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Yan S, Wang Y, Yu B, Gan Y, Lei J, Chen C, Zhu Z, Qiu Z, Cao B. A putative E3 ubiquitin ligase substrate receptor degrades transcription factor SmNAC to enhance bacterial wilt resistance in eggplant. HORTICULTURE RESEARCH 2024; 11:uhad246. [PMID: 38239808 PMCID: PMC10794948 DOI: 10.1093/hr/uhad246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 11/12/2023] [Indexed: 01/22/2024]
Abstract
Bacterial wilt caused by Ralstonia solanacearum is a severe soil-borne disease globally, limiting the production in Solanaceae plants. SmNAC negatively regulated eggplant resistance to Bacterial wilt (BW) though restraining salicylic acid (SA) biosynthesis. However, other mechanisms through which SmNAC regulates BW resistance remain unknown. Here, we identified an interaction factor, SmDDA1b, encoding a substrate receptor for E3 ubiquitin ligase, from the eggplant cDNA library using SmNAC as bait. SmDDA1b expression was promoted by R. solanacearum inoculation and exogenous SA treatment. The virus-induced gene silencing of the SmDDA1b suppressed the BW resistance of eggplants; SmDDA1b overexpression enhanced the BW resistance of tomato plants. SmDDA1b positively regulates BW resistance by inhibiting the spread of R. solanacearum within plants. The SA content and the SA biosynthesis gene ICS1 and signaling pathway genes decreased in the SmDDA1b-silenced plants but increased in SmDDA1b-overexpression plants. Moreover, SmDDB1 protein showed interaction with SmCUL4 and SmDDA1b and protein degradation experiments indicated that SmDDA1b reduced SmNAC protein levels through proteasome degradation. Furthermore, SmNAC could directly bind the SmDDA1b promoter and repress its transcription. Thus, SmDDA1b is a novel regulator functioning in BW resistance of solanaceous crops via the SmNAC-mediated SA pathway. Those results also revealed a negative feedback loop between SmDDA1b and SmNAC controlling BW resistance.
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Affiliation(s)
- Shuangshuang Yan
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops, Ministry of Agriculture and Rural Affairs/Guangdong Vegetable Engineering and Technology Research Center, Guangdong Provincial Key Laboratory of Postharvest Science of Fruits and Vegetables, College of Horticulture, South China Agricultural University, Guangzhou 510642, China
| | - Yixi Wang
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops, Ministry of Agriculture and Rural Affairs/Guangdong Vegetable Engineering and Technology Research Center, Guangdong Provincial Key Laboratory of Postharvest Science of Fruits and Vegetables, College of Horticulture, South China Agricultural University, Guangzhou 510642, China
| | - Bingwei Yu
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops, Ministry of Agriculture and Rural Affairs/Guangdong Vegetable Engineering and Technology Research Center, Guangdong Provincial Key Laboratory of Postharvest Science of Fruits and Vegetables, College of Horticulture, South China Agricultural University, Guangzhou 510642, China
| | - Yuwei Gan
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops, Ministry of Agriculture and Rural Affairs/Guangdong Vegetable Engineering and Technology Research Center, Guangdong Provincial Key Laboratory of Postharvest Science of Fruits and Vegetables, College of Horticulture, South China Agricultural University, Guangzhou 510642, China
| | - Jianjun Lei
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops, Ministry of Agriculture and Rural Affairs/Guangdong Vegetable Engineering and Technology Research Center, Guangdong Provincial Key Laboratory of Postharvest Science of Fruits and Vegetables, College of Horticulture, South China Agricultural University, Guangzhou 510642, China
| | - Changming Chen
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops, Ministry of Agriculture and Rural Affairs/Guangdong Vegetable Engineering and Technology Research Center, Guangdong Provincial Key Laboratory of Postharvest Science of Fruits and Vegetables, College of Horticulture, South China Agricultural University, Guangzhou 510642, China
| | - Zhangsheng Zhu
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops, Ministry of Agriculture and Rural Affairs/Guangdong Vegetable Engineering and Technology Research Center, Guangdong Provincial Key Laboratory of Postharvest Science of Fruits and Vegetables, College of Horticulture, South China Agricultural University, Guangzhou 510642, China
| | - Zhengkun Qiu
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops, Ministry of Agriculture and Rural Affairs/Guangdong Vegetable Engineering and Technology Research Center, Guangdong Provincial Key Laboratory of Postharvest Science of Fruits and Vegetables, College of Horticulture, South China Agricultural University, Guangzhou 510642, China
| | - Bihao Cao
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops, Ministry of Agriculture and Rural Affairs/Guangdong Vegetable Engineering and Technology Research Center, Guangdong Provincial Key Laboratory of Postharvest Science of Fruits and Vegetables, College of Horticulture, South China Agricultural University, Guangzhou 510642, China
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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] [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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Langin G, González-Fuente M, Üstün S. The Plant Ubiquitin-Proteasome System as a Target for Microbial Manipulation. ANNUAL REVIEW OF PHYTOPATHOLOGY 2023; 61:351-375. [PMID: 37253695 DOI: 10.1146/annurev-phyto-021622-110443] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The plant immune system perceives pathogens to trigger defense responses. In turn, pathogens secrete effector molecules to subvert these defense responses. The initiation and maintenance of defense responses involve not only de novo synthesis of regulatory proteins and enzymes but also their regulated degradation. The latter is achieved through protein degradation pathways such as the ubiquitin-proteasome system (UPS). The UPS regulates all stages of immunity, from the perception of the pathogen to the execution of the response, and, therefore, constitutes an ideal candidate for microbial manipulation of the host. Pathogen effector molecules interfere with the plant UPS through several mechanisms. This includes hijacking general UPS functions or perturbing its ability to degrade specific targets. In this review, we describe how the UPS regulates different immunity-related processes and how pathogens subvert this to promote disease.
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Affiliation(s)
- Gautier Langin
- Centre for Plant Molecular Biology (ZMBP), University of Tübingen, Tübingen, Germany;
- Faculty of Biology and Biotechnology, Ruhr-University Bochum, Bochum, Germany
| | | | - Suayib Üstün
- Faculty of Biology and Biotechnology, Ruhr-University Bochum, Bochum, Germany
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Sharma S, Prasad A, Prasad M. Ubiquitination from the perspective of plant pathogens. JOURNAL OF EXPERIMENTAL BOTANY 2023; 74:4367-4376. [PMID: 37226440 DOI: 10.1093/jxb/erad191] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Accepted: 05/18/2023] [Indexed: 05/26/2023]
Abstract
The constant battle of survival between pathogens and host plants has played a crucial role in shaping the course of their co-evolution. However, the major determinants of the outcome of this ongoing arms race are the effectors secreted by pathogens into host cells. These effectors perturb the defense responses of plants to promote successful infection. In recent years, extensive research in the area of effector biology has reported an increase in the repertoire of pathogenic effectors that mimic or target the conserved ubiquitin-proteasome pathway. The role of the ubiquitin-mediated degradation pathway is well known to be indispensable for various aspects of a plant's life, and thus targeting or mimicking it seems to be a smart strategy adopted by pathogens. Therefore, this review summarizes recent findings on how some pathogenic effectors mimic or act as one of the components of the ubiquitin-proteasome machinery while others directly target the plant's ubiquitin-proteasome system.
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Affiliation(s)
| | - Ashish Prasad
- Department of Botany, Kurukshetra University, Kurukshetra, India
| | - Manoj Prasad
- National Institute of Plant Genome Research, New Delhi, India
- Department of Plant Sciences, University of Hyderabad, Hyderabad, India
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5
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Qiu H, Wang B, Huang M, Sun X, Yu L, Cheng D, He W, Zhou D, Wu X, Song B, Tang N, Chen H. A novel effector RipBT contributes to Ralstonia solanacearum virulence on potato. MOLECULAR PLANT PATHOLOGY 2023; 24:947-960. [PMID: 37154802 PMCID: PMC10346376 DOI: 10.1111/mpp.13342] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 03/21/2023] [Accepted: 04/05/2023] [Indexed: 05/10/2023]
Abstract
Ralstonia solanacearum is one of the most destructive plant-pathogenic bacteria, infecting more than 200 plant species, including potato (Solanum tuberosum) and many other solanaceous crops. R. solanacearum has numerous pathogenicity factors, and type III effectors secreted through type III secretion system (T3SS) are key factors to counteract host immunity. Here, we show that RipBT is a novel T3SS-secreted effector by using a cyaA reporter system. Transient expression of RipBT in Nicotiania benthamiana induced strong cell death in a plasma membrane-localization dependent manner. Notably, mutation of RipBT in R. solanacearum showed attenuated virulence on potato, while RipBT transgenic potato plants exhibited enhanced susceptibility to R. solanacearum. Interestingly, transcriptomic analyses suggest that RipBT may interfere with plant reactive oxygen species (ROS) metabolism during the R. solanacearum infection of potato roots. In addition, the expression of RipBT remarkably suppressed the flg22-induced pathogen-associated molecular pattern-triggered immunity responses, such as the ROS burst. Taken together, RipBT acts as a T3SS effector, promoting R. solanacearum infection on potato and presumably disturbing ROS homeostasis.
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Affiliation(s)
- Huishan Qiu
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural CropsHuazhong Agricultural UniversityWuhanChina
- Key Laboratory of Potato Biology and Biotechnology, Ministry of Agriculture and Rural AffairsHuazhong Agricultural UniversityWuhanChina
- Potato Engineering and Technology Research Center of Hubei ProvinceHuazhong Agricultural UniversityWuhanChina
- College of Horticulture and Forestry ScienceHuazhong Agricultural UniversityWuhanChina
| | - Bingsen Wang
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural CropsHuazhong Agricultural UniversityWuhanChina
- Key Laboratory of Potato Biology and Biotechnology, Ministry of Agriculture and Rural AffairsHuazhong Agricultural UniversityWuhanChina
- Potato Engineering and Technology Research Center of Hubei ProvinceHuazhong Agricultural UniversityWuhanChina
- College of Horticulture and Forestry ScienceHuazhong Agricultural UniversityWuhanChina
| | - Mengshu Huang
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural CropsHuazhong Agricultural UniversityWuhanChina
- Key Laboratory of Potato Biology and Biotechnology, Ministry of Agriculture and Rural AffairsHuazhong Agricultural UniversityWuhanChina
- Potato Engineering and Technology Research Center of Hubei ProvinceHuazhong Agricultural UniversityWuhanChina
- College of Horticulture and Forestry ScienceHuazhong Agricultural UniversityWuhanChina
| | - Xiaohu Sun
- State Key Laboratory of Crop Stress Adaptation and ImprovementHenan UniversityKaifengChina
| | - Liu Yu
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural CropsHuazhong Agricultural UniversityWuhanChina
- Key Laboratory of Potato Biology and Biotechnology, Ministry of Agriculture and Rural AffairsHuazhong Agricultural UniversityWuhanChina
- Potato Engineering and Technology Research Center of Hubei ProvinceHuazhong Agricultural UniversityWuhanChina
- College of Horticulture and Forestry ScienceHuazhong Agricultural UniversityWuhanChina
| | - Dong Cheng
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural CropsHuazhong Agricultural UniversityWuhanChina
- Key Laboratory of Potato Biology and Biotechnology, Ministry of Agriculture and Rural AffairsHuazhong Agricultural UniversityWuhanChina
- Potato Engineering and Technology Research Center of Hubei ProvinceHuazhong Agricultural UniversityWuhanChina
- College of Horticulture and Forestry ScienceHuazhong Agricultural UniversityWuhanChina
| | - Wenfeng He
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural CropsHuazhong Agricultural UniversityWuhanChina
- Key Laboratory of Potato Biology and Biotechnology, Ministry of Agriculture and Rural AffairsHuazhong Agricultural UniversityWuhanChina
- Potato Engineering and Technology Research Center of Hubei ProvinceHuazhong Agricultural UniversityWuhanChina
- College of Horticulture and Forestry ScienceHuazhong Agricultural UniversityWuhanChina
| | - Dan Zhou
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural CropsHuazhong Agricultural UniversityWuhanChina
- Key Laboratory of Potato Biology and Biotechnology, Ministry of Agriculture and Rural AffairsHuazhong Agricultural UniversityWuhanChina
- Potato Engineering and Technology Research Center of Hubei ProvinceHuazhong Agricultural UniversityWuhanChina
- College of Horticulture and Forestry ScienceHuazhong Agricultural UniversityWuhanChina
| | - Xintong Wu
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural CropsHuazhong Agricultural UniversityWuhanChina
- Key Laboratory of Potato Biology and Biotechnology, Ministry of Agriculture and Rural AffairsHuazhong Agricultural UniversityWuhanChina
- Potato Engineering and Technology Research Center of Hubei ProvinceHuazhong Agricultural UniversityWuhanChina
- College of Horticulture and Forestry ScienceHuazhong Agricultural UniversityWuhanChina
| | - Botao Song
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural CropsHuazhong Agricultural UniversityWuhanChina
- Key Laboratory of Potato Biology and Biotechnology, Ministry of Agriculture and Rural AffairsHuazhong Agricultural UniversityWuhanChina
- Potato Engineering and Technology Research Center of Hubei ProvinceHuazhong Agricultural UniversityWuhanChina
- College of Horticulture and Forestry ScienceHuazhong Agricultural UniversityWuhanChina
| | - Ning Tang
- State Key Laboratory of Crop Stress Adaptation and ImprovementHenan UniversityKaifengChina
| | - Huilan Chen
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural CropsHuazhong Agricultural UniversityWuhanChina
- Key Laboratory of Potato Biology and Biotechnology, Ministry of Agriculture and Rural AffairsHuazhong Agricultural UniversityWuhanChina
- Potato Engineering and Technology Research Center of Hubei ProvinceHuazhong Agricultural UniversityWuhanChina
- College of Horticulture and Forestry ScienceHuazhong Agricultural UniversityWuhanChina
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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] [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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Effector-Dependent and -Independent Molecular Mechanisms of Soybean-Microbe Interaction. Int J Mol Sci 2022; 23:ijms232214184. [PMID: 36430663 PMCID: PMC9695568 DOI: 10.3390/ijms232214184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 11/09/2022] [Accepted: 11/11/2022] [Indexed: 11/18/2022] Open
Abstract
Soybean is a pivotal staple crop worldwide, supplying the main food and feed plant proteins in some countries. In addition to interacting with mutualistic microbes, soybean also needs to protect itself against pathogens. However, to grow inside plant tissues, plant defense mechanisms ranging from passive barriers to induced defense reactions have to be overcome. Pathogenic but also symbiotic micro-organisms effectors can be delivered into the host cell by secretion systems and can interfere with the immunity system and disrupt cellular processes. This review summarizes the latest advances in our understanding of the interaction between secreted effectors and soybean feedback mechanism and uncovers the conserved and special signaling pathway induced by pathogenic soybean cyst nematode, Pseudomonas, Xanthomonas as well as by symbiotic rhizobium.
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Bullones-Bolaños A, Bernal-Bayard J, Ramos-Morales F. The NEL Family of Bacterial E3 Ubiquitin Ligases. Int J Mol Sci 2022; 23:7725. [PMID: 35887072 PMCID: PMC9320238 DOI: 10.3390/ijms23147725] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 07/08/2022] [Accepted: 07/11/2022] [Indexed: 12/16/2022] Open
Abstract
Some pathogenic or symbiotic Gram-negative bacteria can manipulate the ubiquitination system of the eukaryotic host cell using a variety of strategies. Members of the genera Salmonella, Shigella, Sinorhizobium, and Ralstonia, among others, express E3 ubiquitin ligases that belong to the NEL family. These bacteria use type III secretion systems to translocate these proteins into host cells, where they will find their targets. In this review, we first introduce type III secretion systems and the ubiquitination process and consider the various ways bacteria use to alter the ubiquitin ligation machinery. We then focus on the members of the NEL family, their expression, translocation, and subcellular localization in the host cell, and we review what is known about the structure of these proteins, their function in virulence or symbiosis, and their specific targets.
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Affiliation(s)
| | | | - Francisco Ramos-Morales
- Departamento de Genética, Facultad de Biología, Universidad de Sevilla, 41012 Sevilla, Spain; (A.B.-B.); (J.B.-B.)
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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. MOLECULAR PLANT PATHOLOGY 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] [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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10
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Kan CC, Mendoza-Herrera A, Levy J, Hull JJ, Fabrick JA, Tamborindeguy C. HPE1, an Effector from Zebra Chip Pathogen Interacts with Tomato Proteins and Perturbs Ubiquitinated Protein Accumulation. Int J Mol Sci 2021; 22:9003. [PMID: 34445707 PMCID: PMC8396652 DOI: 10.3390/ijms22169003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 08/10/2021] [Accepted: 08/16/2021] [Indexed: 12/20/2022] Open
Abstract
The gram-negative bacterial genus Liberibacter includes economically important pathogens, such as 'Candidatus Liberibacter asiaticus' that cause citrus greening disease (or Huanglongbing, HLB) and 'Ca. Liberibacter solanacearum' (Lso) that cause zebra chip disease in potato. Liberibacter pathogens are fastidious bacteria transmitted by psyllids. Pathogen manipulation of the host' and vector's immune system for successful colonization is hypothesized to be achieved by Sec translocon-dependent effectors (SDE). In previous work, we identified hypothetical protein effector 1 (HPE1), an SDE from Lso, that acts as a suppressor of the plant's effector-triggered immunity (ETI)-like response. In this study, using a yeast two-hybrid system, we identify binding interactions between tomato RAD23 proteins and HPE1. We further show that HPE1 interacts with RAD23 in both nuclear and cytoplasmic compartments in planta. Immunoblot assays show that HPE1 is not ubiquitinated in the plant cell, but rather the expression of HPE1 induced the accumulation of other ubiquitinated proteins. A similar accumulation of ubiquitinated proteins is also observed in Lso infected tomato plants. Finally, earlier colonization and symptom development following Lso haplotype B infection are observed in HPE1 overexpressing plants compared to wild-type plants. Overall, our results suggest that HPE1 plays a role in virulence in Lso pathogenesis, possibly by perturbing the ubiquitin-proteasome system via direct interaction with the ubiquitin-like domain of RAD23 proteins.
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Affiliation(s)
- Chia-Cheng Kan
- Department of Entomology, Texas A&M University, College Station, TX 77843, USA; (C.-C.K.); (A.M.-H.)
| | - Azucena Mendoza-Herrera
- Department of Entomology, Texas A&M University, College Station, TX 77843, USA; (C.-C.K.); (A.M.-H.)
| | - Julien Levy
- Department of Horticultural Sciences, Texas A&M University, College Station, TX 77843, USA;
| | - J. Joe Hull
- USDA-ARS, Arid Land Agricultural Research Center, Maricopa, AZ 85138, USA; (J.J.H.); (J.A.F.)
| | - Jeffery A. Fabrick
- USDA-ARS, Arid Land Agricultural Research Center, Maricopa, AZ 85138, USA; (J.J.H.); (J.A.F.)
| | - Cecilia Tamborindeguy
- Department of Entomology, Texas A&M University, College Station, TX 77843, USA; (C.-C.K.); (A.M.-H.)
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11
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Schreiber KJ, Chau-Ly IJ, Lewis JD. What the Wild Things Do: Mechanisms of Plant Host Manipulation by Bacterial Type III-Secreted Effector Proteins. Microorganisms 2021; 9:1029. [PMID: 34064647 PMCID: PMC8150971 DOI: 10.3390/microorganisms9051029] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 05/03/2021] [Accepted: 05/04/2021] [Indexed: 01/05/2023] Open
Abstract
Phytopathogenic bacteria possess an arsenal of effector proteins that enable them to subvert host recognition and manipulate the host to promote pathogen fitness. The type III secretion system (T3SS) delivers type III-secreted effector proteins (T3SEs) from bacterial pathogens such as Pseudomonas syringae, Ralstonia solanacearum, and various Xanthomonas species. These T3SEs interact with and modify a range of intracellular host targets to alter their activity and thereby attenuate host immune signaling. Pathogens have evolved T3SEs with diverse biochemical activities, which can be difficult to predict in the absence of structural data. Interestingly, several T3SEs are activated following injection into the host cell. Here, we review T3SEs with documented enzymatic activities, as well as T3SEs that facilitate virulence-promoting processes either indirectly or through non-enzymatic mechanisms. We discuss the mechanisms by which T3SEs are activated in the cell, as well as how T3SEs modify host targets to promote virulence or trigger immunity. These mechanisms may suggest common enzymatic activities and convergent targets that could be manipulated to protect crop plants from infection.
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Affiliation(s)
- Karl J. Schreiber
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94710, USA; (K.J.S.); (I.J.C.-L.)
| | - Ilea J. Chau-Ly
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94710, USA; (K.J.S.); (I.J.C.-L.)
| | - Jennifer D. Lewis
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94710, USA; (K.J.S.); (I.J.C.-L.)
- Plant Gene Expression Center, United States Department of Agriculture, University of California, Berkeley, CA 94710, USA
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12
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Ralstonia solanacearum type III effector RipV2 encoding a novel E3 ubiquitin ligase (NEL) is required for full virulence by suppressing plant PAMP-triggered immunity. Biochem Biophys Res Commun 2021; 550:120-126. [PMID: 33691198 DOI: 10.1016/j.bbrc.2021.02.082] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 02/18/2021] [Indexed: 01/04/2023]
Abstract
Ralstonia solanacearum causes bacterial wilt disease in a broad range of plants, primarily through type Ⅲ secreted effectors. However, the R. solanacearum effectors promoting susceptibility in host plants remain limited. In this study, we determined that the R. solanacearum effector RipV2 functions as a novel E3 ubiquitin ligase (NEL). RipV2 was observed to be locali in the plasma membrane after translocatio into plant cells. Transient expression of RipV2 in Nicotiana benthamiana could induce cell death and suppress the flg22-induced pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI) responses, mediating such effects as attenuation of the expression of several PTI-related genes and ROS bursts. Furthermore, we demonstrated that the conserved catalytic residue is highly important for RipV2. Transient expression of the E3 ubiquitin ligase catalytic mutant RipV2 C403A alleviated the PTI suppression ability and cell death induction, indicating that RipV2 requires its E3 ubiquitin ligase activity for its role in plant-microbe interactions. More importantly, mutation of RipV2 in R. solanacearum reduces the virulence of R. solanacearum on potato. In conclusion, we identified a NEL effector that is required for full virulence of R. solanacearum by suppressing plant PTI.
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13
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Kim TK, Tirloni L, Bencosme-Cuevas E, Kim TH, Diedrich JK, Yates JR, Mulenga A. Borrelia burgdorferi infection modifies protein content in saliva of Ixodes scapularis nymphs. BMC Genomics 2021; 22:152. [PMID: 33663385 PMCID: PMC7930271 DOI: 10.1186/s12864-021-07429-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Accepted: 02/08/2021] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Lyme disease (LD) caused by Borrelia burgdorferi is the most prevalent tick-borne disease. There is evidence that vaccines based on tick proteins that promote tick transmission of B. burgdorferi could prevent LD. As Ixodes scapularis nymph tick bites are responsible for most LD cases, this study sought to identify nymph tick saliva proteins associated with B. burgdorferi transmission using LC-MS/MS. Tick saliva was collected using a non-invasive method of stimulating ticks (uninfected and infected: unfed, and every 12 h during feeding through 72 h, and fully-fed) to salivate into 2% pilocarpine-PBS for protein identification using LC-MS/MS. RESULTS We identified a combined 747 tick saliva proteins of uninfected and B. burgdorferi infected ticks that were classified into 25 functional categories: housekeeping-like (48%), unknown function (18%), protease inhibitors (9%), immune-related (6%), proteases (8%), extracellular matrix (7%), and small categories that account for <5% each. Notably, B. burgdorferi infected ticks secreted high number of saliva proteins (n=645) than uninfected ticks (n=376). Counter-intuitively, antimicrobial peptides, which function to block bacterial infection at tick feeding site were suppressed 23-85 folds in B. burgdorferi infected ticks. Similar to glycolysis enzymes being enhanced in mammalian cells exposed to B. burgdorferi : eight of the 10-glycolysis pathway enzymes were secreted at high abundance by B. burgdorferi infected ticks. Of significance, rabbits exposed to B. burgdorferi infected ticks acquired potent immunity that caused 40-60% mortality of B. burgdorferi infected ticks during the second infestation compared to 15-28% for the uninfected. This might be explained by ELISA data that show that high expression levels of immunogenic proteins in B. burgdorferi infected ticks. CONCLUSION Data here suggest that B. burgdorferi infection modified protein content in tick saliva to promote its survival at the tick feeding site. For instance, enzymes; copper/zinc superoxide dismutase that led to production of H2O2 that is toxic to B. burgdorferi were suppressed, while, catalase and thioredoxin that neutralize H2O2, and pyruvate kinase which yields pyruvate that protects Bb from H2O2 killing were enhanced. We conclude data here is an important resource for discovery of effective antigens for a vaccine to prevent LD.
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Affiliation(s)
- Tae Kwon Kim
- Department of Veterinary Pathobiology, College of Veterinary Medicine, Texas A&M University, College Station, Texas, United States of America
- Department of Diagnostic Medicine and Veterinary Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas, United States of America
| | - Lucas Tirloni
- Department of Veterinary Pathobiology, College of Veterinary Medicine, Texas A&M University, College Station, Texas, United States of America
- Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, Hamilton, Montana, United States of America
| | - Emily Bencosme-Cuevas
- Department of Veterinary Pathobiology, College of Veterinary Medicine, Texas A&M University, College Station, Texas, United States of America
| | - Tae Heung Kim
- Department of Veterinary Pathobiology, College of Veterinary Medicine, Texas A&M University, College Station, Texas, United States of America
| | - Jolene K Diedrich
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California, United States of America
- Mass Spectrometry Core, Salk Institute for Biological Studies, La Jolla, California, United States of America
| | - John R Yates
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California, United States of America
| | - Albert Mulenga
- Department of Veterinary Pathobiology, College of Veterinary Medicine, Texas A&M University, College Station, Texas, United States of America.
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14
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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. MOLECULAR PLANT PATHOLOGY 2020; 21:1377-1388. [PMID: 32770627 PMCID: PMC7488467 DOI: 10.1111/mpp.12977] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [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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15
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Sun T, Wu W, Wu H, Rou W, Zhou Y, Zhuo T, Fan X, Hu X, Zou H. Ralstonia solanacearum elicitor RipX Induces Defense Reaction by Suppressing the Mitochondrial atpA Gene in Host Plant. Int J Mol Sci 2020; 21:E2000. [PMID: 32183439 PMCID: PMC7139787 DOI: 10.3390/ijms21062000] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 03/07/2020] [Accepted: 03/09/2020] [Indexed: 11/16/2022] Open
Abstract
RipX of Ralstonia solanacearum is translocated into host cells by a type III secretion system and acts as a harpin-like protein to induce a hypersensitive response in tobacco plants. The molecular events in association with RipX-induced signaling transduction have not been fully elucidated. This work reports that transient expression of RipX induced a yellowing phenotype in Nicotiana benthamiana, coupled with activation of the defense reaction. Using yeast two-hybrid and split-luciferase complementation assays, mitochondrial ATP synthase F1 subunit α (ATPA) was identified as an interaction partner of RipX from N. benthamiana. Although a certain proportion was found in mitochondria, the YFP-ATPA fusion was able to localize to the cell membrane, cytoplasm, and nucleus. RFP-RipX fusion was found from the cell membrane and cytoplasm. Moreover, ATPA interacted with RipX at both the cell membrane and cytoplasm in vivo. Silencing of the atpA gene had no effect on the appearance of yellowing phenotype induced by RipX. However, the silenced plants improved the resistance to R. solanacearum. Moreover, qRT-PCR and promoter GUS fusion experiments revealed that the transcript levels of atpA were evidently reduced in response to expression of RipX. These data demonstrated that RipX exerts a suppressive effect on the transcription of atpA gene, to induce defense reaction in N. benthamiana.
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Affiliation(s)
- Tingyan Sun
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (T.S.); (W.W.); (H.W.); (W.R.); (Y.Z.); (T.Z.); (X.F.); (X.H.)
| | - Wei Wu
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (T.S.); (W.W.); (H.W.); (W.R.); (Y.Z.); (T.Z.); (X.F.); (X.H.)
| | - Haoxiang Wu
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (T.S.); (W.W.); (H.W.); (W.R.); (Y.Z.); (T.Z.); (X.F.); (X.H.)
| | - Wei Rou
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (T.S.); (W.W.); (H.W.); (W.R.); (Y.Z.); (T.Z.); (X.F.); (X.H.)
| | - Yinghui Zhou
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (T.S.); (W.W.); (H.W.); (W.R.); (Y.Z.); (T.Z.); (X.F.); (X.H.)
| | - Tao Zhuo
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (T.S.); (W.W.); (H.W.); (W.R.); (Y.Z.); (T.Z.); (X.F.); (X.H.)
| | - Xiaojing Fan
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (T.S.); (W.W.); (H.W.); (W.R.); (Y.Z.); (T.Z.); (X.F.); (X.H.)
| | - Xun Hu
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (T.S.); (W.W.); (H.W.); (W.R.); (Y.Z.); (T.Z.); (X.F.); (X.H.)
| | - Huasong Zou
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (T.S.); (W.W.); (H.W.); (W.R.); (Y.Z.); (T.Z.); (X.F.); (X.H.)
- Fujian University Key Laboratory for Plant-Microbe Interaction, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China
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16
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Jeon H, Kim W, Kim B, Lee S, Jayaraman J, Jung G, Choi S, Sohn KH, Segonzac C. Ralstonia solanacearum Type III Effectors with Predicted Nuclear Localization Signal Localize to Various Cell Compartments and Modulate Immune Responses in Nicotiana spp. THE PLANT PATHOLOGY JOURNAL 2020; 36:43-53. [PMID: 32089660 PMCID: PMC7012579 DOI: 10.5423/ppj.oa.08.2019.0227] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 11/19/2019] [Accepted: 11/19/2019] [Indexed: 05/11/2023]
Abstract
Ralstonia solanacearum (Rso) is a causal agent of bacterial wilt in Solanaceae crops worldwide including Republic of Korea. Rso virulence predominantly relies on type III secreted effectors (T3Es). However, only a handful of Rso T3Es have been characterized. In this study, we investigated subcellular localization of and manipulation of plant immunity by 8 Rso T3Es predicted to harbor a nuclear localization signal (NLS). While 2 of these T3Es elicited cell death in both Nicotiana benthamiana and N. tabacum, only one was dependent on suppressor of G2 allele of skp1 (SGT1), a molecular chaperone of nucleotide-binding and leucine-rich repeat immune receptors. We also identified T3Es that differentially regulate flg22-induced reactive oxygen species production and gene expression. Interestingly, several of the NLS-containing T3Es translationally fused with yellow fluorescent protein accumulated in subcellular compartments other than the cell nucleus. Our findings bring new clues to decipher Rso T3E function in planta.
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Affiliation(s)
- Hyelim Jeon
- Department of Plant Science, Plant Genomics and Breeding Institute, Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 08826,
Korea
| | - Wanhui Kim
- Department of Plant Science, Plant Genomics and Breeding Institute, Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 08826,
Korea
- Plant Immunity Research Center, Seoul National University, Seoul 08826,
Korea
| | - Boyoung Kim
- Department of Plant Science, Plant Genomics and Breeding Institute, Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 08826,
Korea
| | - Sookyeong Lee
- Department of Plant Science, Plant Genomics and Breeding Institute, Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 08826,
Korea
| | - Jay Jayaraman
- Department of Life Sciences, Pohang University of Science and Technology, Pohang 37673,
Korea
- New Zealand Institute for Plant & Food Research Limited (PFR), Mt Albert Auckland 1025,
New Zealand
| | - Gayoung Jung
- Department of Life Sciences, Pohang University of Science and Technology, Pohang 37673,
Korea
| | - Sera Choi
- Department of Life Sciences, Pohang University of Science and Technology, Pohang 37673,
Korea
| | - Kee Hoon Sohn
- Department of Life Sciences, Pohang University of Science and Technology, Pohang 37673,
Korea
- School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, Pohang 37673,
Korea
| | - Cécile Segonzac
- Department of Plant Science, Plant Genomics and Breeding Institute, Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 08826,
Korea
- Plant Immunity Research Center, Seoul National University, Seoul 08826,
Korea
- Corresponding author: Phone) +82-2-880-2229, FAX) +82-2-873-2056, E-mail)
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17
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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] [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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18
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Nakano M, Mukaihara T. The type III effector RipB from Ralstonia solanacearum RS1000 acts as a major avirulence factor in Nicotiana benthamiana and other Nicotiana species. MOLECULAR PLANT PATHOLOGY 2019; 20:1237-1251. [PMID: 31218811 PMCID: PMC6715614 DOI: 10.1111/mpp.12824] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Ralstonia solanacearum is the causal agent of bacterial wilt in solanaceous crops. This pathogen injects approximately 70 effector proteins into plant cells via the Hrp type III secretion system in an early stage of infection. To identify an as-yet-unidentified avirulence factor possessed by the Japanese tobacco-avirulent strain RS1000, we transiently expressed RS1000 effectors in Nicotiana benthamiana leaves and monitored their ability to induce effector-triggered immunity (ETI). The expression of RipB strongly induced the production of reactive oxygen species and the expressions of defence-related genes in N. benthamiana. The ripB mutant of RS1002, a nalixidic acid-resistant derivative of RS1000, caused wilting symptoms in N. benthamiana. A pathogenicity test using R. solanacearum mutants revealed that the two already known avirulence factors RipP1 and RipAA contribute in part to the avirulence of RS1002 in N. benthamiana. The Japanese tobacco-virulent strain BK1002 contains mutations in ripB and expresses a C-terminal-truncated RipB that lost the ability to induce ETI in N. benthamiana, indicating a fine-tuning of the pathogen effector repertoire to evade plant recognition. RipB shares homology with Xanthomonas XopQ, which is recognized by the resistance protein Roq1. The RipB-induced resistance against R. solanacearum was abolished in Roq1-silenced plants. These findings indicate that RipB acts as a major avirulence factor in N. benthamiana and that Roq1 is involved in the recognition of RipB.
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Affiliation(s)
- Masahito Nakano
- Research Institute for Biological Sciences, Okayama (RIBS)Yoshikawa, Kibichuo‐choOkayama716‐1241Japan
| | - Takafumi Mukaihara
- Research Institute for Biological Sciences, Okayama (RIBS)Yoshikawa, Kibichuo‐choOkayama716‐1241Japan
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19
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Kud J, Wang W, Gross R, Fan Y, Huang L, Yuan Y, Gray A, Duarte A, Kuhl JC, Caplan A, Goverse A, Liu Y, Dandurand LM, Xiao F. The potato cyst nematode effector RHA1B is a ubiquitin ligase and uses two distinct mechanisms to suppress plant immune signaling. PLoS Pathog 2019; 15:e1007720. [PMID: 30978251 PMCID: PMC6461251 DOI: 10.1371/journal.ppat.1007720] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 03/20/2019] [Indexed: 12/12/2022] Open
Abstract
Plant pathogens, such as bacteria, fungi, oomycetes and nematodes, rely on wide range of virulent effectors delivered into host cells to suppress plant immunity. Although phytobacterial effectors have been intensively investigated, little is known about the function of effectors of plant-parasitic nematodes, such as Globodera pallida, a cyst nematode responsible for vast losses in the potato and tomato industries. Here, we demonstrate using in vivo and in vitro ubiquitination assays the potato cyst nematode (Globodera pallida) effector RHA1B is an E3 ubiquitin ligase that employs multiple host plant E2 ubiquitin conjugation enzymes to catalyze ubiquitination. RHA1B was able to suppress effector-triggered immunity (ETI), as manifested by suppression of hypersensitive response (HR) mediated by a broad range of nucleotide-binding leucine-rich repeat (NB-LRR) immune receptors, presumably via E3-dependent degradation of the NB-LRR receptors. RHA1B also blocked the flg22-triggered expression of Acre31 and WRKY22, marker genes of pathogen‐associated molecular pattern (PAMP)‐triggered immunity (PTI), but this did not require the E3 activity of RHA1B. Moreover, transgenic potato overexpressing the RHA1B transgene exhibited enhanced susceptibility to G. pallida. Thus, our data suggest RHA1B facilitates nematode parasitism not only by triggering degradation of NB-LRR immune receptors to block ETI signaling but also by suppressing PTI signaling via an as yet unknown E3-independent mechanism. Globodera pallida is a plant-parasitic cyst nematode that causes vast losses in economically important crops such as potato and tomato. To successfully parasitize host plants, G. pallida produces proteins called effectors to overcome plant defenses. Here, we report identification of a novel G. pallida effector RHA1B as an E3 ubiquitin ligase, which is responsible for ubiquitin-proteasome-mediated protein degradation in general. We found that RHA1B can suppress plant defense signaling via both E3-dependent and -independent manners. In particular, it promotes degradation of a broad range of NB-LRR immune receptors. In addition, expression of RHA1B in potato plants made the plants more susceptible to G. pallida infection, indicating that RHA1B acts as an effector that aids parasitism. Overall, we found RHA1B as the first effector with ubiquitin ligase activity identified from eukaryotic pathogen infecting plants or animals. Our data suggest nematode uses RHA1B as a powerful weapon to manipulate host cellular signaling pathways, thereby interfering with plant immunity for successful parasitism.
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Affiliation(s)
- Joanna Kud
- Department of Plant Sciences, University of Idaho, Moscow, ID, United States of America
| | - Wenjie Wang
- Department of Plant Sciences, University of Idaho, Moscow, ID, United States of America
- School of Food Science, Hefei University of Technology, Hefei, China
| | - Rachel Gross
- Department of Plant Sciences, University of Idaho, Moscow, ID, United States of America
| | - Youhong Fan
- Department of Plant Sciences, University of Idaho, Moscow, ID, United States of America
- School of Food Science, Hefei University of Technology, Hefei, China
| | - Li Huang
- Department of Plant Sciences, University of Idaho, Moscow, ID, United States of America
| | - Yulin Yuan
- Department of Plant Sciences, University of Idaho, Moscow, ID, United States of America
| | - Amanda Gray
- Department of Entomology, Plant Pathology and Nematology, University of Idaho, Moscow, ID, United States of America
| | - Aida Duarte
- Department of Entomology, Plant Pathology and Nematology, University of Idaho, Moscow, ID, United States of America
| | - Joseph C. Kuhl
- Department of Plant Sciences, University of Idaho, Moscow, ID, United States of America
| | - Allan Caplan
- Department of Plant Sciences, University of Idaho, Moscow, ID, United States of America
| | - Aska Goverse
- Laboratory of Nematology, Department of Plant Sciences, Wageningen University & Research, Wageningen, The Netherlands
| | - Yongsheng Liu
- School of Food Science, Hefei University of Technology, Hefei, China
- School of Horticulture, Anhui Agricultural University, Hefei, China
- Ministry of Education Key Laboratory for Bio-resource and Eco-environment, College of Life Science, State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu, China
| | - Louise-Marie Dandurand
- Department of Entomology, Plant Pathology and Nematology, University of Idaho, Moscow, ID, United States of America
- * E-mail: (LMD); (FX)
| | - Fangming Xiao
- Department of Plant Sciences, University of Idaho, Moscow, ID, United States of America
- * E-mail: (LMD); (FX)
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Sun Y, Li P, Shen D, Wei Q, He J, Lu Y. The Ralstonia solanacearum effector RipN suppresses plant PAMP-triggered immunity, localizes to the endoplasmic reticulum and nucleus, and alters the NADH/NAD + ratio in Arabidopsis. MOLECULAR PLANT PATHOLOGY 2019; 20:533-546. [PMID: 30499216 PMCID: PMC6637912 DOI: 10.1111/mpp.12773] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Ralstonia solanacearum, one of the most destructive plant bacterial pathogens, delivers an array of effector proteins via its type III secretion system for pathogenesis. However, the biochemical functions of most of these proteins remain unclear. RipN is a type III effector with unknown function(s) from the pathogen R. solanacearum. Here, we demonstrate that RipN is a conserved type III effector found within the R. solanacearum species complex that contains a putative Nudix hydrolase domain and has ADP-ribose/NADH pyrophosphorylase activity in vitro. Further analysis shows that RipN localizes to the endoplasmic reticulum (ER) and nucleus in Nicotiana tabacum leaf cells and Arabidopsis protoplasts, and truncation of the C-terminus of RipN results in a loss of nuclear and ER targeting. Furthermore, the expression of RipN in Arabidopsis suppresses callose deposition and the transcription of pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI) marker genes under flg22 treatment, and promotes bacterial growth in planta. In addition, the expression of RipN in plant cells alters NADH/NAD+ , but not GSH/GSSG, ratios, and its Nudix hydrolase activity is indispensable for such biochemical function. These results suggest that RipN acts as a Nudix hydrolase, alters the NADH/NAD+ ratio of the plant and contributes to R. solanacearum virulence by suppression of PTI of the host.
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Affiliation(s)
- Yunhao Sun
- School of Life SciencesSun Yat‐sen UniversityGuangzhou510275China
- State Key Laboratory of BiocontrolSun Yat‐sen UniversityGuangzhou510275China
| | - Pai Li
- School of Life SciencesSun Yat‐sen UniversityGuangzhou510275China
- State Key Laboratory of BiocontrolSun Yat‐sen UniversityGuangzhou510275China
| | - Dong Shen
- School of Life SciencesSun Yat‐sen UniversityGuangzhou510275China
- State Key Laboratory of BiocontrolSun Yat‐sen UniversityGuangzhou510275China
| | - Qiaoling Wei
- School of Life SciencesSun Yat‐sen UniversityGuangzhou510275China
- State Key Laboratory of BiocontrolSun Yat‐sen UniversityGuangzhou510275China
| | - Jianguo He
- School of Life SciencesSun Yat‐sen UniversityGuangzhou510275China
- State Key Laboratory of BiocontrolSun Yat‐sen UniversityGuangzhou510275China
| | - Yongjun Lu
- School of Life SciencesSun Yat‐sen UniversityGuangzhou510275China
- State Key Laboratory of BiocontrolSun Yat‐sen UniversityGuangzhou510275China
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21
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Bastedo DP, Lo T, Laflamme B, Desveaux D, Guttman DS. Diversity and Evolution of Type III Secreted Effectors: A Case Study of Three Families. Curr Top Microbiol Immunol 2019; 427:201-230. [DOI: 10.1007/82_2019_165] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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22
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Regulation of Plant Immunity by the Proteasome. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2019; 343:37-63. [DOI: 10.1016/bs.ircmb.2018.06.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Nakano M, Mukaihara T. Ralstonia solanacearum Type III Effector RipAL Targets Chloroplasts and Induces Jasmonic Acid Production to Suppress Salicylic Acid-Mediated Defense Responses in Plants. PLANT & CELL PHYSIOLOGY 2018; 59:2576-2589. [PMID: 30165674 DOI: 10.1093/pcp/pcy177] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 08/23/2018] [Indexed: 05/06/2023]
Abstract
Ralstonia solanacearum is the causal agent of bacterial wilt disease of plants. This pathogen injects more than 70 type III effector proteins called Rips (Ralstonia-injected proteins) into plant cells to succeed in infection. One of the Rips, RipAL, contains a putative lipase domain that shared homology with Arabidopsis DEFECTIVE IN ANTHER DEHISCENCE1 (DAD1). RipAL significantly suppressed pattern-triggered immunity in leaves of Nicotiana benthamiana. Subcellular localization analyses suggest that RipAL localizes to chloroplasts and targets chloroplast lipids in plant cells. Notably, the expression of RipAL markedly increased the jasmonic acid (JA) and JA-isoleucine levels, and induced the expressions of JA-signaling marker genes in plant leaves. Simultaneously, RipAL greatly reduced the salicylic acid (SA) level and decreased the expression levels of SA-signaling marker genes. Mutations in two putative catalytic residues in the DAD1-like lipase domain abolished the ability of RipAL to induce JA production and suppress SA signaling. Infection of R. solanacearum also induced JA production and simultaneously decreased the SA level in susceptible pepper leaves in a ripAL-dependent manner. The growth of R. solanacearum enhanced in plants with silenced CaICS1, which encodes the SA synthesis enzyme isochorismate synthase 1. These results indicate that SA signaling is involved in the defense response against R. solanacearum and that R. solanacearum uses RipAL to induce JA production and suppress SA signaling in plant cells.
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Affiliation(s)
- Masahito Nakano
- Research Institute for Biological Sciences, Okayama (RIBS), 7549-1 Yoshikawa, Kibichuo-cho, Okayama, Japan
| | - Takafumi Mukaihara
- Research Institute for Biological Sciences, Okayama (RIBS), 7549-1 Yoshikawa, Kibichuo-cho, Okayama, Japan
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Xu CC, Zhang D, Hann DR, Xie ZP, Staehelin C. Biochemical properties and in planta effects of NopM, a rhizobial E3 ubiquitin ligase. J Biol Chem 2018; 293:15304-15315. [PMID: 30120198 DOI: 10.1074/jbc.ra118.004444] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 07/25/2018] [Indexed: 01/18/2023] Open
Abstract
Nodulation outer protein M (NopM) is an IpaH family type three (T3) effector secreted by the nitrogen-fixing nodule bacterium Sinorhizobium sp. strain NGR234. Previous work indicated that NopM is an E3 ubiquitin ligase required for an optimal symbiosis between NGR234 and the host legume Lablab purpureus Here, we continued to analyze the function of NopM. Recombinant NopM was biochemically characterized using an in vitro ubiquitination system with Arabidopsis thaliana proteins. In this assay, NopM forms unanchored polyubiquitin chains and possesses auto-ubiquitination activity. In a NopM variant lacking any lysine residues, auto-ubiquitination was not completely abolished, indicating noncanonical auto-ubiquitination of the protein. In addition, we could show intermolecular ubiquitin transfer from NopM to C338A (enzymatically inactive NopM form) in vitro Bimolecular fluorescence complementation analysis provided clues about NopM-NopM interactions at plasma membranes in planta NopM, but not C338A, expressed in tobacco cells induced cell death, suggesting that E3 ubiquitin ligase activity of NopM induced effector-triggered immunity responses. Likewise, expression of NopM in Lotus japonicus caused reduced nodule formation, whereas expression of C338A showed no obvious effects on symbiosis. Further experiments indicated that serine residue 26 of NopM is phosphorylated in planta and that NopM can be phosphorylated in vitro by salicylic acid-induced protein kinase (NtSIPK), a mitogen-activated protein kinase (MAPK) of tobacco. Hence, NopM is a phosphorylated T3 effector that can interact with itself, with ubiquitin, and with MAPKs.
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Affiliation(s)
- Chang-Chao Xu
- From the State Key Laboratory of Biocontrol and Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, East Campus, Guangzhou 510006, China
| | - Di Zhang
- From the State Key Laboratory of Biocontrol and Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, East Campus, Guangzhou 510006, China
| | - Dagmar R Hann
- the Institute of Genetics, Ludwig-Maximilians-Universität München, D-82152 Martinsried, Germany, and
| | - Zhi-Ping Xie
- From the State Key Laboratory of Biocontrol and Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, East Campus, Guangzhou 510006, China, .,the Shenzhen Research and Development Center of State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Baoan, Shenzhen 518057, China
| | - Christian Staehelin
- From the State Key Laboratory of Biocontrol and Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, East Campus, Guangzhou 510006, China, .,the Shenzhen Research and Development Center of State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Baoan, Shenzhen 518057, China
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