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Zhao JH, Huang YY, Wang H, Yang XM, Li Y, Pu M, Zhou SX, Zhang JW, Zhao ZX, Li GB, Hassan B, Hu XH, Chen X, Xiao S, Wu XJ, Fan J, Wang WM. Golovinomyces cichoracearum effector-associated nuclear localization of RPW8.2 amplifies its expression to boost immunity in Arabidopsis. THE NEW PHYTOLOGIST 2023; 238:367-382. [PMID: 36522832 DOI: 10.1111/nph.18682] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Accepted: 11/30/2022] [Indexed: 06/17/2023]
Abstract
Arabidopsis RESISTANCE TO POWDERY MILDEW 8.2 (RPW8.2) is specifically induced by the powdery mildew (PM) fungus (Golovinomyces cichoracearum) in the infected epidermal cells to activate immunity. However, the mechanism of RPW8.2-induction is not well understood. Here, we identify a G. cichoracearum effector that interacts with RPW8.2, named Gc-RPW8.2 interacting protein 1 (GcR8IP1), by a yeast two-hybrid screen of an Arabidopsis cDNA library. GcR8IP1 is physically associated with RPW8.2 with its REALLY INTERESTING NEW GENE finger domain that is essential and sufficient for the association. GcR8IP1 was secreted and translocated into the nucleus of host cell infected with PM. Association of GcR8IP1 with RPW8.2 led to an increase in RPW8.2 in the nucleus. In turn, the nucleus-localized RPW8.2 promoted the activity of the RPW8.2 promoter, resulting in transcriptional self-amplification of RPW8.2 to boost immunity at infection sites. Additionally, ectopic expression or host-induced gene silencing of GcR8IP1 supported its role as a virulence factor in PM. Altogether, our results reveal a mechanism of RPW8.2-dependent defense strengthening via altered partitioning of RPW8.2 and transcriptional self-amplification triggered by a PM fungal effector, which exemplifies an atypical form of effector-triggered immunity.
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Affiliation(s)
- Jing-Hao Zhao
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China and Rice Research Institute, Sichuan Agricultural University, Chengdu, 611131, China
| | - Yan-Yan Huang
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China and Rice Research Institute, Sichuan Agricultural University, Chengdu, 611131, China
| | - He Wang
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China and Rice Research Institute, Sichuan Agricultural University, Chengdu, 611131, China
| | - Xue-Mei Yang
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China and Rice Research Institute, Sichuan Agricultural University, Chengdu, 611131, China
| | - Yan Li
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China and Rice Research Institute, Sichuan Agricultural University, Chengdu, 611131, China
| | - Mei Pu
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China and Rice Research Institute, Sichuan Agricultural University, Chengdu, 611131, China
| | - Shi-Xin Zhou
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China and Rice Research Institute, Sichuan Agricultural University, Chengdu, 611131, China
| | - Ji-Wei Zhang
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China and Rice Research Institute, Sichuan Agricultural University, Chengdu, 611131, China
| | - Zhi-Xue Zhao
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China and Rice Research Institute, Sichuan Agricultural University, Chengdu, 611131, China
| | - Guo-Bang Li
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China and Rice Research Institute, Sichuan Agricultural University, Chengdu, 611131, China
| | - Beenish Hassan
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China and Rice Research Institute, Sichuan Agricultural University, Chengdu, 611131, China
| | - Xiao-Hong Hu
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China and Rice Research Institute, Sichuan Agricultural University, Chengdu, 611131, China
| | - Xuewei Chen
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China and Rice Research Institute, Sichuan Agricultural University, Chengdu, 611131, China
| | - Shunyuan Xiao
- Institute for Bioscience and Biotechnology Research, University of Maryland, College Park, MD, 20850, USA
| | - Xian-Jun Wu
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China and Rice Research Institute, Sichuan Agricultural University, Chengdu, 611131, China
| | - Jing Fan
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China and Rice Research Institute, Sichuan Agricultural University, Chengdu, 611131, China
| | - Wen-Ming Wang
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China and Rice Research Institute, Sichuan Agricultural University, Chengdu, 611131, China
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Wu X, Chen L, Lin X, Chen X, Han C, Tian F, Wan X, Liu Q, He F, Chen L, Zhong Y, Yang H, Zhang F. Integrating physiological and transcriptome analyses clarified the molecular regulation mechanism of PyWRKY48 in poplar under cadmium stress. Int J Biol Macromol 2023; 238:124072. [PMID: 36934813 DOI: 10.1016/j.ijbiomac.2023.124072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2022] [Revised: 02/22/2023] [Accepted: 03/13/2023] [Indexed: 03/19/2023]
Abstract
WRKY transcription factors (TFs) play an important role in regulating plant growth and responses to environmental stress. However, the molecular mechanism of WRKY to cadmium (Cd) stress is unclear, which prevents phytoremediation of Cd-contaminated soil from widely application. To determine the underlying mechanism, PyWRKY48-overexpressing poplars were obtained (OE-32 and OE-67) to study the Cd tolerance and accumulation in poplars. Results showed that the Cd content in the aboveground part of the two transgenic poplar lines were 1.57 and 1.99 times higher than that of wild type (WT), and lateral roots, GSH, PCs content and GST activity increased significantly. RNA-seq. data about transgenic and WT poplars revealed that 2074 differentially expressed genes (DEGs) in roots, 4325 in leaves, and 499 in both tissues. And these DEGs were mainly concentrated in ABC transport protein (PaABC), heavy-metal binding protein (PaHIPP), and transportation and loading of xylem (PaNPF, PaBSP) proteins, and they enhanced Cd accumulation. Meanwhile, PyWRKY48 increased the Cd tolerance of transgenic poplars by up-regulating the expression of PaGRP, PaPER and PaPHOS, which encode cell wall proteins, antioxidant enzyme, and heavy metal-associated proteins, respectively. In addition, overexpression PyWRKY48 promoted poplar growth by increasing the chlorophyll and carotenoid content. ENVIRONMENTAL IMPLICATION: This study generated PyWRKY48-overexpressing poplars and functionally verified them in Cd-contaminated soil, to analyze the effects of the gene on poplar growth, Cd tolerance and Cd accumulation. RNA seq. data revealed that several genes are involved in Cd exposure. This may provide a strong molecular basis and new ideas for improving the phytoremediation efficiency of Cd-contaminated soils. Importantly, the transgenic poplars grew better and accumulated more Cd than the wild-type. Therefore, PyWRKY48-overexpressing poplars could be considered useful for mitigating environmental pollution.
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Affiliation(s)
- Xiaolu Wu
- College of Landscape Architecture, Sichuan Agricultural University, Chengdu, Sichuan 611130, China
| | - Lulu Chen
- College of Landscape Architecture, Sichuan Agricultural University, Chengdu, Sichuan 611130, China
| | - Xinyi Lin
- College of Landscape Architecture, Sichuan Agricultural University, Chengdu, Sichuan 611130, China
| | - Xiaoxi Chen
- College of Landscape Architecture, Sichuan Agricultural University, Chengdu, Sichuan 611130, China
| | - Chengyu Han
- College of Landscape Architecture, Sichuan Agricultural University, Chengdu, Sichuan 611130, China
| | - Feifei Tian
- College of Landscape Architecture, Sichuan Agricultural University, Chengdu, Sichuan 611130, China
| | - Xueqin Wan
- College of Forestry, Sichuan Agricultural University, Chengdu, Sichuan 611130, China
| | - Qinglin Liu
- College of Landscape Architecture, Sichuan Agricultural University, Chengdu, Sichuan 611130, China
| | - Fang He
- College of Forestry, Sichuan Agricultural University, Chengdu, Sichuan 611130, China
| | - Lianghua Chen
- College of Forestry, Sichuan Agricultural University, Chengdu, Sichuan 611130, China
| | - Yu Zhong
- College of Forestry, Sichuan Agricultural University, Chengdu, Sichuan 611130, China
| | - Hanbo Yang
- College of Forestry, Sichuan Agricultural University, Chengdu, Sichuan 611130, China
| | - Fan Zhang
- College of Landscape Architecture, Sichuan Agricultural University, Chengdu, Sichuan 611130, China.
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Microscopic and Transcriptomic Comparison of Powdery Mildew Resistance in the Progenies of Brassica carinata × B. napus. Int J Mol Sci 2022; 23:ijms23179961. [PMID: 36077359 PMCID: PMC9456427 DOI: 10.3390/ijms23179961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 08/24/2022] [Accepted: 08/29/2022] [Indexed: 11/17/2022] Open
Abstract
Powdery mildew is a widespread disease in rapeseed due to a lack of resistant germplasm. We compared the foliar epidermal features and transcriptomic responses between the resistant (R) and susceptible (S) plants among the two parents and progenies of Brassica carinata × B. napus. The amount of cuticular wax and callose deposition on the R plants was much lower than that on the S plants; hence, these chemicals are not all essential to pre-penetration resistance, although the cuticular wax on the R plants had more needle-like crystals. A total of 1049 genes involved in various defense responses were expressed differentially among the R/S plants. The expression levels of two well-known susceptibility genes, MLO6 and MLO12, were much lower in the R plant, indicating an important role in PM resistance. A set of genes related to wax biosynthesis (KCS6, LACS2, CER and MAH1), cell wall modification (PMR5, PMEI9, RWA2, PDCB1 and C/VIF2), chloroplast function (Chlorophyllase-1, OEP161, PSBO1, CP29B and CSP41b), receptor kinase activity (ERECTA, BAK1, BAM2, LYM1, LYM3, RLK902, RLP11, ERL1 and ERL2), IPCS2, GF14 lambda, RPS4 and RPS6 were highly expressed in the R plants. In the S plants, most highly expressed genes were involved in later defense responses, including CERK1, LYK4, LIK1, NIMIN-1, CHITINASE 10, PECTINESTERASE, CYP81F2 and RBOHF and the genes involved in salicylic acid-dependent systemic acquired resistance and hypersensitive responses, indicating the occurrence of severe fungal infection. The results indicate that some uncertain pre-penetration defenses are pivotal for high resistance, while post-penetration defenses are more important for the S plant survival.
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Wu X, Chen Q, Chen L, Tian F, Chen X, Han C, Mi J, Lin X, Wan X, Jiang B, Liu Q, He F, Chen L, Zhang F. A WRKY transcription factor, PyWRKY75, enhanced cadmium accumulation and tolerance in poplar. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2022; 239:113630. [PMID: 35569299 DOI: 10.1016/j.ecoenv.2022.113630] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 04/06/2022] [Accepted: 05/08/2022] [Indexed: 06/15/2023]
Abstract
Cadmium (Cd) pollution has detrimental effects on the ecological environment and human health. Currently, phytoremediation is considered an environmentally friendly way to remediate Cd pollution. The application of transgenic plants to remediate soil pollution is a new technology that has emerged in recent years. In this study, PyWRKY75 was isolated and cloned from Populus yunnanensis, and the functionality of PyWRKY75 in woody plants (poplar) under Cd stress was verified. The increase in plant height of the OE-41 line (overexpression poplar) was 33.2% higher than that of the wild type (WT). Moreover, PyWRKY75 significantly promoted the absorption and accumulation of Cd in poplar, which increased by 51.32% in the OE-41 line when compared with the WT. The chlorophyll content of transgenic poplar leaves was higher than that of the WT, which reflected a protective mechanism of PyWRKY75. Other antioxidants, such as POD, SOD, CAT, APX, AsA, GSH and PCs, also made the transgenic poplars more tolerant to Cd, and they behaved differently in roots, stems and leaves. In general, PyWRKY75 played a potential role in regulating plant tolerance to Cd stress. This study provides a scientific basis and a new type of modified poplar for Cd pollution remediation.
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Affiliation(s)
- Xiaolu Wu
- College of Landscape Architecture, Sichuan Agricultural University, Chengdu, Sichuan 611130, China
| | - Qi Chen
- College of Landscape Architecture, Sichuan Agricultural University, Chengdu, Sichuan 611130, China
| | - Lulu Chen
- College of Landscape Architecture, Sichuan Agricultural University, Chengdu, Sichuan 611130, China
| | - Feifei Tian
- College of Landscape Architecture, Sichuan Agricultural University, Chengdu, Sichuan 611130, China
| | - Xiaoxi Chen
- College of Landscape Architecture, Sichuan Agricultural University, Chengdu, Sichuan 611130, China
| | - Chengyu Han
- College of Landscape Architecture, Sichuan Agricultural University, Chengdu, Sichuan 611130, China
| | - Jiaxuan Mi
- College of Forestry, Sichuan Agricultural University, Chengdu, Sichuan 611130, China
| | - Xinyi Lin
- College of Landscape Architecture, Sichuan Agricultural University, Chengdu, Sichuan 611130, China
| | - Xueqin Wan
- College of Forestry, Sichuan Agricultural University, Chengdu, Sichuan 611130, China
| | - Beibei Jiang
- College of Landscape Architecture, Sichuan Agricultural University, Chengdu, Sichuan 611130, China
| | - Qinglin Liu
- College of Landscape Architecture, Sichuan Agricultural University, Chengdu, Sichuan 611130, China
| | - Fang He
- College of Forestry, Sichuan Agricultural University, Chengdu, Sichuan 611130, China
| | - Lianghua Chen
- College of Forestry, Sichuan Agricultural University, Chengdu, Sichuan 611130, China
| | - Fan Zhang
- College of Landscape Architecture, Sichuan Agricultural University, Chengdu, Sichuan 611130, China.
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5
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Maruta N, Burdett H, Lim BYJ, Hu X, Desa S, Manik MK, Kobe B. Structural basis of NLR activation and innate immune signalling in plants. Immunogenetics 2022; 74:5-26. [PMID: 34981187 PMCID: PMC8813719 DOI: 10.1007/s00251-021-01242-5] [Citation(s) in RCA: 39] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Accepted: 11/29/2021] [Indexed: 12/18/2022]
Abstract
Animals and plants have NLRs (nucleotide-binding leucine-rich repeat receptors) that recognize the presence of pathogens and initiate innate immune responses. In plants, there are three types of NLRs distinguished by their N-terminal domain: the CC (coiled-coil) domain NLRs, the TIR (Toll/interleukin-1 receptor) domain NLRs and the RPW8 (resistance to powdery mildew 8)-like coiled-coil domain NLRs. CC-NLRs (CNLs) and TIR-NLRs (TNLs) generally act as sensors of effectors secreted by pathogens, while RPW8-NLRs (RNLs) signal downstream of many sensor NLRs and are called helper NLRs. Recent studies have revealed three dimensional structures of a CNL (ZAR1) including its inactive, intermediate and active oligomeric state, as well as TNLs (RPP1 and ROQ1) in their active oligomeric states. Furthermore, accumulating evidence suggests that members of the family of lipase-like EDS1 (enhanced disease susceptibility 1) proteins, which are uniquely found in seed plants, play a key role in providing a link between sensor NLRs and helper NLRs during innate immune responses. Here, we summarize the implications of the plant NLR structures that provide insights into distinct mechanisms of action by the different sensor NLRs and discuss plant NLR-mediated innate immune signalling pathways involving the EDS1 family proteins and RNLs.
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Affiliation(s)
- Natsumi Maruta
- School of Chemistry and Molecular Biosciences, Institute for Molecular Bioscience and Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, QLD, 4072, Australia.
| | - Hayden Burdett
- School of Chemistry and Molecular Biosciences, Institute for Molecular Bioscience and Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, QLD, 4072, Australia
- Wellcome Centre for Cell Biology, University of Edinburgh, Michael Swann Building, Max Born Crescent, Edinburgh, UK
| | - Bryan Y J Lim
- School of Chemistry and Molecular Biosciences, Institute for Molecular Bioscience and Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, QLD, 4072, Australia
| | - Xiahao Hu
- School of Chemistry and Molecular Biosciences, Institute for Molecular Bioscience and Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, QLD, 4072, Australia
| | - Sneha Desa
- School of Chemistry and Molecular Biosciences, Institute for Molecular Bioscience and Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, QLD, 4072, Australia
| | - Mohammad Kawsar Manik
- School of Chemistry and Molecular Biosciences, Institute for Molecular Bioscience and Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, QLD, 4072, Australia
| | - Bostjan Kobe
- School of Chemistry and Molecular Biosciences, Institute for Molecular Bioscience and Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, QLD, 4072, Australia.
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6
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Dongus JA, Parker JE. EDS1 signalling: At the nexus of intracellular and surface receptor immunity. CURRENT OPINION IN PLANT BIOLOGY 2021; 62:102039. [PMID: 33930849 DOI: 10.1016/j.pbi.2021.102039] [Citation(s) in RCA: 69] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 03/08/2021] [Accepted: 03/09/2021] [Indexed: 05/27/2023]
Abstract
The conserved lipase-like protein EDS1 transduces signals from pathogen-activated intracellular nucleotide-binding leucine-rich repeat (NLR) receptors to transcriptional defences and host cell death. In this pivotal NLR signalling role, EDS1 works as a heterodimer with each of its partners, SAG101 and PAD4. Different properties of EDS1-SAG101 and EDS1-PAD4 complexes and functional relationships to sensor and helper NLRs have emerged. EDS1-SAG101 dimers confer effector-triggered immunity mediated by intracellular TNL receptors. In contrast, EDS1-PAD4 dimers have a broader role promoting basal immune responses that can be initiated inside cells by TNL- or CNL-type NLRs, and at the cell surface by LRR-receptor proteins. Characterizing the essential elements of these two EDS1 modules will help to connect intracellular and surface receptor signalling networks in the plant immune system.
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Affiliation(s)
- Joram A Dongus
- Department of Plant-Microbe Interactions, Max-Planck Institute for Plant Breeding Research, Carl-von-Linné-Weg 10, Cologne, 50829, Germany
| | - Jane E Parker
- Cologne-Düsseldorf Cluster of Excellence on Plant Sciences (CEPLAS), 40225, Düsseldorf, Germany; Department of Plant-Microbe Interactions, Max-Planck Institute for Plant Breeding Research, Carl-von-Linné-Weg 10, Cologne, 50829, Germany.
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Zhao ZX, Xu YJ, Lei Y, Li Q, Zhao JQ, Li Y, Fan J, Xiao S, Wang WM. ANNEXIN 8 negatively regulates RPW8.1-mediated cell death and disease resistance in Arabidopsis. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2021; 63:378-392. [PMID: 33073904 DOI: 10.1111/jipb.13025] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 10/15/2020] [Indexed: 06/11/2023]
Abstract
Study on the regulation of broad-spectrum resistance is an active area in plant biology. RESISTANCE TO POWDERY MILDEW 8.1 (RPW8.1) is one of a few broad-spectrum resistance genes triggering the hypersensitive response (HR) to restrict multiple pathogenic infections. To address the question how RPW8.1 signaling is regulated, we performed a genetic screen and tried to identify mutations enhancing RPW8.1-mediated HR. Here, we provided evidence to connect an annexin protein with RPW8.1-mediated resistance in Arabidopsis against powdery mildew. We isolated and characterized Arabidopsis b7-6 mutant. A point mutation in b7-6 at the At5g12380 locus resulted in an amino acid substitution in ANNEXIN 8 (AtANN8). Loss-of-function or RNA-silencing of AtANN8 led to enhanced expression of RPW8.1, RPW8.1-dependent necrotic lesions in leaves, and defense against powdery mildew. Conversely, over-expression of AtANN8 compromised RPW8.1-mediated disease resistance and cell death. Interestingly, the mutation in AtANN8 enhanced RPW8.1-triggered H2 O2 . In addition, mutation in AtANN8 led to hypersensitivity to salt stress. Together, our data indicate that AtANN8 is involved in multiple stress signaling pathways and negatively regulates RPW8.1-mediated resistance against powdery mildew and cell death, thus linking ANNEXIN's function with plant immunity.
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Affiliation(s)
- Zhi-Xue Zhao
- Rice Research Institute and Key Laboratory for Major Crop Diseases, Sichuan Agricultural University, Chengdu, 611130, China
| | - Yong-Ju Xu
- Rice Research Institute and Key Laboratory for Major Crop Diseases, Sichuan Agricultural University, Chengdu, 611130, China
| | - Yang Lei
- Rice Research Institute and Key Laboratory for Major Crop Diseases, Sichuan Agricultural University, Chengdu, 611130, China
| | - Qin Li
- Rice Research Institute and Key Laboratory for Major Crop Diseases, Sichuan Agricultural University, Chengdu, 611130, China
| | - Ji-Qun Zhao
- Rice Research Institute and Key Laboratory for Major Crop Diseases, Sichuan Agricultural University, Chengdu, 611130, China
| | - Yan Li
- Rice Research Institute and Key Laboratory for Major Crop Diseases, Sichuan Agricultural University, Chengdu, 611130, China
| | - Jing Fan
- Rice Research Institute and Key Laboratory for Major Crop Diseases, Sichuan Agricultural University, Chengdu, 611130, China
| | - Shunyuan Xiao
- Institute for Bioscience and Biotechnology Research & Department of Plant Science and Landscape Architecture, University of Maryland, Rockville, Maryland, 20850, USA
| | - Wen-Ming Wang
- Rice Research Institute and Key Laboratory for Major Crop Diseases, Sichuan Agricultural University, Chengdu, 611130, China
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Zhao Z, Feng Q, Liu P, He X, Zhao J, Xu Y, Zhang L, Huang Y, Zhao J, Fan J, Li Y, Xiao S, Wang W. RPW8.1 enhances the ethylene-signaling pathway to feedback-attenuate its mediated cell death and disease resistance in Arabidopsis. THE NEW PHYTOLOGIST 2021; 229:516-531. [PMID: 32767839 PMCID: PMC7754472 DOI: 10.1111/nph.16857] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 07/27/2020] [Indexed: 05/20/2023]
Abstract
The Arabidopsis RESISTANCE TO POWDERY MILDEW 8.1 (RPW8.1) activates confined cell death and defense against different pathogens. However, the underlying regulatory mechanisms still remain elusive. Here, we show that RPW8.1 activates ethylene signaling that, in turn, negatively regulates RPW8.1 expression. RPW8.1 binds and stabilizes 1-aminocyclopropane-1-carboxylate oxidase 4 (ACO4), which may in part explain increased ethylene production and signaling in RPW8.1-expressing plants. In return, ACO4 and other key components of ethylene signaling negatively regulate RPW8.1-mediated cell death and disease resistance via suppressing RPW8.1 expression. Loss of function in ACO4, EIN2, EIN3 EIL1, ERF6, ERF016 or ORA59 increases RPW8.1-mediated cell death and defense response. By contrast, overexpression of EIN3 abolishes or significantly compromises RPW8.1-mediated cell death and disease resistance. Furthermore, ERF6, ERF016 and ORA59 appear to act as trans-repressors of RPW8.1, with OAR59 being able to directly bind to the RPW8.1 promoter. Taken together, our results have revealed a feedback regulatory circuit connecting RPW8.1 and the ethylene-signaling pathway, in which RPW8.1 enhances ethylene signaling, and the latter, in return, negatively regulates RPW8.1-mediated cell death and defense response via suppressing RPW8.1 expression to attenuate its defense activity.
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Affiliation(s)
- Zhi‐Xue Zhao
- Rice Research Institute and Key Lab for Major Crop DiseasesSichuan Agricultural UniversityChengdu611130China
| | - Qin Feng
- Rice Research Institute and Key Lab for Major Crop DiseasesSichuan Agricultural UniversityChengdu611130China
| | - Peng‐Qiang Liu
- Rice Research Institute and Key Lab for Major Crop DiseasesSichuan Agricultural UniversityChengdu611130China
| | - Xiao‐Rong He
- Rice Research Institute and Key Lab for Major Crop DiseasesSichuan Agricultural UniversityChengdu611130China
| | - Jing‐Hao Zhao
- Rice Research Institute and Key Lab for Major Crop DiseasesSichuan Agricultural UniversityChengdu611130China
| | - Yong‐Ju Xu
- Rice Research Institute and Key Lab for Major Crop DiseasesSichuan Agricultural UniversityChengdu611130China
| | - Ling‐Li Zhang
- Rice Research Institute and Key Lab for Major Crop DiseasesSichuan Agricultural UniversityChengdu611130China
| | - Yan‐Yan Huang
- Rice Research Institute and Key Lab for Major Crop DiseasesSichuan Agricultural UniversityChengdu611130China
| | - Ji‐Qun Zhao
- Rice Research Institute and Key Lab for Major Crop DiseasesSichuan Agricultural UniversityChengdu611130China
| | - Jing Fan
- Rice Research Institute and Key Lab for Major Crop DiseasesSichuan Agricultural UniversityChengdu611130China
| | - Yan Li
- Rice Research Institute and Key Lab for Major Crop DiseasesSichuan Agricultural UniversityChengdu611130China
| | - Shunyuan Xiao
- Institute of Biosciences and Biotechnology Research & Department of Plant Science and Landscape ArchitectureUniversity of MarylandCollege ParkMD20850USA
| | - Wen‐Ming Wang
- Rice Research Institute and Key Lab for Major Crop DiseasesSichuan Agricultural UniversityChengdu611130China
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Li L, Habring A, Wang K, Weigel D. Atypical Resistance Protein RPW8/HR Triggers Oligomerization of the NLR Immune Receptor RPP7 and Autoimmunity. Cell Host Microbe 2020; 27:405-417.e6. [PMID: 32101702 DOI: 10.1016/j.chom.2020.01.012] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 10/30/2019] [Accepted: 01/17/2020] [Indexed: 01/08/2023]
Abstract
In certain plant hybrids, immunity signaling is initiated when immune components interact in the absence of a pathogen trigger. In Arabidopsis thaliana, such autoimmunity and cell death are linked to variants of the NLR RPP7 and the RPW8 proteins involved in broad-spectrum resistance. We uncover the molecular basis for this autoimmunity and demonstrate that a homolog of RPW8, HR4Fei-0, can trigger the assembly of a higher-order RPP7 complex, with autoimmunity signaling as a consequence. HR4Fei-0-mediated RPP7 oligomerization occurs via the RPP7 C-terminal leucine-rich repeat (LRR) domain and ATP-binding P-loop. RPP7 forms a higher-order complex only in the presence of HR4Fei-0 and not with the standard HR4 variant, which is distinguished from HR4Fei-0 by length variation in C-terminal repeats. Additionally, HR4Fei-0 can independently form self-oligomers, which directly kill cells in an RPP7-independent manner. Our work provides evidence for a plant resistosome complex and the mechanisms by which RPW8/HR proteins trigger cell death.
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Affiliation(s)
- Lei Li
- Department of Molecular Biology, Max Planck Institute for Developmental Biology, 72076 Tübingen, Germany
| | - Anette Habring
- Department of Molecular Biology, Max Planck Institute for Developmental Biology, 72076 Tübingen, Germany
| | - Kai Wang
- Department of Cell Biology, Max Planck Institute for Developmental Biology, 72076 Tübingen, Germany
| | - Detlef Weigel
- Department of Molecular Biology, Max Planck Institute for Developmental Biology, 72076 Tübingen, Germany.
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Li Y, Zhang L, Zhu P, Cao Q, Sun J, Li Z, Xu T. Genome-wide identification, characterisation and functional evaluation of WRKY genes in the sweet potato wild ancestor Ipomoea trifida (H.B.K.) G. Don. under abiotic stresses. BMC Genet 2019; 20:90. [PMID: 31795942 PMCID: PMC6889533 DOI: 10.1186/s12863-019-0789-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Accepted: 11/14/2019] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND WRKY DNA-binding protein (WRKY) is a large gene family involved in plant responses and adaptation to salt, drought, cold and heat stresses. Sweet potato from the genus Ipomoea is a staple food crop, but the WRKY genes in Ipomoea species remain unknown to date. Hence, we carried out a genome-wide analysis of WRKYs in Ipomoea trifida (H.B.K.) G. Don., the wild ancestor of sweet potato. RESULTS A total of 83 WRKY genes encoding 96 proteins were identified in I. trifida, and their gene distribution, duplication, structure, phylogeny and expression patterns were studied. ItfWRKYs were distributed on 15 chromosomes of I. trifida. Gene duplication analysis showed that segmental duplication played an important role in the WRKY gene family expansion in I. trifida. Gene structure analysis showed that the intron-exon model of the ItfWRKY gene was highly conserved. Meanwhile, the ItfWRKYs were divided into five groups (I, IIa + IIb, IIc, IId + IIe and III) on the basis of the phylogenetic analysis on I. trifida and Arabidopsis thaliana WRKY proteins. In addition, gene expression profiles confirmed by quantitative polymerase chain reaction showed that ItfWRKYs were highly up-regulated or down-regulated under salt, drought, cold and heat stress conditions, implying that these genes play important roles in response and adaptation to abiotic stresses. CONCLUSIONS In summary, genome-wide identification, gene structure, phylogeny and expression analysis of WRKY gene in I. trifida provide basic information for further functional studies of ItfWRKYs and for the molecular breeding of sweet potato.
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Affiliation(s)
- Yuxia Li
- Key lab of phylogeny and comparative genomics of the Jiangsu province, Institute of Integrative Plant Biology, School of Life Sciences, Jiangsu Normal University, Xuzhou, 221116, Jiangsu Province, China
| | - Lei Zhang
- Key lab of phylogeny and comparative genomics of the Jiangsu province, Institute of Integrative Plant Biology, School of Life Sciences, Jiangsu Normal University, Xuzhou, 221116, Jiangsu Province, China
| | - Panpan Zhu
- Department of Plant Biotechnology, College of Agriculture and Life Sciences, Chonnam National University, Gwangju, 500-757, South Korea
| | - Qinghe Cao
- Xuzhou Academy of Agricultural Sciences/Sweet Potato Research Institute, CAAS, Xuzhou, 221121, Jiangsu, China
| | - Jian Sun
- Key lab of phylogeny and comparative genomics of the Jiangsu province, Institute of Integrative Plant Biology, School of Life Sciences, Jiangsu Normal University, Xuzhou, 221116, Jiangsu Province, China
| | - Zongyun Li
- Key lab of phylogeny and comparative genomics of the Jiangsu province, Institute of Integrative Plant Biology, School of Life Sciences, Jiangsu Normal University, Xuzhou, 221116, Jiangsu Province, China.
| | - Tao Xu
- Key lab of phylogeny and comparative genomics of the Jiangsu province, Institute of Integrative Plant Biology, School of Life Sciences, Jiangsu Normal University, Xuzhou, 221116, Jiangsu Province, China.
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The CaAP2/ERF064 Regulates Dual Functions in Pepper: Plant Cell Death and Resistance to Phytophthora capsici. Genes (Basel) 2019; 10:genes10070541. [PMID: 31319566 PMCID: PMC6678779 DOI: 10.3390/genes10070541] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Revised: 07/15/2019] [Accepted: 07/15/2019] [Indexed: 02/07/2023] Open
Abstract
Phytophthora blight is one of the most destructive diseases of pepper (Capsicum annuum L.) globally. The APETALA2/Ethylene Responsive Factors (AP2/ERF) genes play a crucial role in plant response to biotic stresses but, to date, have not been studied in the context of Phytophthora resistance in pepper. Here, we documented potential roles for the pepper CaAP2/ERF064 gene in inducing cell death and conferring resistance to Phytophthora capsici (P. capsici) infection. Results revealed that the N-terminal, AP2 domain, and C-terminal of CaAP2/ERF064 protein is responsible for triggering cell death in Nicotiana benthamiana (N. benthamiana). Moreover, the transcription of CaAP2/ERF064 in plant is synergistically regulated by the Methyl-Jasmonate (MeJA) and ethephon (ET) signaling pathway. CaAP2/ERF064 was found to regulate the expression of CaBPR1, which is a pathogenesis-related (PR) gene of pepper. Furthermore, the silencing of CaAP2/ERF064 compromised the pepper plant resistance to P.capsici by reducing the transcript level of defense-related genes CaBPR1, CaPO2, and CaSAR82, while the ectopic expression of CaAP2/ERF064 in N. benthamiana plant elevated the expression level of NbPR1b and enhanced resistance to P.capsici. These results suggest that CaAP2/ERF064 could positively regulate the defense response against P. capsici by modulating the transcription of PR genes in the plant.
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