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Lu K, Chen R, Yang Y, Xu H, Jiang J, Li L. Involvement of the Cell Wall-Integrity Pathway in Signal Recognition, Cell-Wall Biosynthesis, and Virulence in Magnaporthe oryzae. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2023; 36:608-622. [PMID: 37140471 DOI: 10.1094/mpmi-11-22-0231-cr] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The fungal cell wall is the first layer exposed to the external environment. The cell wall has key roles in regulating cell functions, such as cellular stability, permeability, and protection against stress. Understanding the structure of the cell wall and the mechanism of its biogenesis is important for the study of fungi. Highly conserved in fungi, including Magnaporthe oryzae, the cell wall-integrity (CWI) pathway is the primary signaling cascade regulating cell-wall structure and function. The CWI pathway has been demonstrated to correlate with pathogenicity in many phytopathogenic fungi. In the synthesis of the cell wall, the CWI pathway cooperates with multiple signaling pathways to regulate cell morphogenesis and secondary metabolism. Many questions have arisen regarding the cooperation of different signaling pathways with the CWI pathway in regulating cell-wall synthesis and pathogenicity. In this review, we summarized the latest advances in the M. oryzae CWI pathway and cell-wall structure. We discussed the CWI pathway components and their involvement in different aspects, such as virulence factors, the possibility of the pathway as a target for antifungal therapies, and crosstalk with other signaling pathways. This information will aid in better understanding the universal functions of the CWI pathway in regulating cell-wall synthesis and pathogenicity in M. oryzae. [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)
- Kailun Lu
- School of Life Sciences, Jiangsu Normal University, Xuzhou 221116, China
| | - Rangrang Chen
- School of Life Sciences, Jiangsu Normal University, Xuzhou 221116, China
| | - Yi Yang
- School of Life Sciences, Jiangsu Normal University, Xuzhou 221116, China
| | - Hui Xu
- School of Life Sciences, Jiangsu Normal University, Xuzhou 221116, China
| | - Jihong Jiang
- School of Life Sciences, Jiangsu Normal University, Xuzhou 221116, China
| | - Lianwei Li
- School of Life Sciences, Jiangsu Normal University, Xuzhou 221116, China
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China
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Liu J, Wang C, Kong L, Yang Y, Cui X, Li K, Nian H. Rho2 involved in development, stress response and pathogenicity of Fusarium oxysporum. World J Microbiol Biotechnol 2023; 39:272. [PMID: 37548840 DOI: 10.1007/s11274-023-03720-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Accepted: 08/02/2023] [Indexed: 08/08/2023]
Abstract
Rho GTPases regulate the activity of cell wall biosynthesis, actin assembly and polar cell secretion. However, the function of Rho GTPase in filamentous fungi is poorly understood. To understand the role of Rho2 GTPase in Fusarium oxysporum, which is one of root rot pathogens of Panax notoginseng, △rho2 mutant was constructed. Phenotypes of △rho2, including conidiation, germination of spores, stresses (osmotic-, cell membrane-, cell wall disturbing-, metal-, and high temperature-) tolerance and pathogenicity were analyzed. The results showed that the growth of △rho2 was destroyed under cell wall disturbing stress and high temperature stress, suggesting that Rho2 regulated the response of F. oxysporum to cell wall synthesis inhibitors and high temperature stress. Germination of spores and pathogenicity to P. notoginseng were reduced in △rho2 mutant. Western blot results showed that rho2 deletion increased the phosphorylation level of Mpk1. To identify genes regulated by Rho2, transcriptome sequencing was carried out. 2477 genes were identified as upregulated genes and 2177 genes were identified as downregulated genes after rho2 was deleted. These genes provide clues for further study of rho2 function.
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Affiliation(s)
- Jia Liu
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, 650500, China
| | - Chengsong Wang
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, 650500, China
| | - Lei Kong
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, 650500, China
| | - Ye Yang
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, 650500, China
- Key Laboratory of Panax notoginseng Resources Sustainable Development and Utilization of State Administration of Traditional Chinese Medicine, Kunming, 650500, China
| | - Xiuming Cui
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, 650500, China
- Key Laboratory of Panax notoginseng Resources Sustainable Development and Utilization of State Administration of Traditional Chinese Medicine, Kunming, 650500, China
| | - Kunzhi Li
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, 650500, China
| | - Hongjuan Nian
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, 650500, China.
- Key Laboratory of Panax notoginseng Resources Sustainable Development and Utilization of State Administration of Traditional Chinese Medicine, Kunming, 650500, China.
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Zhang W, Wang S, Jiang B, Guo M. MoRts1, a regulatory subunit of PP2A, is required for fungal development and pathogenicity of Magnaporthe oryzae. Microbiol Res 2023; 269:127313. [PMID: 36696866 DOI: 10.1016/j.micres.2023.127313] [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: 09/01/2022] [Revised: 01/18/2023] [Accepted: 01/18/2023] [Indexed: 01/22/2023]
Abstract
Protein phosphatase 2 A (PP2A) is a major heterotrimeric serine/threonine protein phosphatase comprised of three subunits, including structural subunits (A), regulatory subunits (B), and catalytic subunits (C). PP2A has been widely shown to involve in a series of cell signal transduction processes such as cell metabolism, cell cycle regulation, DNA replication, gene transcription and protein translation in yeast and mammalian. However, the roles of PP2A in pathogenic fungi Magnaporthe oryzae still remain unclear. We here found that MoRts1, a gene encoding B regulatory subunit of PP2A homologous to Saccharomyces cerevisiae Rts1, showed up-regulated transcription during conidia and initially infectious stage. Subcellular localization revealed that MoRts1-eGFP was localized to the cytoplasm and septum. Targeted disruption of MoRts1 leads to a reduction of mycelial growth and sporulation, as well as the defects of hydrophobicity, melanin pigmentation and cell wall integrity (CWI). The MoRts1 mutants were less pathogenic to the host plants, compared to the Ku80 strain, and the transcriptional levels of several pathogenicity-related Rho GTPase genes, including MoCdc42, MoRho2, MoRho3, MoRho4, MoRhoX and MoRac1, were significantly decreased in the MoRts1 mutants. Besides, two splicing variants of MoRts1 with unique functions of regulating the growth and pathogenicity were identified, and the B56 domain is vital for determining the sporulation and pathogenicity of M. oryzae. Furthermore, MoRts1 was identified to interact with PP2A catalytic subunit MoPPG1 in vivo in M. oryzae. In summary, our results showed that MoRts1 is an important regulator contributing to the fungal development, and pathogenicity of M. oryzae.
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Affiliation(s)
- Weiwei Zhang
- Key Laboratory of Biology and Sustainable Management of Plant Diseases and Pests of Anhui Higher Education Institutes, Hefei 230036, China; College of Plant Protection, Anhui Agricultural University, Hefei 230036, China
| | - Shuaishuai Wang
- Key Laboratory of Biology and Sustainable Management of Plant Diseases and Pests of Anhui Higher Education Institutes, Hefei 230036, China; College of Plant Protection, Anhui Agricultural University, Hefei 230036, China
| | - Bingxin Jiang
- Key Laboratory of Biology and Sustainable Management of Plant Diseases and Pests of Anhui Higher Education Institutes, Hefei 230036, China; College of Plant Protection, Anhui Agricultural University, Hefei 230036, China
| | - Min Guo
- Key Laboratory of Biology and Sustainable Management of Plant Diseases and Pests of Anhui Higher Education Institutes, Hefei 230036, China; College of Plant Protection, Anhui Agricultural University, Hefei 230036, China.
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Li Q, Chen X, Lin L, Zhang L, Wang L, Bao J, Zhang D. Transcriptomic Dynamics of Active and Inactive States of Rho GTPase MoRho3 in Magnaporthe oryzae. J Fungi (Basel) 2022; 8:jof8101060. [PMID: 36294629 PMCID: PMC9605073 DOI: 10.3390/jof8101060] [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: 08/26/2022] [Revised: 10/04/2022] [Accepted: 10/05/2022] [Indexed: 11/17/2022] Open
Abstract
The small Rho GTPase acts as a molecular switch in eukaryotic signal transduction, which plays a critical role in polar cell growth and vesicle trafficking. Previous studies demonstrated that constitutively active (CA) mutant strains, of MoRho3-CA were defective in appressorium formation. While dominant-negative (DN) mutant strains MoRho3-DN shows defects in polar growth. However, the molecular dynamics of MoRho3-mediated regulatory networks in the pathogenesis of Magnaporthe oryzae still needs to be uncovered. Here, we perform comparative transcriptomic profiling of MoRho3-CA and MoRho3-DN mutant strains using a high-throughput RNA sequencing approach. We find that genetic manipulation of MoRho3 significantly disrupts the expression of 28 homologs of Saccharomyces cerevisiae Rho3-interacting proteins, including EXO70, BNI1, and BNI2 in the MoRho3 CA, DN mutant strains. Functional enrichment analyses of up-regulated DEGs reveal a significant enrichment of genes associated with ribosome biogenesis in the MoRho3-CA mutant strain. Down-regulated DEGs in the MoRho3-CA mutant strains shows significant enrichment in starch/sucrose metabolism and the ABC transporter pathway. Moreover, analyses of down-regulated DEGs in the in MoRho3-DN reveals an over-representation of genes enriched in metabolic pathways. In addition, we observe a significant suppression in the expression levels of secreted proteins suppressed in both MoRho3-CA and DN mutant strains. Together, our results uncover expression dynamics mediated by two states of the small GTPase MoRho3, demonstrating its crucial roles in regulating the expression of ribosome biogenesis and secreted proteins.
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Affiliation(s)
- Qian Li
- Meishan Vocational Technical College, Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Correspondence: (Q.L.); (D.Z.)
| | - Xi Chen
- State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Lianyu Lin
- State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Lianhu Zhang
- State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- College of Agronomy, Jiangxi Agricultural University, Nanchang 330045, China
| | - Li Wang
- Meishan Vocational Technical College, Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Jiandong Bao
- State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Dongmei Zhang
- State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Correspondence: (Q.L.); (D.Z.)
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Transcriptomic Analysis Reveals That Rho GTPases Regulate Trap Development and Lifestyle Transition of the Nematode-Trapping Fungus Arthrobotrys oligospora. Microbiol Spectr 2022; 10:e0175921. [PMID: 35019695 PMCID: PMC8754127 DOI: 10.1128/spectrum.01759-21] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Nematode-trapping (NT) fungi can form unique infection structures (traps) to capture and kill free-living nematodes and, thus, can play a potential role in the biocontrol of nematodes. Arthrobotrys oligospora is a representative species of NT fungi. Here, we performed a time course transcriptome sequencing (RNA-seq) analysis of transcriptomes to understand the global gene expression levels of A. oligospora during trap formation and predation. We identified 5,752 unique differentially expressed genes, among which the rac gene was significantly upregulated. Alternative splicing events occurred in 2,012 genes, including the rac and rho2 gene. Furthermore, we characterized three Rho GTPases (Rho2, Rac, and Cdc42) in A. oligospora using gene disruption and multiphenotypic analysis. Our analyses showed that AoRac and AoCdc42 play an important role in mycelium growth, lipid accumulation, DNA damage, sporulation, trap formation, pathogenicity, and stress response in A. oligospora. AoCdc42 and AoRac specifically interacted with components of the Nox complex, thus regulating the production of reactive oxygen species. Moreover, the transcript levels of several genes associated with protein kinase A, mitogen-activated protein kinase, and p21-activated kinase were also altered in the mutants, suggesting that Rho GTPases might function upstream from these kinases. This study highlights the important role of Rho GTPases in A. oligospora and provides insights into the regulatory mechanisms of signaling pathways in the trap morphogenesis and lifestyle transition of NT fungi. IMPORTANCE Nematode-trapping (NT) fungi are widely distributed in terrestrial and aquatic ecosystems. Their broad adaptability and flexible lifestyles make them ideal agents for controlling pathogenic nematodes. Arthrobotrys oligospora is a model species employed for understanding the interaction between fungi and nematodes. Here, we revealed that alternative splicing events play a crucial role in the trap development and lifestyle transition in A. oligospora. Furthermore, Rho GTPases exert differential effects on the growth, development, and pathogenicity of A. oligospora. In particular, AoRac is required for sporulation and trap morphogenesis. In addition, our analysis showed that Rho GTPases regulate the production of reactive oxygen species and function upstream from several kinases. Collectively, these results expand our understanding of gene expression and alternative splicing events in A. oligospora and the important roles of Rho GTPases in NT fungi, thereby providing a foundation for exploring their potential application in the biocontrol of pathogenic nematodes.
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Lee NH, Fu T, Shin JH, Song YW, Jang DC, Kim KS. The Small GTPase CsRAC1 Is Important for Fungal Development and Pepper Anthracnose in Colletotrichum scovillei. THE PLANT PATHOLOGY JOURNAL 2021; 37:607-618. [PMID: 34897252 PMCID: PMC8666242 DOI: 10.5423/ppj.oa.09.2021.0140] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 10/27/2021] [Accepted: 10/31/2021] [Indexed: 06/14/2023]
Abstract
The pepper anthracnose fungus, Colletotrichum scovillei, causes severe losses of pepper fruit production in the tropical and temperate zones. RAC1 is a highly conserved small GTP-binding protein in the Rho GTPase family. This protein has been demonstrated to play a role in fungal development, and pathogenicity in several plant pathogenic fungi. However, the functional roles of RAC1 are not characterized in C. scovillei causing anthracnose on pepper fruits. Here, we generated a deletion mutant (ΔCsrac1) via homologous recombination to investigate the functional roles of CsRAC1. The ΔCsrac1 showed pleiotropic defects in fungal growth and developments, including vegetative growth, conidiogenesis, conidial germination and appressorium formation, compared to wild-type. Although ΔCsrac1 was able to develop appressoria, it failed to differentiate appressorium pegs. However, ΔCsrac1 still caused anthracnose disease with significantly reduced rate on wounded pepper fruits. Further analyses revealed that ΔCsrac1 was defective in tolerance to oxidative stress and suppression of host-defense genes. Taken together, our results suggest that CsRAC1 plays essential roles in fungal development and pathogenicity in C. scovillei-pepper fruit pathosystem.
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Affiliation(s)
- Noh-Hyun Lee
- Division of Bio-Resource Sciences, BioHerb Research Institute, and Interdisciplinary Program in Smart Agriculture, Kangwon National University, Chuncheon 24341,
Korea
| | - Teng Fu
- Division of Bio-Resource Sciences, BioHerb Research Institute, and Interdisciplinary Program in Smart Agriculture, Kangwon National University, Chuncheon 24341,
Korea
| | - Jong-Hwan Shin
- Division of Bio-Resource Sciences, BioHerb Research Institute, and Interdisciplinary Program in Smart Agriculture, Kangwon National University, Chuncheon 24341,
Korea
| | - Yong-Won Song
- Division of Bio-Resource Sciences, BioHerb Research Institute, and Interdisciplinary Program in Smart Agriculture, Kangwon National University, Chuncheon 24341,
Korea
| | - Dong-Cheol Jang
- Department of Horticulture, Kangwon National University, Chuncheon 24341,
Korea
| | - Kyoung Su Kim
- Division of Bio-Resource Sciences, BioHerb Research Institute, and Interdisciplinary Program in Smart Agriculture, Kangwon National University, Chuncheon 24341,
Korea
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Fu T, Han JH, Shin JH, Song H, Ko J, Lee YH, Kim KT, Kim KS. Homeobox Transcription Factors Are Required for Fungal Development and the Suppression of Host Defense Mechanisms in the Colletotrichum scovillei-Pepper Pathosystem. mBio 2021; 12:e0162021. [PMID: 34425710 PMCID: PMC8406175 DOI: 10.1128/mbio.01620-21] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 07/20/2021] [Indexed: 11/28/2022] Open
Abstract
Colletotrichum scovillei, an ascomycete phytopathogenic fungus, is the main causal agent of serious yield losses of economic crops worldwide. The fungus causes anthracnose disease on several fruits, including peppers. However, little is known regarding the underlying molecular mechanisms involved in the development of anthracnose caused by this fungus. In an initial step toward understanding the development of anthracnose on pepper fruits, we retrieved 624 transcription factors (TFs) from the whole genome of C. scovillei and comparatively analyzed the entire repertoire of TFs among phytopathogenic fungi. Evolution and proliferation of members of the homeobox-like superfamily, including homeobox (HOX) TFs that regulate the development of eukaryotic organisms, were demonstrated in the genus Colletotrichum. C. scovillei was found to contain 10 HOX TF genes (CsHOX1 to CsHOX10), which were functionally characterized using deletion mutants of each CsHOX gene. Notably, CsHOX1 was identified as a pathogenicity factor required for the suppression of host defense mechanisms, which represents a new role for HOX TFs in pathogenic fungi. CsHOX2 and CsHOX7 were found to play essential roles in conidiation and appressorium development, respectively, in a stage-specific manner in C. scovillei. Our study provides a molecular basis for understanding the mechanisms associated with the development of anthracnose on fruits caused by C. scovillei, which will aid in the development of novel approaches for disease management. IMPORTANCE The ascomycete phytopathogenic fungus, Colletotrichum scovillei, causes serious yield loss on peppers. However, little is known about molecular mechanisms involved in the development of anthracnose caused by this fungus. We analyzed whole-genome sequences of C. scovillei and isolated 624 putative TFs, revealing the existence of 10 homeobox (HOX) transcription factor (TF) genes. We found that CsHOX1 is a pathogenicity factor required for the suppression of host defense mechanism, which represents a new role for HOX TFs in pathogenic fungi. We also found that CsHOX2 and CsHOX7 play essential roles in conidiation and appressorium development, respectively, in a stage-specific manner in C. scovillei. Our study contributes to understanding the mechanisms associated with the development of anthracnose on fruits caused by C. scovillei, which will aid for initiating novel approaches for disease management.
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Affiliation(s)
- Teng Fu
- Division of Bio-Resource Sciences, BioHerb Research Institute, and Interdisciplinary Program in Smart Agriculture, Kangwon National University, Chuncheon, South Korea
| | - Joon-Hee Han
- Department of Research and Development, Chuncheon Bioindustry Foundation, Chuncheon, South Korea
| | - Jong-Hwan Shin
- Division of Bio-Resource Sciences, BioHerb Research Institute, and Interdisciplinary Program in Smart Agriculture, Kangwon National University, Chuncheon, South Korea
| | - Hyeunjeong Song
- Department of Agricultural Biotechnology, Interdisciplinary Program in Agricultural Genomics, Center for Fungal Genetic Resources, Plant Immunity Research Center, and Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, South Korea
| | - Jaeho Ko
- Department of Agricultural Biotechnology, Interdisciplinary Program in Agricultural Genomics, Center for Fungal Genetic Resources, Plant Immunity Research Center, and Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, South Korea
| | - Yong-Hwan Lee
- Department of Agricultural Biotechnology, Interdisciplinary Program in Agricultural Genomics, Center for Fungal Genetic Resources, Plant Immunity Research Center, and Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, South Korea
| | - Ki-Tae Kim
- Department of Agricultural Life Science, Sunchon National University, Suncheon, South Korea
| | - Kyoung Su Kim
- Division of Bio-Resource Sciences, BioHerb Research Institute, and Interdisciplinary Program in Smart Agriculture, Kangwon National University, Chuncheon, South Korea
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Lopez-Moya F, Martin-Urdiroz M, Oses-Ruiz M, Were VM, Fricker MD, Littlejohn G, Lopez-Llorca LV, Talbot NJ. Chitosan inhibits septin-mediated plant infection by the rice blast fungus Magnaporthe oryzae in a protein kinase C and Nox1 NADPH oxidase-dependent manner. THE NEW PHYTOLOGIST 2021; 230:1578-1593. [PMID: 33570748 DOI: 10.1111/nph.17268] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Accepted: 01/25/2021] [Indexed: 06/12/2023]
Abstract
Chitosan is a partially deacetylated linear polysaccharide composed of β-1,4-linked units of d-glucosamine and N-acetyl glucosamine. As well as a structural component of fungal cell walls, chitosan is a potent antifungal agent. However, the mode of action of chitosan is poorly understood. Here, we report that chitosan is effective for control of rice blast disease. Chitosan application impairs growth of the blast fungus Magnaporthe oryzae and has a pronounced effect on appressorium-mediated plant infection. Chitosan inhibits septin-mediated F-actin remodelling at the appressorium pore, thereby preventing repolarization of the infection cell. Chitosan causes plasma membrane permeabilization of M. oryzae and affects NADPH oxidase-dependent synthesis of reactive oxygen species, essential for septin ring formation and fungal pathogenicity. We further show that toxicity of chitosan to M. oryzae requires the protein kinase C-dependent cell wall integrity pathway, the Mps1 mitogen-activated protein kinase and the Nox1 NADPH oxidase. A conditionally lethal, analogue (PP1)-sensitive mutant of Pkc1 is partially remediated for growth in the presence of chitosan, while ∆nox1 mutants increase their glucan : chitin cell wall ratio, rendering them resistant to chitosan. Taken together, our data show that chitosan is a potent fungicide which requires the cell integrity pathway, disrupts plasma membrane function and inhibits septin-mediated plant infection.
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Affiliation(s)
- Federico Lopez-Moya
- Laboratory of Plant Pathology, Department of Marine Sciences and Applied Biology, University of Alicante, Alicante, 03690, Spain
| | | | - Miriam Oses-Ruiz
- School of Biosciences, University of Exeter, Exeter,, EX4 4QD, UK
- The Sainsbury Laboratory, Norwich Research Park, Norwich,, NR4 7UH, UK
| | - Vincent M Were
- School of Biosciences, University of Exeter, Exeter,, EX4 4QD, UK
- The Sainsbury Laboratory, Norwich Research Park, Norwich,, NR4 7UH, UK
| | - Mark D Fricker
- Department of Plant Science, University of Oxford, South Parks Road, Oxford, OX1 3RB, UK
| | - George Littlejohn
- School of Biosciences, University of Exeter, Exeter,, EX4 4QD, UK
- School of Biological and Marine Sciences, Plymouth University, Portland Square Building Room A404, Drake Circus, Plymouth, PL4 8AA, UK
| | - Luis V Lopez-Llorca
- Laboratory of Plant Pathology, Department of Marine Sciences and Applied Biology, University of Alicante, Alicante, 03690, Spain
| | - Nicholas J Talbot
- School of Biosciences, University of Exeter, Exeter,, EX4 4QD, UK
- The Sainsbury Laboratory, Norwich Research Park, Norwich,, NR4 7UH, UK
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The deubiquitinating enzyme MoUbp8 is required for infection-related development, pathogenicity, and carbon catabolite repression in Magnaporthe oryzae. Appl Microbiol Biotechnol 2020; 104:5081-5094. [PMID: 32274561 DOI: 10.1007/s00253-020-10572-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 02/29/2020] [Accepted: 03/22/2020] [Indexed: 12/22/2022]
Abstract
Deubiquitination is an essential regulatory step in the Ub-dependent pathway. Deubiquitinating enzymes (DUBs) mediate the removal of ubiquitin moieties from substrate proteins, which are involved in many regulatory mechanisms. As a component of the DUB module (Ubp8/Sgf11/Sus1/Sgf73) in the SAGA (Spt-Ada-Gcn5-acetyltransferase) complex, Ubp8 plays a crucial role in both Saccharomyces cerevisiae and humans. In S. cerevisiae, Ubp8-mediated deubiquitination regulates transcriptional activation processes. To investigate the contributions of Ubp8 to physiological and pathological development of filamentous fungi, we generated the deletion mutant of ortholog MoUBP8 (MGG-03527) in Magnaporthe oryzae (syn. Pyricularia oryzae). The ΔMoubp8 strain showed reduced sporulation, pathogenicity, and resistance to distinct stresses. Even though the conidia of the ΔMoubp8 mutant were delayed in appressorium formation, the normal and abnormal (none-septum or one-septum) conidia could finally form appressoria. Reduced melanin in the ΔMoubp8 mutant is highly responsible for the attenuated pathogenicity since the appressoria of the ΔMoubp8 mutant was much more fragile than those of the wild type, due to the defective turgidity. The weakened ability to detoxify or scavenge host-derived reactive oxygen species (ROS) further restricted the invasion of the pathogen. We also showed that carbon derepression, on the one hand, rendered the ΔMoubp8 strain highly sensitive to allyl alcohol, on the other hand, it enhances the resistance of the MoUBP8 defective strain to deoxyglucose. Overall, we suggest that MoUbp8 is not only required for sporulation, melanin formation, appressoria development, and pathogenicity but also involved in carbon catabolite repression of M. oryzae.
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Fu T, Park GC, Han JH, Shin JH, Park HH, Kim KS. MoRBP9 Encoding a Ran-Binding Protein Microtubule-Organizing Center Is Required for Asexual Reproduction and Infection in the Rice Blast Pathogen Magnaporthe oryzae. THE PLANT PATHOLOGY JOURNAL 2019; 35:564-574. [PMID: 31832037 PMCID: PMC6901248 DOI: 10.5423/ppj.oa.07.2019.0204] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 09/18/2019] [Indexed: 06/10/2023]
Abstract
Like many fungal pathogens, the conidium and appressorium play key roles during polycyclic dissemination and infection of Magnaporthe oryzae. Ran-binding protein microtubule-organizing center (RanBPM) is a highly conserved nucleocytoplasmic protein. In animalia, RanBPM has been implicated in apoptosis, cell morphology, and transcription. However, the functional roles of RanBPM, encoded by MGG_00753 (named MoRBP9) in M. oryzae, have not been elucidated. Here, the deletion mutant ΔMorbp9 for MoRBP9 was generated via homologous recombination to investigate the functions of this gene. The ΔMorbp9 exhibited normal conidial germination and vegetative growth but dramatically reduced conidiation compared with the wild type, suggesting that MoRBP9 is involved in conidial production. ΔMorbp9 conidia failed to produce appressoria on hydrophobic surfaces, whereas ΔMorbp9 still developed aberrantly shaped appressorium-like structures at hyphal tips on the same surface, suggesting that MoRBP9 is involved in the morphology of appressorium-like structures from hyphal tips and is critical for development of appressorium from germ tubes. Taken together, our results indicated that MoRBP9 played a pleiotropic role in polycyclic dissemination and infection-related morphogenesis of M. oryzae.
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Affiliation(s)
| | | | | | | | | | - Kyoung Su Kim
- Corresponding author.: Phone) +82-33-250-6435, FAX) +82-33-259-5558, E-mail)
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Shin JH, Gumilang A, Kim MJ, Han JH, Kim KS. A PAS-Containing Histidine Kinase is Required for Conidiation, Appressorium Formation, and Disease Development in the Rice Blast Fungus, Magnaporthe oryzae. MYCOBIOLOGY 2019; 47:473-482. [PMID: 32010469 PMCID: PMC6968698 DOI: 10.1080/12298093.2019.1689037] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 10/29/2019] [Accepted: 10/31/2019] [Indexed: 06/10/2023]
Abstract
Rice blast disease, caused by the ascomycete fungus Magnaporthe oryzae, is one of the most important diseases in rice production. PAS (period circadian protein, aryl hydrocarbon receptor nuclear translocator protein, single-minded protein) domains are known to be involved in signal transduction pathways, but their functional roles have not been well studied in fungi. In this study, targeted gene deletion was carried out to investigate the functional roles of the PAS-containing gene MoPAS1 (MGG_02665) in M. oryzae. The deletion mutant ΔMopas1 exhibited easily wettable mycelia, reduced conidiation, and defects in appressorium formation and disease development compared to the wild type and complemented transformant. Exogenous cAMP restored appressorium formation in ΔMopas1, but the shape of the restored appressorium was irregular, indicating that MoPAS1 is involved in sensing the hydrophobic surface. To examine the expression and localization of MoPAS1 in M. oryzae during appressorium development and plant infection, we constructed a MoPAS1:GFP fusion construct. MoPAS1:GFP was observed in conidia and germ tubes at 0 and 2 h post-infection (hpi) on hydrophobic cover slips. By 8 hpi, most of the GFP signal was observed in the appressoria. During invasive growth in host cells, MoPAS1:GFP was found to be fully expressed in not only the appressoria but also invasive hyphae, suggesting that MoPAS may contribute to disease development in host cells. These results expand our knowledge of the roles of PAS-containing regulatory genes in the plant-pathogenic fungus M. oryzae.
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Affiliation(s)
- Jong-Hwan Shin
- Division of Bio-Resource Sciences and BioHerb Research Institute, Kangwon National University, Chuncheon, Korea
| | - Adiyantara Gumilang
- Division of Bio-Resource Sciences and BioHerb Research Institute, Kangwon National University, Chuncheon, Korea
| | - Moon-Jong Kim
- Division of Bio-Resource Sciences and BioHerb Research Institute, Kangwon National University, Chuncheon, Korea
| | - Joon-Hee Han
- Division of Bio-Resource Sciences and BioHerb Research Institute, Kangwon National University, Chuncheon, Korea
| | - Kyoung Su Kim
- Division of Bio-Resource Sciences and BioHerb Research Institute, Kangwon National University, Chuncheon, Korea
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Aboelfotoh Hendy A, Xing J, Chen X, Chen X. The farnesyltransferase β-subunit RAM1 regulates localization of RAS proteins and appressorium-mediated infection in Magnaporthe oryzae. MOLECULAR PLANT PATHOLOGY 2019; 20:1264-1278. [PMID: 31250536 PMCID: PMC6715606 DOI: 10.1111/mpp.12838] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Post-translational farnesylation can regulate subcellular localization and protein-protein interaction in eukaryotes. The function of farnesylation is not well identified in plant pathogenic fungi, particularly during the process of fungal infection. Here, through functional analyses of the farnesyltransferase β-subunit gene, RAM1, we examine the importance of protein farnesylation in the rice blast fungus Magnaporthe oryzae. Targeted disruption of RAM1 resulted in the reduction of hyphal growth and sporulation, and an increase in the sensitivity to various stresses. Importantly, loss of RAM1 also led to the attenuation of virulence on the plant host, characterized by decreased appressorium formation and invasive growth. Interestingly, the defect in appressoria formation of the Δram1 mutant can be recovered by adding exogenous cAMP and IBMX, suggesting that RAM1 functions upstream of the cAMP signalling pathway. We found that two Ras GTPases, RAS1 and RAS2, can interact with Ram1, and their plasma membrane localization was regulated by Ram1 through their C-terminal farnesylation sites. Adding a farnesyltransferase inhibitor Tipifarnib can result in similar defects as in Δram1 mutant, including decreased appressorium formation and invasive growth, as well as mislocalized RAS proteins. Our findings indicate that protein farnesylation regulates the RAS protein-mediated signaling pathways required for appressorium formation and host infection, and suggest that abolishing farnesyltransferase could be an effective strategy for disease control.
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Affiliation(s)
- Ahmed Aboelfotoh Hendy
- The Provincial Key Lab of Plant Pathology of Hubei Province, College of Plant Science and TechnologyHuazhong Agricultural UniversityWuhan430070China
- Department of Agricultural Botany, Faculty of Agriculture (Saba Basha)Alexandria UniversityAlexandria21531Egypt
| | - Junjie Xing
- State Key Laboratory of Hybrid RiceHunan Hybrid Rice Research CenterChangsha410125China
| | - Xiaoyang Chen
- The Provincial Key Lab of Plant Pathology of Hubei Province, College of Plant Science and TechnologyHuazhong Agricultural UniversityWuhan430070China
| | - Xiao‐Lin Chen
- The Provincial Key Lab of Plant Pathology of Hubei Province, College of Plant Science and TechnologyHuazhong Agricultural UniversityWuhan430070China
- State Key Laboratory of Hybrid RiceHunan Hybrid Rice Research CenterChangsha410125China
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