1
|
Zdrzałek R, Xi Y, Langner T, Bentham AR, Petit-Houdenot Y, De la Concepcion JC, Harant A, Shimizu M, Were V, Talbot NJ, Terauchi R, Kamoun S, Banfield MJ. Bioengineering a plant NLR immune receptor with a robust binding interface toward a conserved fungal pathogen effector. Proc Natl Acad Sci U S A 2024; 121:e2402872121. [PMID: 38968126 PMCID: PMC11252911 DOI: 10.1073/pnas.2402872121] [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: 02/11/2024] [Accepted: 05/21/2024] [Indexed: 07/07/2024] Open
Abstract
Bioengineering of plant immune receptors has emerged as a key strategy for generating novel disease resistance traits to counteract the expanding threat of plant pathogens to global food security. However, current approaches are limited by rapid evolution of plant pathogens in the field and may lack durability when deployed. Here, we show that the rice nucleotide-binding, leucine-rich repeat (NLR) immune receptor Pik-1 can be engineered to respond to a conserved family of effectors from the multihost blast fungus pathogen Magnaporthe oryzae. We switched the effector binding and response profile of the Pik NLR from its cognate rice blast effector AVR-Pik to the host-determining factor pathogenicity toward weeping lovegrass 2 (Pwl2) by installing a putative host target, OsHIPP43, in place of the native integrated heavy metal-associated domain (generating Pikm-1OsHIPP43). This chimeric receptor also responded to other PWL alleles from diverse blast isolates. The crystal structure of the Pwl2/OsHIPP43 complex revealed a multifaceted, robust interface that cannot be easily disrupted by mutagenesis, and may therefore provide durable, broad resistance to blast isolates carrying PWL effectors in the field. Our findings highlight how the host targets of pathogen effectors can be used to bioengineer recognition specificities that have more robust properties compared to naturally evolved disease resistance genes.
Collapse
Affiliation(s)
- Rafał Zdrzałek
- Department of Biochemistry and Metabolism, John Innes Centre, NorwichNR4 7UH, United Kingdom
| | - Yuxuan Xi
- Department of Biochemistry and Metabolism, John Innes Centre, NorwichNR4 7UH, United Kingdom
| | - Thorsten Langner
- The Sainsbury Laboratory, University of East Anglia, NorwichNR4 7UH, United Kingdom
| | - Adam R. Bentham
- Department of Biochemistry and Metabolism, John Innes Centre, NorwichNR4 7UH, United Kingdom
- The Sainsbury Laboratory, University of East Anglia, NorwichNR4 7UH, United Kingdom
| | | | - Juan Carlos De la Concepcion
- Department of Biochemistry and Metabolism, John Innes Centre, NorwichNR4 7UH, United Kingdom
- The Sainsbury Laboratory, University of East Anglia, NorwichNR4 7UH, United Kingdom
| | - Adeline Harant
- The Sainsbury Laboratory, University of East Anglia, NorwichNR4 7UH, United Kingdom
| | - Motoki Shimizu
- Division of Genomics and Breeding, Iwate Biotechnology Research Center, Iwate024-0003, Japan
| | - Vincent Were
- The Sainsbury Laboratory, University of East Anglia, NorwichNR4 7UH, United Kingdom
| | - Nicholas J. Talbot
- The Sainsbury Laboratory, University of East Anglia, NorwichNR4 7UH, United Kingdom
| | - Ryohei Terauchi
- Division of Genomics and Breeding, Iwate Biotechnology Research Center, Iwate024-0003, Japan
- Laboratory of Crop Evolution, Graduate School of Agriculture, Kyoto University, Kyoto606-8501, Japan
| | - Sophien Kamoun
- The Sainsbury Laboratory, University of East Anglia, NorwichNR4 7UH, United Kingdom
| | - Mark J. Banfield
- Department of Biochemistry and Metabolism, John Innes Centre, NorwichNR4 7UH, United Kingdom
| |
Collapse
|
2
|
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.
Collapse
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
| |
Collapse
|
3
|
Sutherland CA, Prigozhin DM, Monroe JG, Krasileva KV. High allelic diversity in Arabidopsis NLRs is associated with distinct genomic features. EMBO Rep 2024; 25:2306-2322. [PMID: 38528170 PMCID: PMC11093987 DOI: 10.1038/s44319-024-00122-9] [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: 10/23/2023] [Revised: 03/07/2024] [Accepted: 03/08/2024] [Indexed: 03/27/2024] Open
Abstract
Plants rely on Nucleotide-binding, Leucine-rich repeat Receptors (NLRs) for pathogen recognition. Highly variable NLRs (hvNLRs) show remarkable intraspecies diversity, while their low-variability paralogs (non-hvNLRs) are conserved between ecotypes. At a population level, hvNLRs provide new pathogen-recognition specificities, but the association between allelic diversity and genomic and epigenomic features has not been established. Our investigation of NLRs in Arabidopsis Col-0 has revealed that hvNLRs show higher expression, less gene body cytosine methylation, and closer proximity to transposable elements than non-hvNLRs. hvNLRs show elevated synonymous and nonsynonymous nucleotide diversity and are in chromatin states associated with an increased probability of mutation. Diversifying selection maintains variability at a subset of codons of hvNLRs, while purifying selection maintains conservation at non-hvNLRs. How these features are established and maintained, and whether they contribute to the observed diversity of hvNLRs is key to understanding the evolution of plant innate immune receptors.
Collapse
Affiliation(s)
- Chandler A Sutherland
- Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, CA, 94720, USA
| | - Daniil M Prigozhin
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - J Grey Monroe
- Department of Plant Sciences, University of California Davis, Davis, CA, 95616, USA
| | - Ksenia V Krasileva
- Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, CA, 94720, USA.
| |
Collapse
|
4
|
Dodds PN, Chen J, Outram MA. Pathogen perception and signaling in plant immunity. THE PLANT CELL 2024; 36:1465-1481. [PMID: 38262477 PMCID: PMC11062475 DOI: 10.1093/plcell/koae020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 12/19/2023] [Accepted: 01/16/2024] [Indexed: 01/25/2024]
Abstract
Plant diseases are a constant and serious threat to agriculture and ecological biodiversity. Plants possess a sophisticated innate immunity system capable of detecting and responding to pathogen infection to prevent disease. Our understanding of this system has grown enormously over the past century. Early genetic descriptions of plant disease resistance and pathogen virulence were embodied in the gene-for-gene hypothesis, while physiological studies identified pathogen-derived elicitors that could trigger defense responses in plant cells and tissues. Molecular studies of these phenomena have now coalesced into an integrated model of plant immunity involving cell surface and intracellular detection of specific pathogen-derived molecules and proteins culminating in the induction of various cellular responses. Extracellular and intracellular receptors engage distinct signaling processes but converge on many similar outputs with substantial evidence now for integration of these pathways into interdependent networks controlling disease outcomes. Many of the molecular details of pathogen recognition and signaling processes are now known, providing opportunities for bioengineering to enhance plant protection from disease. Here we provide an overview of the current understanding of the main principles of plant immunity, with an emphasis on the key scientific milestones leading to these insights.
Collapse
Affiliation(s)
- Peter N Dodds
- Commonwealth Scientific and Industrial Research Organization, Agriculture and Food, Canberra, ACT 2601, Australia
| | - Jian Chen
- Commonwealth Scientific and Industrial Research Organization, Agriculture and Food, Canberra, ACT 2601, Australia
| | - Megan A Outram
- Commonwealth Scientific and Industrial Research Organization, Agriculture and Food, Canberra, ACT 2601, Australia
| |
Collapse
|
5
|
Lubega J, Figueroa M, Dodds PN, Kanyuka K. Comparative Analysis of the Avirulence Effectors Produced by the Fungal Stem Rust Pathogen of Wheat. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2024; 37:171-178. [PMID: 38170736 DOI: 10.1094/mpmi-10-23-0169-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: 01/05/2024]
Abstract
Crops are constantly exposed to pathogenic microbes. Rust fungi are examples of these harmful microorganisms, which have a major economic impact on wheat production. To protect themselves from pathogens like rust fungi, plants employ a multilayered immune system that includes immunoreceptors encoded by resistance genes. Significant efforts have led to the isolation of numerous resistance genes against rust fungi in cereals, especially in wheat. However, the evolution of virulence of rust fungi hinders the durability of resistance genes as a strategy for crop protection. Rust fungi, like other biotrophic pathogens, secrete an arsenal of effectors to facilitate infection, and these are the molecules that plant immunoreceptors target for pathogen recognition and mounting defense responses. When recognized, these effector proteins are referred to as avirulence (Avr) effectors. Despite the many predicted effectors in wheat rust fungi, only five Avr genes have been identified, all from wheat stem rust. Knowledge of the Avr genes and their variation in the fungal population will inform deployment of the most appropriate wheat disease-resistance genes for breeding and farming. The review provides an overview of methodologies as well as the validation techniques that have been used to characterize Avr effectors from wheat stem rust. [Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY 4.0 International license.
Collapse
Affiliation(s)
- Jibril Lubega
- National Institute of Agricultural Botany (NIAB), Cambridge CB3 0LE, U.K
| | - Melania Figueroa
- Commonwealth Scientific and Industrial Research Organization, Agriculture and Food, Canberra 2601, Australia
| | - Peter N Dodds
- Commonwealth Scientific and Industrial Research Organization, Agriculture and Food, Canberra 2601, Australia
| | - Kostya Kanyuka
- National Institute of Agricultural Botany (NIAB), Cambridge CB3 0LE, U.K
| |
Collapse
|
6
|
Thynne E, Kobe B. Mixed-organism enzyme in plant defense. Science 2024; 383:707-708. [PMID: 38359137 DOI: 10.1126/science.adn8306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2024]
Abstract
Plants commandeer a pathogen's virulence factor to bolster immunity.
Collapse
Affiliation(s)
- Elisha Thynne
- Botanical Institute, Christian-Albrechts University, Kiel, Germany
- Max Planck Institute for Molecular Biology, Plön, Germany
| | - Bostjan Kobe
- School of Chemistry and Molecular Biosciences , The University of Queensland, Brisbane, QLD, Australia
| |
Collapse
|
7
|
Zhang X, Liu Y, Yuan G, Wang S, Wang D, Zhu T, Wu X, Ma M, Guo L, Guo H, Bhadauria V, Liu J, Peng YL. The synthetic NLR RGA5 HMA5 requires multiple interfaces within and outside the integrated domain for effector recognition. Nat Commun 2024; 15:1104. [PMID: 38321036 PMCID: PMC10847126 DOI: 10.1038/s41467-024-45380-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Accepted: 01/19/2024] [Indexed: 02/08/2024] Open
Abstract
Some plant sensor nucleotide-binding leucine-rich repeat (NLR) receptors detect pathogen effectors through their integrated domains (IDs). Rice RGA5 sensor NLR recognizes its corresponding effectors AVR-Pia and AVR1-CO39 from the blast fungus Magnaporthe oryzae through direct binding to its heavy metal-associated (HMA) ID to trigger the RGA4 helper NLR-dependent resistance in rice. Here, we report a mutant of RGA5 named RGA5HMA5 that confers complete resistance in transgenic rice plants to the M. oryzae strains expressing the noncorresponding effector AVR-PikD. RGA5HMA5 carries three engineered interfaces, two of which lie in the HMA ID and the other in the C-terminal Lys-rich stretch tailing the ID. However, RGA5 variants having one or two of the three interfaces, including replacing all the Lys residues with Glu residues in the Lys-rich stretch, failed to activate RGA4-dependent cell death of rice protoplasts. Altogether, this work demonstrates that sensor NLRs require a concerted action of multiple surfaces within and outside the IDs to both recognize effectors and activate helper NLR-mediated resistance, and has implications in structure-guided designing of sensor NLRs.
Collapse
Affiliation(s)
- Xin Zhang
- The State Key Laboratory of Maize Bio-breeding, Joint International Research Laboratory of Crop Molecular Breeding, Ministry of Agriculture Key Laboratory for Crop Pest Monitoring and Green Control, College of Plant Protection, China Agricultural University, 100193, Beijing, China
- Frontiers Science Center for Molecular Design Breeding, China Agricultural University, 100193, Beijing, China
| | - Yang Liu
- The State Key Laboratory of Maize Bio-breeding, Joint International Research Laboratory of Crop Molecular Breeding, Ministry of Agriculture Key Laboratory for Crop Pest Monitoring and Green Control, College of Plant Protection, China Agricultural University, 100193, Beijing, China
- Joint International Research Laboratory of Crop Molecular Breeding, China Agricultural University, 100193, Beijing, China
| | - Guixin Yuan
- The State Key Laboratory of Maize Bio-breeding, Joint International Research Laboratory of Crop Molecular Breeding, Ministry of Agriculture Key Laboratory for Crop Pest Monitoring and Green Control, College of Plant Protection, China Agricultural University, 100193, Beijing, China
- Frontiers Science Center for Molecular Design Breeding, China Agricultural University, 100193, Beijing, China
| | - Shiwei Wang
- The State Key Laboratory of Maize Bio-breeding, Joint International Research Laboratory of Crop Molecular Breeding, Ministry of Agriculture Key Laboratory for Crop Pest Monitoring and Green Control, College of Plant Protection, China Agricultural University, 100193, Beijing, China
- Frontiers Science Center for Molecular Design Breeding, China Agricultural University, 100193, Beijing, China
| | - Dongli Wang
- The State Key Laboratory of Maize Bio-breeding, Joint International Research Laboratory of Crop Molecular Breeding, Ministry of Agriculture Key Laboratory for Crop Pest Monitoring and Green Control, College of Plant Protection, China Agricultural University, 100193, Beijing, China
- Joint International Research Laboratory of Crop Molecular Breeding, China Agricultural University, 100193, Beijing, China
| | - Tongtong Zhu
- The State Key Laboratory of Maize Bio-breeding, Joint International Research Laboratory of Crop Molecular Breeding, Ministry of Agriculture Key Laboratory for Crop Pest Monitoring and Green Control, College of Plant Protection, China Agricultural University, 100193, Beijing, China
- Joint International Research Laboratory of Crop Molecular Breeding, China Agricultural University, 100193, Beijing, China
| | - Xuefeng Wu
- The State Key Laboratory of Maize Bio-breeding, Joint International Research Laboratory of Crop Molecular Breeding, Ministry of Agriculture Key Laboratory for Crop Pest Monitoring and Green Control, College of Plant Protection, China Agricultural University, 100193, Beijing, China
- Joint International Research Laboratory of Crop Molecular Breeding, China Agricultural University, 100193, Beijing, China
| | - Mengqi Ma
- The State Key Laboratory of Maize Bio-breeding, Joint International Research Laboratory of Crop Molecular Breeding, Ministry of Agriculture Key Laboratory for Crop Pest Monitoring and Green Control, College of Plant Protection, China Agricultural University, 100193, Beijing, China
- Joint International Research Laboratory of Crop Molecular Breeding, China Agricultural University, 100193, Beijing, China
| | - Liwei Guo
- The State Key Laboratory of Maize Bio-breeding, Joint International Research Laboratory of Crop Molecular Breeding, Ministry of Agriculture Key Laboratory for Crop Pest Monitoring and Green Control, College of Plant Protection, China Agricultural University, 100193, Beijing, China
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan Agricultural University, 650201, Kunming, China
| | - Hailong Guo
- The State Key Laboratory of Maize Bio-breeding, Joint International Research Laboratory of Crop Molecular Breeding, Ministry of Agriculture Key Laboratory for Crop Pest Monitoring and Green Control, College of Plant Protection, China Agricultural University, 100193, Beijing, China
| | - Vijai Bhadauria
- The State Key Laboratory of Maize Bio-breeding, Joint International Research Laboratory of Crop Molecular Breeding, Ministry of Agriculture Key Laboratory for Crop Pest Monitoring and Green Control, College of Plant Protection, China Agricultural University, 100193, Beijing, China
| | - Junfeng Liu
- The State Key Laboratory of Maize Bio-breeding, Joint International Research Laboratory of Crop Molecular Breeding, Ministry of Agriculture Key Laboratory for Crop Pest Monitoring and Green Control, College of Plant Protection, China Agricultural University, 100193, Beijing, China.
- Joint International Research Laboratory of Crop Molecular Breeding, China Agricultural University, 100193, Beijing, China.
| | - You-Liang Peng
- The State Key Laboratory of Maize Bio-breeding, Joint International Research Laboratory of Crop Molecular Breeding, Ministry of Agriculture Key Laboratory for Crop Pest Monitoring and Green Control, College of Plant Protection, China Agricultural University, 100193, Beijing, China.
- Frontiers Science Center for Molecular Design Breeding, China Agricultural University, 100193, Beijing, China.
| |
Collapse
|
8
|
Chicowski AS, Bredow M, Utiyama AS, Marcelino‐Guimarães FC, Whitham SA. Soybean-Phakopsora pachyrhizi interactions: towards the development of next-generation disease-resistant plants. PLANT BIOTECHNOLOGY JOURNAL 2024; 22:296-315. [PMID: 37883664 PMCID: PMC10826999 DOI: 10.1111/pbi.14206] [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: 07/06/2023] [Revised: 09/19/2023] [Accepted: 10/08/2023] [Indexed: 10/28/2023]
Abstract
Soybean rust (SBR), caused by the obligate biotrophic fungus Phakopsora pachyrhizi, is a devastating foliar disease threatening soybean production. To date, no commercial cultivars conferring durable resistance to SBR are available. The development of long-lasting SBR resistance has been hindered by the lack of understanding of this complex pathosystem, encompassing challenges posed by intricate genetic structures in both the host and pathogen, leading to a gap in the knowledge of gene-for-gene interactions between soybean and P. pachyrhizi. In this review, we focus on recent advancements and emerging technologies that can be used to improve our understanding of the P. pachyrhizi-soybean molecular interactions. We further explore approaches used to combat SBR, including conventional breeding, transgenic approaches and RNA interference, and how advances in our understanding of plant immune networks, the availability of new molecular tools, and the recent sequencing of the P. pachyrhizi genome could be used to aid in the development of better genetic resistance against SBR. Lastly, we discuss the research gaps of this pathosystem and how new technologies can be used to shed light on these questions and to develop durable next-generation SBR-resistant soybean plants.
Collapse
Affiliation(s)
- Aline Sartor Chicowski
- Department of Plant Pathology, Entomology and MicrobiologyIowa State UniversityAmesIowaUSA
| | - Melissa Bredow
- Department of Plant Pathology, Entomology and MicrobiologyIowa State UniversityAmesIowaUSA
| | - Alice Satiko Utiyama
- Brazilian Agricultural Research Corporation – National Soybean Research Center (Embrapa Soja)LondrinaParanáBrazil
- Department of AgronomyFederal University of ViçosaViçosaMinas GeraisBrazil
| | | | - Steven A. Whitham
- Department of Plant Pathology, Entomology and MicrobiologyIowa State UniversityAmesIowaUSA
| |
Collapse
|
9
|
Crean EE, Bilstein-Schloemer M, Maekawa T, Schulze-Lefert P, Saur IML. A dominant-negative avirulence effector of the barley powdery mildew fungus provides mechanistic insight into barley MLA immune receptor activation. JOURNAL OF EXPERIMENTAL BOTANY 2023; 74:5854-5869. [PMID: 37474129 PMCID: PMC10540733 DOI: 10.1093/jxb/erad285] [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: 01/16/2023] [Accepted: 07/18/2023] [Indexed: 07/22/2023]
Abstract
Nucleotide-binding leucine-rich repeat receptors (NLRs) recognize pathogen effectors to mediate plant disease resistance often involving host cell death. Effectors escape NLR recognition through polymorphisms, allowing the pathogen to proliferate on previously resistant host plants. The powdery mildew effector AVRA13-1 is recognized by the barley NLR MLA13 and activates host cell death. We demonstrate here that a virulent form of AVRA13, called AVRA13-V2, escapes MLA13 recognition by substituting a serine for a leucine residue at the C-terminus. Counterintuitively, this substitution in AVRA13-V2 resulted in an enhanced MLA13 association and prevented the detection of AVRA13-1 by MLA13. Therefore, AVRA13-V2 is a dominant-negative form of AVRA13 and has probably contributed to the breakdown of Mla13 resistance. Despite this dominant-negative activity, AVRA13-V2 failed to suppress host cell death mediated by the MLA13 autoactive MHD variant. Neither AVRA13-1 nor AVRA13-V2 interacted with the MLA13 autoactive variant, implying that the binding moiety in MLA13 that mediates association with AVRA13-1 is altered after receptor activation. We also show that mutations in the MLA13 coiled-coil domain, which were thought to impair Ca2+ channel activity and NLR function, instead resulted in MLA13 autoactive cell death. Our results constitute an important step to define intermediate receptor conformations during NLR activation.
Collapse
Affiliation(s)
- Emma E Crean
- Institute for Plant Sciences, University of Cologne, D-50674 Cologne, Germany
| | | | - Takaki Maekawa
- Institute for Plant Sciences, University of Cologne, D-50674 Cologne, Germany
- Department for Plant Microbe Interactions, Max-Planck Institute for Plant Breeding Research, D-50829 Cologne, Germany
- Cluster of Excellence on Plant Sciences (CEPLAS), Germany
| | - Paul Schulze-Lefert
- Department for Plant Microbe Interactions, Max-Planck Institute for Plant Breeding Research, D-50829 Cologne, Germany
- Cluster of Excellence on Plant Sciences (CEPLAS), Germany
| | - Isabel M L Saur
- Institute for Plant Sciences, University of Cologne, D-50674 Cologne, Germany
- Cluster of Excellence on Plant Sciences (CEPLAS), Germany
| |
Collapse
|
10
|
Jost M, Outram MA, Dibley K, Zhang J, Luo M, Ayliffe M. Plant and pathogen genomics: essential approaches for stem rust resistance gene stacks in wheat. FRONTIERS IN PLANT SCIENCE 2023; 14:1223504. [PMID: 37727853 PMCID: PMC10505659 DOI: 10.3389/fpls.2023.1223504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Accepted: 07/27/2023] [Indexed: 09/21/2023]
Abstract
The deployment of disease resistance genes is currently the most economical and environmentally sustainable method of crop protection. However, disease resistance genes can rapidly break down because of constant pathogen evolution, particularly when they are deployed singularly. Polygenic resistance is, therefore, considered the most durable, but combining and maintaining these genes by breeding is a laborious process as effective genes are usually unlinked. The deployment of polygenic resistance with single-locus inheritance is a promising innovation that overcomes these difficulties while enhancing resistance durability. Because of major advances in genomic technologies, increasing numbers of plant resistance genes have been cloned, enabling the development of resistance transgene stacks (RTGSs) that encode multiple genes all located at a single genetic locus. Gene stacks encoding five stem rust resistance genes have now been developed in transgenic wheat and offer both breeding simplicity and potential resistance durability. The development of similar genomic resources in phytopathogens has advanced effector gene isolation and, in some instances, enabled functional validation of individual resistance genes in RTGS. Here, the wheat stem rust pathosystem is used as an illustrative example of how host and pathogen genomic advances have been instrumental in the development of RTGS, which is a strategy applicable to many other agricultural crop species.
Collapse
Affiliation(s)
| | | | | | | | | | - Michael Ayliffe
- Commonwealth Scientific and Industrial Research Organisation (CSIRO) Agriculture and Food, Canberra, ACT, Australia
| |
Collapse
|
11
|
Förderer A, Kourelis J. NLR immune receptors: structure and function in plant disease resistance. Biochem Soc Trans 2023; 51:1473-1483. [PMID: 37602488 PMCID: PMC10586772 DOI: 10.1042/bst20221087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 07/23/2023] [Accepted: 08/07/2023] [Indexed: 08/22/2023]
Abstract
Nucleotide-binding and leucine-rich repeat receptors (NLRs) are a diverse family of intracellular immune receptors that play crucial roles in recognizing and responding to pathogen invasion in plants. This review discusses the overall model of NLR activation and provides an in-depth analysis of the different NLR domains, including N-terminal executioner domains, the nucleotide-binding oligomerization domain (NOD) module, and the leucine-rich repeat (LRR) domain. Understanding the structure-function relationship of these domains is essential for developing effective strategies to improve plant disease resistance and agricultural productivity.
Collapse
Affiliation(s)
- Alexander Förderer
- Max-Planck-Institute of Molecular Plant Physiology, 14476 Potsdam, Germany
| | - Jiorgos Kourelis
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, NR4 7UH Norwich, U.K
| |
Collapse
|