology Research CenterGyeongsang National UniversityJinjuRepublic of Korea
| | - Minh Huy Vu
- Division of Applied Life Science (BK21 Four Program)Plant Molecular Biology and Biotechnology Research CenterGyeongsang National UniversityJinjuRepublic of Korea
| | - Sharon Pike
- Division of Plant SciencesChristopher S. Bond Life Sciences Center and Interdisciplinary Plant GroupUniversity of MissouriColumbiaMissouriUSA
| | - Jihyun Lee
- Division of Applied Life Science (BK21 Four Program)Plant Molecular Biology and Biotechnology Research CenterGyeongsang National UniversityJinjuRepublic of Korea
| | - Hobin Kang
- Division of Applied Life Science (BK21 Four Program)Plant Molecular Biology and Biotechnology Research CenterGyeongsang National UniversityJinjuRepublic of Korea
| | - Geon Hui Son
- Division of Applied Life Science (BK21 Four Program)Plant Molecular Biology and Biotechnology Research CenterGyeongsang National UniversityJinjuRepublic of Korea
| | - Jae‐Yean Kim
- Division of Applied Life Science (BK21 Four Program)Plant Molecular Biology and Biotechnology Research CenterGyeongsang National UniversityJinjuRepublic of Korea
- Division of Life ScienceGyeongsang National UniversityJinjuRepublic of Korea
| | - Sang Hee Kim
- Division of Applied Life Science (BK21 Four Program)Plant Molecular Biology and Biotechnology Research CenterGyeongsang National UniversityJinjuRepublic of Korea
- Division of Life ScienceGyeongsang National UniversityJinjuRepublic of Korea
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22
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Raman V, Rojas CM, Vasudevan B, Dunning K, Kolape J, Oh S, Yun J, Yang L, Li G, Pant BD, Jiang Q, Mysore KS. Agrobacterium expressing a type III secretion system delivers Pseudomonas effectors into plant cells to enhance transformation. Nat Commun 2022; 13:2581. [PMID: 35546550 PMCID: PMC9095702 DOI: 10.1038/s41467-022-30180-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 04/20/2022] [Indexed: 01/07/2023] Open
Abstract
Agrobacterium-mediated plant transformation (AMT) is the basis of modern-day plant biotechnology. One major drawback of this technology is the recalcitrance of many plant species/varieties to Agrobacterium infection, most likely caused by elicitation of plant defense responses. Here, we develop a strategy to increase AMT by engineering Agrobacterium tumefaciens to express a type III secretion system (T3SS) from Pseudomonas syringae and individually deliver the P. syringae effectors AvrPto, AvrPtoB, or HopAO1 to suppress host defense responses. Using the engineered Agrobacterium, we demonstrate increase in AMT of wheat, alfalfa and switchgrass by ~250%-400%. We also show that engineered A. tumefaciens expressing a T3SS can deliver a plant protein, histone H2A-1, to enhance AMT. This strategy is of great significance to both basic research and agricultural biotechnology for transient and stable transformation of recalcitrant plant species/varieties and to deliver proteins into plant cells in a non-transgenic manner.
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Affiliation(s)
- Vidhyavathi Raman
- Noble Research Institute, LLC, Ardmore, OK, 73401, USA
- Department of Plant and Microbial Biology, University of Minnesota, St. Paul, MN, 55108, USA
| | - Clemencia M Rojas
- Noble Research Institute, LLC, Ardmore, OK, 73401, USA
- Department of Entomology and Plant Pathology, University of Arkansas, Fayetteville, AR, 72701, USA
| | | | - Kevin Dunning
- Noble Research Institute, LLC, Ardmore, OK, 73401, USA
| | | | - Sunhee Oh
- Noble Research Institute, LLC, Ardmore, OK, 73401, USA
| | - Jianfei Yun
- Noble Research Institute, LLC, Ardmore, OK, 73401, USA
| | - Lishan Yang
- Noble Research Institute, LLC, Ardmore, OK, 73401, USA
| | - Guangming Li
- Noble Research Institute, LLC, Ardmore, OK, 73401, USA
| | - Bikram D Pant
- Noble Research Institute, LLC, Ardmore, OK, 73401, USA
- Institute for Agricultural Biosciences, Oklahoma State University, Ardmore, OK, 73401, USA
- Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK, 74078, USA
| | | | - Kirankumar S Mysore
- Noble Research Institute, LLC, Ardmore, OK, 73401, USA.
- Institute for Agricultural Biosciences, Oklahoma State University, Ardmore, OK, 73401, USA.
- Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK, 74078, USA.
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23
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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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24
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Microbial interaction mediated programmed cell death in plants. 3 Biotech 2022; 12:43. [PMID: 35096500 PMCID: PMC8761208 DOI: 10.1007/s13205-021-03099-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Accepted: 12/26/2021] [Indexed: 02/03/2023] Open
Abstract
Food demand of growing population can only be met by finding solutions for sustaining the crop yield. The understanding of basic mechanisms employed by microorganisms for the establishment of parasitic relationship with plants is a complex phenomenon. Symbionts and biotrophs are dependent on living hosts for completing their life cycle, whereas necrotrophs utilize dead cells for their growth and establishment. Hemibiotrophs as compared to other microbes associate themselves with plants in two phase's, viz. early bio-phase and later necro-phase. Plants and microbes interact with each other using receptors present on host cell surface and elicitors (PAMPs and effectors) produced by microbes. Plant-microbe interaction either leads to compatible or incompatible reaction. In response to various biotic and abiotic stress factors, plant undergoes programmed cell death which restricts the growth of biotrophs or hemibiotrophs while necrotrophs as an opportunist starts growing on dead tissue for their own benefit. PCD regulation is an outcome of plant-microbe crosstalk which entirely depends on various biochemical events like generation of reactive oxygen species, nitric oxide, ionic efflux/influx, CLPs, biosynthesis of phytohormones, phytoalexins, polyamines and certain pathogenesis-related proteins. This phenomenon mostly occurs in resistant and non-host plants during invasion of pathogenic microbes. The compatible or incompatible host-pathogen interaction depends upon the presence or absence of host plant resistance and pathogenic race. In addition to host-pathogen interaction, the defense induction by beneficial microbes must also be explored and used to the best of its potential. This review highlights the mechanism of microbe- or symbiont-mediated PCD along with defense induction in plants towards symbionts, biotrophs, necrotrophs and hemibiotrophs. Here we have also discussed the possible use of beneficial microbes in inducing systemic resistance in plants against pathogenic microbes.
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25
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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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26
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Tsushima A, Narusaka M, Gan P, Kumakura N, Hiroyama R, Kato N, Takahashi S, Takano Y, Narusaka Y, Shirasu K. The Conserved Colletotrichum spp. Effector Candidate CEC3 Induces Nuclear Expansion and Cell Death in Plants. Front Microbiol 2021; 12:682155. [PMID: 34539598 PMCID: PMC8446390 DOI: 10.3389/fmicb.2021.682155] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 08/11/2021] [Indexed: 01/25/2023] Open
Abstract
Plant pathogens secrete proteins, known as effectors, that promote infection by manipulating host cells. Members of the phytopathogenic fungal genus Colletotrichum collectively have a broad host range and generally adopt a hemibiotrophic lifestyle that includes an initial biotrophic phase and a later necrotrophic phase. We hypothesized that Colletotrichum fungi use a set of conserved effectors during infection to support the two phases of their hemibiotrophic lifestyle. This study aimed to examine this hypothesis by identifying and characterizing conserved effectors among Colletotrichum fungi. Comparative genomic analyses using genomes of ascomycete fungi with different lifestyles identified seven effector candidates that are conserved across the genus Colletotrichum. Transient expression assays showed that one of these putative conserved effectors, CEC3, induces nuclear expansion and cell death in Nicotiana benthamiana, suggesting that CEC3 is involved in promoting host cell death during infection. Nuclear expansion and cell death induction were commonly observed in CEC3 homologs from four different Colletotrichum species that vary in host specificity. Thus, CEC3 proteins could represent a novel class of core effectors with functional conservation in the genus Colletotrichum.
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Affiliation(s)
- Ayako Tsushima
- Graduate School of Science, The University of Tokyo, Bunkyo, Japan
- Center for Sustainable Resource Science, RIKEN, Yokohama, Japan
| | - Mari Narusaka
- Research Institute for Biological Sciences Okayama, Kaga-gun, Japan
| | - Pamela Gan
- Center for Sustainable Resource Science, RIKEN, Yokohama, Japan
| | | | - Ryoko Hiroyama
- Center for Sustainable Resource Science, RIKEN, Yokohama, Japan
| | - Naoki Kato
- Center for Sustainable Resource Science, RIKEN, Wako, Japan
| | | | | | | | - Ken Shirasu
- Graduate School of Science, The University of Tokyo, Bunkyo, Japan
- Center for Sustainable Resource Science, RIKEN, Yokohama, Japan
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27
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Wang Y, Zhao A, Morcillo RJL, Yu G, Xue H, Rufian JS, Sang Y, Macho AP. A bacterial effector protein uncovers a plant metabolic pathway involved in tolerance to bacterial wilt disease. MOLECULAR PLANT 2021; 14:1281-1296. [PMID: 33940211 DOI: 10.1016/j.molp.2021.04.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Revised: 03/15/2021] [Accepted: 04/28/2021] [Indexed: 05/27/2023]
Abstract
Bacterial wilt caused by the soil-borne plant pathogen Ralstonia solanacearum is a devastating disease worldwide. Upon plant colonization, R. solanacearum replicates massively, causing plant wilting and death; collapsed infected tissues then serve as a source of inoculum. In this work, we show that the plant metabolic pathway mediated by pyruvate decarboxylases (PDCs) contributes to plant tolerance to bacterial wilt disease. Arabidopsis and tomato plants respond to R. solanacearum infection by increasing PDC activity, and plants with deficient PDC activity are more susceptible to bacterial wilt. Treatment with either pyruvic acid or acetic acid (substrate and product of the PDC pathway, respectively) enhances plant tolerance to bacterial wilt disease. An effector protein secreted by R. solanacearum, RipAK, interacts with PDCs and inhibits their oligomerization and enzymatic activity. Collectively, our work reveals a metabolic pathway involved in plant resistance to biotic and abiotic stresses, and a bacterial virulence strategy to promote disease and the completion of the pathogenic life cycle.
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Affiliation(s)
- Yaru Wang
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences; Chinese Academy of Sciences, Shanghai 201602, China; University of Chinese Academy of Sciences, Beijing, China
| | - Achen Zhao
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences; Chinese Academy of Sciences, Shanghai 201602, China; University of Chinese Academy of Sciences, Beijing, China
| | - Rafael J L Morcillo
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences; Chinese Academy of Sciences, Shanghai 201602, China
| | - Gang Yu
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences; Chinese Academy of Sciences, Shanghai 201602, China
| | - Hao Xue
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences; Chinese Academy of Sciences, Shanghai 201602, China; University of Chinese Academy of Sciences, Beijing, China
| | - Jose S Rufian
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences; Chinese Academy of Sciences, Shanghai 201602, China
| | - Yuying Sang
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences; Chinese Academy of Sciences, Shanghai 201602, China
| | - Alberto P Macho
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences; Chinese Academy of Sciences, Shanghai 201602, China.
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28
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Sharma S, Sundaresha S, Bhardwaj V. Biotechnological approaches in management of oomycetes diseases. 3 Biotech 2021; 11:274. [PMID: 34040923 DOI: 10.1007/s13205-021-02810-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 04/24/2021] [Indexed: 11/26/2022] Open
Abstract
Plant pathogenic oomycetes cause significant impact on agriculture and, therefore, their management is utmost important. Though conventional methods to combat these pathogens (resistance breeding and use of fungicides) are available but these are limited by the availability of resistant cultivars due to evolution of new pathogenic races, development of resistance in the pathogens against agrochemicals and their potential hazardous effects on the environment and human health. This has fuelled a continual search for novel and alternate strategies for management of phytopathogens. The recent advances in oomycetes genome (Phytophthora infestans, P. ramorum, P. sojae, Pythium ultimum, Albugo candida etc.) would further help in understanding host-pathogen interactions essentially needed for designing effective management strategies. In the present communication the novel and alternate strategies for the management of oomycetes diseases are discussed.
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Affiliation(s)
- Sanjeev Sharma
- ICAR-Central Potato Research Institute, Shimla, Himachal Pradesh 171001 India
| | - S Sundaresha
- ICAR-Central Potato Research Institute, Shimla, Himachal Pradesh 171001 India
| | - Vinay Bhardwaj
- ICAR-Central Potato Research Institute, Shimla, Himachal Pradesh 171001 India
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29
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Effectors of Puccinia striiformis f. sp. tritici Suppressing the Pathogenic-Associated Molecular Pattern-Triggered Immune Response Were Screened by Transient Expression of Wheat Protoplasts. Int J Mol Sci 2021; 22:ijms22094985. [PMID: 34067160 PMCID: PMC8125866 DOI: 10.3390/ijms22094985] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 04/29/2021] [Accepted: 05/03/2021] [Indexed: 11/17/2022] Open
Abstract
Puccinia striiformis f. sp. tritici (Pst) is an important pathogen of wheat (Triticum aestivum L.) stripe rust, and the effector protein secreted by haustoria is a very important component involved in the pathogenic process. Although the candidate effector proteins secreted by Pst haustoria have been predicted to be abundant, few have been functionally validated. Our study confirmed that chitin and flg22 could be used as elicitors of the pathogenic-associated molecular pattern-triggered immune (PTI) reaction in wheat leaves and that TaPr-1-14 could be used as a marker gene to detect the PTI reaction. In addition, the experimental results were consistent in wheat protoplasts. A rapid and efficient method for screening and identifying the effector proteins of Pst was established by using the wheat protoplast transient expression system. Thirty-nine Pst haustorial effector genes were successfully cloned and screened for expression in the protoplast. We identified three haustorial effector proteins, PSEC2, PSEC17, and PSEC45, that may inhibit the response of wheat to PTI. These proteins are localized in the somatic cytoplasm and nucleus of wheat protoplasts and are highly expressed during the infection and parasitism of wheat.
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30
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Chen S, Ma T, Song S, Li X, Fu P, Wu W, Liu J, Gao Y, Ye W, Dry IB, Lu J. Arabidopsis downy mildew effector HaRxLL470 suppresses plant immunity by attenuating the DNA-binding activity of bZIP transcription factor HY5. THE NEW PHYTOLOGIST 2021; 230:1562-1577. [PMID: 33586184 DOI: 10.1111/nph.17280] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Accepted: 02/01/2021] [Indexed: 05/27/2023]
Abstract
The oomycete pathogen Hyaloperonospora arabidopsidis delivers diverse effector proteins into host plant cells to suppress the plant's innate immunity. In this study, we investigate the mechanism of action of a conserved RxLR effector, HaRxLL470, in suppressing plant immunity. Genomic, molecular and biochemical analyses were performed to investigate the function of HaRxLL470 and the mechanism of the interaction between HaRxLL470 and the target host protein during H. arabidopsidis infection. We report that HaRxLL470 enhances plant susceptibility to H. arabidopsidis isolate Noco2 by interacting with the host photomorphogenesis regulator protein HY5. Our results demonstrate that HY5 is not only an important component in the regulation of light signalling, but also positively regulates host plant immunity against H. arabidopsidis by transcriptional activation of defense-related genes. We show that the interaction between HaRxLL470 and HY5 compromises the function of HY5 as a transcription factor by attenuating its DNA-binding activity. The present study demonstrates that HY5 positively regulates host plant defense against H. arabidopsidis whereas HaRxLL470, a conserved RxLR effector across oomycete pathogens, enhances pathogenicity by interacting with HY5 and suppressing transcriptional activation of defense-related genes.
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Affiliation(s)
- Shuyun Chen
- Center for Viticulture and Enology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Tao Ma
- Center for Viticulture and Enology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Shiren Song
- Center for Viticulture and Enology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Xinlong Li
- Center for Viticulture and Enology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Peining Fu
- Center for Viticulture and Enology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Wei Wu
- Center for Viticulture and Enology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Jiaqi Liu
- Center for Viticulture and Enology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Yu Gao
- Center for Viticulture and Enology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Wenxiu Ye
- Center for Viticulture and Enology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Ian B Dry
- CSIRO Agriculture & Food, Urrbrae, SA, 5064, Australia
| | - Jiang Lu
- Center for Viticulture and Enology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, China
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31
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Ökmen B, Schwammbach D, Bakkeren G, Neumann U, Doehlemann G. The Ustilago hordei-Barley Interaction Is a Versatile System for Characterization of Fungal Effectors. J Fungi (Basel) 2021; 7:86. [PMID: 33513785 PMCID: PMC7912019 DOI: 10.3390/jof7020086] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 01/19/2021] [Accepted: 01/22/2021] [Indexed: 12/02/2022] Open
Abstract
Obligate biotrophic fungal pathogens, such as Blumeria graminis and Puccinia graminis, are amongst the most devastating plant pathogens, causing dramatic yield losses in many economically important crops worldwide. However, a lack of reliable tools for the efficient genetic transformation has hampered studies into the molecular basis of their virulence or pathogenicity. In this study, we present the Ustilago hordei-barley pathosystem as a model to characterize effectors from different plant pathogenic fungi. We generate U. hordei solopathogenic strains, which form infectious filaments without the presence of a compatible mating partner. Solopathogenic strains are suitable for heterologous expression system for fungal virulence factors. A highly efficient Crispr/Cas9 gene editing system is made available for U. hordei. In addition, U. hordei infection structures during barley colonization are analyzed using transmission electron microscopy, showing that U. hordei forms intracellular infection structures sharing high similarity to haustoria formed by obligate rust and powdery mildew fungi. Thus, U. hordei has high potential as a fungal expression platform for functional studies of heterologous effector proteins in barley.
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Affiliation(s)
- Bilal Ökmen
- BioCenter, Institute for Plant Sciences, University of Cologne, Zülpicher Straße 47a, 50674 Cologne, Germany
| | - Daniela Schwammbach
- Max Planck Institute for Terrestrial Microbiology, Karl von Frisch Straße, 35043 Marburg, Germany;
| | - Guus Bakkeren
- Summerland Research and Development Centre, Agriculture and Agri-Food Canada, Summerland, BC V0H 1Z0, Canada;
| | - Ulla Neumann
- Central Microscopy, Max Planck Institute for Plant Breeding Research, Carl-von-Linné-Weg 10, 50829 Cologne, Germany;
| | - Gunther Doehlemann
- BioCenter, Institute for Plant Sciences, University of Cologne, Zülpicher Straße 47a, 50674 Cologne, Germany
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32
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Zhu P, Kou M, Liu C, Zhang S, Lü R, Xia Z, Yu M, Zhao A. Genome Sequencing of Ciboria shiraiana Provides Insights into the Pathogenic Mechanisms of Hypertrophy Sorosis Scleroteniosis. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2021; 34:62-74. [PMID: 33021883 DOI: 10.1094/mpmi-07-20-0201-r] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Ciboria shiraiana causes hypertrophy sorosis scleroteniosis in mulberry trees, resulting in huge economic losses, and exploring its pathogenic mechanism at a genomic level is important for developing new control methods. Here, genome sequencing of C. shiraiana based on PacBio RSII and Illumina HiSeq 2500 platform as well as manual gap filling was performed. Synteny analysis with Sclerotinia sclerotiorum revealed 16 putative chromosomes corresponding to 16 chromosomes of C. shiraiana. Screening of rapid-evolution genes revealed that 97 and 2.4% of genes had undergone purifying selection and positive selection, respectively. When compared with S. sclerotiorum, fewer secreted effector proteins were found in C. shiraiana. The number of genes involved in pathogenicity, including secondary metabolites, carbohydrate active enzymes, and P450s, in the C. shiraiana genome was comparable with that of other necrotrophs but higher than that of biotrophs and saprotrophs. The growth-related genes and plant cell-wall-degradation-related genes in C. shiraiana were expressed in different developmental and infection stages, and may be potential targets for prevention and control of this pathogen. These results provide new insights into C. shiraiana pathogenic mechanisms, especially host range and necrotrophy features, and lay the foundation for further study of the underlying molecular mechanisms.[Formula: see text] The author(s) have dedicated the work to the public domain under the Creative Commons CC0 "No Rights Reserved" license by waiving all of his or her rights to the work worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.
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Affiliation(s)
- Panpan Zhu
- The State Key Laboratory of Silkworm Genome Biology, College of Biotechnology, Southwest University, Chongqing, China
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, Chongqing University, Chongqing, China
| | - Min Kou
- The State Key Laboratory of Silkworm Genome Biology, College of Biotechnology, Southwest University, Chongqing, China
| | - Changying Liu
- The State Key Laboratory of Silkworm Genome Biology, College of Biotechnology, Southwest University, Chongqing, China
| | - Shuai Zhang
- The State Key Laboratory of Silkworm Genome Biology, College of Biotechnology, Southwest University, Chongqing, China
| | - Ruihua Lü
- The State Key Laboratory of Silkworm Genome Biology, College of Biotechnology, Southwest University, Chongqing, China
- College of Medical Technology, Shanxi University of Chinese Medicine, Xianyang, Shanxi Province, China
| | - Zhongqiang Xia
- The State Key Laboratory of Silkworm Genome Biology, College of Biotechnology, Southwest University, Chongqing, China
| | - Maode Yu
- The State Key Laboratory of Silkworm Genome Biology, College of Biotechnology, Southwest University, Chongqing, China
| | - Aichun Zhao
- The State Key Laboratory of Silkworm Genome Biology, College of Biotechnology, Southwest University, Chongqing, China
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33
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Arroyo-Velez N, González-Fuente M, Peeters N, Lauber E, Noël LD. From effectors to effectomes: Are functional studies of individual effectors enough to decipher plant pathogen infectious strategies? PLoS Pathog 2020; 16:e1009059. [PMID: 33270803 PMCID: PMC7714205 DOI: 10.1371/journal.ppat.1009059] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Affiliation(s)
- Noe Arroyo-Velez
- LIPM, Université de Toulouse, INRAE, CNRS, Castanet-Tolosan, France
| | | | - Nemo Peeters
- LIPM, Université de Toulouse, INRAE, CNRS, Castanet-Tolosan, France
| | | | - Laurent D. Noël
- LIPM, Université de Toulouse, INRAE, CNRS, Castanet-Tolosan, France
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34
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Panstruga R, Moscou MJ. What is the Molecular Basis of Nonhost Resistance? MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2020; 33:1253-1264. [PMID: 32808862 DOI: 10.1094/mpmi-06-20-0161-cr] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
This article is part of the Top 10 Unanswered Questions in MPMI invited review series.Nonhost resistance is typically considered the ability of a plant species to repel all attempts of a pathogen species to colonize it and reproduce on it. Based on this common definition, nonhost resistance is presumed to be very durable and, thus, of great interest for its potential use in agriculture. Despite considerable research efforts, the molecular basis of this type of plant immunity remains nebulous. We here stress the fact that "nonhost resistance" is a phenomenological rather than a mechanistic concept that comprises more facets than typically considered. We further argue that nonhost resistance essentially relies on the very same genes and pathways as other types of plant immunity, of which some may act as bottlenecks for particular pathogens on a given plant species or under certain conditions. Thus, in our view, the frequently used term "nonhost genes" is misleading and should be avoided. Depending on the plant-pathogen combination, nonhost resistance may involve the recognition of pathogen effectors by host immune sensor proteins, which might give rise to host shifts or host range expansions due to evolutionary-conditioned gains and losses in respective armories. Thus, the extent of nonhost resistance also defines pathogen host ranges. In some instances, immune-related genes can be transferred across plant species to boost defense, resulting in augmented disease resistance. We discuss future routes for deepening our understanding of nonhost resistance and argue that the confusing term "nonhost resistance" should be used more cautiously in the light of a holistic view of plant immunity.
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Affiliation(s)
- Ralph Panstruga
- RWTH Aachen University, Institute for Biology I, Unit of Plant Molecular Cell Biology, Worringer Weg 1, 52056 Aachen, Germany
| | - Matthew J Moscou
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich, NR4 7UK, United Kingdom
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35
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Kanja C, Hammond‐Kosack KE. Proteinaceous effector discovery and characterization in filamentous plant pathogens. MOLECULAR PLANT PATHOLOGY 2020; 21:1353-1376. [PMID: 32767620 PMCID: PMC7488470 DOI: 10.1111/mpp.12980] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 06/03/2020] [Accepted: 07/05/2020] [Indexed: 05/26/2023]
Abstract
The complicated interplay of plant-pathogen interactions occurs on multiple levels as pathogens evolve to constantly evade the immune responses of their hosts. Many economically important crops fall victim to filamentous pathogens that produce small proteins called effectors to manipulate the host and aid infection/colonization. Understanding the effector repertoires of pathogens is facilitating an increased understanding of the molecular mechanisms underlying virulence as well as guiding the development of disease control strategies. The purpose of this review is to give a chronological perspective on the evolution of the methodologies used in effector discovery from physical isolation and in silico predictions, to functional characterization of the effectors of filamentous plant pathogens and identification of their host targets.
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Affiliation(s)
- Claire Kanja
- Department of Biointeractions and Crop ProtectionRothamsted ResearchHarpendenUK
- School of BiosciencesUniversity of NottinghamNottinghamUK
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36
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Pogorelko G, Wang J, Juvale PS, Mitchum MG, Baum TJ. Screening soybean cyst nematode effectors for their ability to suppress plant immunity. MOLECULAR PLANT PATHOLOGY 2020; 21:1240-1247. [PMID: 32672422 PMCID: PMC7411561 DOI: 10.1111/mpp.12972] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 05/15/2020] [Accepted: 06/05/2020] [Indexed: 05/19/2023]
Abstract
The soybean cyst nematode (SCN), Heterodera glycines, is one of the most destructive pathogens of soybeans. SCN is an obligate and sedentary parasite that transforms host plant root cells into an elaborate permanent feeding site, a syncytium. Formation and maintenance of a viable syncytium is an absolute requirement for nematode growth and reproduction. In turn, sensing pathogen attack, plants activate defence responses and may trigger programmed cell death at the sites of infection. For successful parasitism, H. glycines must suppress these host defence responses to establish and maintain viable syncytia. Similar to other pathogens, H. glycines engages in these molecular interactions with its host via effector proteins. The goal of this study was to conduct a comprehensive screen to identify H. glycines effectors that interfere with plant immune responses. We used Nicotiana benthamiana plants infected by Pseudomonas syringae and Pseudomonas fluorescens strains. Using these pathosystems, we screened 51 H. glycines effectors to identify candidates that could inhibit effector-triggered immunity (ETI) and/or pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI). We identified three effectors as ETI suppressors and seven effectors as PTI suppressors. We also assessed expression modulation of plant immune marker genes as a function of these suppressors.
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Affiliation(s)
- Gennady Pogorelko
- Department of Plant Pathology and MicrobiologyIowa State UniversityAmesIAUSA
| | - Jianying Wang
- Division of Plant Sciences and Bond Life Sciences CenterUniversity of MissouriColumbiaMOUSA
| | - Parijat S. Juvale
- Department of Plant Pathology and MicrobiologyIowa State UniversityAmesIAUSA
| | - Melissa G. Mitchum
- Division of Plant Sciences and Bond Life Sciences CenterUniversity of MissouriColumbiaMOUSA
- Department of Plant Pathology and Institute of Plant Breeding, Genetics, and GenomicsUniversity of GeorgiaAthensGAUSA
| | - Thomas J. Baum
- Department of Plant Pathology and MicrobiologyIowa State UniversityAmesIAUSA
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Navarro-Escalante L, Zhao C, Shukle R, Stuart J. BSA-Seq Discovery and Functional Analysis of Candidate Hessian Fly ( Mayetiola destructor) Avirulence Genes. FRONTIERS IN PLANT SCIENCE 2020; 11:956. [PMID: 32670342 PMCID: PMC7330099 DOI: 10.3389/fpls.2020.00956] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Accepted: 06/10/2020] [Indexed: 05/17/2023]
Abstract
The Hessian fly (HF, Mayetiola destructor) is a plant-galling parasite of wheat (Triticum spp.). Seven percent of its genome is composed of highly diversified signal-peptide-encoding genes that are transcribed in HF larval salivary glands. These observations suggest that they encode effector proteins that are injected into wheat cells to suppress basal wheat immunity and redirect wheat development towards gall formation. Genetic mapping has determined that mutations in four of these genes are associated with HF larval survival (virulence) on plants carrying four different resistance (R) genes. Here, this line of investigation was pursued further using bulked-segregant analysis combined with whole genome resequencing (BSA-seq). Virulence to wheat R genes H6, Hdic, and H5 was examined. Mutations associated with H6 virulence had been mapped previously. Therefore, we used H6 to test the capacity of BSA-seq to map virulence using a field-derived HF population. This was the first time a non-structured HF population had been used to map HF virulence. Hdic virulence had not been mapped previously. Using a structured laboratory population, BSA-seq associated Hdic virulence with mutations in two candidate effector-encoding genes. Using a laboratory population, H5 virulence was previously positioned in a region spanning the centromere of HF autosome 2. BSA-seq resolved H5 virulence to a 1.3 Mb fragment on the same chromosome but failed to identify candidate mutations. Map-based candidate effectors were then delivered to Nicotiana plant cells via the type III secretion system of Burkholderia glumae bacteria. These experiments demonstrated that the genes associated with virulence to wheat R genes H6 and H13 are capable of suppressing plant immunity. Results are consistent with the hypothesis that effector proteins underlie the ability of HFs to survive on wheat.
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Affiliation(s)
| | - Chaoyang Zhao
- Department of Botany and Plant Sciences, University of California, Riverside, Riverside, CA, United States
| | - Richard Shukle
- USDA-ARS and Department of Entomology, Purdue University, West Lafayette, IN, United States
| | - Jeffrey Stuart
- Department of Entomology, Purdue University, West Lafayette, IN, United States
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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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Situ J, Jiang L, Fan X, Yang W, Li W, Xi P, Deng Y, Kong G, Jiang Z. An RXLR effector PlAvh142 from Peronophythora litchii triggers plant cell death and contributes to virulence. MOLECULAR PLANT PATHOLOGY 2020; 21:415-428. [PMID: 31912634 PMCID: PMC7036370 DOI: 10.1111/mpp.12905] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 12/05/2019] [Accepted: 12/06/2019] [Indexed: 05/09/2023]
Abstract
Litchi downy blight, caused by the phytopathogenic oomycete Peronophythora litchii, results in tremendous economic loss in litchi production every year. To successfully colonize the host cell, Phytophthora species secret hundreds of RXLR effectors that interfere with plant immunity and facilitate the infection process. Previous work has already predicted 245 candidate RXLR effector-encoding genes in P. litchii, 212 of which have been cloned and tested for plant cell death-inducing activity in this study. We found three such RXLR effectors could trigger plant cell death through transient expression in Nicotiana benthamiana. Further experiments demonstrated that PlAvh142 could induce cell death and immune responses in several plants. We also found that PlAvh142 localized in both the cytoplasm and nucleus of plant cells. The cytoplasmic localization was critical for its cell death-inducing activity. Moreover, deletion either of the two internal repeats in PlAvh142 abolished the cell death-inducing activity. Virus-induced gene silencing assays showed that cell death triggered by PlAvh142 was dependent on the plant transduction components RAR1 (require for Mla12 resistance), SGT1 (suppressor of the G2 allele of skp1) and HSP90 (heat shock protein 90). Finally, knockout of PlAvh142 resulted in significantly attenuated P. litchii virulence on litchi plants, whereas the PlAvh142-overexpressed mutants were more aggressive. These data indicated that PlAvh142 could be recognized in plant cytoplasm and is an important virulence RXLR effector of P. litchii.
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Affiliation(s)
- Junjian Situ
- Department of Plant Pathology/Guangdong Province Key Laboratory of Microbial Signals and Disease ControlSouth China Agricultural UniversityGuangzhouChina
| | - Liqun Jiang
- Department of Plant Pathology/Guangdong Province Key Laboratory of Microbial Signals and Disease ControlSouth China Agricultural UniversityGuangzhouChina
- Guangdong Province Key Laboratory of New Technology in Rice Breeding/Rice Research InstituteGuangdong Academy of Agricultural SciencesGuangzhouChina
| | - Xiaoning Fan
- Department of Plant Pathology/Guangdong Province Key Laboratory of Microbial Signals and Disease ControlSouth China Agricultural UniversityGuangzhouChina
| | - Wensheng Yang
- Department of Plant Pathology/Guangdong Province Key Laboratory of Microbial Signals and Disease ControlSouth China Agricultural UniversityGuangzhouChina
| | - Wen Li
- Department of Plant Pathology/Guangdong Province Key Laboratory of Microbial Signals and Disease ControlSouth China Agricultural UniversityGuangzhouChina
| | - Pinggen Xi
- Department of Plant Pathology/Guangdong Province Key Laboratory of Microbial Signals and Disease ControlSouth China Agricultural UniversityGuangzhouChina
| | - Yizhen Deng
- Department of Plant Pathology/Guangdong Province Key Laboratory of Microbial Signals and Disease ControlSouth China Agricultural UniversityGuangzhouChina
| | - Guanghui Kong
- Department of Plant Pathology/Guangdong Province Key Laboratory of Microbial Signals and Disease ControlSouth China Agricultural UniversityGuangzhouChina
| | - Zide Jiang
- Department of Plant Pathology/Guangdong Province Key Laboratory of Microbial Signals and Disease ControlSouth China Agricultural UniversityGuangzhouChina
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40
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Martel A, Lo T, Desveaux D, Guttman DS. A High-Throughput, Seedling Screen for Plant Immunity. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2020; 33:394-401. [PMID: 31851574 DOI: 10.1094/mpmi-10-19-0295-ta] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
An understanding of how biological diversity affects plant-microbe interactions is becoming increasingly important, particularly with respect to components of the pathogen effector arsenal and the plant immune system. Although technological improvements have greatly advanced our ability to examine molecular sequences and interactions, relatively few advances have been made that facilitate high-throughput, in vivo pathology screens. Here, we present a high-throughput, microplate-based, nondestructive seedling pathology assay, and apply it to identify Arabidopsis thaliana effector-triggered immunity (ETI) responses against Pseudomonas syringae type III secreted effectors. The assay was carried out in a 48-well microplate format with spray inoculation, and disease symptoms were quantitatively recorded in a semiautomated manner, thereby greatly reducing both time and costs. The assay requires only slight modifications of common labware and uses no proprietary software. We validated the assay by recapitulating known ETI responses induced by P. syringae in Arabidopsis. We also demonstrated that we can quantitatively differentiate responses from a diversity of plant genotypes grown in the same microplate. Finally, we showed that the results obtained from our assay can be used to perform genome-wide association studies to identify host immunity genes, recapitulating results that have been independently obtained with mature plants.
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Affiliation(s)
- Alexandre Martel
- Department of Cell and Systems Biology, University of Toronto, Ontario, Canada
| | - Timothy Lo
- Department of Cell and Systems Biology, University of Toronto, Ontario, Canada
| | - Darrell Desveaux
- Department of Cell and Systems Biology, University of Toronto, Ontario, Canada
- Centre for the Analysis of Genome Evolution & Function, University of Toronto, Ontario, Canada
| | - David S Guttman
- Department of Cell and Systems Biology, University of Toronto, Ontario, Canada
- Centre for the Analysis of Genome Evolution & Function, University of Toronto, Ontario, Canada
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41
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Wang Y, Tyler BM, Wang Y. Defense and Counterdefense During Plant-Pathogenic Oomycete Infection. Annu Rev Microbiol 2019; 73:667-696. [DOI: 10.1146/annurev-micro-020518-120022] [Citation(s) in RCA: 69] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Plant-pathogenic oomycetes include numerous species that are ongoing threats to agriculture and natural ecosystems. Understanding the molecular dialogs between oomycetes and plants is instrumental for sustaining effective disease control. Plants respond to oomycete infection by multiple defense actions including strengthening of physical barriers, production of antimicrobial molecules, and programmed cell death. These responses are tightly controlled and integrated via a three-layered immune system consisting of a multiplex recognition layer, a resilient signal-integration layer, and a diverse defense-action layer. Adapted oomycete pathogens utilize apoplastic and intracellular effector arsenals to counter plant immunity mechanisms within each layer, including by evasion or suppression of recognition, interference with numerous signaling components, and neutralization or suppression of defense actions. A coevolutionary arms race continually drives the emergence of new mechanisms of plant defense and oomycete counterdefense.
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Affiliation(s)
- Yan Wang
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing 210095, China;,
- Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing 210095, China
| | - Brett M. Tyler
- Center for Genome Research and Biocomputing and Department of Botany and Plant Pathology, Oregon State University, Corvallis, Oregon 97331, USA
| | - Yuanchao Wang
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing 210095, China;,
- Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing 210095, China
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42
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Herlihy J, Ludwig NR, van den Ackerveken G, McDowell JM. Oomycetes Used in Arabidopsis Research. THE ARABIDOPSIS BOOK 2019; 17:e0188. [PMID: 33149730 PMCID: PMC7592078 DOI: 10.1199/tab.0188] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Arabidopsis plants in their natural environment are susceptible to infection by oomycete pathogens, in particular to downy mildew and white rust diseases. These naturally occurring infectious agents have imposed evolutionary pressures on Arabidopsis populations and are therefore highly relevant for the study of host-pathogen co-evolution. In addition, the study of oomycete diseases, including infections caused by several Phytophthora species, has led to many scientific discoveries on Arabidopsis immunity and disease. Herein, we describe the major oomycete species used for experiments on Arabidopsis, and how these pathosystems have been used to provide significant insights into mechanistic and evolutionary aspects of plant-oomycete interactions. We also highlight understudied aspects of plant-oomycete interactions, as well as translational approaches, that can be productively addressed using the reference pathosystems described in this article.
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Affiliation(s)
- John Herlihy
- School of Plant and Environmental Sciences, Virginia Tech, Blacksburg, VA 24061, USA
| | - Nora R. Ludwig
- Plant–Microbe Interactions, Department of Biology, Utrecht University, Padualaan 8, 3584 CH, Utrecht, the Netherlands
| | - Guido van den Ackerveken
- Plant–Microbe Interactions, Department of Biology, Utrecht University, Padualaan 8, 3584 CH, Utrecht, the Netherlands
| | - John M. McDowell
- School of Plant and Environmental Sciences, Virginia Tech, Blacksburg, VA 24061, USA
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Wang A, Pan L, Niu X, Shu X, Yi X, Yamamoto N, Li S, Deng Q, Zhu J, Liang Y, Wang L, Li P, Zheng A. Comparative secretome analysis of different smut fungi and identification of plant cell death-inducing secreted proteins from Tilletia horrida. BMC PLANT BIOLOGY 2019; 19:360. [PMID: 31419944 PMCID: PMC6697988 DOI: 10.1186/s12870-019-1924-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Accepted: 07/04/2019] [Indexed: 05/08/2023]
Abstract
BACKGROUND Tilletia horrida is a basidiomycete fungus that causes rice kernel smut, one of the most important rice diseases in hybrid rice growing areas worldwide. However, little is known about its mechanisms of pathogenicity. We previously reported the genome of T. horrida, and 597 genes that encoded secreted proteins were annotated. Among these were some important effector genes related to pathogenicity. RESULTS A secretome analysis suggested that five Tilletia fungi shared more gene families than were found in other smuts, and there was high conservation between them. Furthermore, we screened 597 secreted proteins from the T. horrida genome, some of which induced expression in host-pathogen interaction processes. Through transient expression, we demonstrated that two putative effectors could induce necrosis phenotypes in Nicotiana benthamiana. These two encoded genes were up-regulated during early infection, and the encoded proteins were confirmed to be secreted using a yeast secretion system. For the putative effector gene smut_5844, a signal peptide was required to induce non-host cell death, whereas ribonuclease catalytic active sites were required for smut_2965. Moreover, both putative effectors could induce an immune response in N. benthamiana leaves. Interestingly, one of the identified potential host interactors of smut_5844 was laccase-10 protein (OsLAC10), which has been predicted to be involved in plant lignification and iron metabolism. CONCLUSIONS Overall, this study identified two secreted proteins in T. horrida that induce cell death or are involved in defense machinery in non-host plants. This research provides a useful foundation for understanding the interaction between rice and T. horrida.
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Affiliation(s)
- Aijun Wang
- Rice Research Institute of Sichuan Agricultural University, Chengdu, China
- Key laboratory of Sichuan Crop Major Disease, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Southwest Crop Gene Resource and Genetic Improvement of Ministry of Education, Sichuan Agricultural University, Yaan, China
| | - Linxiu Pan
- Rice Research Institute of Sichuan Agricultural University, Chengdu, China
| | - Xianyu Niu
- Rice Research Institute of Sichuan Agricultural University, Chengdu, China
- Key laboratory of Sichuan Crop Major Disease, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Southwest Crop Gene Resource and Genetic Improvement of Ministry of Education, Sichuan Agricultural University, Yaan, China
| | - Xinyue Shu
- Rice Research Institute of Sichuan Agricultural University, Chengdu, China
- Key laboratory of Sichuan Crop Major Disease, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Southwest Crop Gene Resource and Genetic Improvement of Ministry of Education, Sichuan Agricultural University, Yaan, China
| | - Xiaoqun Yi
- Rice Research Institute of Sichuan Agricultural University, Chengdu, China
| | - Naoki Yamamoto
- Rice Research Institute of Sichuan Agricultural University, Chengdu, China
- Key laboratory of Sichuan Crop Major Disease, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Southwest Crop Gene Resource and Genetic Improvement of Ministry of Education, Sichuan Agricultural University, Yaan, China
| | - Shuangcheng Li
- Rice Research Institute of Sichuan Agricultural University, Chengdu, China
- Key laboratory of Sichuan Crop Major Disease, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Southwest Crop Gene Resource and Genetic Improvement of Ministry of Education, Sichuan Agricultural University, Yaan, China
| | - Qiming Deng
- Rice Research Institute of Sichuan Agricultural University, Chengdu, China
- Key laboratory of Sichuan Crop Major Disease, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Southwest Crop Gene Resource and Genetic Improvement of Ministry of Education, Sichuan Agricultural University, Yaan, China
| | - Jun Zhu
- Rice Research Institute of Sichuan Agricultural University, Chengdu, China
- Key laboratory of Sichuan Crop Major Disease, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Southwest Crop Gene Resource and Genetic Improvement of Ministry of Education, Sichuan Agricultural University, Yaan, China
| | - Yueyang Liang
- Rice Research Institute of Sichuan Agricultural University, Chengdu, China
- Key laboratory of Sichuan Crop Major Disease, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Southwest Crop Gene Resource and Genetic Improvement of Ministry of Education, Sichuan Agricultural University, Yaan, China
| | - Lingxia Wang
- Rice Research Institute of Sichuan Agricultural University, Chengdu, China
- Key laboratory of Sichuan Crop Major Disease, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Southwest Crop Gene Resource and Genetic Improvement of Ministry of Education, Sichuan Agricultural University, Yaan, China
| | - Ping Li
- Rice Research Institute of Sichuan Agricultural University, Chengdu, China
- Key laboratory of Sichuan Crop Major Disease, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Southwest Crop Gene Resource and Genetic Improvement of Ministry of Education, Sichuan Agricultural University, Yaan, China
| | - Aiping Zheng
- Rice Research Institute of Sichuan Agricultural University, Chengdu, China
- Key laboratory of Sichuan Crop Major Disease, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Southwest Crop Gene Resource and Genetic Improvement of Ministry of Education, Sichuan Agricultural University, Yaan, China
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A set of Arabidopsis genes involved in the accommodation of the downy mildew pathogen Hyaloperonospora arabidopsidis. PLoS Pathog 2019; 15:e1007747. [PMID: 31299058 PMCID: PMC6625732 DOI: 10.1371/journal.ppat.1007747] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2018] [Accepted: 04/03/2019] [Indexed: 12/14/2022] Open
Abstract
The intracellular accommodation structures formed by plant cells to host arbuscular mycorrhiza fungi and biotrophic hyphal pathogens are cytologically similar. Therefore we investigated whether these interactions build on an overlapping genetic framework. In legumes, the malectin-like domain leucine-rich repeat receptor kinase SYMRK, the cation channel POLLUX and members of the nuclear pore NUP107-160 subcomplex are essential for symbiotic signal transduction and arbuscular mycorrhiza development. We identified members of these three groups in Arabidopsis thaliana and explored their impact on the interaction with the oomycete downy mildew pathogen Hyaloperonospora arabidopsidis (Hpa). We report that mutations in the corresponding genes reduced the reproductive success of Hpa as determined by sporangiophore and spore counts. We discovered that a developmental transition of haustorial shape occurred significantly earlier and at higher frequency in the mutants. Analysis of the multiplication of extracellular bacterial pathogens, Hpa-induced cell death or callose accumulation, as well as Hpa- or flg22-induced defence marker gene expression, did not reveal any traces of constitutive or exacerbated defence responses. These findings point towards an overlap between the plant genetic toolboxes involved in the interaction with biotrophic intracellular hyphal symbionts and pathogens in terms of the gene families involved. Our work reveals genetic commonalities between biotrophic intracellular interactions with symbiotic and pathogenic hyphal microbes. The majority of land plants engages in arbuscular mycorrhiza (AM) symbiosis with phosphate-acquiring arbuscular mycorrhizal fungi to avoid phosphate starvation. Nutrient exchange in this interaction occurs via arbuscules, tree-shaped fungal structures, hosted within plant root cells. A series of plant genes including the Symbiosis Receptor-like kinase (SYMRK), members of the NUP107-160 subcomplex and nuclear envelope localised cation channels are required for a signalling process leading to the development of AM. The model plant Arabidopsis thaliana lost the ability to form AM. Although the ortholog of SYMRK was deleted during evolution, members of the malectin-like domain leucine-rich repeat receptor kinase (MLD-LRR-RK) gene family, components of the NUP107-160 subcomplex, and an ortholog of the nuclear envelope-localized cation channel POLLUX, are still present in the Arabidopsis genome, and Arabidopsis leaf cells retained the ability to accommodate haustoria, presumed feeding structures of the obligate biotrophic downy mildew pathogen Hyaloperonospora arabidopsidis. We discovered that both of these plant-microbe interactions utilize a corresponding set of genes including the ortholog of POLLUX, members of the NUP107-160 subcomplex and members of the MLD-LRR-RK gene family, thus revealing similarities in the plant program for the intracellular accommodation of biotrophic organisms in symbiosis and disease.
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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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Ma Z, Liu JJ, Zamany A. Identification and Functional Characterization of an Effector Secreted by Cronartium ribicola. PHYTOPATHOLOGY 2019; 109:942-951. [PMID: 31066346 DOI: 10.1094/phyto-11-18-0427-r] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Cri-9402 was identified as a protein effector from Cronartium ribicola, based on the effect of its expression on growth of Pseudomonas syringae Psm ES4326 introduced into transiently transformed tobacco leaves and stably transformed Arabidopsis seedlings. In tobacco leaves transiently expressing its coding sequence, growth of P. syringae Psm ES4326 was inhibited. Expression of pathogenesis-related (PR) protein 2 (PR2), PR4a, endochitinase B, hypersensitive-related 201 (HSR201), HSR203J, and proteinase inhibitor 1 was upregulated but expression of PR1, coronatine insensitive 1, and abscisic acid 1 was significantly suppressed. In transformed Arabidopsis seedlings, the effector stimulated growth of P. syringae Psm ES4326; significantly suppressed expression of PR1, PR2, nonexpresser of pathogenesis-related genes 1 (NPR1), NPR3, NPR4, phytoalexin deficient 4, and salicylic acid induction deficient 2; and enhanced expression of plant defensin 1.2 (PDF1.2). The above results showed that the majority of responses to this effector in tobacco leaves were converse to those in transformed Arabidopsis. We could conclude that Cri-9402 promoted disease resistance in tobacco leaves and disease susceptibility in Arabidopsis seedlings. Its transcript was mainly expressed in aeciospores of C. ribicola and was probably involved in production or germination of aeciospores, and it was an effector potentially functioning in white pine-blister rust interactions.
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Affiliation(s)
- Zhenguo Ma
- Canadian Forest Service, Natural Resources Canada, 506 West Burnside Road, Victoria, BC V8Z 1M5, Canada
| | - Jun-Jun Liu
- Canadian Forest Service, Natural Resources Canada, 506 West Burnside Road, Victoria, BC V8Z 1M5, Canada
| | - Arezoo Zamany
- Canadian Forest Service, Natural Resources Canada, 506 West Burnside Road, Victoria, BC V8Z 1M5, Canada
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Courville KJ, Frantzeskakis L, Gul S, Haeger N, Kellner R, Heßler N, Day B, Usadel B, Gupta YK, van Esse HP, Brachmann A, Kemen E, Feldbrügge M, Göhre V. Smut infection of perennial hosts: the genome and the transcriptome of the Brassicaceae smut fungus Thecaphora thlaspeos reveal functionally conserved and novel effectors. THE NEW PHYTOLOGIST 2019; 222:1474-1492. [PMID: 30663769 DOI: 10.1111/nph.15692] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 01/09/2019] [Indexed: 05/25/2023]
Abstract
Biotrophic fungal plant pathogens can balance their virulence and form intricate relationships with their hosts. Sometimes, this leads to systemic host colonization over long time scales without macroscopic symptoms. However, how plant-pathogenic endophytes manage to establish their sustained systemic infection remains largely unknown. Here, we present a genomic and transcriptomic analysis of Thecaphora thlaspeos. This relative of the well studied grass smut Ustilago maydis is the only smut fungus adapted to Brassicaceae hosts. Its ability to overwinter with perennial hosts and its systemic plant infection including roots are unique characteristics among smut fungi. The T. thlaspeos genome was assembled to the chromosome level. It is a typical smut genome in terms of size and genome characteristics. In silico prediction of candidate effector genes revealed common smut effector proteins and unique members. For three candidates, we have functionally demonstrated effector activity. One of these, TtTue1, suggests a potential link to cold acclimation. On the plant side, we found evidence for a typical immune response as it is present in other infection systems, despite the absence of any macroscopic symptoms during infection. Our findings suggest that T. thlaspeos distinctly balances its virulence during biotrophic growth ultimately allowing for long-lived infection of its perennial hosts.
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Affiliation(s)
- Kaitlyn J Courville
- Institute for Microbiology, Cluster of Excellence on Plant Sciences, Heinrich-Heine University, Building 26.12.01, Universitätsstr. 1, Düsseldorf, 40225, Germany
| | - Lamprinos Frantzeskakis
- Institute for Microbiology, Cluster of Excellence on Plant Sciences, Heinrich-Heine University, Building 26.12.01, Universitätsstr. 1, Düsseldorf, 40225, Germany
| | - Summia Gul
- Institute for Microbiology, Cluster of Excellence on Plant Sciences, Heinrich-Heine University, Building 26.12.01, Universitätsstr. 1, Düsseldorf, 40225, Germany
| | - Natalie Haeger
- Institute for Microbiology, Cluster of Excellence on Plant Sciences, Heinrich-Heine University, Building 26.12.01, Universitätsstr. 1, Düsseldorf, 40225, Germany
| | - Ronny Kellner
- Institute for Microbiology, Cluster of Excellence on Plant Sciences, Heinrich-Heine University, Building 26.12.01, Universitätsstr. 1, Düsseldorf, 40225, Germany
- Max Planck Institute for Plant Breeding Research, Carl-von-Linné-Weg 10, Cologne, 50829, Germany
| | - Natascha Heßler
- Institute for Microbiology, Cluster of Excellence on Plant Sciences, Heinrich-Heine University, Building 26.12.01, Universitätsstr. 1, Düsseldorf, 40225, Germany
| | - Brad Day
- Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, MI, 48824-6254, USA
| | - Björn Usadel
- Unit of Botany and Molecular Genetics, Institute for Biology I, BioSC, RWTH Aachen University, 52074, Aachen, Germany
| | | | | | - Andreas Brachmann
- Faculty of Biology, Genetics, Ludwig-Maximilians-Universität München, Großhaderner Str. 2-4, Planegg-Martinsried, 82152, Germany
| | - Eric Kemen
- Max Planck Institute for Plant Breeding Research, Carl-von-Linné-Weg 10, Cologne, 50829, Germany
| | - Michael Feldbrügge
- Institute for Microbiology, Cluster of Excellence on Plant Sciences, Heinrich-Heine University, Building 26.12.01, Universitätsstr. 1, Düsseldorf, 40225, Germany
| | - Vera Göhre
- Institute for Microbiology, Cluster of Excellence on Plant Sciences, Heinrich-Heine University, Building 26.12.01, Universitätsstr. 1, Düsseldorf, 40225, Germany
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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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Kapos P, Devendrakumar KT, Li X. Plant NLRs: From discovery to application. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2019; 279:3-18. [PMID: 30709490 DOI: 10.1016/j.plantsci.2018.03.010] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 03/01/2018] [Accepted: 03/02/2018] [Indexed: 05/09/2023]
Abstract
Plants require a complex immune system to defend themselves against a wide range of pathogens which threaten their growth and development. The nucleotide-binding leucine-rich repeat proteins (NLRs) are immune sensors that recognize effectors delivered by pathogens. The first NLR was cloned more than twenty years ago. Since this initial discovery, NLRs have been described as key components of plant immunity responsible for pathogen recognition and triggering defense responses. They have now been described in most of the well-studied mulitcellular plant species, with most having large NLR repertoires. As research has progressed so has the understanding of how NLRs interact with their recognition substrates and how they in turn activate downstream signalling. It has also become apparent that NLR regulation occurs at the transcriptional, post-transcriptional, translational, and post-translational levels. Even before the first NLR was cloned, breeders were utilising such genes to increase crop performance. Increased understanding of the mechanistic details of the plant immune system enable the generation of plants resistant against devastating pathogens. This review aims to give an updated summary of the NLR field.
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Affiliation(s)
- Paul Kapos
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada; Department of Botany, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| | - Karen Thulasi Devendrakumar
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada; 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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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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