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Wang S, McLellan H, Boevink PC, Birch PRJ. RxLR Effectors: Master Modulators, Modifiers and Manipulators. Mol Plant Microbe Interact 2023; 36:754-763. [PMID: 37750829 DOI: 10.1094/mpmi-05-23-0054-cr] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/27/2023]
Abstract
Cytoplasmic effectors with an Arg-any amino acid-Arg-Leu (RxLR) motif are encoded by hundreds of genes within the genomes of oomycete Phytophthora spp. and downy mildew pathogens. There has been a dramatic increase in our understanding of the evolution, function, and recognition of these effectors. Host proteins with a wide range of subcellular localizations and functions are targeted by RxLR effectors. Many processes are manipulated, including transcription, post-translational modifications, such as phosphorylation and ubiquitination, secretion, and intracellular trafficking. This involves an array of RxLR effector modes-of-action, including stabilization or destabilization of protein targets, altering or disrupting protein complexes, inhibition or utility of target enzyme activities, and changing the location of protein targets. Interestingly, approximately 50% of identified host proteins targeted by RxLR effectors are negative regulators of immunity. Avirulence RxLR effectors may be directly or indirectly detected by nucleotide-binding leucine-rich repeat resistance (NLR) proteins. Direct recognition by a single NLR of RxLR effector orthologues conserved across multiple Phytophthora pathogens may provide wide protection of diverse crops. Failure of RxLR effectors to interact with or appropriately manipulate target proteins in nonhost plants has been shown to restrict host range. This knowledge can potentially be exploited to alter host targets to prevent effector interaction, providing a barrier to host infection. Finally, recent evidence suggests that RxLR effectors, like cytoplasmic effectors from fungal pathogen Magnaporthe oryzae, may enter host cells via clathrin-mediated endocytosis. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
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Affiliation(s)
- Shumei Wang
- Department of Microbiology and Plant Pathology, Center for Plant Cell Biology, Institute for Integrative Genome Biology, University of California, Riverside, CA, U.S.A
| | - Hazel McLellan
- Division of Plant Sciences, School of Life Sciences, University of Dundee, at James Hutton Institute, Invergowrie, Dundee DD2 5DA, U.K
| | - Petra C Boevink
- Cell and Molecular Sciences, James Hutton Institute, Invergowrie, Dundee DD2 5DA, U.K
| | - Paul R J Birch
- Division of Plant Sciences, School of Life Sciences, University of Dundee, at James Hutton Institute, Invergowrie, Dundee DD2 5DA, U.K
- Cell and Molecular Sciences, James Hutton Institute, Invergowrie, Dundee DD2 5DA, U.K
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Koseoglou E, van der Wolf JM, Visser RGF, Bai Y. Susceptibility reversed: modified plant susceptibility genes for resistance to bacteria. Trends Plant Sci 2022; 27:69-79. [PMID: 34400073 DOI: 10.1016/j.tplants.2021.07.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 07/20/2021] [Accepted: 07/24/2021] [Indexed: 05/26/2023]
Abstract
Plants have evolved complex defence mechanisms to avoid invasion of potential pathogens. Despite this, adapted pathogens deploy effector proteins to manipulate host susceptibility (S) genes, rendering plant defences ineffective. The identification and mutation of plant S genes exploited by bacterial pathogens are important for the generation of crops with durable and broad-spectrum resistance. Application of mutant S genes in the breeding of resistant crops is limited because of potential pleiotropy. New genome editing techniques open up new possibilities for the modification of S genes. In this review, we focus on S genes manipulated by bacteria and propose ways for their identification and precise modification. Finally, we propose that genes coding for transporter proteins represent a new group of S genes.
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Affiliation(s)
- Eleni Koseoglou
- Plant Breeding, Wageningen University & Research, Droevendaalsesteeg 1, 6708 PB, Wageningen, The Netherlands
| | - Jan M van der Wolf
- Biointeractions & Plant Health, Wageningen University & Research, Droevendaalsesteeg 1, 6708 PB, Wageningen, The Netherlands
| | - Richard G F Visser
- Plant Breeding, Wageningen University & Research, Droevendaalsesteeg 1, 6708 PB, Wageningen, The Netherlands
| | - Yuling Bai
- Plant Breeding, Wageningen University & Research, Droevendaalsesteeg 1, 6708 PB, Wageningen, The Netherlands.
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Du Y, Chen X, Guo Y, Zhang X, Zhang H, Li F, Huang G, Meng Y, Shan W. Erratum. New Phytol 2021; 230:878. [PMID: 33729595 DOI: 10.1111/nph.17188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Affiliation(s)
- Yu Du
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Horticulture, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Xiaokang Chen
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Horticulture, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Yalu Guo
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Horticulture, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Xiaojiang Zhang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Horticulture, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Houxiao Zhang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Horticulture, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Fangfang Li
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Horticulture, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Guiyan Huang
- College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, 712100, China
- China-USA Citrus Huanglongbing Joint Laboratory, National Navel Orange Engineering Research Center, College of Life Sciences, Gannan Normal University, Ganzhou, 341000, China
| | - Yuling Meng
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Agronomy, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Weixing Shan
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Agronomy, Northwest A&F University, Yangling, Shaanxi, 712100, China
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Du Y, Chen X, Guo Y, Zhang X, Zhang H, Li F, Huang G, Meng Y, Shan W. Phytophthora infestans RXLR effector PITG20303 targets a potato MKK1 protein to suppress plant immunity. New Phytol 2021; 229:501-515. [PMID: 32772378 DOI: 10.1111/nph.16861] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Accepted: 07/27/2020] [Indexed: 05/21/2023]
Abstract
Pathogens secret a plethora of effectors into the host cell to modulate plant immunity. Analysing the role of effectors in altering the function of their host target proteins will reveal critical components of the plant immune system. Here we show that Phytophthora infestans RXLR effector PITG20303, a virulent variant of AVRblb2 (PITG20300) that escapes recognition by the resistance protein Rpi-blb2, suppresses PAMP-triggered immunity (PTI) and promotes pathogen colonization by targeting and stabilizing a potato MAPK cascade protein, StMKK1. Both PITG20300 and PITG20303 target StMKK1, as confirmed by multiple in vivo and in vitro assays, and StMKK1 was shown to be a negative regulator of plant immunity, as determined by overexpression and gene silencing. StMKK1 is a negative regulator of plant PTI, and the kinase activities of StMKK1 are required for its suppression of PTI and effector interaction. PITG20303 depends partially on MKK1, PITG20300 does not depend on MKK1 for suppression of PTI-induced reactive oxygen species burst, while the full virulence activities of nuclear targeted PITG20303 and PITG20300 are dependent on MKK1. Our results show that PITG20303 and PITG20300 target and stabilize the plant MAPK cascade signalling protein StMKK1 to negatively regulate plant PTI response.
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Affiliation(s)
- Yu Du
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Horticulture, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Xiaokang Chen
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Horticulture, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Yalu Guo
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Horticulture, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Xiaojiang Zhang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Horticulture, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Houxiao Zhang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Horticulture, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Fangfang Li
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Horticulture, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Guiyan Huang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Agronomy, Northwest A&F University, Yangling, Shaanxi, 712100, China
- College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Yuling Meng
- China-USA Citrus Huanglongbing Joint Laboratory, National Navel Orange Engineering Research Center, College of Life Sciences, Gannan Normal University, Ganzhou, 341000, China
| | - Weixing Shan
- China-USA Citrus Huanglongbing Joint Laboratory, National Navel Orange Engineering Research Center, College of Life Sciences, Gannan Normal University, Ganzhou, 341000, China
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Abstract
Quantitative resistance (QR) refers to a resistance that is phenotypically incomplete and is based on the joined effect of several genes, each contributing quantitatively to the level of plant defense. Often, QR remains durably effective, which is the primary driver behind the interest in it. The various terms that are used to refer to QR, such as field resistance, adult plant resistance, and basal resistance, reflect the many properties attributed to it. In this article, we discuss aspects connected to those attributions, in particular the hypothesis that much of the QR to biotrophic filamentous pathogens is basal resistance, i.e., poor suppression of PAMP-triggered defense by effectors. We discuss what role effectors play in suppressing defense or improving access to nutrients. Based on the functions of the few plant proteins identified as involved in QR, vesicle trafficking and protein/metabolite transportation are likely to be common physiological processes relevant to QR.
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Affiliation(s)
- Rients E Niks
- Laboratory of Plant Breeding, Wageningen University and Research Centre, 6700 AJ Wageningen, The Netherlands;
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