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Outram MA, Chen J, Broderick S, Li Z, Aditya S, Tasneem N, Arndell T, Blundell C, Ericsson DJ, Figueroa M, Sperschneider J, Dodds PN, Williams SJ. AvrSr27 is a zinc-bound effector with a modular structure important for immune recognition. THE NEW PHYTOLOGIST 2024; 243:314-329. [PMID: 38730532 DOI: 10.1111/nph.19801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Accepted: 04/17/2024] [Indexed: 05/13/2024]
Abstract
Effector proteins are central to the success of plant pathogens, while immunity in host plants is driven by receptor-mediated recognition of these effectors. Understanding the molecular details of effector-receptor interactions is key for the engineering of novel immune receptors. Here, we experimentally determined the crystal structure of the Puccinia graminis f. sp. tritici (Pgt) effector AvrSr27, which was not accurately predicted using AlphaFold2. We characterised the role of the conserved cysteine residues in AvrSr27 using in vitro biochemical assays and examined Sr27-mediated recognition using transient expression in Nicotiana spp. and wheat protoplasts. The AvrSr27 structure contains a novel β-strand rich modular fold consisting of two structurally similar domains that bind to Zn2+ ions. The N-terminal domain of AvrSr27 is sufficient for interaction with Sr27 and triggering cell death. We identified two Pgt proteins structurally related to AvrSr27 but with low sequence identity that can also associate with Sr27, albeit more weakly. Though only the full-length proteins, trigger Sr27-dependent cell death in transient expression systems. Collectively, our findings have important implications for utilising protein prediction platforms for effector proteins, and those embarking on bespoke engineering of immunity receptors as solutions to plant disease.
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Affiliation(s)
- Megan A Outram
- Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
- Commonwealth Scientific and Industrial Research Organisation, Agriculture and Food, Canberra, ACT, 2601, Australia
| | - Jian Chen
- Commonwealth Scientific and Industrial Research Organisation, Agriculture and Food, Canberra, ACT, 2601, Australia
| | - Sean Broderick
- Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
| | - Zhao Li
- Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
| | - Shouvik Aditya
- Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
| | - Nuren Tasneem
- Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
| | - Taj Arndell
- Commonwealth Scientific and Industrial Research Organisation, Agriculture and Food, Canberra, ACT, 2601, Australia
| | - Cheryl Blundell
- Commonwealth Scientific and Industrial Research Organisation, Agriculture and Food, Canberra, ACT, 2601, Australia
| | - Daniel J Ericsson
- Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
- Australian Synchrotron, Macromolecular Crystallography, Clayton, Vic., 3186, Australia
| | - Melania Figueroa
- Commonwealth Scientific and Industrial Research Organisation, Agriculture and Food, Canberra, ACT, 2601, Australia
| | - Jana Sperschneider
- Commonwealth Scientific and Industrial Research Organisation, Agriculture and Food, Canberra, ACT, 2601, Australia
| | - Peter N Dodds
- Commonwealth Scientific and Industrial Research Organisation, Agriculture and Food, Canberra, ACT, 2601, Australia
| | - Simon J Williams
- Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
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Li X, Wang D, Yin X, Dai M, Staiger CJ, Zhang C. A chemical genetic screen with the EXO70 inhibitor Endosidin2 uncovers potential modulators of exocytosis in Arabidopsis. PLANT DIRECT 2024; 8:e592. [PMID: 38881683 PMCID: PMC11176578 DOI: 10.1002/pld3.592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Revised: 04/09/2024] [Accepted: 04/26/2024] [Indexed: 06/18/2024]
Abstract
Exocytosis plays an essential role in delivering proteins, lipids, and cell wall polysaccharides to the plasma membrane and extracellular spaces. Accurate secretion through exocytosis is key to normal plant development as well as responses to biotic and abiotic stresses. During exocytosis, an octameric protein complex named the exocyst facilitates the tethering of secretory vesicles to the plasma membrane. Despite some understanding of molecular and cellular aspects of exocyst function obtained through reverse genetics and direct interaction assays, knowledge about upstream modulators and genetic interactors remains limited. Traditional genetic screens encounter practical issues in exocyst subunit mutant backgrounds, such as lethality of certain knockout mutants and/or potential redundancy of EXO70 homologs. To address these challenges, this study leverages the tunable and reversible nature of chemical genetics, employing Endosidin2 (ES2)-a synthetic inhibitor of EXO70-for a large-scale chemical genetic mutant screen in Arabidopsis. This approach led to the identification of 70 ES2-hypersensitive mutants, named es2s. Through a whole-genome sequencing-based mapping strategy, 14 nonallelic es2s mutants were mapped and the candidate mutations reported here. In addition, T-DNA insertion lines were tested as alternative alleles to identify causal mutations. We found that T-DNA insertion alleles for DCP5, VAS1/ISS1, ArgJ, and MEF11 were hypersensitive to ES2 for root growth inhibition. This research not only offers new genetic resources for systematically identifying molecular players interacting with the exocyst in Arabidopsis but also enhances understanding of the regulation of exocytosis.
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Affiliation(s)
- Xiaohui Li
- Department of Botany and Plant Pathology Purdue University West Lafayette Indiana USA
- Center for Plant Biology Purdue University West Lafayette Indiana USA
| | - Diwen Wang
- Department of Botany and Plant Pathology Purdue University West Lafayette Indiana USA
- Center for Plant Biology Purdue University West Lafayette Indiana USA
| | - Xianglin Yin
- Department of Chemistry Purdue University West Lafayette Indiana USA
| | - Mingji Dai
- Department of Chemistry Purdue University West Lafayette Indiana USA
- Present address: Department of Chemistry Emory University Atlanta Georgia USA
- Present address: Department of Chemistry Emory University Atlanta Georgia USA
| | - Christopher J Staiger
- Department of Botany and Plant Pathology Purdue University West Lafayette Indiana USA
- Center for Plant Biology Purdue University West Lafayette Indiana USA
- Department of Biological Sciences Purdue University West Lafayette Indiana USA
| | - Chunhua Zhang
- Department of Botany and Plant Pathology Purdue University West Lafayette Indiana USA
- Center for Plant Biology Purdue University West Lafayette Indiana USA
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De la Concepcion JC, Langner T, Fujisaki K, Yan X, Were V, Lam AHC, Saado I, Brabham HJ, Win J, Yoshida K, Talbot NJ, Terauchi R, Kamoun S, Banfield MJ. Zinc-finger (ZiF) fold secreted effectors form a functionally diverse family across lineages of the blast fungus Magnaporthe oryzae. PLoS Pathog 2024; 20:e1012277. [PMID: 38885263 PMCID: PMC11213319 DOI: 10.1371/journal.ppat.1012277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 06/28/2024] [Accepted: 05/20/2024] [Indexed: 06/20/2024] Open
Abstract
Filamentous plant pathogens deliver effector proteins into host cells to suppress host defence responses and manipulate metabolic processes to support colonization. Understanding the evolution and molecular function of these effectors provides knowledge about pathogenesis and can suggest novel strategies to reduce damage caused by pathogens. However, effector proteins are highly variable, share weak sequence similarity and, although they can be grouped according to their structure, only a few structurally conserved effector families have been functionally characterized to date. Here, we demonstrate that Zinc-finger fold (ZiF) secreted proteins form a functionally diverse effector family in the blast fungus Magnaporthe oryzae. This family relies on the Zinc-finger motif for protein stability and is ubiquitously present in blast fungus lineages infecting 13 different host species, forming different effector tribes. Homologs of the canonical ZiF effector, AVR-Pii, from rice infecting isolates are present in multiple M. oryzae lineages. Wheat infecting strains of the fungus also possess an AVR-Pii like allele that binds host Exo70 proteins and activates the immune receptor Pii. Furthermore, ZiF tribes may vary in the proteins they bind to, indicating functional diversification and an intricate effector/host interactome. Altogether, we uncovered a new effector family with a common protein fold that has functionally diversified in lineages of M. oryzae. This work expands our understanding of the diversity of M. oryzae effectors, the molecular basis of plant pathogenesis and may ultimately facilitate the development of new sources for pathogen resistance.
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Affiliation(s)
- Juan Carlos De la Concepcion
- Department of Biochemistry and Metabolism, John Innes Centre, Norwich Research Park, Norwich, United Kingdom
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich, United Kingdom
| | - Thorsten Langner
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich, United Kingdom
| | - Koki Fujisaki
- Division of Genomics and Breeding, Iwate Biotechnology Research Center, Iwate, Japan
| | - Xia Yan
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich, United Kingdom
| | - Vincent Were
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich, United Kingdom
| | - Anson Ho Ching Lam
- Department of Biochemistry and Metabolism, John Innes Centre, Norwich Research Park, Norwich, United Kingdom
| | - Indira Saado
- Department of Biochemistry and Metabolism, John Innes Centre, Norwich Research Park, Norwich, United Kingdom
| | - Helen J. Brabham
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich, United Kingdom
| | - Joe Win
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich, United Kingdom
| | - Kentaro Yoshida
- Laboratory of Plant Genetics, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Nicholas J. Talbot
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich, United Kingdom
| | - Ryohei Terauchi
- Division of Genomics and Breeding, Iwate Biotechnology Research Center, Iwate, Japan
- Laboratory of Crop Evolution, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Sophien Kamoun
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich, United Kingdom
| | - Mark J. Banfield
- Department of Biochemistry and Metabolism, John Innes Centre, Norwich Research Park, Norwich, United Kingdom
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Yin B, Jia J, Sun X, Hu X, Ao M, Liu W, Tian Z, Liu H, Li D, Tian W, Hao Y, Xia X, Sade N, Brotman Y, Fernie AR, Chen J, He Z, Chen W. Dynamic metabolite QTL analyses provide novel biochemical insights into kernel development and nutritional quality improvement in common wheat. PLANT COMMUNICATIONS 2024; 5:100792. [PMID: 38173227 PMCID: PMC11121174 DOI: 10.1016/j.xplc.2024.100792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2023] [Revised: 12/20/2023] [Accepted: 01/01/2024] [Indexed: 01/05/2024]
Abstract
Despite recent advances in crop metabolomics, the genetic control and molecular basis of the wheat kernel metabolome at different developmental stages remain largely unknown. Here, we performed widely targeted metabolite profiling of kernels from three developmental stages (grain-filling kernels [FKs], mature kernels [MKs], and germinating kernels [GKs]) using a population of 159 recombinant inbred lines. We detected 625 annotated metabolites and mapped 3173, 3143, and 2644 metabolite quantitative trait loci (mQTLs) in FKs, MKs, and GKs, respectively. Only 52 mQTLs were mapped at all three stages, indicating the high stage specificity of the wheat kernel metabolome. Four candidate genes were functionally validated by in vitro enzymatic reactions and/or transgenic approaches in wheat, three of which mediated the tricin metabolic pathway. Metabolite flux efficiencies within the tricin pathway were evaluated, and superior candidate haplotypes were identified, comprehensively delineating the tricin metabolism pathway in wheat. Finally, additional wheat metabolic pathways were re-constructed by updating them to incorporate the 177 candidate genes identified in this study. Our work provides new information on variations in the wheat kernel metabolome and important molecular resources for improvement of wheat nutritional quality.
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Affiliation(s)
- Bo Yin
- National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan 430070, China; Hubei Hongshan Laboratory, Wuhan 430070, China
| | - Jingqi Jia
- National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan 430070, China; Hubei Hongshan Laboratory, Wuhan 430070, China
| | - Xu Sun
- National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan 430070, China; Hubei Hongshan Laboratory, Wuhan 430070, China
| | - Xin Hu
- National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan 430070, China; Hubei Hongshan Laboratory, Wuhan 430070, China
| | - Min Ao
- National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan 430070, China; Hubei Hongshan Laboratory, Wuhan 430070, China
| | - Wei Liu
- National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan 430070, China; Hubei Hongshan Laboratory, Wuhan 430070, China
| | - Zhitao Tian
- National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan 430070, China; Hubei Hongshan Laboratory, Wuhan 430070, China
| | - Hongbo Liu
- National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan 430070, China
| | - Dongqin Li
- National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan 430070, China
| | - Wenfei Tian
- National Wheat Improvement Center, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Yuanfeng Hao
- National Wheat Improvement Center, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Xianchun Xia
- National Wheat Improvement Center, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Nir Sade
- School of Plant Sciences and Food Security, The Institute for Cereal Crops Improvement, Tel Aviv University, Tel Aviv 69978, Israel
| | - Yariv Brotman
- School of Plant Sciences and Food Security, The Institute for Cereal Crops Improvement, Tel Aviv University, Tel Aviv 69978, Israel
| | - Alisdair R Fernie
- Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
| | - Jie Chen
- National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan 430070, China; Hubei Hongshan Laboratory, Wuhan 430070, China; Yazhouwan National Laboratory, Sanya 572025, China.
| | - Zhonghu He
- National Wheat Improvement Center, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, China.
| | - Wei Chen
- National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan 430070, China; Hubei Hongshan Laboratory, Wuhan 430070, China.
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5
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Liu N, Jiang X, Zhong G, Wang W, Hake K, Matschi S, Lederer S, Hoehenwarter W, Sun Q, Lee J, Romeis T, Tang D. CAMTA3 repressor destabilization triggers TIR domain protein TN2-mediated autoimmunity in the Arabidopsis exo70B1 mutant. THE PLANT CELL 2024; 36:2021-2040. [PMID: 38309956 PMCID: PMC11062451 DOI: 10.1093/plcell/koae036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 01/10/2024] [Accepted: 01/27/2024] [Indexed: 02/05/2024]
Abstract
Calcium-dependent protein kinases (CPKs) can decode and translate intracellular calcium signals to induce plant immunity. Mutation of the exocyst subunit gene EXO70B1 causes autoimmunity that depends on CPK5 and the Toll/interleukin-1 receptor (TIR) domain resistance protein TIR-NBS2 (TN2), where direct interaction with TN2 stabilizes CPK5 kinase activity. However, how the CPK5-TN2 interaction initiates downstream immune responses remains unclear. Here, we show that, besides CPK5 activity, the physical interaction between CPK5 and functional TN2 triggers immune activation in exo70B1 and may represent reciprocal regulation between CPK5 and the TIR domain functions of TN2 in Arabidopsis (Arabidopsis thaliana). Moreover, we detected differential phosphorylation of the calmodulin-binding transcription activator 3 (CAMTA3) in the cpk5 background. CPK5 directly phosphorylates CAMTA3 at S964, contributing to its destabilization. The gain-of-function CAMTA3A855V variant that resists CPK5-induced degradation rescues immunity activated through CPK5 overexpression or exo70B1 mutation. Thus, CPK5-mediated immunity is executed through CAMTA3 repressor degradation via phosphorylation-induced and/or calmodulin-regulated processes. Conversely, autoimmunity in camta3 also partially requires functional CPK5. While the TIR domain activity of TN2 remains to be tested, our study uncovers a TN2-CPK5-CAMTA3 signaling module for exo70B1-mediated autoimmunity, highlighting the direct embedding of a calcium-sensing decoder element within resistance signalosomes.
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Affiliation(s)
- Na Liu
- State Key Laboratory of Ecological Control of Fujian-Taiwan Crop Pests, Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, Plant Immunity Center, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Xiyuan Jiang
- Department for Biochemistry of Plant Interactions, Leibniz Institute of Plant Biochemistry, Halle (Saale) 06120, Germany
| | - Guitao Zhong
- State Key Laboratory of Ecological Control of Fujian-Taiwan Crop Pests, Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, Plant Immunity Center, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Wei Wang
- State Key Laboratory of Ecological Control of Fujian-Taiwan Crop Pests, Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, Plant Immunity Center, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Katharina Hake
- Department for Biochemistry of Plant Interactions, Leibniz Institute of Plant Biochemistry, Halle (Saale) 06120, Germany
- Dahlem Centre of Plant Sciences, Freie Universität Berlin, Berlin 14195, Germany
| | - Susanne Matschi
- Department for Biochemistry of Plant Interactions, Leibniz Institute of Plant Biochemistry, Halle (Saale) 06120, Germany
| | - Sarah Lederer
- Department for Biochemistry of Plant Interactions, Leibniz Institute of Plant Biochemistry, Halle (Saale) 06120, Germany
| | - Wolfgang Hoehenwarter
- Department for Biochemistry of Plant Interactions, Leibniz Institute of Plant Biochemistry, Halle (Saale) 06120, Germany
| | - Qianqian Sun
- State Key Laboratory of Ecological Control of Fujian-Taiwan Crop Pests, Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, Plant Immunity Center, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Justin Lee
- Department for Biochemistry of Plant Interactions, Leibniz Institute of Plant Biochemistry, Halle (Saale) 06120, Germany
| | - Tina Romeis
- Department for Biochemistry of Plant Interactions, Leibniz Institute of Plant Biochemistry, Halle (Saale) 06120, Germany
- Dahlem Centre of Plant Sciences, Freie Universität Berlin, Berlin 14195, Germany
| | - Dingzhong Tang
- State Key Laboratory of Ecological Control of Fujian-Taiwan Crop Pests, Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, Plant Immunity Center, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou 350002, China
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6
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John E, Chau MQ, Hoang CV, Chandrasekharan N, Bhaskar C, Ma LS. Fungal Cell Wall-Associated Effectors: Sensing, Integration, Suppression, and Protection. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2024; 37:196-210. [PMID: 37955547 DOI: 10.1094/mpmi-09-23-0142-fi] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2023]
Abstract
The cell wall (CW) of plant-interacting fungi, as the direct interface with host plants, plays a crucial role in fungal development. A number of secreted proteins are directly associated with the fungal CW, either through covalent or non-covalent interactions, and serve a range of important functions. In the context of plant-fungal interactions many are important for fungal development in the host environment and may therefore be considered fungal CW-associated effectors (CWAEs). Key CWAE functions include integrating chemical/physical signals to direct hyphal growth, interfering with plant immunity, and providing protection against plant defenses. In recent years, a diverse range of mechanisms have been reported that underpin their roles, with some CWAEs harboring conserved motifs or functional domains, while others are reported to have novel features. As such, the current understanding regarding fungal CWAEs is systematically presented here from the perspective of their biological functions in plant-fungal interactions. An overview of the fungal CW architecture and the mechanisms by which proteins are secreted, modified, and incorporated into the CW is first presented to provide context for their biological roles. Some CWAE functions are reported across a broad range of pathosystems or symbiotic/mutualistic associations. Prominent are the chitin interacting-effectors that facilitate fungal CW modification, protection, or suppression of host immune responses. However, several alternative functions are now reported and are presented and discussed. CWAEs can play diverse roles, some possibly unique to fungal lineages and others conserved across a broad range of plant-interacting fungi. [Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY 4.0 International license.
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Affiliation(s)
- Evan John
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Minh-Quang Chau
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Cuong V Hoang
- Centro de Biotecnología y Genómica de Plantas, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA/CSIC), Universidad Politécnica de Madrid (UPM), Campus de Montegancedo UPM, 28223 Pozuelo de Alarcón, Spain
| | | | - Chibbhi Bhaskar
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Lay-Sun Ma
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
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7
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De la Concepcion JC. The exocyst complex is an evolutionary battleground in plant-microbe interactions. CURRENT OPINION IN PLANT BIOLOGY 2023; 76:102482. [PMID: 37924562 DOI: 10.1016/j.pbi.2023.102482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 10/03/2023] [Accepted: 10/05/2023] [Indexed: 11/06/2023]
Abstract
Exocytosis is a conserved trafficking pathway that transports secretory vesicles to the extracellular space, replenishes the plasma membrane and is essential for establishing cell polarity. Its spatiotemporal regulation is mediated by an evolutionary conserved octameric tethering complex, the exocyst. In plants, certain subunits of this complex have diversified and acquired multiple functions, including a central role in defense against pathogens and pests. Here, I review the latest evidence suggesting the dramatic expansion and functional diversification of the exocyst subunit Exo70 is likely driven by a coevolutionary arms race, in which Exo70 proteins are repeatedly targeted by effectors from multiple pathogens and, in turn, are monitored by plant immune receptors for pathogen perception.
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8
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Bentham AR, De la Concepcion JC, Benjumea JV, Kourelis J, Jones S, Mendel M, Stubbs J, Stevenson CEM, Maidment JHR, Youles M, Zdrzałek R, Kamoun S, Banfield MJ. Allelic compatibility in plant immune receptors facilitates engineering of new effector recognition specificities. THE PLANT CELL 2023; 35:3809-3827. [PMID: 37486356 PMCID: PMC10533329 DOI: 10.1093/plcell/koad204] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 06/01/2023] [Accepted: 06/05/2023] [Indexed: 07/25/2023]
Abstract
Engineering the plant immune system offers genetic solutions to mitigate crop diseases caused by diverse agriculturally significant pathogens and pests. Modification of intracellular plant immune receptors of the nucleotide-binding leucine-rich repeat (NLR) receptor superfamily for expanded recognition of pathogen virulence proteins (effectors) is a promising approach for engineering disease resistance. However, engineering can cause NLR autoactivation, resulting in constitutive defense responses that are deleterious to the plant. This may be due to plant NLRs associating in highly complex signaling networks that coevolve together, and changes through breeding or genetic modification can generate incompatible combinations, resulting in autoimmune phenotypes. The sensor and helper NLRs of the rice (Oryza sativa) NLR pair Pik have coevolved, and mismatching between noncoevolved alleles triggers constitutive activation and cell death. This limits the extent to which protein modifications can be used to engineer pathogen recognition and enhance disease resistance mediated by these NLRs. Here, we dissected incompatibility determinants in the Pik pair in Nicotiana benthamiana and found that heavy metal-associated (HMA) domains integrated in Pik-1 not only evolved to bind pathogen effectors but also likely coevolved with other NLR domains to maintain immune homeostasis. This explains why changes in integrated domains can lead to autoactivation. We then used this knowledge to facilitate engineering of new effector recognition specificities, overcoming initial autoimmune penalties. We show that by mismatching alleles of the rice sensor and helper NLRs Pik-1 and Pik-2, we can enable the integration of synthetic domains with novel and enhanced recognition specificities. Taken together, our results reveal a strategy for engineering NLRs, which has the potential to allow an expanded set of integrations and therefore new disease resistance specificities in plants.
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Affiliation(s)
- Adam R Bentham
- Department of Biochemistry and Metabolism, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | | | - Javier Vega Benjumea
- Department of Biochemistry and Metabolism, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Jiorgos Kourelis
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
| | - Sally Jones
- Department of Biochemistry and Metabolism, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Melanie Mendel
- Department of Biochemistry and Metabolism, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Jack Stubbs
- Department of Biochemistry and Metabolism, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Clare E M Stevenson
- Department of Biochemistry and Metabolism, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Josephine H R Maidment
- Department of Biochemistry and Metabolism, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
| | - Mark Youles
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
| | - Rafał Zdrzałek
- Department of Biochemistry and Metabolism, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Sophien Kamoun
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
| | - Mark J Banfield
- Department of Biochemistry and Metabolism, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
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9
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Abstract
Investigation of fungal biology has been frequently motivated by the fact that many fungal species are important plant and animal pathogens. Such efforts have contributed significantly toward our understanding of fungal pathogenic lifestyles (virulence factors and strategies) and the interplay with host immune systems. In parallel, work on fungal allorecognition systems leading to the characterization of fungal regulated cell death determinants and pathways, has been instrumental for the emergent concept of fungal immunity. The uncovered evolutionary trans-kingdom parallels between fungal regulated cell death pathways and innate immune systems incite us to reflect further on the concept of a fungal immune system. Here, I briefly review key findings that have shaped the fungal immunity paradigm, providing a perspective on what I consider its most glaring knowledge gaps. Undertaking to fill such gaps would establish firmly the fungal immune system inside the broader field of comparative immunology.
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Affiliation(s)
- Asen Daskalov
- State Key Laboratory for Managing Biotic and Chemical Treats to the Quality and Safety of Agro-products, Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
- ImmunoConcEpT, CNRS UMR 5164, University of Bordeaux, Bordeaux, France
- Corresponding author
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Andreo-Jimenez B, Te Beest DE, Kruijer W, Vannier N, Kadam NN, Melandri G, Jagadish SVK, van der Linden G, Ruyter-Spira C, Vandenkoornhuyse P, Bouwmeester HJ. Genetic Mapping of the Root Mycobiota in Rice and its Role in Drought Tolerance. RICE (NEW YORK, N.Y.) 2023; 16:26. [PMID: 37212977 DOI: 10.1186/s12284-023-00641-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 02/05/2023] [Accepted: 05/11/2023] [Indexed: 05/23/2023]
Abstract
BACKGROUND Rice is the second most produced crop worldwide, but is highly susceptible to drought. Micro-organisms can potentially alleviate the effects of drought. The aim of the present study was to unravel the genetic factors involved in the rice-microbe interaction, and whether genetics play a role in rice drought tolerance. For this purpose, the composition of the root mycobiota was characterized in 296 rice accessions (Oryza sativa L. subsp. indica) under control and drought conditions. Genome wide association mapping (GWAS) resulted in the identification of ten significant (LOD > 4) single nucleotide polymorphisms (SNPs) associated with six root-associated fungi: Ceratosphaeria spp., Cladosporium spp., Boudiera spp., Chaetomium spp., and with a few fungi from the Rhizophydiales order. Four SNPs associated with fungi-mediated drought tolerance were also found. Genes located around those SNPs, such as a DEFENSIN-LIKE (DEFL) protein, EXOCYST TETHERING COMPLEX (EXO70), RAPID ALKALINIZATION FACTOR-LIKE (RALFL) protein, peroxidase and xylosyltransferase, have been shown to be involved in pathogen defense, abiotic stress responses and cell wall remodeling processes. Our study shows that rice genetics affects the recruitment of fungi, and that some fungi affect yield under drought. We identified candidate target genes for breeding to improve rice-fungal interactions and hence drought tolerance.
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Affiliation(s)
- Beatriz Andreo-Jimenez
- Laboratory of Plant Physiology, Wageningen University and Research, Wageningen, The Netherlands.
- Biointeractions and Plant Health, Wageningen University and Research, Droevendaalsesteeg 1, 6708PB, Wageningen, The Netherlands.
| | - Dennis E Te Beest
- Biometris, Wageningen University and Research, Wageningen, The Netherlands
| | - Willem Kruijer
- Biometris, Wageningen University and Research, Wageningen, The Netherlands
| | | | - Niteen N Kadam
- International Rice Research Institute, Los Baños, Laguna, Philippines
- Centre for Crop Systems Analysis, Wageningen University and Research, Wageningen, The Netherlands
| | - Giovanni Melandri
- Laboratory of Plant Physiology, Wageningen University and Research, Wageningen, The Netherlands
- School of Plant Sciences, University of Arizona, Tucson, USA
| | - S V Krishna Jagadish
- International Rice Research Institute, Los Baños, Laguna, Philippines
- Kansas State University, Manhattan, KS, 66506, USA
| | | | - Carolien Ruyter-Spira
- Laboratory of Plant Physiology, Wageningen University and Research, Wageningen, The Netherlands
| | | | - Harro J Bouwmeester
- Laboratory of Plant Physiology, Wageningen University and Research, Wageningen, The Netherlands.
- Plant Hormone Biology Group, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, The Netherlands.
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Zhu X, Chen X. A "protector" model for membrane trafficking-regulated and NLR-mediated plant immunity. MOLECULAR PLANT 2023; 16:303-305. [PMID: 36482769 DOI: 10.1016/j.molp.2022.12.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 12/04/2022] [Accepted: 12/05/2022] [Indexed: 06/17/2023]
Affiliation(s)
- Xiaobo Zhu
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University at Wenjiang, Chengdu, Sichuan 611130, China
| | - Xuewei Chen
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University at Wenjiang, Chengdu, Sichuan 611130, China.
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12
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Disentangling the complex gene interaction networks between rice and the blast fungus identifies a new pathogen effector. PLoS Biol 2023; 21:e3001945. [PMID: 36656825 PMCID: PMC9851567 DOI: 10.1371/journal.pbio.3001945] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Accepted: 12/05/2022] [Indexed: 01/20/2023] Open
Abstract
Studies focused solely on single organisms can fail to identify the networks underlying host-pathogen gene-for-gene interactions. Here, we integrate genetic analyses of rice (Oryza sativa, host) and rice blast fungus (Magnaporthe oryzae, pathogen) and uncover a new pathogen recognition specificity of the rice nucleotide-binding domain and leucine-rich repeat protein (NLR) immune receptor Pik, which mediates resistance to M. oryzae expressing the avirulence effector gene AVR-Pik. Rice Piks-1, encoded by an allele of Pik-1, recognizes a previously unidentified effector encoded by the M. oryzae avirulence gene AVR-Mgk1, which is found on a mini-chromosome. AVR-Mgk1 has no sequence similarity to known AVR-Pik effectors and is prone to deletion from the mini-chromosome mediated by repeated Inago2 retrotransposon sequences. AVR-Mgk1 is detected by Piks-1 and by other Pik-1 alleles known to recognize AVR-Pik effectors; recognition is mediated by AVR-Mgk1 binding to the integrated heavy metal-associated (HMA) domain of Piks-1 and other Pik-1 alleles. Our findings highlight how complex gene-for-gene interaction networks can be disentangled by applying forward genetics approaches simultaneously to the host and pathogen. We demonstrate dynamic coevolution between an NLR integrated domain and multiple families of effector proteins.
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