1
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Cao P, Shi H, Zhang S, Chen J, Wang R, Liu P, Zhu Y, An Y, Zhang M. A robust high-throughput functional screening assay for plant pathogen effectors using the TMV-GFP vector. Plant J 2024. [PMID: 38647454 DOI: 10.1111/tpj.16774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2023] [Revised: 04/02/2024] [Accepted: 04/08/2024] [Indexed: 04/25/2024]
Abstract
Uncovering the function of phytopathogen effectors is crucial for understanding mechanisms of pathogen pathogenicity and for improving our ability to protect plants from diseases. An increasing number of effectors have been predicted in various plant pathogens. Functional characterization of these effectors has become a major focus in the study of plant-pathogen interactions. In this study, we designed a novel screening system that combines the TMV (tobacco mosaic virus)-GFP vector and Agrobacterium-mediated transient expression in the model plant Nicotiana benthamiana. This system enables the rapid identification of effectors that interfere with plant immunity. The biological function of these effectors can be easily evaluated by observing the GFP fluorescence signal using a UV lamp within just a few days. To evaluate the TMV-GFP system, we initially tested it with well-described virulence and avirulence type III effectors from the bacterial pathogen Ralstonia solanacearum. After proving the accuracy and efficiency of the TMV-GFP system, we successfully screened a novel virulence effector, RipS1, using this approach. Furthermore, using the TMV-GFP system, we reproduced consistent results with previously known cytoplasmic effectors from a diverse array of pathogens. Additionally, we demonstrated the effectiveness of the TMV-GFP system in identifying apoplastic effectors. The easy operation, time-saving nature, broad effectiveness, and low technical requirements of the TMV-GFP system make it a promising approach for high-throughput screening of effectors with immune interference activity from various pathogens.
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Affiliation(s)
- Peng Cao
- College of Life Sciences, Shaanxi Normal University, Xi'an, 710119, China
| | - Haotian Shi
- College of Life Sciences, Shaanxi Normal University, Xi'an, 710119, China
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China
| | - Shuangxi Zhang
- College of Life Sciences, Shaanxi Normal University, Xi'an, 710119, China
| | - Jialan Chen
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China
| | - Rongbo Wang
- Fujian Key Laboratory for Monitoring and Integrated Management of Crop Pests, Institute of Plant Protection, Fujian Academy of Agricultural Sciences, Fuzhou, 350003, China
| | - Peiqing Liu
- Fujian Key Laboratory for Monitoring and Integrated Management of Crop Pests, Institute of Plant Protection, Fujian Academy of Agricultural Sciences, Fuzhou, 350003, China
| | - Yingfang Zhu
- State Key Laboratory of Crop Stress Adaptation and Improvement, Key Laboratory of Cotton Biology, School of Life Sciences, Henan University, Kaifeng, 475001, China
| | - Yuyan An
- College of Life Sciences, Shaanxi Normal University, Xi'an, 710119, China
| | - Meixiang Zhang
- College of Life Sciences, Shaanxi Normal University, Xi'an, 710119, China
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2
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Yang L, Wang R, Lin W, Li B, Jin T, Weng Q, Zhang M, Liu P. Efficacy of 2,4-Di- tert-butylphenol in Reducing Ralstonia solanacearum Virulence: Insights into the Underlying Mechanisms. ACS Omega 2024; 9:4647-4655. [PMID: 38313526 PMCID: PMC10831823 DOI: 10.1021/acsomega.3c07887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 12/23/2023] [Accepted: 12/28/2023] [Indexed: 02/06/2024]
Abstract
Ralstonia solanacearum can induce severe wilt disease in vital crops. Therefore, there is an urgent need to develop novel antifungal solutions. The natural compound 2,4-di-tert-butylphenol (2,4-DTBP) exhibits diverse physiological activities and affects soil function. However, its specific impact on the R. solanacearum remains unclear. Here, we investigated the antimicrobial potential of 2,4-DTBP. The results demonstrated that 2,4-DTBP effectively inhibited its growth and altered morphology. In addition, it substantially impeded biofilm formation, motility, and exopolysaccharide secretion. Transcriptomic analysis revealed that 2,4-DTBP inhibited energy production and membrane transport. Additionally, 2,4-DTBP hindered the growth by interfering with the membrane permeability, reactive oxygen species (ROS) production, and electrolyte leakage. Concomitantly, this led to a significant reduction in pathogenicity, as evidenced by the biomass of R. solanacearum in the invaded roots. Overall, our data strongly support the potential utility of 2,4-DTBP as a potent antibacterial agent capable of effectively preventing the onset of bacterial wilt caused by R. solanacearum.
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Affiliation(s)
- Le Yang
- Fujian
Key Laboratory for Monitoring and Integrated Management of Crop Pests,
Institute of Plant Protection, Fujian Academy
of Agricultural Sciences, 247 Wusi Road, Fuzhou 350003, China
| | - Rongbo Wang
- Fujian
Key Laboratory for Monitoring and Integrated Management of Crop Pests,
Institute of Plant Protection, Fujian Academy
of Agricultural Sciences, 247 Wusi Road, Fuzhou 350003, China
| | - Wei Lin
- Institute
of Tobacco Science, Nanping Tobacco Company, 389 Binjiang Road, Nanping 353000, China
| | - Benjing Li
- Fujian
Key Laboratory for Monitoring and Integrated Management of Crop Pests,
Institute of Plant Protection, Fujian Academy
of Agricultural Sciences, 247 Wusi Road, Fuzhou 350003, China
| | - Ting Jin
- Research
and Development Center, Xiamen Canco Biotechnology
Co., Ltd., 2068 Wengjiao
Road, Xiamen 361013, China
| | - Qiyong Weng
- Fujian
Key Laboratory for Monitoring and Integrated Management of Crop Pests,
Institute of Plant Protection, Fujian Academy
of Agricultural Sciences, 247 Wusi Road, Fuzhou 350003, China
| | - Meixiang Zhang
- College
of Life Sciences, Shaanxi Normal University, 620 West Changan Road, Xian 710119, China
| | - Peiqing Liu
- Fujian
Key Laboratory for Monitoring and Integrated Management of Crop Pests,
Institute of Plant Protection, Fujian Academy
of Agricultural Sciences, 247 Wusi Road, Fuzhou 350003, China
- Institute
of Tobacco Science, Nanping Tobacco Company, 389 Binjiang Road, Nanping 353000, China
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3
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Liu K, Shi L, Luo H, Zhang K, Liu J, Qiu S, Li X, He S, Liu Z. Ralstonia solanacearum effector RipAK suppresses homodimerization of the host transcription factor ERF098 to enhance susceptibility and the sensitivity of pepper plants to dehydration. Plant J 2024; 117:121-144. [PMID: 37738430 DOI: 10.1111/tpj.16479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 08/03/2023] [Accepted: 08/25/2023] [Indexed: 09/24/2023]
Abstract
Plants have evolved a sophisticated immune system to defend against invasion by pathogens. In response, pathogens deploy copious effectors to evade the immune responses. However, the molecular mechanisms used by pathogen effectors to suppress plant immunity remain unclear. Herein, we report that an effector secreted by Ralstonia solanacearum, RipAK, modulates the transcriptional activity of the ethylene-responsive factor ERF098 to suppress immunity and dehydration tolerance, which causes bacterial wilt in pepper (Capsicum annuum L.) plants. Silencing ERF098 enhances the resistance of pepper plants to R. solanacearum infection not only by inhibiting the host colonization of R. solanacearum but also by increasing the immunity and tolerance of pepper plants to dehydration and including the closure of stomata to reduce the loss of water in an abscisic acid signal-dependent manner. In contrast, the ectopic expression of ERF098 in Nicotiana benthamiana enhances wilt disease. We also show that RipAK targets and inhibits the ERF098 homodimerization to repress the expression of salicylic acid-dependent PR1 and dehydration tolerance-related OSR1 and OSM1 by cis-elements in their promoters. Taken together, our study reveals a regulatory mechanism used by the R. solanacearum effector RipAK to increase virulence by specifically inhibiting the homodimerization of ERF098 and reprogramming the transcription of PR1, OSR1, and OSM1 to boost susceptibility and dehydration sensitivity. Thus, our study sheds light on a previously unidentified strategy by which a pathogen simultaneously suppresses plant immunity and tolerance to dehydration by secreting an effector to interfere with the activity of a transcription factor and manipulate plant transcriptional programs.
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Affiliation(s)
- Kaisheng Liu
- Key Laboratory of Applied Genetics of Universities in Fujian Province, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
- Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
- College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Lanping Shi
- Key Laboratory of Applied Genetics of Universities in Fujian Province, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
- Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
- College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Hongli Luo
- Key Laboratory of Applied Genetics of Universities in Fujian Province, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
- Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
- College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Kan Zhang
- Key Laboratory of Applied Genetics of Universities in Fujian Province, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
- Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
- College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Jianxin Liu
- Key Laboratory of Applied Genetics of Universities in Fujian Province, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
- Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
- College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Shanshan Qiu
- Key Laboratory of Applied Genetics of Universities in Fujian Province, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
- Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
- College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Xia Li
- Key Laboratory of Applied Genetics of Universities in Fujian Province, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
- Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
- College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Shuilin He
- Key Laboratory of Applied Genetics of Universities in Fujian Province, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
- Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
- College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Zhiqin Liu
- Key Laboratory of Applied Genetics of Universities in Fujian Province, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
- Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
- College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
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4
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Sun ZM, Zhang Q, Feng YX, Zhang SX, Bai BX, Ouyang X, Xiao ZL, Meng H, Wang XT, He JM, An YY, Zhang MX. The Ralstonia solanacearum Type III Effector RipAW Targets the Immune Receptor Complex to Suppress PAMP-Triggered Immunity. Int J Mol Sci 2023; 25:183. [PMID: 38203354 PMCID: PMC10779406 DOI: 10.3390/ijms25010183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2023] [Revised: 12/10/2023] [Accepted: 12/20/2023] [Indexed: 01/12/2024] Open
Abstract
Bacterial wilt, caused by Ralstonia solanacearum, one of the most destructive phytopathogens, leads to significant annual crop yield losses. Type III effectors (T3Es) mainly contribute to the virulence of R. solanacearum, usually by targeting immune-related proteins. Here, we clarified the effect of a novel E3 ubiquitin ligase (NEL) T3E, RipAW, from R. solanacearum on pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI) and further explored its action mechanism. In the susceptible host Arabidopsis thaliana, we monitored the expression of PTI marker genes, flg22-induced ROS burst, and callose deposition in RipAW- and RipAWC177A-transgenic plants. Our results demonstrated that RipAW suppressed host PTI in an NEL-dependent manner. By Split-Luciferase Complementation, Bimolecular Fluorescent Complimentary, and Co-Immunoprecipitation assays, we further showed that RipAW associated with three crucial components of the immune receptor complex, namely FLS2, XLG2, and BIK1. Furthermore, RipAW elevated the ubiquitination levels of FLS2, XLG2, and BIK1, accelerating their degradation via the 26S proteasome pathway. Additionally, co-expression of FLS2, XLG2, or BIK1 with RipAW partially but significantly restored the RipAW-suppressed ROS burst, confirming the involvement of the immune receptor complex in RipAW-regulated PTI. Overall, our results indicate that RipAW impairs host PTI by disrupting the immune receptor complex. Our findings provide new insights into the virulence mechanism of R. solanacearum.
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Affiliation(s)
- Zhi-Mao Sun
- College of Life Sciences, Shaanxi Normal University, Xi’an 710119, China; (Z.-M.S.); (Q.Z.); (Y.-X.F.); (S.-X.Z.); (B.-X.B.); (X.O.); (X.-T.W.); (J.-M.H.)
| | - Qi Zhang
- College of Life Sciences, Shaanxi Normal University, Xi’an 710119, China; (Z.-M.S.); (Q.Z.); (Y.-X.F.); (S.-X.Z.); (B.-X.B.); (X.O.); (X.-T.W.); (J.-M.H.)
| | - Yu-Xin Feng
- College of Life Sciences, Shaanxi Normal University, Xi’an 710119, China; (Z.-M.S.); (Q.Z.); (Y.-X.F.); (S.-X.Z.); (B.-X.B.); (X.O.); (X.-T.W.); (J.-M.H.)
| | - Shuang-Xi Zhang
- College of Life Sciences, Shaanxi Normal University, Xi’an 710119, China; (Z.-M.S.); (Q.Z.); (Y.-X.F.); (S.-X.Z.); (B.-X.B.); (X.O.); (X.-T.W.); (J.-M.H.)
| | - Bi-Xin Bai
- College of Life Sciences, Shaanxi Normal University, Xi’an 710119, China; (Z.-M.S.); (Q.Z.); (Y.-X.F.); (S.-X.Z.); (B.-X.B.); (X.O.); (X.-T.W.); (J.-M.H.)
| | - Xue Ouyang
- College of Life Sciences, Shaanxi Normal University, Xi’an 710119, China; (Z.-M.S.); (Q.Z.); (Y.-X.F.); (S.-X.Z.); (B.-X.B.); (X.O.); (X.-T.W.); (J.-M.H.)
| | - Zhi-Liang Xiao
- Chinese Academy of Agricultural Sciences, Qingdao 266101, China; (Z.-L.X.); (H.M.)
| | - He Meng
- Chinese Academy of Agricultural Sciences, Qingdao 266101, China; (Z.-L.X.); (H.M.)
| | - Xiao-Ting Wang
- College of Life Sciences, Shaanxi Normal University, Xi’an 710119, China; (Z.-M.S.); (Q.Z.); (Y.-X.F.); (S.-X.Z.); (B.-X.B.); (X.O.); (X.-T.W.); (J.-M.H.)
| | - Jun-Min He
- College of Life Sciences, Shaanxi Normal University, Xi’an 710119, China; (Z.-M.S.); (Q.Z.); (Y.-X.F.); (S.-X.Z.); (B.-X.B.); (X.O.); (X.-T.W.); (J.-M.H.)
| | - Yu-Yan An
- College of Life Sciences, Shaanxi Normal University, Xi’an 710119, China; (Z.-M.S.); (Q.Z.); (Y.-X.F.); (S.-X.Z.); (B.-X.B.); (X.O.); (X.-T.W.); (J.-M.H.)
| | - Mei-Xiang Zhang
- College of Life Sciences, Shaanxi Normal University, Xi’an 710119, China; (Z.-M.S.); (Q.Z.); (Y.-X.F.); (S.-X.Z.); (B.-X.B.); (X.O.); (X.-T.W.); (J.-M.H.)
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5
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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 Commun 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] [What about the content of this article? (0)] [Affiliation(s)] [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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6
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Kim B, Kim I, Yu W, Li M, Kim H, Ahn YJ, Sohn KH, Macho AP, Segonzac C. The Ralstonia pseudosolanacearum effector RipE1 is recognized at the plasma membrane by NbPtr1, the Nicotiana benthamiana homologue of Pseudomonas tomato race 1. Mol Plant Pathol 2023; 24:1312-1318. [PMID: 37310613 PMCID: PMC10502825 DOI: 10.1111/mpp.13363] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 05/07/2023] [Accepted: 05/22/2023] [Indexed: 06/14/2023]
Abstract
The bacterial wilt disease caused by soilborne bacteria of the Ralstonia solanacearum species complex (RSSC) threatens important crops worldwide. Only a few immune receptors conferring resistance to this devastating disease are known so far. Individual RSSC strains deliver around 70 different type III secretion system effectors into host cells to manipulate the plant physiology. RipE1 is an effector conserved across the RSSC and triggers immune responses in the model solanaceous plant Nicotiana benthamiana. Here, we used multiplexed virus-induced gene silencing of the nucleotide-binding and leucine-rich repeat receptor family to identify the genetic basis of RipE1 recognition. Specific silencing of the N. benthamiana homologue of Solanum lycopersicoides Ptr1 (confers resistance to Pseudomonas syringae pv. tomato race 1) gene (NbPtr1) completely abolished RipE1-induced hypersensitive response and immunity to Ralstonia pseudosolanacearum. The expression of the native NbPtr1 coding sequence was sufficient to restore RipE1 recognition in Nb-ptr1 knockout plants. Interestingly, RipE1 association with the host cell plasma membrane was necessary for NbPtr1-dependent recognition. Furthermore, NbPtr1-dependent recognition of RipE1 natural variants is polymorphic, providing additional evidence for the indirect mode of activation of NbPtr1. Altogether, this work supports NbPtr1 relevance for resistance to bacterial wilt disease in Solanaceae.
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Affiliation(s)
- Boyoung Kim
- Department of Agriculture, Forestry and BioresourcesSeoul National UniversitySeoulRepublic of Korea
- Plant Immunity Research CenterSeoul National UniversitySeoulRepublic of Korea
| | - Injae Kim
- Department of Agriculture, Forestry and BioresourcesSeoul National UniversitySeoulRepublic of Korea
- Plant Immunity Research CenterSeoul National UniversitySeoulRepublic of Korea
| | - Wenjia Yu
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant SciencesChinese Academy of SciencesShanghaiChina
| | - Meng Li
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant SciencesChinese Academy of SciencesShanghaiChina
| | - Haseong Kim
- Plant Immunity Research CenterSeoul National UniversitySeoulRepublic of Korea
| | - Ye Jin Ahn
- Department of Life SciencesPohang University of Science and TechnologyPohangRepublic of Korea
| | - Kee Hoon Sohn
- Plant Immunity Research CenterSeoul National UniversitySeoulRepublic of Korea
- Department of Agricultural BiotechnologySeoul National UniversitySeoulRepublic of Korea
- Research Institute of Agriculture and Life SciencesSeoul National UniversitySeoulRepublic of Korea
| | - Alberto P. Macho
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant SciencesChinese Academy of SciencesShanghaiChina
| | - Cécile Segonzac
- Department of Agriculture, Forestry and BioresourcesSeoul National UniversitySeoulRepublic of Korea
- Plant Immunity Research CenterSeoul National UniversitySeoulRepublic of Korea
- Research Institute of Agriculture and Life SciencesSeoul National UniversitySeoulRepublic of Korea
- Plant Genomics and Breeding InstituteSeoul National UniversitySeoulRepublic of Korea
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7
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Takasato S, Bando T, Ohnishi K, Tsuzuki M, Hikichi Y, Kiba A. Phosphatidylinositol-phospholipase C3 negatively regulates the hypersensitive response via complex signaling with MAP kinase, phytohormones, and reactive oxygen species in Nicotiana benthamiana. J Exp Bot 2023; 74:4721-4735. [PMID: 37191942 PMCID: PMC10433933 DOI: 10.1093/jxb/erad184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 05/15/2023] [Indexed: 05/17/2023]
Abstract
Phospholipid signaling plays important roles in plant immune responses. Here, we focused on two phospholipase C3 (PLC3) orthologs in the Nicotiana benthamiana genome, NbPLC3-1 and NbPLC3-2. We generated NbPLC3-1 and NbPLC3-2-double-silenced plants (NbPLC3s-silenced plants). In NbPLC3s-silenced plants challenged with Ralstonia solanacearum 8107, induction of hypersensitive response (HR)-related cell death and bacterial population reduction was accelerated, and the expression level of Nbhin1, a HR marker gene, was enhanced. Furthermore, the expression levels of genes involved in salicylic acid and jasmonic acid signaling drastically increased, reactive oxygen species production was accelerated, and NbMEK2-induced HR-related cell death was also enhanced. Accelerated HR-related cell death was also observed by bacterial pathogens Pseudomonas cichorii, P. syringae, bacterial AvrA, oomycete INF1, and TMGMV-CP with L1 in NbPLC3s-silenced plants. Although HR-related cell death was accelerated, the bacterial population was not reduced in double NbPLC3s and NbCoi1-suppressed plants nor in NbPLC3s-silenced NahG plants. HR-related cell death acceleration and bacterial population reduction resulting from NbPLC3s-silencing were compromised by the concomitant suppression of either NbPLC3s and NbrbohB (respiratory oxidase homolog B) or NbPLC3s and NbMEK2 (mitogen activated protein kinase kinase 2). Thus, NbPLC3s may negatively regulate both HR-related cell death and disease resistance through MAP kinase- and reactive oxygen species-dependent signaling. Disease resistance was also regulated by NbPLC3s through jasmonic acid- and salicylic acid-dependent pathways.
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Affiliation(s)
- Shiori Takasato
- Laboratory of Plant Pathology and Biotechnology, Faculty of Agriculture and Marine Science Kochi University, Nankoku, Kochi 783-8502, Japan
| | - Takuya Bando
- Laboratory of Plant Pathology and Biotechnology, Faculty of Agriculture and Marine Science Kochi University, Nankoku, Kochi 783-8502, Japan
| | - Kouhei Ohnishi
- Laboratory of Defense in Plant–Pathogen Interactions, Research Institute of Molecular Genetics, Kochi University, Nankoku, Kochi 783-8502, Japan
| | - Masayuki Tsuzuki
- Laboratory of Plant Pathology and Biotechnology, Faculty of Agriculture and Marine Science Kochi University, Nankoku, Kochi 783-8502, Japan
| | - Yasufumi Hikichi
- Laboratory of Plant Pathology and Biotechnology, Faculty of Agriculture and Marine Science Kochi University, Nankoku, Kochi 783-8502, Japan
| | - Akinori Kiba
- Laboratory of Plant Pathology and Biotechnology, Faculty of Agriculture and Marine Science Kochi University, Nankoku, Kochi 783-8502, Japan
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Ouyang X, Chen J, Sun Z, Wang R, Wu X, Li B, Song C, Liu P, Zhang M. Ubiquitin E3 ligase activity of Ralstonia solanacearum effector RipAW is not essential for induction of plant defense in Nicotiana benthamiana. Front Microbiol 2023; 14:1201444. [PMID: 37293211 PMCID: PMC10244751 DOI: 10.3389/fmicb.2023.1201444] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Accepted: 05/04/2023] [Indexed: 06/10/2023] Open
Abstract
As one of the most destructive bacterial phytopathogens, Ralstonia solanacearum causes substantial annual yield losses of many important crops. Deciphering the functional mechanisms of type III effectors, the crucial factors mediating R. solanacearum-plant interactions, will provide a valuable basis for protecting crop plants from R. solanacearum. Recently, the NEL (novel E3 ligase) effector RipAW was found to induce cell death on Nicotiana benthamiana in a E3 ligase activity-dependent manner. Here, we further deciphered the role of the E3 ligase activity in RipAW-triggered plant immunity. We found that RipAWC177A, the E3 ligase mutant of RipAW, could not induce cell death but retained the ability of triggering plant immunity in N. benthamiana, indicating that the E3 ligase activity is not essential for RipAW-triggered immunity. By generating truncated mutants of RipAW, we further showed that the N-terminus, NEL domain and C-terminus are all required but not sufficient for RipAW-induced cell death. Furthermore, all truncated mutants of RipAW triggered ETI immune responses in N. benthamiana, confirming that the E3 ligase activity is not essential for RipAW-triggered plant immunity. Finally, we demonstrated that RipAW- and RipAWC177A-triggered immunity in N. benthamiana requires SGT1 (suppressor of G2 allele of skp1), but not EDS1 (enhanced disease susceptibility), NRG1 (N requirement gene 1), NRC (NLR required for cell death) proteins or SA (salicylic acid) pathway. Our findings provide a typical case in which the effector-induced cell death can be uncoupled with immune responses, shedding new light on effector-triggered plant immunity. Our data also provide clues for further in-depth study of mechanism underlying RipAW-induced plant immunity.
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Affiliation(s)
- Xue Ouyang
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, China
| | - Jialan Chen
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, China
| | - Zhimao Sun
- National Engineering Laboratory for Endangered Medicinal Resource Development in Northwest China, Key Laboratory of Medicinal Resources and Natural Pharmaceutical Chemistry of Ministry of Education, College of Life Sciences, Shaanxi Normal University, Xi’an, China
| | - Rongbo Wang
- Fujian Key Laboratory for Monitoring and Integrated Management of Crop Pests, Institute of Plant Protection, Fujian Academy of Agricultural Sciences, Fuzhou, China
| | - Xuan Wu
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, China
| | - Benjin Li
- Fujian Key Laboratory for Monitoring and Integrated Management of Crop Pests, Institute of Plant Protection, Fujian Academy of Agricultural Sciences, Fuzhou, China
| | - Congfeng Song
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, China
| | - Peiqing Liu
- Fujian Key Laboratory for Monitoring and Integrated Management of Crop Pests, Institute of Plant Protection, Fujian Academy of Agricultural Sciences, Fuzhou, China
| | - Meixiang Zhang
- National Engineering Laboratory for Endangered Medicinal Resource Development in Northwest China, Key Laboratory of Medicinal Resources and Natural Pharmaceutical Chemistry of Ministry of Education, College of Life Sciences, Shaanxi Normal University, Xi’an, China
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Miao Y, Wu L, Xue Q, Zhang Q, Zou H. Ralstonia solanacearum type III effector RipAA targets chloroplastic AtpB to modulate an incompatible interaction on Nicotiana benthamiana. Front Microbiol 2023; 14:1179824. [PMID: 37275133 PMCID: PMC10232776 DOI: 10.3389/fmicb.2023.1179824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2023] [Accepted: 03/30/2023] [Indexed: 06/07/2023] Open
Abstract
Introduction The type III effector RipAA of Ralstonia solanacearum GMI1000 plays a critical role in the incompatible interaction on Nicotiana benthamiana. Methods The RipAA was transiently expressed in N. benthamiana by Agrobacterium-mediated transformation. Chemical staining with trypan blue and DAB were conducted to examine the cell death and the accumulation of hydrogen peroxide (H2O2), respectively. The expression of the marker genes for salicylic acid (SA) and jasmonic acid (JA) signaling was evaluated by quantitative reverse transcription PCR (qRT-PCR). The proteins interacted with RipAA was identified from N. benthamiana by yeast two-hybrid and pull-down assays. A TRV-mediated gene silencing was used to assess the role of host gene in response to RipAA expression and R. solanacearum infection. Results and discussion RipAA induced the accumulation of hydrogen peroxide (H2O2) and genome DNA degradation in N. benthamiana, which were accompanied by a hypersensitive reaction. Simultaneously, the marker genes for salicylic acid (SA) signaling were induced and those for jasmonic acid (JA) signaling were reduced. N. benthamiana chloroplastic AtpB, the ATPase β subunit, was identified as an interactor with RipAA. The silencing of atpB in N. benthamiana resulted in the inability of RipAA to induce a hypersensitive response, a compatible interaction with GMI1000, and an enhanced sensitivity to bacterial wilt. Our data support the concept that RipAA determines host-range specificity by targeting the host chloroplastic AtpB.
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Cong S, Li JZ, Xiong ZZ, Wei HL. Diverse interactions of five core type III effectors from Ralstonia solanacearum with plants. J Genet Genomics 2023; 50:341-352. [PMID: 35597445 DOI: 10.1016/j.jgg.2022.04.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Revised: 04/29/2022] [Accepted: 04/30/2022] [Indexed: 11/24/2022]
Abstract
Ralstonia solanacearum is a widespread plant bacterial pathogen that can launch a range of type III effectors (T3Es) to cause disease. In this study, we isolate a pathogenic R. solanacearum strain named P380 from tomato rhizosphere. Five out of 12 core T3Es of strain P380 are introduced into Pseudomonas syringae DC3000D36E separately to determine their functions in interacting with plants. DC3000D36E that harbors each effector suppresses FliC-triggered Pti5 and ACRE31 expression, ROS burst, and callose deposition. RipAE, RipU, and RipW elicit cell death as well as upregulate the MAPK cascades in Nicotiana benthamiana. The derivatives RipC1ΔDXDX(T/V) and RipWΔDKXXQ but not RipAEK310R fail to suppress ROS burst. Moreover, RipAEK310R and RipWΔDKXXQ retain the cell death elicitation ability. RipAE and RipW are associated with salicylic acid and jasmonic acid pathways, respectively. RipAE and RipAQ significantly promote the propagation of DC3000D36E in plants. The five core T3Es localize in diverse subcellular organelles of nucleus, plasma membrane, endoplasmic reticulum, and Golgi network. The suppressor of G2 allele of Skp1 is required for RipAE but not RipU-triggered cell death in N. benthamiana. These results indicate that the core T3Es in R. solanacearum play diverse roles in plant-pathogen interactions.
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Affiliation(s)
- Shen Cong
- Key Laboratory of Microbial Resources Collection and Preservation, Ministry of Agriculture and Rural Affairs, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Jun-Zhou Li
- Key Laboratory of Microbial Resources Collection and Preservation, Ministry of Agriculture and Rural Affairs, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Zheng-Zhong Xiong
- Key Laboratory of Microbial Resources Collection and Preservation, Ministry of Agriculture and Rural Affairs, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Hai-Lei Wei
- Key Laboratory of Microbial Resources Collection and Preservation, Ministry of Agriculture and Rural Affairs, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
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Fukui K, Ohnishi K, Hikichi Y, Kiba A. Phosphatidylinositol-phospholipase C4 suppresses the hypersensitive response of Nicotiana benthamiana. Plant Biotechnol (Tokyo) 2023; 40:87-92. [PMID: 38213930 PMCID: PMC10777131 DOI: 10.5511/plantbiotechnology.22.1207a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Accepted: 12/07/2022] [Indexed: 01/13/2024]
Abstract
Phospholipid signaling plays an important role in plant immune responses. Here, we isolated two phospholipase C4 (PLC4) orthologs in the Nicotiana benthamiana genome, designated as N. benthamiana PLC4-1 and PLC4-2 (NbPLC4-1 and NbPLC4-2). We created NbPLC4-1- and NbPLC4-2- silenced plants. Induction of the hypersensitive response (HR), including HR cell death and bacterial population reduction, was accelerated in both NbPLC4-1- and NbPLC4-2-silenced plants challenged with N. benthamiana-incompatible Ralstonia solanacearum 8107. The NbPLC4-1- and NbPLC4-2-silenced plants also showed enhanced expression of Nbhin1, a HR marker gene. Expressions of genes for salicylic acid (SA) and jasmonic acid (JA) signaling were drastically increased in NbPLC4-1- and NbPLC4-2-silenced plants by R. solanacearum inoculation. In addition, NbPLC4-1 and NbPLC4-2 silencing triggered reactive oxygen species (ROS) hyper-production. These results suggest that NbPLC4s are closely associated with JA, SA, and ROS signaling and act as negative regulators of the HR in N. benthamiana.
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Affiliation(s)
- Kotoko Fukui
- Laboratory of Plant Pathology and Biotechnology, Faculty of Agriculture and Marine Science, Kochi University, Nankoku, Kochi 783-8502, Japan
| | - Kouhei Ohnishi
- Laboratory of Defense in Plant-Pathogen Interactions, Research Institute of Molecular Genetics, Kochi University, Nankoku, Kochi 783-8502, Japan
| | - Yasufumi Hikichi
- Laboratory of Plant Pathology and Biotechnology, Faculty of Agriculture and Marine Science, Kochi University, Nankoku, Kochi 783-8502, Japan
| | - Akinori Kiba
- Laboratory of Plant Pathology and Biotechnology, Faculty of Agriculture and Marine Science, Kochi University, Nankoku, Kochi 783-8502, Japan
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Huang M, Tan X, Song B, Wang Y, Cheng D, Wang B, Chen H. Comparative genomic analysis of Ralstonia solanacearum reveals candidate avirulence effectors in HA4-1 triggering wild potato immunity. Front Plant Sci 2023; 14:1075042. [PMID: 36909411 PMCID: PMC9997847 DOI: 10.3389/fpls.2023.1075042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Accepted: 02/13/2023] [Indexed: 06/18/2023]
Abstract
Ralstonia solanacearum is the causal agent of potato bacterial wilt, a major potato bacterial disease. Among the pathogenicity determinants, the Type III Secretion System Effectors (T3Es) play a vital role in the interaction. Investigating the avirulent T3Es recognized by host resistance proteins is an effective method to uncover the resistance mechanism of potato against R. solanacearum. Two closely related R. solanacearum strains HA4-1 and HZAU091 were found to be avirulent and highly virulent to the wild potato Solanum albicans 28-1, respectively. The complete genome of HZAU091 was sequenced in this study. HZAU091 and HA4-1 shared over 99.9% nucleotide identity with each other. Comparing genomics of closely related strains provides deeper insights into the interaction between hosts and pathogens, especially the mechanism of virulence. The comparison of type III effector repertoires between HA4-1 and HZAU091 uncovered seven distinct effectors. Two predicted effectors RipA5 and the novel effector RipBS in HA4-1 could significantly reduce the virulence of HZAU091 when they were transformed into HZAU091. Furthermore, the pathogenicity assays of mutated strains HA4-1 ΔRipS6, HA4-1 ΔRipO1, HA4-1 ΔRipBS, and HA4-1 ΔHyp6 uncovered that the absence of these T3Es enhanced the HA4-1 virulence to wild potato S. albicans 28-1. This result indicated that these T3Es may be recognized by S. albicans 28-1 as avirulence proteins to trigger the resistance. In summary, this study provides a foundation to unravel the R. solanacearum-potato interaction and facilitates the development of resistance potato against bacterial wilt.
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Affiliation(s)
- Mengshu Huang
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Huazhong Agricultural University, Wuhan, Hubei, China
- Key Laboratory of Potato Biology and Biotechnology (HZAU), Ministry of Agriculture and Rural Affairs, Wuhan, Hubei, China
- College of Horticulture and Forestry Science, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Xiaodan Tan
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Huazhong Agricultural University, Wuhan, Hubei, China
- Key Laboratory of Potato Biology and Biotechnology (HZAU), Ministry of Agriculture and Rural Affairs, Wuhan, Hubei, China
- College of Horticulture and Forestry Science, Huazhong Agricultural University, Wuhan, Hubei, China
- Guangdong University Key Laboratory for Sustainable Control of Fruit and Vegetable Diseases and Pests & Key Laboratory of Green Prevention and Control on Fruits and Vegetables in South China, Ministry of Agriculture and Rural Affairs, Zhongkai University of Agriculture and Engineering, Guangzhou, China
| | - Botao Song
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Huazhong Agricultural University, Wuhan, Hubei, China
- Key Laboratory of Potato Biology and Biotechnology (HZAU), Ministry of Agriculture and Rural Affairs, Wuhan, Hubei, China
- College of Horticulture and Forestry Science, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Yuqi Wang
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Huazhong Agricultural University, Wuhan, Hubei, China
- Key Laboratory of Potato Biology and Biotechnology (HZAU), Ministry of Agriculture and Rural Affairs, Wuhan, Hubei, China
- College of Horticulture and Forestry Science, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Dong Cheng
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Huazhong Agricultural University, Wuhan, Hubei, China
- Key Laboratory of Potato Biology and Biotechnology (HZAU), Ministry of Agriculture and Rural Affairs, Wuhan, Hubei, China
- College of Horticulture and Forestry Science, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Bingsen Wang
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Huazhong Agricultural University, Wuhan, Hubei, China
- Key Laboratory of Potato Biology and Biotechnology (HZAU), Ministry of Agriculture and Rural Affairs, Wuhan, Hubei, China
- College of Horticulture and Forestry Science, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Huilan Chen
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Huazhong Agricultural University, Wuhan, Hubei, China
- Key Laboratory of Potato Biology and Biotechnology (HZAU), Ministry of Agriculture and Rural Affairs, Wuhan, Hubei, China
- College of Horticulture and Forestry Science, Huazhong Agricultural University, Wuhan, Hubei, China
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Liu JY, Zhang JF, Wu HL, Chen Z, Li SY, Li HM, Zhang CP, Zhou YQ, Lu CH. Proposal to classify Ralstonia solanacearum phylotype I strains as Ralstonia nicotianae sp. nov., and a genomic comparison between members of the genus Ralstonia. Front Microbiol 2023; 14:1135872. [PMID: 37032877 PMCID: PMC10073495 DOI: 10.3389/fmicb.2023.1135872] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Accepted: 03/07/2023] [Indexed: 04/11/2023] Open
Abstract
A Gram-negative, aerobic, rod-shaped, motile bacterium with multi-flagella, strain RST, was isolated from bacterial wilt of tobacco in Yuxi city of Yunnan province, China. The strain contains the major fatty acids of C16:0, summed feature 3 (C16:1 ω7c and/or C16:1 ω6c), and summed feature 8 (C18:1 ω7c and/or C18:1 ω6c). The polar lipid profile of strain RST consists of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, and unidentified aminophospholipid. Strain RST contains ubiquinones Q-7 and Q-8. 16S rRNA gene sequence (1,407 bp) analysis showed that strain RST is closely related to members of the genus Ralstonia and shares the highest sequence identities with R. pseudosolanacearum LMG 9673T (99.50%), R. syzygii subsp. indonesiensis LMG 27703T (99.50%), R. solanacearum LMG 2299T (99.28%), and R. syzygii subsp. celebesensis LMG 27706T (99.21%). The 16S rRNA gene sequence identities between strain RST and other members of the genus Ralstonia were below 98.00%. Genome sequencing yielded a genome size of 5.61 Mbp and a G + C content of 67.1 mol%. The genomic comparison showed average nucleotide identity (ANIb) values between strain RST and R. pseudosolanacearum LMG 9673T, R. solanacearum LMG 2299T, and R. syzygii subsp. indonesiensis UQRS 627T of 95.23, 89.43, and 91.41%, respectively, and the corresponding digital DNA-DNA hybridization (dDDH) values (yielded by formula 2) were 66.20, 44.80, and 47.50%, respectively. In addition, strains belonging to R. solanacearum phylotype I shared both ANIb and dDDH with strain RST above the species cut-off values of 96 and 70%, respectively. The ANIb and dDDH values between the genome sequences from 12 strains of R. solanacearum phylotype III (Current R. pseudosolanacearum) and those of strain RST were below the species cut-off values. Based on these data, we concluded that strains of phylotype I, including RST, represent a novel species of the genus Ralstonia, for which the name Ralstonia nicotianae sp. nov. is proposed. The type strain of Ralstonia nicotianae sp. nov. is RST (=GDMCC 1.3533T = JCM 35814T).
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Affiliation(s)
- Jun-Ying Liu
- College of Chemistry Biology and Environment, Yuxi Normal University, Yuxi, China
- Institute of Biology and Environmental Engineering, Yuxi Normal University, Yuxi, China
| | - Jian-Feng Zhang
- College of Plant Health and Medicine, Qingdao Agricultural University, Qingdao, China
| | - Han-Lian Wu
- College of Chemistry Biology and Environment, Yuxi Normal University, Yuxi, China
| | - Zhen Chen
- College of Chemistry Biology and Environment, Yuxi Normal University, Yuxi, China
| | - Shu-Ying Li
- College of Chemistry Biology and Environment, Yuxi Normal University, Yuxi, China
| | - Hong-Mei Li
- College of Chemistry Biology and Environment, Yuxi Normal University, Yuxi, China
| | - Cui-Ping Zhang
- College of Chemistry Biology and Environment, Yuxi Normal University, Yuxi, China
| | - Yuan-Qing Zhou
- College of Chemistry Biology and Environment, Yuxi Normal University, Yuxi, China
- Yuan-Qing Zhou,
| | - Can-Hua Lu
- Institute of Biology and Environmental Engineering, Yuxi Normal University, Yuxi, China
- *Correspondence: Can-Hua Lu,
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Todd JNA, Carreón-Anguiano KG, Islas-Flores I, Canto-Canché B. Fungal Effectoromics: A World in Constant Evolution. Int J Mol Sci 2022; 23:13433. [PMID: 36362218 PMCID: PMC9656242 DOI: 10.3390/ijms232113433] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 10/25/2022] [Accepted: 10/31/2022] [Indexed: 10/28/2023] Open
Abstract
Effectors are small, secreted molecules that mediate the establishment of interactions in nature. While some concepts of effector biology have stood the test of time, this area of study is ever-evolving as new effectors and associated characteristics are being revealed. In the present review, the different characteristics that underly effector classifications are discussed, contrasting past and present knowledge regarding these molecules to foster a more comprehensive understanding of effectors for the reader. Research gaps in effector identification and perspectives for effector application in plant disease management are also presented, with a focus on fungal effectors in the plant-microbe interaction and interactions beyond the plant host. In summary, the review provides an amenable yet thorough introduction to fungal effector biology, presenting noteworthy examples of effectors and effector studies that have shaped our present understanding of the field.
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Affiliation(s)
- Jewel Nicole Anna Todd
- Unidad de Biotecnología, Centro de Investigación Científica de Yucatán, A.C., Calle 43 No. 130 x 32 y 34, Colonia Chuburná de Hidalgo, Mérida C.P. 97205, Yucatán, Mexico
| | - Karla Gisel Carreón-Anguiano
- Unidad de Biotecnología, Centro de Investigación Científica de Yucatán, A.C., Calle 43 No. 130 x 32 y 34, Colonia Chuburná de Hidalgo, Mérida C.P. 97205, Yucatán, Mexico
| | - Ignacio Islas-Flores
- Unidad de Bioquímica y Biología Molecular de Plantas, Centro de Investigación Científica de Yucatán, A.C., Calle 43 No. 130 x 32 y 34, Colonia Chuburná de Hidalgo, Mérida C.P. 97205, Yucatán, Mexico
| | - Blondy Canto-Canché
- Unidad de Biotecnología, Centro de Investigación Científica de Yucatán, A.C., Calle 43 No. 130 x 32 y 34, Colonia Chuburná de Hidalgo, Mérida C.P. 97205, Yucatán, Mexico
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An Y, Chen J, Xu Z, Ouyang X, Cao P, Wang R, Liu P, Zhang M. Three amino acid residues are required for the recognition of Ralstonia solanacearum RipTPS in Nicotiana tabacum. Front Plant Sci 2022; 13:1040826. [PMID: 36311066 PMCID: PMC9606615 DOI: 10.3389/fpls.2022.1040826] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Accepted: 09/27/2022] [Indexed: 06/10/2023]
Abstract
Ralstonia solanacearum causes devastating diseases in a wide range of economically important crops. It secretes a large number of virulence factors, also known as effectors, to promote its infection, and some of them are recognized when the host plant contains corresponding resistance genes. In this study we showed that a type III effector RipTPS from the avirulent R. solanacearum strain GMI1000 (RipTPSG) specifically induced cell death in Nicotiana tabacum, but not in Nicotiana benthamiana, whereas the RipTPS homolog in the virulent strain CQPS-1 (RipTPSC) induced cell death in neither N. tabacum nor N. benthamiana. These results indicated that RipTPSG is recognized in N. tabacum. Expression of RipTPSG induced upregulation of hypersensitive response (HR) -related genes in N. tabacum. The virulence of CQPS-1 was reduced when RipTPSG was genetically introduced into CQPS-1, further confirming that RipTPSG functions as an avirulence determinant. Protein sequence alignment indicated that there are only three amino acid polymorphisms between RipTPSG and RipTPSC. Site-directed mutagenesis analyses confirmed that the three amino acid residues are jointly required for the recognition of RipTPSG in N. tabacum. Expression of either RipTPSG or RipTPSC suppressed flg22-triggered reactive oxygen species (ROS) burst in N. benthamiana, suggesting that RipTPS contributes to pathogen virulence. Mutating the conserved residues in RipTPS's trehalose-phosphate synthase (TPS) domain did not block its HR induction and defense suppression activity, indicating that the TPS activity is not required for RipTPS's avirulence and virulence function.
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Affiliation(s)
- Yuyan An
- National Engineering Laboratory for Endangered Medicinal Resource Development in Northwest China, Key Laboratory of Medicinal Resources and Natural Pharmaceutical Chemistry of Ministry of Education, College of Life Sciences, Shaanxi Normal University, Xi’an, China
| | - Jialan Chen
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, China
| | - Zhangyan Xu
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, China
| | - Xue Ouyang
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, China
| | - Peng Cao
- National Engineering Laboratory for Endangered Medicinal Resource Development in Northwest China, Key Laboratory of Medicinal Resources and Natural Pharmaceutical Chemistry of Ministry of Education, College of Life Sciences, Shaanxi Normal University, Xi’an, China
| | - Rongbo Wang
- Fujian Key Laboratory for Monitoring and Integrated Management of Crop Pests, Institute of Plant Protection, Fujian Academy of Agricultural Sciences, Fuzhou, China
| | - Peiqing Liu
- Fujian Key Laboratory for Monitoring and Integrated Management of Crop Pests, Institute of Plant Protection, Fujian Academy of Agricultural Sciences, Fuzhou, China
| | - Meixiang Zhang
- National Engineering Laboratory for Endangered Medicinal Resource Development in Northwest China, Key Laboratory of Medicinal Resources and Natural Pharmaceutical Chemistry of Ministry of Education, College of Life Sciences, Shaanxi Normal University, Xi’an, China
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Cao P, Chen J, Wang R, Zhao M, Zhang S, An Y, Liu P, Zhang M. A conserved type III effector RipB is recognized in tobacco and contributes to Ralstonia solanacearum virulence in susceptible host plants. Biochem Biophys Res Commun 2022; 631:18-24. [PMID: 36162325 DOI: 10.1016/j.bbrc.2022.09.062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Accepted: 09/15/2022] [Indexed: 11/02/2022]
Abstract
Ralstonia solanacearum, the causal agent of bacterial wilt, causes devastating diseases in a wide range of plants including potato, tomato, pepper and tobacco. The pathogen delivers approximately 70 type III effectors (T3Es) into plant cells during infection. In this study, we confirmed that a T3E RipB is recognized in tobacco. We further demonstrated that RipB is conserved among R. solanacearum isolates and five different ripB alleles are all recognized in tobacco. The ripB from GMI1000 was transformed into susceptible host Arabidopsis, and a defect in root development was observed in ripB-transgenic plants. Pathogen inoculation assays showed that ripB expression promoted plant susceptibility to R. solanacearum infection, indicating that RipB contributes to pathogen virulence in Arabidopsis. Expression of ripB in roq1 mutant partially suppressed reactive oxygen species production, confirming that RipB interferes with plant basal defense. Interestingly, ripB expression promoted cytokinin-related gene expression in Arabidopsis, suggesting a role of cytokinin signaling pathway in plant-R. solanacearum interactions. Finally, RipB harbors potential 14-3-3 binding motifs, but the associations between RipB and 14-3-3 proteins were undetectable in yeast two-hybrid assay. Together, our results demonstrate that multiple ripB alleles are recognized in Nicotiana, and RipB suppresses basal defense in susceptible host to promote R. solanacearum infection.
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Affiliation(s)
- Peng Cao
- National Engineering Laboratory for Endangered Medicinal Resource Development in Northwest China, Key Laboratory of Medicinal Resources and Natural Pharmaceutical Chemistry of Ministry of Education, College of Life Sciences, Shaanxi Normal University, Xi'an, China
| | - Jialan Chen
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China
| | - Rongbo Wang
- Fujian Key Laboratory for Monitoring and Integrated Management of Crop Pests, Fuzhou, 350013, China
| | - Mengwei Zhao
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China
| | - Shuangxi Zhang
- National Engineering Laboratory for Endangered Medicinal Resource Development in Northwest China, Key Laboratory of Medicinal Resources and Natural Pharmaceutical Chemistry of Ministry of Education, College of Life Sciences, Shaanxi Normal University, Xi'an, China
| | - Yuyan An
- National Engineering Laboratory for Endangered Medicinal Resource Development in Northwest China, Key Laboratory of Medicinal Resources and Natural Pharmaceutical Chemistry of Ministry of Education, College of Life Sciences, Shaanxi Normal University, Xi'an, China
| | - Peiqing Liu
- Fujian Key Laboratory for Monitoring and Integrated Management of Crop Pests, Fuzhou, 350013, China.
| | - Meixiang Zhang
- National Engineering Laboratory for Endangered Medicinal Resource Development in Northwest China, Key Laboratory of Medicinal Resources and Natural Pharmaceutical Chemistry of Ministry of Education, College of Life Sciences, Shaanxi Normal University, Xi'an, China.
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17
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Suraby EJ, Sruthi KB, Antony G. Genome-wide identification of type III effectors and other virulence factors in Ralstonia pseudosolanacearum causing bacterial wilt in ginger (Zingiber officinale). Mol Genet Genomics 2022; 297:1371-1388. [PMID: 35879566 DOI: 10.1007/s00438-022-01925-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Accepted: 07/04/2022] [Indexed: 10/16/2022]
Abstract
Ralstonia pseudosolanacearum causes bacterial wilt in ginger, reducing ginger production worldwide. We sequenced the whole genome of a highly virulent phylotype I, race 4, biovar 3 Ralstonia pseudosolanacearum strain GRsMep isolated from a severely infected ginger field in India. R. pseudosolanacearum GRsMep genome is organised into two replicons: chromosome and megaplasmid with a total genome size of 5,810,605 bp. This strain encodes approximately 72 effectors which include a combination of core effectors as well as highly variable, diverse repertoire of type III effectors. Comparative genome analysis with GMI1000 identified conservation in the genes involved in the general virulence mechanism. Our analysis identified type III effectors, RipBJ and RipBO as present in GRsMep but absent in the reported genomes of other strains infecting Zingiberaceae family. GRsMep contains 126 unique genes when compared to the pangenome of the Ralstonia strains that infect the Zingiberaceae family. The whole-genome data of R. pseudosolanacearum strain will serve as a resource for exploring the evolutionary processes that structure and regulate the virulence determinants of the strain. Pathogenicity testing of the transposon insertional mutant library of GRsMep through virulence assay on ginger plants identified a few candidate virulence determinants specific to bacterial wilt in ginger.
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Affiliation(s)
- Erinjery Jose Suraby
- Department of Plant Science, Central University of Kerala, Periye, 671320, Kasaragod, Kerala, India
| | - K Bharathan Sruthi
- Department of Plant Science, Central University of Kerala, Periye, 671320, Kasaragod, Kerala, India
| | - Ginny Antony
- Department of Plant Science, Central University of Kerala, Periye, 671320, Kasaragod, Kerala, India.
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18
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Zhuo T, Chen S, Wang D, Fan X, Zhang X, Zou H. Expression of the ripAA Gene in the Soilborne Pseudomonas mosselii Can Promote the Control Efficacy against Tobacco Bacterial Wilt. Biology 2022; 11:1170. [PMID: 36009798 PMCID: PMC9405386 DOI: 10.3390/biology11081170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 07/27/2022] [Accepted: 07/30/2022] [Indexed: 11/19/2022]
Abstract
Simple Summary Tobacco bacterial wilt caused by Ralstonia solanacearum brings large economic losses every year. Currently, an increasing number of biocontrol agents have been widely used in the control of this disease, but they cannot replace chemical agents, mostly due to the poorer control effect. Therefore, in this study, the avirulence gene ripAA from Ralstonia solanacearum, which determines incompatible interactions with tobacco plants, was introduced into the biocontrol agent Pseudomonas mosselii to increase the efficacy against Ralstonia solanacearum. The newly engineered strain can improve the systemic resistance and elicit a primary immune response of plants. Our research not only provides a new strategy for the genetic modification of biocontrol agents, in which a number of avirulence genes from the pathogen or plant can be tested to be expressed in different biocontrol agents to antagonize this plant disease, but also helps the study of the interaction between the phytopathogenic avirulence gene and the host. Abstract The environmental bacterium Pseudomonas mosselii produces antagonistic secondary metabolites with inhibitory effects on multiple plant pathogens, including Ralstonia solanacearum, the causal agent of bacterial wilt. In this study, an engineered P. mosselii strain was generated to express R. solanacearum ripAA, which determines the incompatible interactions with tobacco plants. The ripAA gene, together with its native promoter, was integrated into the P. mosselii chromosome. The resulting strain showed no difference in antimicrobial activity against R. solanacearum. Promoter-LacZ fusion and RT-PCR experiments demonstrated that the ripAA gene was transcribed in culture media. Compared with that of the wild type, the engineered strain reduced the disease index by 9.1% for bacterial wilt on tobacco plants. A transcriptome analysis was performed to identify differentially expressed genes in tobacco plants, and the results revealed that ethylene- and jasmonate-dependent defense signaling pathways were induced. These data demonstrates that the engineered P. mosselii expressing ripAA can improve biological control against tobacco bacterial wilt by the activation of host defense responses.
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19
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Tan X, Dai X, Chen T, Wu Y, Yang D, Zheng Y, Chen H, Wan X, Yang Y. Complete Genome Sequence Analysis of Ralstonia solanacearum Strain PeaFJ1 Provides Insights Into Its Strong Virulence in Peanut Plants. Front Microbiol 2022; 13:830900. [PMID: 35273586 PMCID: PMC8904134 DOI: 10.3389/fmicb.2022.830900] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 01/12/2022] [Indexed: 11/22/2022] Open
Abstract
The bacterial wilt of peanut (Arachis hypogaea L.) caused by Ralstonia solanacearum is a devastating soil-borne disease that seriously restricted the world peanut production. However, the molecular mechanism of R. solanacearum–peanut interaction remains largely unknown. We found that R. solanacearum HA4-1 and PeaFJ1 isolated from peanut plants showed different pathogenicity by inoculating more than 110 cultivated peanuts. Phylogenetic tree analysis demonstrated that HA4-1 and PeaFJ1 both belonged to phylotype I and sequevar 14M, which indicates a high degree of genomic homology between them. Genomic sequencing and comparative genomic analysis of PeaFJ1 revealed 153 strain-specific genes compared with HA4-1. The PeaFJ1 strain-specific genes consisted of diverse virulence-related genes including LysR-type transcriptional regulators, two-component system-related genes, and genes contributing to motility and adhesion. In addition, the repertoire of the type III effectors of PeaFJ1 was bioinformatically compared with that of HA4-1 to find the candidate effectors responsible for their different virulences. There are 79 effectors in the PeaFJ1 genome, only 4 of which are different effectors compared with HA4-1, including RipS4, RipBB, RipBS, and RS_T3E_Hyp6. Based on the virulence profiles of the two strains against peanuts, we speculated that RipS4 and RipBB are candidate virulence effectors in PeaFJ1 while RipBS and RS_T3E_Hyp6 are avirulence effectors in HA4-1. In general, our research greatly reduced the scope of virulence-related genes and made it easier to find out the candidates that caused the difference in pathogenicity between the two strains. These results will help to reveal the molecular mechanism of peanut–R. solanacearum interaction and develop targeted control strategies in the future.
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Affiliation(s)
- Xiaodan Tan
- Guangzhou Key Laboratory for Research and Development of Crop Germplasm Resources, Zhongkai University of Agriculture and Engineering, Guangzhou, China
| | - Xiaoqiu Dai
- Guangzhou Key Laboratory for Research and Development of Crop Germplasm Resources, Zhongkai University of Agriculture and Engineering, Guangzhou, China
| | - Ting Chen
- Guangzhou Key Laboratory for Research and Development of Crop Germplasm Resources, Zhongkai University of Agriculture and Engineering, Guangzhou, China
| | - Yushuang Wu
- Guangzhou Key Laboratory for Research and Development of Crop Germplasm Resources, Zhongkai University of Agriculture and Engineering, Guangzhou, China
| | - Dong Yang
- Guangzhou Key Laboratory for Research and Development of Crop Germplasm Resources, Zhongkai University of Agriculture and Engineering, Guangzhou, China
| | - Yixiong Zheng
- Guangzhou Key Laboratory for Research and Development of Crop Germplasm Resources, Zhongkai University of Agriculture and Engineering, Guangzhou, China
| | - Huilan Chen
- Key Laboratory of Horticultural Plant Biology (HZAU), Ministry of Education, Key Laboratory of Potato Biology and Biotechnology (HZAU), Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan, China
| | - Xiaorong Wan
- Guangzhou Key Laboratory for Research and Development of Crop Germplasm Resources, Zhongkai University of Agriculture and Engineering, Guangzhou, China
| | - Yong Yang
- Guangzhou Key Laboratory for Research and Development of Crop Germplasm Resources, Zhongkai University of Agriculture and Engineering, Guangzhou, China
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20
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Niu Y, Fu S, Chen G, Wang H, Wang Y, Hu J, Jin X, Zhang M, Lu M, He Y, Wang D, Chen Y, Zhang Y, Coll NS, Valls M, Zhao C, Chen Q, Lu H. Different epitopes of Ralstonia solanacearum effector RipAW are recognized by two Nicotiana species and trigger immune responses. Mol Plant Pathol 2022; 23:188-203. [PMID: 34719088 PMCID: PMC8743020 DOI: 10.1111/mpp.13153] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 09/27/2021] [Accepted: 09/27/2021] [Indexed: 05/17/2023]
Abstract
Diverse pathogen effectors convergently target conserved components in plant immunity guarded by intracellular nucleotide-binding domain leucine-rich repeat receptors (NLRs) and activate effector-triggered immunity (ETI), often causing cell death. Little is known of the differences underlying ETI in different plants triggered by the same effector. In this study, we demonstrated that effector RipAW triggers ETI on Nicotiana benthamiana and Nicotiana tabacum. Both the first 107 amino acids (N1-107 ) and RipAW E3-ligase activity are required but not sufficient for triggering ETI on N. benthamiana. However, on N. tabacum, the N1-107 fragment is essential and sufficient for inducing cell death. The first 60 amino acids of the protein are not essential for RipAW-triggered cell death on either N. benthamiana or N. tabacum. Furthermore, simultaneous mutation of both R75 and R78 disrupts RipAW-triggered ETI on N. tabacum, but not on N. benthamiana. In addition, N. tabacum recognizes more RipAW orthologs than N. benthamiana. These data showcase the commonalities and specificities of RipAW-activated ETI in two evolutionally related species, suggesting Nicotiana species have acquired different abilities to perceive RipAW and activate plant defences during plant-pathogen co-evolution.
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Affiliation(s)
- Yang Niu
- State Key Laboratory of Crop Stress Biology for Arid AreasCollege of AgronomyNorthwest A&F UniversityYanglingChina
| | - Shouyang Fu
- State Key Laboratory of Crop Stress Biology for Arid AreasCollege of AgronomyNorthwest A&F UniversityYanglingChina
| | - Gong Chen
- State Key Laboratory of Crop Stress Biology for Arid AreasCollege of AgronomyNorthwest A&F UniversityYanglingChina
| | - Huijuan Wang
- State Key Laboratory of Crop Stress Biology for Arid AreasCollege of AgronomyNorthwest A&F UniversityYanglingChina
| | - Yisa Wang
- State Key Laboratory of Crop Stress Biology for Arid AreasCollege of AgronomyNorthwest A&F UniversityYanglingChina
| | - JinXue Hu
- State Key Laboratory of Crop Stress Biology for Arid AreasCollege of AgronomyNorthwest A&F UniversityYanglingChina
| | - Xin Jin
- State Key Laboratory of Crop Stress Biology for Arid AreasCollege of AgronomyNorthwest A&F UniversityYanglingChina
| | - Mancang Zhang
- State Key Laboratory of Crop Stress Biology for Arid AreasCollege of AgronomyNorthwest A&F UniversityYanglingChina
| | - Mingxia Lu
- State Key Laboratory of Crop Stress Biology for Arid AreasCollege of AgronomyNorthwest A&F UniversityYanglingChina
| | - Yizhe He
- State Key Laboratory of Crop Stress Biology for Arid AreasCollege of AgronomyNorthwest A&F UniversityYanglingChina
| | - Dongdong Wang
- Shaanxi Key State Laboratory of Crop HeterosisNorthwest A&F UniversityYanglingChina
| | - Yue Chen
- State Key Laboratory of Crop Stress Biology for Arid AreasCollege of AgronomyNorthwest A&F UniversityYanglingChina
| | - Yong Zhang
- College of Food Science and EngineeringNorthwest A&F UniversityYanglingChina
- College of Resources and EnvironmentSouthwest UniversityChongqingChina
| | - Núria S. Coll
- Interdisciplinary Research Center for Agriculture Green Development in Yangtze River BasinSoutheast UniversityChongqingChina
| | - Marc Valls
- Interdisciplinary Research Center for Agriculture Green Development in Yangtze River BasinSoutheast UniversityChongqingChina
- Centre for Research in Agricultural GenomicsCSIC‐IRTA‐UAB‐UBBellaterraCataloniaSpain
| | - Cuizhu Zhao
- State Key Laboratory of Crop Stress Biology for Arid AreasCollege of AgronomyNorthwest A&F UniversityYanglingChina
| | - Qin Chen
- Shaanxi Key State Laboratory of Crop HeterosisNorthwest A&F UniversityYanglingChina
| | - Haibin Lu
- State Key Laboratory of Crop Stress Biology for Arid AreasCollege of AgronomyNorthwest A&F UniversityYanglingChina
- Department of GeneticsUniversity of BarcelonaBarcelonaSpain
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21
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Laili N, Mukaihara T, Matsui H, Yamamoto M, Noutoshi Y, Toyoda K, Ichinose Y. Role of Trehalose Synthesis in Ralstonia syzygii subsp. indonesiensis PW1001 in Inducing Hypersensitive Response on Eggplant (Solanum melongena cv. Senryo-nigou). Plant Pathol J 2021; 37:566-579. [PMID: 34897249 PMCID: PMC8666247 DOI: 10.5423/ppj.oa.06.2021.0087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 10/08/2021] [Accepted: 10/12/2021] [Indexed: 06/14/2023]
Abstract
Ralstonia syzygii subsp. indonesiensis (Rsi, former name: Ralstonia solanacearum phylotype IV) PW1001, a causal agent of potato wilt disease, induces hypersensitive response (HR) on its non-host eggplant (Solanum melongena cv. Senryo-nigou). The disaccharide trehalose is involved in abiotic and biotic stress tolerance in many organisms. We found that trehalose is required for eliciting HR on eggplant by plant pathogen Rsi PW1001. In R. solanacearum, it is known that the OtsA/OtsB pathway is the dominant trehalose synthesis pathway, and otsA and otsB encode trehalose-6-phosphate (T6P) synthase and T6P phosphatase, respectively. We generated otsA and otsB mutant strains and found that these mutant strains reduced the bacterial trehalose concentration and HR induction on eggplant leaves compared to wild-type. Trehalose functions intracellularly in Rsi PW1001 because addition of exogenous trehalose did not affect the HR level and ion leakage. Requirement of trehalose in HR induction is not common in R. solanacearum species complex because mutation of otsA in Ralstonia pseudosolanacearum (former name: Ralstonia solanacearum phylotype I) RS1002 did not affect HR on the leaves of its non-host tobacco and wild eggplant Solanum torvum. Further, we also found that each otsA and otsB mutant had reduced ability to grow in a medium containing NaCl and sucrose, indicating that trehalose also has an important role in osmotic stress tolerance.
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Affiliation(s)
- Nur Laili
- Graduate School of Environmental and Life Science, Okayama University, Tsushima-naka 1-1-1, Kita-ku, Okayama 700-8530,
Japan
- Research Center for Biology, Research Organization for Life Sciences, National Research and Innovation Agency (BRIN), Jl. Raya Jakarta-Bogor Km. 46, Cibinong, Bogor, West Java 16911,
Indonesia
| | - Takafumi Mukaihara
- Research Institute for Biological Sciences, Okayama (RIBS), 7549-1 Yoshikawa, Kibichuo-cho, Okayama 716-1241,
Japan
| | - Hidenori Matsui
- Graduate School of Environmental and Life Science, Okayama University, Tsushima-naka 1-1-1, Kita-ku, Okayama 700-8530,
Japan
| | - Mikihiro Yamamoto
- Graduate School of Environmental and Life Science, Okayama University, Tsushima-naka 1-1-1, Kita-ku, Okayama 700-8530,
Japan
| | - Yoshiteru Noutoshi
- Graduate School of Environmental and Life Science, Okayama University, Tsushima-naka 1-1-1, Kita-ku, Okayama 700-8530,
Japan
| | - Kazuhiro Toyoda
- Graduate School of Environmental and Life Science, Okayama University, Tsushima-naka 1-1-1, Kita-ku, Okayama 700-8530,
Japan
| | - Yuki Ichinose
- Graduate School of Environmental and Life Science, Okayama University, Tsushima-naka 1-1-1, Kita-ku, Okayama 700-8530,
Japan
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22
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Denne NL, Hiles RR, Kyrysyuk O, Iyer-Pascuzzi AS, Mitra RM. Ralstonia solanacearum Effectors Localize to Diverse Organelles in Solanum Hosts. Phytopathology 2021; 111:2213-2226. [PMID: 33720750 DOI: 10.1094/phyto-10-20-0483-r] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Phytopathogenic bacteria secrete type III effector (T3E) proteins directly into host plant cells. T3Es can interact with plant proteins and frequently manipulate plant host physiological or developmental processes. The proper subcellular localization of T3Es is critical for their ability to interact with plant targets, and knowledge of T3E localization can be informative for studies of effector function. Here we investigated the subcellular localization of 19 T3Es from the phytopathogenic bacteria Ralstonia pseudosolanacearum and Ralstonia solanacearum. Approximately 45% of effectors in our library localize to both the plant cell periphery and the nucleus, 15% exclusively to the cell periphery, 15% exclusively to the nucleus, and 25% to other organelles, including tonoplasts and peroxisomes. Using tomato hairy roots, we show that T3E localization is similar in both leaves and roots and is not impacted by Solanum species. We find that in silico prediction programs are frequently inaccurate, highlighting the value of in planta localization experiments. Our data suggest that Ralstonia targets a wide diversity of cellular organelles and provides a foundation for developing testable hypotheses about Ralstonia effector function.
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Affiliation(s)
- Nina L Denne
- Department of Biology, Carleton College, Northfield, MN 55057
| | - Rachel R Hiles
- Department of Botany and Plant Pathology and Center for Plant Biology, Purdue University, West Lafayette, IN 47907
| | | | - Anjali S Iyer-Pascuzzi
- Department of Botany and Plant Pathology and Center for Plant Biology, Purdue University, West Lafayette, IN 47907
| | - Raka M Mitra
- Department of Biology, Carleton College, Northfield, MN 55057
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23
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Pandey A, Moon H, Choi S, Yoon H, Prokchorchik M, Jayaraman J, Sujeevan R, Kang YM, McCann HC, Segonzac C, Kim CM, Park SJ, Sohn KH. Ralstonia solanacearum Type III Effector RipJ Triggers Bacterial Wilt Resistance in Solanum pimpinellifolium. Mol Plant Microbe Interact 2021; 34:962-972. [PMID: 33881922 DOI: 10.1094/mpmi-09-20-0256-r] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Ralstonia solanacearum causes bacterial wilt disease in solanaceous crops. Identification of avirulence type III-secreted effectors recognized by specific disease resistance proteins in host plant species is an important step toward developing durable resistance in crops. In the present study, we show that R. solanacearum effector RipJ functions as an avirulence determinant in Solanum pimpinellifolium LA2093. In all, 10 candidate avirulence effectors were shortlisted based on the effector repertoire comparison between avirulent Pe_9 and virulent Pe_1 strains. Infection assays with transgenic strain Pe_1 individually carrying a candidate avirulence effector from Pe_9 revealed that only RipJ elicits strong bacterial wilt resistance in S. pimpinellifolium LA2093. Furthermore, we identified that several RipJ natural variants do not induce bacterial wilt resistance in S. pimpinellifolium LA2093. RipJ belongs to the YopJ family of acetyltransferases. Our sequence analysis indicated the presence of partially conserved putative catalytic residues. Interestingly, the conserved amino acid residues in the acetyltransferase catalytic triad are not required for effector-triggered immunity. In addition, we show that RipJ does not autoacetylate its lysine residues. Our study reports the identification of the first R. solanacearum avirulence protein that triggers bacterial wilt resistance in tomato. We expect that our discovery of RipJ as an avirulence protein will accelerate the development of bacterial wilt-resistant tomato varieties in the future.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY 4.0 International license.
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Affiliation(s)
- Ankita Pandey
- Department of Life Sciences, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
| | - Hayoung Moon
- Department of Life Sciences, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
| | - Sera Choi
- Department of Life Sciences, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
| | - Hayeon Yoon
- Department of Life Sciences, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
| | - Maxim Prokchorchik
- Department of Life Sciences, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
- Institute of Crop Science and Resource Conservation (INRES), University of Bonn, Germany
| | - Jay Jayaraman
- New Zealand Institute for Plant & Food Research Limited (PFR), Mt Albert Auckland 1025, New Zealand
| | - Rajendran Sujeevan
- Division of Biological Sciences and Research Institute for Basic Science, Wonkwang University, Iksan 54538, Republic of Korea
| | - Yu Mi Kang
- Division of Horticulture Industry, Wonkwang University, Iksan 554438, Republic of Korea
| | - Honour C McCann
- Institute of Advanced Studies, Massey University, Auckland 0745, New Zealand
- Max Planck Institute for Developmental Biology, Tübingen, Germany
| | - Cécile Segonzac
- Department of Plant Science, Plant Genome and Breeding Institute, Agricultural Life Science Research Institute, Seoul National University, 08826, Seoul, Republic of Korea
- Plant Immunity Research Center, Seoul National University, 08826, Seoul, Republic of Korea
- Department of Agriculture, Forestry and Bioresources, Seoul National University, 08826, Seoul, Republic of Korea
| | - Chul Min Kim
- Division of Horticulture Industry, Wonkwang University, Iksan 554438, Republic of Korea
| | - Soon Ju Park
- Division of Biological Sciences and Research Institute for Basic Science, Wonkwang University, Iksan 54538, Republic of Korea
| | - Kee Hoon Sohn
- Department of Life Sciences, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
- School of Interdisciplinary Biosciences and Bioengineering, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
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Li Y, Jiao M, Li Y, Zhong Y, Li X, Chen Z, Chen S, Wang J. Penicillium chrysogenum polypeptide extract protects tobacco plants from tobacco mosaic virus infection through modulation of ABA biosynthesis and callose priming. J Exp Bot 2021; 72:3526-3539. [PMID: 33687058 PMCID: PMC8096601 DOI: 10.1093/jxb/erab102] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Accepted: 03/02/2021] [Indexed: 05/26/2023]
Abstract
The polypeptide extract of the dry mycelium of Penicillium chrysogenum (PDMP) can protect tobacco plants from tobacco mosaic virus (TMV), although the mechanism underlying PDMP-mediated TMV resistance remains unknown. In our study, we analysed a potential mechanism via RNA sequencing (RNA-seq) and found that the abscisic acid (ABA) biosynthetic pathway and β-1,3-glucanase, a callose-degrading enzyme, might play an important role in PDMP-induced priming of resistance to TMV. To test our hypothesis, we successfully generated a Nicotiana benthamiana ABA biosynthesis mutant and evaluated the role of the ABA pathway in PDMP-induced callose deposition during resistance to TMV infection. Our results suggested that PDMP can induce callose priming to defend against TMV movement. PDMP inhibited TMV movement by increasing callose deposition around plasmodesmata, but this phenomenon did not occur in the ABA biosynthesis mutant; moreover, these effects of PDMP on callose deposition could be rescued by treatment with exogenous ABA. Our results suggested that callose deposition around plasmodesmata in wild-type plants is mainly responsible for the restriction of TMV movement during the PDMP-induced defensive response to TMV infection, and that ABA biosynthesis apparently plays a crucial role in PDMP-induced callose priming for enhancing defence against TMV.
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Affiliation(s)
- Yu Li
- Biocontrol Engineering Research Center of Crop Disease & Pest of Yunnan Province, School of Life Science, Yunnan University, Kunming, China
- Biocontrol Engineering Research Center of Plant Disease & Pest, School of Life Science, Yunnan University, Kunming, China
| | - Mengting Jiao
- Biocontrol Engineering Research Center of Crop Disease & Pest of Yunnan Province, School of Life Science, Yunnan University, Kunming, China
- Biocontrol Engineering Research Center of Plant Disease & Pest, School of Life Science, Yunnan University, Kunming, China
| | - Yingjuan Li
- Biocontrol Engineering Research Center of Crop Disease & Pest of Yunnan Province, School of Life Science, Yunnan University, Kunming, China
- Biocontrol Engineering Research Center of Plant Disease & Pest, School of Life Science, Yunnan University, Kunming, China
| | - Yu Zhong
- Biocontrol Engineering Research Center of Crop Disease & Pest of Yunnan Province, School of Life Science, Yunnan University, Kunming, China
- Biocontrol Engineering Research Center of Plant Disease & Pest, School of Life Science, Yunnan University, Kunming, China
| | - Xiaoqin Li
- Biocontrol Engineering Research Center of Crop Disease & Pest of Yunnan Province, School of Life Science, Yunnan University, Kunming, China
- Biocontrol Engineering Research Center of Plant Disease & Pest, School of Life Science, Yunnan University, Kunming, China
| | - Zhuangzhuang Chen
- Biocontrol Engineering Research Center of Crop Disease & Pest of Yunnan Province, School of Life Science, Yunnan University, Kunming, China
- Biocontrol Engineering Research Center of Plant Disease & Pest, School of Life Science, Yunnan University, Kunming, China
| | - Suiyun Chen
- Biocontrol Engineering Research Center of Crop Disease & Pest of Yunnan Province, School of Life Science, Yunnan University, Kunming, China
- Biocontrol Engineering Research Center of Plant Disease & Pest, School of Life Science, Yunnan University, Kunming, China
| | - Jianguang Wang
- Biocontrol Engineering Research Center of Crop Disease & Pest of Yunnan Province, School of Life Science, Yunnan University, Kunming, China
- Biocontrol Engineering Research Center of Plant Disease & Pest, School of Life Science, Yunnan University, Kunming, China
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25
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Chen K, Wang L, Chen H, Zhang C, Wang S, Chu P, Li S, Fu H, Sun T, Liu M, Yang Q, Zou H, Zhuang W. Complete genome sequence analysis of the peanut pathogen Ralstonia solanacearum strain Rs-P.362200. BMC Microbiol 2021; 21:118. [PMID: 33874906 PMCID: PMC8056632 DOI: 10.1186/s12866-021-02157-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2020] [Accepted: 03/08/2021] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Bacterial wilt caused by Ralstonia solanacearum species complex is an important soil-borne disease worldwide that affects more than 450 plant species, including peanut, leading to great yield and quality losses. However, there are no effective measures to control bacterial wilt. The reason is the lack of research on the pathogenic mechanism of bacterial wilt. RESULTS Here, we report the complete genome of a toxic Ralstonia solanacearum species complex strain, Rs-P.362200, a peanut pathogen, with a total genome size of 5.86 Mb, encoding 5056 genes and the average G + C content of 67%. Among the coding genes, 75 type III effector proteins and 12 pseudogenes were predicted. Phylogenetic analysis of 41 strains including Rs-P.362200 shows that genetic distance mainly depended on geographic origins then phylotypes and host species, which associated with the complexity of the strain. The distribution and numbers of effectors and other virulence factors changed among different strains. Comparative genomic analysis showed that 29 families of 113 genes were unique to this strain compared with the other four pathogenic strains. Through the analysis of specific genes, two homologous genes (gene ID: 2_657 and 3_83), encoding virulence protein (such as RipP1) may be associated with the host range of the Rs-P.362200 strain. It was found that the bacteria contained 30 pathogenicity islands and 6 prophages containing 378 genes, 7 effectors and 363 genes, 8 effectors, respectively, which may be related to the mechanism of horizontal gene transfer and pathogenicity evaluation. Although the hosts of HA4-1 and Rs-P.362200 strains are the same, they have specific genes to their own genomes. The number of genomic islands and prophages in HA4-1 genome is more than that in Rs-P.36220, indicating a rapid change of the bacterial wilt pathogens. CONCLUSION The complete genome sequence analysis of peanut bacterial wilt pathogen enhanced the information of R. solanacearum genome. This research lays a theoretical foundation for future research on the interaction between Ralstonia solanacearum and peanut.
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Affiliation(s)
- Kun Chen
- College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, 350002, Fujian, China
| | - Lihui Wang
- College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, 350002, Fujian, China
| | - Hua Chen
- College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, 350002, Fujian, China
- College of Agronomy, Fujian Agriculture and Forestry University, Fuzhou, 350002, Fujian, China
| | - Chong Zhang
- College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, 350002, Fujian, China
- College of Agronomy, Fujian Agriculture and Forestry University, Fuzhou, 350002, Fujian, China
| | - Shanshan Wang
- College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, 350002, Fujian, China
| | - Panpan Chu
- College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, 350002, Fujian, China
| | - Shaokang Li
- College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, 350002, Fujian, China
| | - Huiwen Fu
- College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, 350002, Fujian, China
| | - Tao Sun
- College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, 350002, Fujian, China
| | - Menghan Liu
- College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, 350002, Fujian, China
| | - Qiang Yang
- College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, 350002, Fujian, China
| | - Huasong Zou
- College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, 350002, Fujian, China
| | - Weijian Zhuang
- College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, 350002, Fujian, China.
- College of Agronomy, Fujian Agriculture and Forestry University, Fuzhou, 350002, Fujian, China.
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Moon H, Pandey A, Yoon H, Choi S, Jeon H, Prokchorchik M, Jung G, Witek K, Valls M, McCann HC, Kim M, Jones JDG, Segonzac C, Sohn KH. Identification of RipAZ1 as an avirulence determinant of Ralstonia solanacearum in Solanum americanum. Mol Plant Pathol 2021; 22:317-333. [PMID: 33389783 PMCID: PMC7865085 DOI: 10.1111/mpp.13030] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Revised: 11/07/2020] [Accepted: 11/23/2020] [Indexed: 05/08/2023]
Abstract
Ralstonia solanacearum causes bacterial wilt disease in many plant species. Type III-secreted effectors (T3Es) play crucial roles in bacterial pathogenesis. However, some T3Es are recognized by corresponding disease resistance proteins and activate plant immunity. In this study, we identified the R. solanacearum T3E protein RipAZ1 (Ralstonia injected protein AZ1) as an avirulence determinant in the black nightshade species Solanum americanum. Based on the S. americanum accession-specific avirulence phenotype of R. solanacearum strain Pe_26, 12 candidate avirulence T3Es were selected for further analysis. Among these candidates, only RipAZ1 induced a cell death response when transiently expressed in a bacterial wilt-resistant S. americanum accession. Furthermore, loss of ripAZ1 in the avirulent R. solanacearum strain Pe_26 resulted in acquired virulence. Our analysis of the natural sequence and functional variation of RipAZ1 demonstrated that the naturally occurring C-terminal truncation results in loss of RipAZ1-triggered cell death. We also show that the 213 amino acid central region of RipAZ1 is sufficient to induce cell death in S. americanum. Finally, we show that RipAZ1 may activate defence in host cell cytoplasm. Taken together, our data indicate that the nucleocytoplasmic T3E RipAZ1 confers R. solanacearum avirulence in S. americanum. Few avirulence genes are known in vascular bacterial phytopathogens and ripAZ1 is the first one in R. solanacearum that is recognized in black nightshades. This work thus opens the way for the identification of disease resistance genes responsible for the specific recognition of RipAZ1, which can be a source of resistance against the devastating bacterial wilt disease.
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Affiliation(s)
- Hayoung Moon
- Department of Life SciencesPohang University of Science and TechnologyPohangRepublic of Korea
| | - Ankita Pandey
- Department of Life SciencesPohang University of Science and TechnologyPohangRepublic of Korea
| | - Hayeon Yoon
- Department of Life SciencesPohang University of Science and TechnologyPohangRepublic of Korea
| | - Sera Choi
- Department of Life SciencesPohang University of Science and TechnologyPohangRepublic of Korea
| | - Hyelim Jeon
- Department of Agriculture, Forestry and BioresourcesSeoul National UniversitySeoulRepublic of Korea
- Plant Immunity Research CenterSeoul National UniversitySeoulRepublic of Korea
| | - Maxim Prokchorchik
- Department of Life SciencesPohang University of Science and TechnologyPohangRepublic of Korea
| | - Gayoung Jung
- Department of Life SciencesPohang University of Science and TechnologyPohangRepublic of Korea
| | - Kamil Witek
- The Sainsbury LaboratoryUniversity of East AngliaNorwichUK
| | - Marc Valls
- Department of GeneticsUniversity of BarcelonaBarcelonaSpain
- Centre for Research in Agricultural Genomics (CSIC‐IRTA‐UAB‐UB)BellaterraSpain
| | - Honour C. McCann
- New Zealand Institute of Advanced StudiesMassey UniversityAucklandNew Zealand
- Max Planck Institute for Developmental BiologyTübingenGermany
| | - Min‐Sung Kim
- Department of Life SciencesPohang University of Science and TechnologyPohangRepublic of Korea
- Division of Integrative Biosciences and BiotechnologyPohang University of Science and TechnologyRepublic of Korea
| | | | - Cécile Segonzac
- Department of Agriculture, Forestry and BioresourcesSeoul National UniversitySeoulRepublic of Korea
- Plant Immunity Research CenterSeoul National UniversitySeoulRepublic of Korea
- Department of Plant Science, Plant Genomics and Breeding InstituteAgricultural Life Science Research InstituteSeoul National UniversitySeoulRepublic of Korea
| | - Kee Hoon Sohn
- Department of Life SciencesPohang University of Science and TechnologyPohangRepublic of Korea
- School of Interdisciplinary Bioscience and BioengineeringPohang University of Science and TechnologyPohangRepublic of Korea
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27
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Gonçalves OS, Souza FDO, Bruckner FP, Santana MF, Alfenas-Zerbini P. Widespread distribution of prophages signaling the potential for adaptability and pathogenicity evolution of Ralstonia solanacearum species complex. Genomics 2021; 113:992-1000. [PMID: 33626339 DOI: 10.1016/j.ygeno.2021.02.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 01/16/2021] [Accepted: 02/18/2021] [Indexed: 12/27/2022]
Abstract
Integrated bacteriophages (prophages) can impact host cells, affecting their lifestyle, genomic diversity, and fitness. However, many basic aspects of how these organisms affect the host cell remain poorly understood. Ralstonia solanacearum is a gram-negative plant pathogenic bacterium that encompasses a great diversity of ecotypes regarded as a species complex (R. solanacearum Species Complex - RSSC). RSSC genomes have a mosaic structure containing numerous elements, signaling the potential for its evolution through horizontal gene transfer. Here, we analyzed 120 Ralstonia spp. genomes from the public database to identify prophage sequences. In total, 379 prophage-like elements were found in the chromosome and megaplasmid of Ralstonia spp. These elements encode genes related to host fitness, virulence factors, antibiotic resistance, and niche adaptation, which might contribute to RSSC adaptability. Prophage-like elements are widespread into the complex in different species and geographic origins, suggesting that the RSSC phages are ancestrally acquired. Complete prophages belonging to the families Inoviridae, Myoviridae, and Siphoviridae were found, being the members of Inoviridae the most abundant. Analysis of CRISPR-Cas spacer sequences demonstrated the presence of prophages sequences that indicate successive infection events during bacterial evolution. Besides complete prophages, we also demonstrated 14 novel putative prophages integrated into Ralstonia spp. genomes. Altogether, our results provide insights into the diversity of prophages in RSSC genomes and suggest that these elements may deeply affect the virulence and host adaptation and shaping the genomes among the strains of this important pathogen.
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Affiliation(s)
- Osiel Silva Gonçalves
- Departamento de Microbiologia, Instituto de Biotecnologia Aplicada à Agropecuária (BIOAGRO), Universidade Federal de Viçosa, Viçosa, MG CEP 36570-000, Brazil
| | - Flávia de Oliveira Souza
- Departamento de Microbiologia, Instituto de Biotecnologia Aplicada à Agropecuária (BIOAGRO), Universidade Federal de Viçosa, Viçosa, MG CEP 36570-000, Brazil
| | - Fernanda Prieto Bruckner
- Departamento de Microbiologia, Instituto de Biotecnologia Aplicada à Agropecuária (BIOAGRO), Universidade Federal de Viçosa, Viçosa, MG CEP 36570-000, Brazil
| | - Mateus Ferreira Santana
- Departamento de Microbiologia, Instituto de Biotecnologia Aplicada à Agropecuária (BIOAGRO), Universidade Federal de Viçosa, Viçosa, MG CEP 36570-000, Brazil.
| | - Poliane Alfenas-Zerbini
- Departamento de Microbiologia, Instituto de Biotecnologia Aplicada à Agropecuária (BIOAGRO), Universidade Federal de Viçosa, Viçosa, MG CEP 36570-000, Brazil.
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28
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Nakano M, Ichinose Y, Mukaihara T. Ralstonia solanacearum Type III Effector RipAC Targets SGT1 to Suppress Effector-Triggered Immunity. Plant Cell Physiol 2021; 61:2067-2076. [PMID: 32991707 DOI: 10.1093/pcp/pcaa122] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Accepted: 09/14/2020] [Indexed: 06/11/2023]
Abstract
Ralstonia solanacearum injects type III effectors into host cells to cause bacterial wilt in Solanaceae plants. To identify R. solanacearum effectors that suppress effector-triggered immunity (ETI) in plants, we evaluated R. solanacearum RS1000 effectors for their ability to suppress a hypersensitive response (HR) induced by the avirulence (Avr) effector RipAA in Nicotiana benthamiana. Out of the 11 effectors tested, 4 suppressed RipAA-triggered HR cell death. Among them, RipAC contains tandem repeats of the leucine-rich repeat (LRR) motif, which serves as the structural scaffold for a protein-protein interaction. We found that the LRR domain of RipAC was indispensable for the suppression of HR cell death during the recognition of RipAA and another Avr effector RipP1. By yeast two-hybrid screening, we identified N. benthamiana SGT1, an adaptor protein that forms a molecular chaperone complex with RAR1, as a host factor of the RipAC target. RipAC interacted with NbSGT1 in yeast and plant cells. Upon the formation of the molecular chaperone complex, the presence of RipAC markedly inhibits the interaction between NbSGT1 and NbRAR1. The RipAA- and RipP1-triggered HR cell deaths were not observed in NbSGT1-silenced plants. The introduction of RipAC was complementary to the reduced growth of the R. solanacearum mutant strain in N. benthamiana. These findings indicate that R. solanacearum uses RipAC to subvert the NbSGT1-mediated formation of the molecular chaperone complex and suppress ETI responses during the recognition of Avr effectors.
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Affiliation(s)
- Masahito Nakano
- Graduate School of Environmental and Life Science, Okayama University, 1-1-1 Tsushima-naka, Kita-ku, Okayama, 700-8530 Japan
| | - Yuki Ichinose
- Graduate School of Environmental and Life Science, Okayama University, 1-1-1 Tsushima-naka, Kita-ku, Okayama, 700-8530 Japan
| | - Takafumi Mukaihara
- Research Institute for Biological Sciences, Okayama (RIBS), 7549-1 Yoshikawa, Kibichuo-cho, Okayama, 716-1241 Japan
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29
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Prokchorchik M, Pandey A, Moon H, Kim W, Jeon H, Jung G, Jayaraman J, Poole S, Segonzac C, Sohn KH, McCann HC. Host adaptation and microbial competition drive Ralstonia solanacearum phylotype I evolution in the Republic of Korea. Microb Genom 2020; 6:mgen000461. [PMID: 33151139 PMCID: PMC7725338 DOI: 10.1099/mgen.0.000461] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 10/06/2020] [Indexed: 12/13/2022] Open
Abstract
Bacterial wilt caused by the Ralstonia solanacearum species complex (RSSC) threatens the cultivation of important crops worldwide. We sequenced 30 RSSC phylotype I (R. pseudosolanacearum) strains isolated from pepper (Capsicum annuum) and tomato (Solanum lycopersicum) across the Republic of Korea. These isolates span the diversity of phylotype I, have extensive effector repertoires and are subject to frequent recombination. Recombination hotspots among South Korean phylotype I isolates include multiple predicted contact-dependent inhibition loci, suggesting that microbial competition plays a significant role in Ralstonia evolution. Rapid diversification of secreted effectors presents challenges for the development of disease-resistant plant varieties. We identified potential targets for disease resistance breeding by testing for allele-specific host recognition of T3Es present among South Korean phyloype I isolates. The integration of pathogen population genomics and molecular plant pathology contributes to the development of location-specific disease control and development of plant cultivars with durable resistance to relevant threats.
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Affiliation(s)
- Maxim Prokchorchik
- Department of Life Sciences, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
| | - Ankita Pandey
- Department of Life Sciences, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
| | - Hayoung Moon
- Department of Life Sciences, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
| | - Wanhui Kim
- Department of Plant Science, Plant Genome and Breeding Institute, Agricultural Life Science Research Institute, Seoul National University, Seoul 08826, Republic of Korea
- Plant Immunity Research Center, Seoul National University, Seoul 08826, Republic of Korea
| | - Hyelim Jeon
- Plant Immunity Research Center, Seoul National University, Seoul 08826, Republic of Korea
- Department of Agriculture, Forestry and Bioresources, Seoul National University, Seoul 08826, Republic of Korea
| | - Gayoung Jung
- Department of Life Sciences, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
| | - Jay Jayaraman
- The New Zealand Institute for Plant and Food Research, Auckland, New Zealand
| | - Stephen Poole
- Department of Molecular, Cellular and Developmental Biology, University of California Santa Barbara, Santa Barbara, USA
| | - Cécile Segonzac
- Department of Plant Science, Plant Genome and Breeding Institute, Agricultural Life Science Research Institute, Seoul National University, Seoul 08826, Republic of Korea
- Plant Immunity Research Center, Seoul National University, Seoul 08826, Republic of Korea
- Department of Agriculture, Forestry and Bioresources, Seoul National University, Seoul 08826, Republic of Korea
| | - Kee Hoon Sohn
- Department of Life Sciences, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
- School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
| | - Honour C. McCann
- New Zealand Institute for Advanced Study, Massey University Albany, New Zealand
- Max Planck Institute for Developmental Biology, Tübingen, Germany
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30
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Landry D, González‐Fuente M, Deslandes L, Peeters N. The large, diverse, and robust arsenal of Ralstonia solanacearum type III effectors and their in planta functions. Mol Plant Pathol 2020; 21:1377-1388. [PMID: 32770627 PMCID: PMC7488467 DOI: 10.1111/mpp.12977] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 06/15/2020] [Accepted: 06/22/2020] [Indexed: 05/25/2023]
Abstract
The type III secretion system with its delivered type III effectors (T3Es) is one of the main virulence determinants of Ralstonia solanacearum, a worldwide devastating plant pathogenic bacterium affecting many crop species. The pan-effectome of the R. solanacearum species complex has been exhaustively identified and is composed of more than 100 different T3Es. Among the reported strains, their content ranges from 45 to 76 T3Es. This considerably large and varied effectome could be considered one of the factors contributing to the wide host range of R. solanacearum. In order to understand how R. solanacearum uses its T3Es to subvert the host cellular processes, many functional studies have been conducted over the last three decades. It has been shown that R. solanacearum effectors, as those from other plant pathogens, can suppress plant defence mechanisms, modulate the host metabolism, or avoid bacterial recognition through a wide variety of molecular mechanisms. R. solanacearum T3Es can also be perceived by the plant and trigger immune responses. To date, the molecular mechanisms employed by R. solanacearum T3Es to modulate these host processes have been described for a growing number of T3Es, although they remain unknown for the majority of them. In this microreview, we summarize and discuss the current knowledge on the characterized R. solanacearum species complex T3Es.
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Affiliation(s)
- David Landry
- Laboratoire des Interactions Plantes Micro‐organismes (LIPM)INRAE, CNRS, Université de ToulouseCastanet‐TolosanFrance
| | - Manuel González‐Fuente
- Laboratoire des Interactions Plantes Micro‐organismes (LIPM)INRAE, CNRS, Université de ToulouseCastanet‐TolosanFrance
| | - Laurent Deslandes
- Laboratoire des Interactions Plantes Micro‐organismes (LIPM)INRAE, CNRS, Université de ToulouseCastanet‐TolosanFrance
| | - Nemo Peeters
- Laboratoire des Interactions Plantes Micro‐organismes (LIPM)INRAE, CNRS, Université de ToulouseCastanet‐TolosanFrance
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31
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Lei N, Chen L, Kiba A, Hikichi Y, Zhang Y, Ohnishi K. Super-Multiple Deletion Analysis of Type III Effectors in Ralstonia solanacearum OE1-1 for Full Virulence Toward Host Plants. Front Microbiol 2020; 11:1683. [PMID: 32849353 PMCID: PMC7409329 DOI: 10.3389/fmicb.2020.01683] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 06/29/2020] [Indexed: 11/16/2022] Open
Abstract
Ralstonia solanacearum species complex (RSSC) posses extremely abundant type III effectors (T3Es) that are translocated into plant cells via a syringe-like apparatus assembled by a type III secretion system (T3SS) to subvert host defense initiated by innate immunity. More than 100 T3Es are predicted among different RSSC strains, with an average of about 70 T3Es in each strain. Among them, 32 T3Es are found to be conserved among the RSSC and hence called the core T3Es. Here, we genetically characterized contribution of abundant T3Es to virulence of a Japanese RSSC strain OE1-1 toward host plants. While all the T3Es members of AWR family contributed slightly to virulence, those of the GALA, HLK, and SKWP families did not influence full virulence of OE1-1. Mutant OE1-1D21E (with deletion of all 21 T3Es members of four families) exhibited slightly impaired virulence, while mutant OE1-1D36E (deleting all 21 T3Es of 4 families and 15 core T3Es) exhibited substantially reduced virulence. Mutant OE1-1D42E (deleting all 21 T3Es of 4 families, 15 core T3Es and 6 extended core T3Es) failed to cause any disease on tobacco plants with leaf infiltration but retained faint virulence on tobacco plants with petiole inoculation. The proliferation of mutant OE1-1D42E in tobacco stems was substantially impaired with about three orders of magnitude less than that of OE1-1, while no impact in tobacco leaves if directly infiltrated into leaves. On the contrary, the OE1-1D42E mutant retained faint virulence on eggplants with leaf infiltration but completely lost virulence on eggplants with root-cutting inoculation. The proliferation of OE1-1D42E mutant both in eggplant leaves and stems was substantially impaired. Intriguingly, mutant OE1-1D42E still caused necrotic lesions in tobacco and eggplant leaves, indicating that some other than the 42 removed effectors are involved in expansion of necrotic lesions in host leaves. All taken together, we here genetically demonstrated that all the core and extended core T3Es are nearly crucial for virulence of OE1-1 toward host plants and provided currently a kind of T3Es-free strain that enables primary functional studies of individual T3Es in host cells.
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Affiliation(s)
- Ni Lei
- The United Graduate School of Agricultural Sciences, Ehime University, Matsuyama, Japan
| | - Li Chen
- College of Food Engineering and Nutritional Science, Shaanxi Normal University, Xi'an, China
| | - Akinori Kiba
- Faculty of Agriculture and Marine Science, Kochi University, Kochi, Japan
| | - Yasufumi Hikichi
- Faculty of Agriculture and Marine Science, Kochi University, Kochi, Japan
| | - Yong Zhang
- College of Resources and Environment, Southwest University, Chongqing, China.,Interdisciplinary Research Center for Agriculture Green Development in Yangtze River Basin, Southwest University, Chongqing, China
| | - Kouhei Ohnishi
- Research Institute of Molecular Genetics, Kochi University, Kochi, Japan
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32
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Sang Y, Yu W, Zhuang H, Wei Y, Derevnina L, Yu G, Luo J, Macho AP. Intra-strain Elicitation and Suppression of Plant Immunity by Ralstonia solanacearum Type-III Effectors in Nicotiana benthamiana. Plant Commun 2020; 1:100025. [PMID: 33367244 PMCID: PMC7747989 DOI: 10.1016/j.xplc.2020.100025] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 12/12/2019] [Accepted: 01/16/2020] [Indexed: 05/11/2023]
Abstract
Effector proteins delivered inside plant cells are powerful weapons for bacterial pathogens, but this exposes the pathogen to potential recognition by the plant immune system. Therefore, the effector repertoire of a given pathogen must be balanced for a successful infection. Ralstonia solanacearum is an aggressive pathogen with a large repertoire of secreted effectors. One of these effectors, RipE1, is conserved in most R. solanacearum strains sequenced to date. In this work, we found that RipE1 triggers immunity in N. benthamiana, which requires the immune regulator SGT1, but not EDS1 or NRCs. Interestingly, RipE1-triggered immunity induces the accumulation of salicylic acid (SA) and the overexpression of several genes encoding phenylalanine-ammonia lyases (PALs), suggesting that the unconventional PAL-mediated pathway is responsible for the observed SA biosynthesis. Surprisingly, RipE1 recognition also induces the expression of jasmonic acid (JA)-responsive genes and JA biosynthesis, suggesting that both SA and JA may act cooperatively in response to RipE1. We further found that RipE1 expression leads to the accumulation of glutathione in plant cells, which precedes the activation of immune responses. R. solanacearum secretes another effector, RipAY, which is known to inhibit immune responses by degrading cellular glutathione. Accordingly, RipAY inhibits RipE1-triggered immune responses. This work shows a strategy employed by R. solanacearum to counteract the perception of its effector proteins by plant immune system.
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Affiliation(s)
- Yuying Sang
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institutes of Biological Sciences, Chinese Academy of Sciences, Shanghai 201602, China
| | - Wenjia Yu
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institutes of Biological Sciences, Chinese Academy of Sciences, Shanghai 201602, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Haiyan Zhuang
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institutes of Biological Sciences, Chinese Academy of Sciences, Shanghai 201602, China
| | - Yali Wei
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institutes of Biological Sciences, Chinese Academy of Sciences, Shanghai 201602, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Lida Derevnina
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
| | - Gang Yu
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institutes of Biological Sciences, Chinese Academy of Sciences, Shanghai 201602, China
| | - Jiamin Luo
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institutes of Biological Sciences, Chinese Academy of Sciences, Shanghai 201602, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Alberto P. Macho
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institutes of Biological Sciences, Chinese Academy of Sciences, Shanghai 201602, China
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33
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Li J, Han L, Chen N, Zhu C, Gao Y, Shi X, Xu C, Hikichi Y, Zhang Y, Ohnishi K. Functional Characterization of RsRsgA for Ribosome Biosynthesis and Expression of the Type III Secretion System in Ralstonia solanacearum. MPMI 2020; 33:972-981. [PMID: 32240066 DOI: 10.1094/mpmi-10-19-0294-r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
RsgA plays an important role in maturation of 30S subunit in many bacteria that assists in the release of RbfA from the 30S subunit during a late stage of ribosome biosynthesis. Here, we genetically characterized functional roles of RsgA in Ralstonia solanacearum, hereafter designated RsRsgA. Deletion of R. solanacearum rsgA or rbfA resulted in distinct deficiency of 16S ribosomal RNA, significantly slowed growth in broth medium, and diminished growth in nutrient-limited medium, which are similar as phenotypes of rsgA mutants and rbfA mutants of Escherichia coli and other bacteria. Our gene-expression studies revealed that RsRsgA is important for expression of genes encoding the type III secretion system (T3SS) (a pathogenicity determinant of R. solanacearum) both in vitro and in planta. Compared with the wild-type R. solanacearum strain, proliferation of the rsgA and rbfA mutants in tobacco leaves was significantly impaired, while they failed to migrate into tobacco xylem vessels from infiltrated leaves, and hence, these two mutants failed to cause any bacterial wilt disease in tobacco plants. It was further revealed that rsgA expression was highly enhanced under nutrient-limited conditions compared with that in broth medium and RsRsgA affects T3SS expression through the PrhN-PrhG-HrpB pathway. Moreover, expression of a subset of type III effectors was substantially impaired in the rsgA mutant, some of which are responsible for R. solanacearum GMI1000 elicitation of a hypersensitive response (HR) in tobacco leaves, while RsRsgA is not required for HR elicitation of GMI1000 in tobacco leaves. All these results provide novel insights into understanding various biological functions of RsgA proteins and complex regulation on the T3SS in R. solanacearum.
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Affiliation(s)
- Jiaman Li
- College of Resources and Environment, Southwest University, Chongqing, China
| | - Liangliang Han
- College of Resources and Environment, Southwest University, Chongqing, China
- Faculty of Agriculture and Marine Science, Kochi University, Kochi, Japan
| | - Nan Chen
- College of Chemistry and Chemical Engineering, Chongqing University of Science and Technology, Chongqing, China
| | - Chao Zhu
- Faculty of Agriculture and Marine Science, Kochi University, Kochi, Japan
| | - Yuwei Gao
- Faculty of Agriculture and Marine Science, Kochi University, Kochi, Japan
| | - Xiaojun Shi
- College of Resources and Environment, Southwest University, Chongqing, China
- Key Laboratory of Efficient Utilization of Soil and Fertilizer Resources, Chongqing, China
| | - Changzheng Xu
- College of Life Science, Southwest University, Chongqing, China
| | - Yasufumi Hikichi
- Faculty of Agriculture and Marine Science, Kochi University, Kochi, Japan
| | - Yong Zhang
- College of Resources and Environment, Southwest University, Chongqing, China
- Key Laboratory of Efficient Utilization of Soil and Fertilizer Resources, Chongqing, China
| | - Kouhei Ohnishi
- Faculty of Agriculture and Marine Science, Kochi University, Kochi, Japan
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Zhuo T, Wang X, Chen Z, Cui H, Zeng Y, Chen Y, Fan X, Hu X, Zou H. The Ralstonia solanacearum effector RipI induces a defence reaction by interacting with the bHLH93 transcription factor in Nicotiana benthamiana. Mol Plant Pathol 2020; 21:999-1004. [PMID: 32285606 PMCID: PMC7279998 DOI: 10.1111/mpp.12937] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 02/26/2020] [Accepted: 03/12/2020] [Indexed: 05/11/2023]
Abstract
Ralstonia solanacearum releases a set of effectors into plant cells that modify the host defence reaction. The role of the effector protein RipI during infection has not been elucidated. In this study, we demonstrated that transient overexpression of RipI induces the hypersensitive response (HR), up-regulating the HR marker gene hin1, in Nicotiana benthamiana. Deletion of R. solanacearum ripI led to increased virulence in tomato (Solanum lycopersicum) plants. Through yeast two-hybrid and pull-down assays, we identified an interaction between the N. benthamiana transcription factor bHLH93 and RipI, both of which could be localized in the nucleus of Arabidopsis protoplasts. Silencing of bHLH93 markedly attenuated the RipI-induced HR and induced expression of the PDF1.2 defence gene. These data demonstrate that the R. solanacearum effector RipI induces a host defence reaction by interacting with the bHLH93 transcription factor.
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Affiliation(s)
- Tao Zhuo
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan CropsCollege of Plant ProtectionFujian Agriculture and Forestry UniversityFuzhouChina
| | - Xue Wang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan CropsCollege of Plant ProtectionFujian Agriculture and Forestry UniversityFuzhouChina
| | - Zhengyu Chen
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan CropsCollege of Plant ProtectionFujian Agriculture and Forestry UniversityFuzhouChina
| | - Haitao Cui
- Plant Immunity CenterHaixia Institute of Science and TechnologyFujian Agriculture and Forestry UniversityFuzhouChina
| | - Yanhong Zeng
- Plant Immunity CenterHaixia Institute of Science and TechnologyFujian Agriculture and Forestry UniversityFuzhouChina
| | - Yang Chen
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan CropsCollege of Plant ProtectionFujian Agriculture and Forestry UniversityFuzhouChina
| | - Xiaojing Fan
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan CropsCollege of Plant ProtectionFujian Agriculture and Forestry UniversityFuzhouChina
| | - Xun Hu
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan CropsCollege of Plant ProtectionFujian Agriculture and Forestry UniversityFuzhouChina
| | - Huasong Zou
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan CropsCollege of Plant ProtectionFujian Agriculture and Forestry UniversityFuzhouChina
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Thomas NC, Hendrich CG, Gill US, Allen C, Hutton SF, Schultink A. The Immune Receptor Roq1 Confers Resistance to the Bacterial Pathogens Xanthomonas, Pseudomonas syringae, and Ralstonia in Tomato. Front Plant Sci 2020; 11:463. [PMID: 32391034 PMCID: PMC7192161 DOI: 10.3389/fpls.2020.00463] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Accepted: 03/30/2020] [Indexed: 05/22/2023]
Abstract
Xanthomonas species, Pseudomonas syringae and Ralstonia species are bacterial plant pathogens that cause significant yield loss in many crop species. Generating disease-resistant crop varieties can provide a more sustainable solution to control yield loss compared to chemical methods. Plant immune receptors encoded by nucleotide-binding, leucine-rich repeat (NLR) genes typically confer resistance to pathogens that produce a cognate elicitor, often an effector protein secreted by the pathogen to promote virulence. The diverse sequence and presence/absence variation of pathogen effector proteins within and between pathogen species usually limits the utility of a single NLR gene to protecting a plant from a single pathogen species or particular strains. The NLR protein Recognition of XopQ 1 (Roq1) was recently identified from the plant Nicotiana benthamiana and mediates perception of the effector proteins XopQ and HopQ1 from Xanthomonas and P. syringae respectively. Unlike most recognized effectors, alleles of XopQ/HopQ1 are highly conserved and present in most plant pathogenic strains of Xanthomonas and P. syringae. A homolog of XopQ/HopQ1, named RipB, is present in most Ralstonia strains. We found that Roq1 confers immunity to Xanthomonas, P. syringae, and Ralstonia when expressed in tomato. Strong resistance to Xanthomonas perforans was observed in three seasons of field trials with both natural and artificial inoculation. The Roq1 gene can therefore be used to provide safe, economical, and effective control of these pathogens in tomato and other crop species and reduce or eliminate the need for traditional chemical controls.
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Affiliation(s)
- Nicholas C. Thomas
- Fortiphyte Inc., Berkeley, CA, United States
- Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA, United States
| | - Connor G. Hendrich
- Department of Plant Pathology, University of Wisconsin–Madison, Madison, WI, United States
| | - Upinder S. Gill
- IFAS, Gulf Coast Research and Education Center, University of Florida, Wimauma, FL, United States
- Department of Plant Pathology, North Dakota State University, Fargo, ND, United States
| | - Caitilyn Allen
- Department of Plant Pathology, University of Wisconsin–Madison, Madison, WI, United States
| | - Samuel F. Hutton
- IFAS, Gulf Coast Research and Education Center, University of Florida, Wimauma, FL, United States
| | - Alex Schultink
- Fortiphyte Inc., Berkeley, CA, United States
- Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA, United States
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Xue H, Lozano-Durán R, Macho AP. Insights into the Root Invasion by the Plant Pathogenic Bacterium Ralstonia solanacearum. Plants (Basel) 2020; 9:E516. [PMID: 32316375 PMCID: PMC7238422 DOI: 10.3390/plants9040516] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/22/2020] [Revised: 04/03/2020] [Accepted: 04/05/2020] [Indexed: 12/17/2022]
Abstract
The plant pathogenic bacterium Ralstonia solanacearum, causal agent of the devastating bacterial wilt disease, is a soil-borne microbe that infects host plants through their roots. The initial mutual recognition between host plants and bacteria and the ensuing invasion of root tissues by R. solanacearum are critical steps in the establishment of the infection, and can determine the outcome of the interaction between plant and pathogen. In this minireview, we will focus on the early stages of the bacterial invasion, offering an overview of the defence mechanisms deployed by the host plants, the manipulation exerted by the pathogen in order to promote virulence, and the alterations in root development concomitant to bacterial colonization.
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Affiliation(s)
- Hao Xue
- Shanghai Center for Plant Stress Biology, Center for Excellence in Molecular Plant Science, Chinese Academy of Sciences, Shanghai 201602, China;
- University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Rosa Lozano-Durán
- Shanghai Center for Plant Stress Biology, Center for Excellence in Molecular Plant Science, Chinese Academy of Sciences, Shanghai 201602, China;
| | - Alberto P. Macho
- Shanghai Center for Plant Stress Biology, Center for Excellence in Molecular Plant Science, Chinese Academy of Sciences, Shanghai 201602, China;
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Nakano M, Mukaihara T. Comprehensive Identification of PTI Suppressors in Type III Effector Repertoire Reveals that Ralstonia solanacearum Activates Jasmonate Signaling at Two Different Steps. Int J Mol Sci 2019; 20:E5992. [PMID: 31795135 PMCID: PMC6928842 DOI: 10.3390/ijms20235992] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Revised: 11/26/2019] [Accepted: 11/26/2019] [Indexed: 02/04/2023] Open
Abstract
Ralstonia solanacearum is the causative agent of bacterial wilt in many plants. To identify R. solanacearum effectors that suppress pattern-triggered immunity (PTI) in plants, we transiently expressed R. solanacearum RS1000 effectors in Nicotiana benthamiana leaves and evaluated their ability to suppress the production of reactive oxygen species (ROS) triggered by flg22. Out of the 61 effectors tested, 11 strongly and five moderately suppressed the flg22-triggered ROS burst. Among them, RipE1 shared homology with the Pseudomonas syringae cysteine protease effector HopX1. By yeast two-hybrid screening, we identified jasmonate-ZIM-domain (JAZ) proteins, which are transcriptional repressors of the jasmonic acid (JA) signaling pathway in plants, as RipE1 interactors. RipE1 promoted the degradation of JAZ repressors and induced the expressions of JA-responsive genes in a cysteine-protease-activity-dependent manner. Simultaneously, RipE1, similarly to the previously identified JA-producing effector RipAL, decreased the expression level of the salicylic acid synthesis gene that is required for the defense responses against R. solanacearum. The undecuple mutant that lacks 11 effectors with a strong PTI suppression activity showed reduced growth of R. solanacearum in Nicotiana plants. These results indicate that R. solanacearum subverts plant PTI responses using multiple effectors and manipulates JA signaling at two different steps to promote infection.
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Affiliation(s)
- Masahito Nakano
- Research Institute for Biological Sciences, Okayama (RIBS), 7549-1 Yoshikawa, Kibichuo-cho, Okayama 716-1241, Japan
- Graduate School of Environmental and Life Science, Okayama University, 1-1-1 Tsushima-naka, Kita-ku, Okayama 700-8530, Japan
| | - Takafumi Mukaihara
- Research Institute for Biological Sciences, Okayama (RIBS), 7549-1 Yoshikawa, Kibichuo-cho, Okayama 716-1241, Japan
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