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Jayaprakash A, Roy A, Thanmalagan RR, Arunachalam A, P T V L. Understanding the mechanism of pathogenicity through interactome studies between Arachis hypogaea L. and Aspergillus flavus. J Proteomics 2023; 287:104975. [PMID: 37482270 DOI: 10.1016/j.jprot.2023.104975] [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: 02/06/2023] [Revised: 06/28/2023] [Accepted: 07/15/2023] [Indexed: 07/25/2023]
Abstract
Aspergillus flavus (A. flavus) infects the peanut seeds during pre-and post-harvest stages, causing seed quality destruction for humans and livestock consumption. Even though many resistant varieties were developed, the molecular mechanism of defense interactions of peanut against A. flavus still needs further investigation. Hence, an interologous host-pathogen protein interaction (HPPI) network was constructed to understand the subcellular level interaction mechanism between peanut and A. flavus. Out of the top 10 hub proteins of both organisms, protein phosphatase 2C and cyclic nucleotide-binding/kinase domain-containing protein and different ribosomal proteins were identified as candidate proteins involved in defense. Functional annotation and subcellular localization based characterization of HPPI identified protein SGT1 homolog, calmodulin and Rac-like GTP-binding proteins to be involved in defense response against fungus. The relevance of HPPI in infectious conditions was assessed using two transcriptome data which identified the interplay of host kinase class R proteins, bHLH TFs and cell wall related proteins to impart resistance against pathogen infection. Further, the pathogenicity analysis identified glycogen phosphorylase and molecular chaperone and allergen Mod-E/Hsp90/Hsp1 as potential pathogen targets to enhance the host defense mechanism. Hence, the computationally predicted host-pathogen PPI network could provide valuable support for molecular biology experiments to understand the host-pathogen interaction. SIGNIFICANCE: Protein-protein interactions execute significant cellular interactions in an organism and are influenced majorly by stress conditions. Here we reported the host-pathogen protein-protein interaction between peanut and A. flavus, and a detailed network analysis based on function, subcellular localization, gene co-expression, and pathogenicity was performed. The network analysis identified key proteins such as host kinase class R proteins, calmodulin, SGT1 homolog, Rac-like GTP-binding proteins bHLH TFs and cell wall related to impart resistance against pathogen infection. We observed the interplay of defense related proteins and cell wall related proteins predominantly, which could be subjected to further studies. The network analysis described in this study could be applied to understand other host-pathogen systems generally.
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Affiliation(s)
- Aiswarya Jayaprakash
- Department of Bioinformatics, School of Life Sciences, Pondicherry University, R. V. Nagar Kalapet, Pondicherry 605014, India
| | - Abhijeet Roy
- Department of Bioinformatics, School of Life Sciences, Pondicherry University, R. V. Nagar Kalapet, Pondicherry 605014, India
| | - Raja Rajeswary Thanmalagan
- Department of Bioinformatics, School of Life Sciences, Pondicherry University, R. V. Nagar Kalapet, Pondicherry 605014, India
| | - Annamalai Arunachalam
- Department of Food Science & Technology, School of Life Sciences, Pondicherry University, R. V. Nagar Kalapet, Pondicherry 605014, India
| | - Lakshmi P T V
- Department of Bioinformatics, School of Life Sciences, Pondicherry University, R. V. Nagar Kalapet, Pondicherry 605014, India.
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Zhu M, Liu Y, Yang X, Zhu L, Shen Y, Duan S, Yang J. p21-activated kinase is involved in the sporulation, pathogenicity, and stress response of Arthrobotrys oligospora under the indirect regulation of Rho GTPase-activating protein. Front Microbiol 2023; 14:1235283. [PMID: 37779704 PMCID: PMC10537225 DOI: 10.3389/fmicb.2023.1235283] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Accepted: 09/04/2023] [Indexed: 10/03/2023] Open
Abstract
The p21-GTPase-activated protein kinases (PAKs) participate in signal transduction downstream of Rho GTPases, which are regulated by Rho GTPase-activating proteins (Rho-GAP). Herein, we characterized two orthologous Rho-GAPs (AoRga1 and AoRga2) and two PAKs (AoPak1 and AoPak2) through bioinformatics analysis and reverse genetics in Arthrobotrys oligospora, a typical nematode-trapping (NT) fungus. The transcription analyses performed at different development stages suggested that Aopaks and Aorga1 play a crucial role during sporulation and trap formation, respectively. In addition, we successfully deleted Aopak1 and Aorga1 via the homologous recombination method. The disruption of Aopak1 and Aorga1 caused a remarkable reduction in spore yield and the number of nuclei per cell, but did not affect mycelial growth. In ∆Aopak1 mutants, the trap number was decreased at 48 h after the introduction of nematodes, but nematode predatory efficiency was not affected because the extracellular proteolytic activity was increased. On the contrary, the number of traps in ∆Aorga1 mutants was significantly increased at 36 h and 48 h. In addition, Aopak1 and Aorga1 had different effects on the sensitivity to cell-wall-disturbing reagent and oxidant. A yeast two-hybrid assay revealed that AoPak1 and AoRga1 both interacted with AoRac, and AoPak1 also interacted with AoCdc42. Furthermore, the Aopaks were up-regulated in ∆Aorga1 mutants, and Aorga1 was down-regulated in ∆Aopak1 mutants. These results reveal that AoRga1 indirectly regulated AoPAKs by regulating small GTPases.
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Affiliation(s)
- Meichen Zhu
- State Key Laboratory for Conservation and Utilization of Bio-Resources and Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming, China
- School of Life Sciences, Yunnan University, Kunming, China
| | - Yankun Liu
- State Key Laboratory for Conservation and Utilization of Bio-Resources and Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming, China
- School of Life Sciences, Yunnan University, Kunming, China
| | - Xuewei Yang
- State Key Laboratory for Conservation and Utilization of Bio-Resources and Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming, China
- School of Life Sciences, Yunnan University, Kunming, China
| | - Lirong Zhu
- State Key Laboratory for Conservation and Utilization of Bio-Resources and Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming, China
- School of Life Sciences, Yunnan University, Kunming, China
| | - Yanmei Shen
- State Key Laboratory for Conservation and Utilization of Bio-Resources and Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming, China
- School of Life Sciences, Yunnan University, Kunming, China
| | - Shipeng Duan
- State Key Laboratory for Conservation and Utilization of Bio-Resources and Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming, China
- School of Life Sciences, Yunnan University, Kunming, China
| | - Jinkui Yang
- State Key Laboratory for Conservation and Utilization of Bio-Resources and Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming, China
- School of Life Sciences, Yunnan University, Kunming, China
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3
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Guo C, Yang X, Shi H, Chen C, Hu Z, Zheng X, Yang X, Xie C. Identification of VdASP F2-interacting protein as a regulator of microsclerotial formation in Verticillium dahliae. Microb Biotechnol 2022; 15:2040-2054. [PMID: 35478269 PMCID: PMC9249328 DOI: 10.1111/1751-7915.14066] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 04/12/2022] [Accepted: 04/15/2022] [Indexed: 12/15/2022] Open
Abstract
Verticillium dahliae, a notorious phytopathogenic fungus, causes vascular wilt diseases in many plant species. The melanized microsclerotia enable V. dahliae to survive for years in soil and are crucial for its disease cycle. In a previous study, we characterized the secretory protein VdASP F2 from V. dahliae and found that VdASP F2 deletion significantly affected the formation of microsclerotia under adverse environmental conditions. In this study, we clarified that VdASP F2 is localized to the cell wall. However, the underlying mechanism of VdASP F2 in microsclerotial formation remains unclear. Transmembrane ion channel protein VdTRP was identified as a candidate protein that interacts with VdASP F2 using pull‐down assays followed by liquid chromatography‐tandem mass spectrometry (LC‐MS/MS) analysis, and interaction of VdASP F2 and VdTRP was confirmed by bimolecular fluorescence complementary and coimmunoprecipitation assays. The deletion mutant was analysed to reveal that VdTRP is required for microsclerotial production, but it is not essential for stress resistance, carbon utilization and pathogenicity of V. dahliae. RNA‐seq revealed some differentially expressed genes related to melanin synthesis and microsclerotial formation were significantly downregulated in the VdTRP deletion mutants. Taken together, these results indicate that VdASP F2 regulates the formation of melanized microsclerotia by interacting with VdTRP.
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Affiliation(s)
- Cuimei Guo
- The Chongqing Key Laboratory of Molecular Biology of Plant Environmental Adaptations, Chongqing Normal University, Chongqing, 401331, China.,Chongqing Engineering Research Center of Specialty Crop Resources and The College of Life Science, Chongqing Normal University, Chongqing, 401331, China
| | - Xing Yang
- The Chongqing Key Laboratory of Molecular Biology of Plant Environmental Adaptations, Chongqing Normal University, Chongqing, 401331, China.,Chongqing Engineering Research Center of Specialty Crop Resources and The College of Life Science, Chongqing Normal University, Chongqing, 401331, China
| | - Hongli Shi
- The Chongqing Key Laboratory of Molecular Biology of Plant Environmental Adaptations, Chongqing Normal University, Chongqing, 401331, China.,Chongqing Engineering Research Center of Specialty Crop Resources and The College of Life Science, Chongqing Normal University, Chongqing, 401331, China
| | - Chi Chen
- The Chongqing Key Laboratory of Molecular Biology of Plant Environmental Adaptations, Chongqing Normal University, Chongqing, 401331, China.,Chongqing Engineering Research Center of Specialty Crop Resources and The College of Life Science, Chongqing Normal University, Chongqing, 401331, China
| | - Zhijuan Hu
- The Chongqing Key Laboratory of Molecular Biology of Plant Environmental Adaptations, Chongqing Normal University, Chongqing, 401331, China.,Chongqing Engineering Research Center of Specialty Crop Resources and The College of Life Science, Chongqing Normal University, Chongqing, 401331, China
| | - Xinyao Zheng
- The Chongqing Key Laboratory of Molecular Biology of Plant Environmental Adaptations, Chongqing Normal University, Chongqing, 401331, China.,Chongqing Engineering Research Center of Specialty Crop Resources and The College of Life Science, Chongqing Normal University, Chongqing, 401331, China
| | - Xingyong Yang
- College of Pharmacy, Chengdu University, Chengdu, 610106, China
| | - Chengjian Xie
- The Chongqing Key Laboratory of Molecular Biology of Plant Environmental Adaptations, Chongqing Normal University, Chongqing, 401331, China.,Chongqing Engineering Research Center of Specialty Crop Resources and The College of Life Science, Chongqing Normal University, Chongqing, 401331, China
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Taylor JT, Harting R, Shalaby S, Kenerley CM, Braus GH, Horwitz BA. Adhesion as a Focus in Trichoderma-Root Interactions. J Fungi (Basel) 2022; 8:372. [PMID: 35448603 PMCID: PMC9026816 DOI: 10.3390/jof8040372] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 03/31/2022] [Accepted: 04/03/2022] [Indexed: 02/06/2023] Open
Abstract
Fungal spores, germlings, and mycelia adhere to substrates, including host tissues. The adhesive forces depend on the substrate and on the adhesins, the fungal cell surface proteins. Attachment is often a prerequisite for the invasion of the host, hence its importance. Adhesion visibly precedes colonization of root surfaces and outer cortex layers, but little is known about the molecular details. We propose that by starting from what is already known from other fungi, including yeast and other filamentous pathogens and symbionts, the mechanism and function of Trichoderma adhesion will become accessible. There is a sequence, and perhaps functional, homology to other rhizosphere-competent Sordariomycetes. Specifically, Verticillium dahliae is a soil-borne pathogen that establishes itself in the xylem and causes destructive wilt disease. Metarhizium species are best-known as insect pathogens with biocontrol potential, but they also colonize roots. Verticillium orthologs of the yeast Flo8 transcription factor, Som1, and several other relevant genes are already under study for their roles in adhesion. Metarhizium encodes relevant adhesins. Trichoderma virens encodes homologs of Som1, as well as adhesin candidates. These genes should provide exciting leads toward the first step in the establishment of beneficial interactions with roots in the rhizosphere.
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Affiliation(s)
- James T. Taylor
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX 77843, USA; (J.T.T.); (C.M.K.)
| | - Rebekka Harting
- Department of Molecular Microbiology and Genetics, Institute of Microbiology and Genetics, University of Göttingen, 37077 Göttingen, Germany; (R.H.); (G.H.B.)
| | - Samer Shalaby
- Faculty of Biology, Technion—Israel Institute of Technology, Haifa 3200000, Israel;
| | - Charles M. Kenerley
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX 77843, USA; (J.T.T.); (C.M.K.)
| | - Gerhard H. Braus
- Department of Molecular Microbiology and Genetics, Institute of Microbiology and Genetics, University of Göttingen, 37077 Göttingen, Germany; (R.H.); (G.H.B.)
| | - Benjamin A. Horwitz
- Faculty of Biology, Technion—Israel Institute of Technology, Haifa 3200000, Israel;
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The sat1 Gene Is Required for the Growth and Virulence of the Human Pathogenic Fungus Aspergillus fumigatus. Microbiol Spectr 2022; 10:e0155821. [PMID: 35107385 PMCID: PMC8809347 DOI: 10.1128/spectrum.01558-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Aspergillus fumigatus is an important opportunistic pathogenic fungus that causes invasive aspergillosis in immunocompromised humans. Regulated fungal growth is essential for disease development and progression. Thus, screening for genes that regulate fungal growth may lead to the identification of potential therapeutic targets for invasive aspergillosis (IA). Screening of the transfer DNA (T-DNA) random-insertion A. fumigatus mutants identified a severe growth deficiency mutant AFM2954 and featured sat1 as the mutated gene described as a putative intracellular protein transporter of unknown function. The deletion of sat1 exhibited severe growth defects and significantly increased the nematode and mouse survival rates and decreased the fungal loads and histopathological damages in mouse lungs. Transcriptomic analyses revealed expression changes associated with the cell wall synthesis, the tricarboxylic acid cycle (TCA cycle), and oxidative phosphorylation genes in the sat1 mutant. Deletion of the gene resulted in resistance to cell wall-perturbing agents and thickened cell wall as well as reduced ATP contents and mitochondrial membrane potential, suggested that sat1 affected the cell wall synthesis and mitochondrial function of A. fumigatus. All together, our study uncovered novel functions of sat1 in growth and virulence of A. fumigatus and provided a theoretical basis for the development of new therapeutic target for treating IA patients. IMPORTANCE Aspergillus fumigatus is the main causative agent of invasive aspergillosis in immunocompromised hosts, with up to 90% lethality. Nevertheless, the fungal factors that regulate the pathogenesis of A. fumigatus remain largely unknown. Better understanding of the mechanisms controlling growth of A. fumigatus may provide novel therapeutic targets. In the present study, we characterized sat1 in the opportunistic pathogen A. fumigatus. The function of sat1 remains unknown. We proved its important role in growth and virulence, likely because of its effects on cell wall synthesis and mitochondrial functions.
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6
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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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Role of Exopolygalacturonase-Related Genes in Potato- Verticillium dahliae Interaction. Pathogens 2021; 10:pathogens10060642. [PMID: 34071016 PMCID: PMC8224799 DOI: 10.3390/pathogens10060642] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 05/18/2021] [Accepted: 05/20/2021] [Indexed: 11/17/2022] Open
Abstract
Verticillium dahliae is a hemibiotrophic pathogen responsible for great losses in dicot crop production. An ExoPG gene (VDAG_03463,) identified using subtractive hybridization/cDNA-AFLP, showed higher expression levels in highly aggressive than in weakly aggressive V. dahliae isolates. We used a vector-free split-marker recombination method with PEG-mediated protoplast to delete the ExoPG gene in V. dahliae. This is the first instance of using this method for V. dahliae transformation. Only two PCR steps and one transformation step were required, markedly reducing the necessary time for gene deletion. Six mutants were identified. ExoPG expressed more in the highly aggressive than in the weakly aggressive isolate in response to potato leaf and stem extracts. Its expression increased in both isolates during infection, with higher levels in the highly aggressive isolate at early infection stages. The disruption of ExoPG did not influence virulence, nor did it affect total exopolygalacturonase activity in V. dahliae. Full genome analysis showed 8 more genes related to polygalacturonase/pectinase activity in V. dahliae. Transcripts of PGA increased in the △exopg mutant in response to potato leaf extracts, compared to the wild type. The expression pattern of those eight genes showed similar trends in the △exopg mutant and in the weakly aggressive isolate in response to potato extracts, but without the increase of PGA in the weakly aggressive isolate to leaf extracts. This indicated that the △exopg mutant of V. dahliae compensated by the suppression of ExoPG by activating other related gene.
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Gene Expression of Putative Pathogenicity-Related Genes in Verticillium dahliae in Response to Elicitation with Potato Extracts and during Infection Using Quantitative Real-Time PCR. Pathogens 2021; 10:pathogens10050510. [PMID: 33922492 PMCID: PMC8146963 DOI: 10.3390/pathogens10050510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 04/19/2021] [Accepted: 04/21/2021] [Indexed: 11/17/2022] Open
Abstract
Quantitative real-time PCR was used to monitor the expression of 15 Verticillium dahliae's genes, putatively involved in pathogenicity, highly (HAV) and weakly aggressive (WAV) V. dahliae isolates after either (i) elicitation with potato leaf, stem, or root extracts, or (ii) inoculation of potato detached petioles. These genes, i.e., coding for Ras-GAP-like protein, serine/threonine protein kinase, Ubiquitin-conjugating enzyme variant-MMS2, NADH-ubiquinone oxidoreductase, Thioredoxin, Pyruvate dehydrogenase E1 VdPDHB, myo-inositol 2-dehydrogenase, and HAD-superfamily hydrolase, showed differential upregulation in the HAV versus WAV isolate in response to plant extracts or after inoculation of potato leaf petioles. This suggests their potential involvement in the observed differential aggressiveness between isolates. However, other genes like glucan endo-1,3-alpha-glucosidase and nuc-1 negative regulatory protein VdPREG showed higher activity in the WAV than in the HAV in response to potato extracts and/or during infection. This, in contrast, may suggest a role in their lower aggressiveness. These findings, along with future functional analysis of selected genes, will contribute to improving our understanding of V. dahliae's pathogenesis. For example, expression of VdPREG negatively regulates phosphorus-acquisition enzymes, which may indicate a lower phosphorus acquisition activity in the WAV. Therefore, integrating the knowledge about the activity of both genes enhancing pathogenicity and those restraining it will provide a guild line for further functional characterization of the most critical genes, thus driving new ideas towards better Verticillium wilt management.
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Märker R, Blank-Landeshammer B, Beier-Rosberger A, Sickmann A, Kück U. Phosphoproteomic analysis of STRIPAK mutants identifies a conserved serine phosphorylation site in PAK kinase CLA4 to be important in fungal sexual development and polarized growth. Mol Microbiol 2020; 113:1053-1069. [PMID: 32022307 DOI: 10.1111/mmi.14475] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Revised: 01/16/2020] [Accepted: 01/20/2020] [Indexed: 02/06/2023]
Abstract
The highly conserved striatin-interacting phosphatases and kinases (STRIPAK) complex regulates phosphorylation/dephosphorylation of developmental proteins in eukaryotic microorganisms, animals and humans. To first identify potential targets of STRIPAK, we performed extensive isobaric tags for relative and absolute quantification-based proteomic and phosphoproteomic analyses in the filamentous fungus Sordaria macrospora. In total, we identified 4,193 proteins and 2,489 phosphoproteins, which are represented by 10,635 phosphopeptides. By comparing phosphorylation data from wild type and mutants, we identified 228 phosphoproteins to be regulated in all three STRIPAK mutants, thus representing potential targets of STRIPAK. To provide an exemplarily functional analysis of a STRIPAK-dependent phosphorylated protein, we selected CLA4, a member of the conserved p21-activated kinase family. Functional characterization of the ∆cla4 deletion strain showed that CLA4 controls sexual development and polarized growth. To determine the functional relevance of CLA4 phosphorylation and the impact of specific phosphorylation sites on development, we next generated phosphomimetic and -deficient variants of CLA4. This analysis identified (de)phosphorylation of a highly conserved serine (S685) residue in the catalytic domain of CLA4 as being important for fungal cellular development. Collectively, these analyses significantly contribute to the understanding of the mechanistic function of STRIPAK as a phosphatase and kinase signaling complex.
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Affiliation(s)
- Ramona Märker
- Lehrstuhl für Allgemeine und Molekulare Botanik, Ruhr-Universität, Bochum, Germany
| | | | - Anna Beier-Rosberger
- Lehrstuhl für Allgemeine und Molekulare Botanik, Ruhr-Universität, Bochum, Germany
| | - Albert Sickmann
- Leibniz-Institut für Analytische Wissenschaften-ISAS-e.V., Dortmund, Germany
| | - Ulrich Kück
- Lehrstuhl für Allgemeine und Molekulare Botanik, Ruhr-Universität, Bochum, Germany
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11
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Li X, Su X, Lu G, Sun G, Zhang Z, Guo H, Guo N, Cheng H. VdOGDH is involved in energy metabolism and required for virulence of Verticillium dahliae. Curr Genet 2019; 66:345-359. [PMID: 31422448 DOI: 10.1007/s00294-019-01025-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Revised: 07/28/2019] [Accepted: 08/08/2019] [Indexed: 01/21/2023]
Abstract
Verticillium dahliae, a soil-borne fungus, can invade plant vascular tissue and cause Verticillium wilt. The enzyme α-oxoglutarate dehydrogenase (OGDH), catalyzing the oxidation of α-oxoglutarate in the tricarboxylic acid cycle (TCA), is vital for energy metabolism in the fungi. Here, we identified the OGDH gene in V. dahliae (VdOGDH, VDAG_10018) and investigated its function in virulence by generating gene deletion mutants (ΔVdOGDH) and complementary mutants (ΔVdOGDH-C). When the ΔVdOGDH mutants were supplemented with different carbon sources, vegetative growth on Czapek Dox medium was significantly impaired, suggesting that VdOGDH is crucial for vegetative growth and carbon utilization. Conidia of the ΔVdOGDH mutants were atypically rounded or spherical, and hyphae were irregularly branched and lacked typical whorled branches. Mutants ΔVdOGDH-1 and ΔVdOGDH-2 were highly sensitive to H2O2 in the medium plates and had higher intracellular ROS levels. ΔVdOGDH mutants also had elevated expression of oxidative response-related genes, indicating that VdOGDH is involved in response to oxidative stress. In addition, the disruption of VdOGDH caused a significant increase in the expression of energy metabolism-related genes VdICL, VdICDH, VdMDH, and VdPDH and melanin-related genes Vayg1, VdSCD, VdLAC, VT4HR, and VaflM in the ΔVdOGDH mutants; thus, VdOGDH is also important for energy metabolism and melanin accumulation. Cotton plants inoculated with ΔVdOGDH mutants exhibited mild leaf chlorosis and the disease index was lower compared with wild type and ΔVdOGDH-C strains. These results together show that VdOGDH involved in energy metabolism of V. dahliae, is also essential for full virulence by regulating multiple fungal developmental factors.
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Affiliation(s)
- Xiaokang Li
- School of Life Science, Anhui Agricultural University, Hefei, 230036, China.,Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Xiaofeng Su
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Guoqing Lu
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Guoqing Sun
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Zhuo Zhang
- Hunan Plant Protection Institute, Hunan Academy of Agricultural Sciences, Changsha, 410125, China
| | - Huiming Guo
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Ning Guo
- School of Life Science, Anhui Agricultural University, Hefei, 230036, China.
| | - Hongmei Cheng
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
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12
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Kitade Y, Sumita T, Izumitsu K, Tanaka C. Cla4 PAK-like kinase is required for pathogenesis, asexual/sexual development and polarized growth in Bipolaris maydis. Curr Genet 2019; 65:1229-1242. [DOI: 10.1007/s00294-019-00977-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 04/10/2019] [Accepted: 04/16/2019] [Indexed: 12/23/2022]
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13
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Hühn J, Musielak M, Schmitz HP, Heinisch JJ. Fungal homologues of human Rac1 as emerging players in signal transduction and morphogenesis. Int Microbiol 2019; 23:43-53. [PMID: 31020478 DOI: 10.1007/s10123-019-00077-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 03/28/2019] [Accepted: 04/02/2019] [Indexed: 02/06/2023]
Abstract
A wealth of data is accumulating on the physiological functions of human Rac1, a member of the Rho GTPase family of molecular switches and substrate of botulinum toxin, which was first identified as a regulator of cell motility through its effect on the actin cytoskeleton. Later on, it was found to be involved in different diseases like cancers, cardiac function, neuronal disorders, and apoptotic cell death. Despite the presence of Rac1 homologues in most fungi investigated so far, including Rho5 in the genetically tractable model yeast Saccharomyces cerevisiae, knowledge on their physiological functions is still scarce, let alone the details of the molecular mechanisms of their actions and interactions. Nevertheless, all functions proposed for human Rac1 seem to be conserved in one or the other fungus. This includes the regulation of MAPK cascades, polarized growth, and actin dynamics. Moreover, both the production and response to reactive oxygen species, as well as the reaction to nutrient availability, can be affected. We here summarize the studies performed on fungal Rac1 homologues, with a special focus on S. cerevisiae Rho5, which may be of use in drug development in medicine and agriculture.
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Affiliation(s)
- Julia Hühn
- Department of Biology and Chemistry, Genetics group, University of Osnabrück, Barbarastrasse 11, 49076, Osnabrück, Germany
| | - Marius Musielak
- Department of Biology and Chemistry, Genetics group, University of Osnabrück, Barbarastrasse 11, 49076, Osnabrück, Germany
| | - Hans-Peter Schmitz
- Department of Biology and Chemistry, Genetics group, University of Osnabrück, Barbarastrasse 11, 49076, Osnabrück, Germany
| | - Jürgen J Heinisch
- Department of Biology and Chemistry, Genetics group, University of Osnabrück, Barbarastrasse 11, 49076, Osnabrück, Germany.
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14
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Qin J, Wang K, Sun L, Xing H, Wang S, Li L, Chen S, Guo HS, Zhang J. The plant-specific transcription factors CBP60g and SARD1 are targeted by a Verticillium secretory protein VdSCP41 to modulate immunity. eLife 2018; 7:34902. [PMID: 29757140 PMCID: PMC5993538 DOI: 10.7554/elife.34902] [Citation(s) in RCA: 87] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Accepted: 05/11/2018] [Indexed: 11/13/2022] Open
Abstract
The vascular pathogen Verticillium dahliae infects the roots of plants to cause Verticillium wilt. The molecular mechanisms underlying V. dahliae virulence and host resistance remain elusive. Here, we demonstrate that a secretory protein, VdSCP41, functions as an intracellular effector that promotes V. dahliae virulence. The Arabidopsis master immune regulators CBP60g and SARD1 and cotton GhCBP60b are targeted by VdSCP41. VdSCP41 binds the C-terminal portion of CBP60g to inhibit its transcription factor activity. Further analyses reveal a transcription activation domain within CBP60g that is required for VdSCP41 targeting. Mutations in both CBP60g and SARD1 compromise Arabidopsis resistance against V. dahliae and partially impair VdSCP41-mediated virulence. Moreover, virus-induced silencing of GhCBP60b compromises cotton resistance to V. dahliae. This work uncovers a virulence strategy in which the V. dahliae secretory protein VdSCP41 directly targets plant transcription factors to inhibit immunity, and reveals CBP60g, SARD1 and GhCBP60b as crucial components governing V. dahliae resistance. Like animals, plants have an immune system to protect themselves from disease. When a plant detects a disease-causing microbe, proteins that serve as master regulators of its immune system activate defense-related genes. Yet some microbes can overcome these defenses and successfully infect plants. Verticillium dahliae is a fungus, found in soil, that infects the roots of many plants – including cotton, tomatoes and potatoes. Infection by this fungus causes the leaves to curl and discolor, and the plant to wilt. The V. dahliae fungus releases, or secretes, nearly 800 proteins during an infection. Yet it remains unknown if and how any of these proteins help the fungus to infect plants. A better understanding of how V. dahliae impairs plant immunity to infect its hosts could give insights into ways to improve plant resistance against this fungus. Now, Qin et al. show that a secreted protein called VdSCP41 promotes V. dahliae infection in both cotton and Arabidopsis plants. Further experiments showed that after leaving the fungus, VdSCP41 enters into the plant’s own cells. Protein-protein interaction and biochemical studies then indicated VdSCP41 associates with a master immune regulator in Arabidopsis called CBP60g. This interaction interferes with CBP60g’s ability to activate the defense-related genes. Now that this role for VdSCP41 has been confirmed, the next step would be to see if targeting it would make plants more resistant to this fungus. One approach would be to genetically engineer plants so that they can specifically shut down, or ‘silence’, the fungal gene that encodes for this protein. Further experiments are required to see whether using this technique – known as host-induced gene silencing (or HIGS for short) – against VdSCP41would enhance plant resistance to V. dahliae. If it does prove effective, this approach may eventually reduce the need for chemical pesticides to protect crop plants.
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Affiliation(s)
- Jun Qin
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Kailun Wang
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Lifan Sun
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Haiying Xing
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Sheng Wang
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Lin Li
- National Institute of Biological Sciences, Beijing, China
| | - She Chen
- National Institute of Biological Sciences, Beijing, China
| | - Hui-Shan Guo
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Jie Zhang
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
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15
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Feng Z, Tian J, Han L, Geng Y, Sun J, Kong Z. The Myosin5-mediated actomyosin motility system is required for Verticillium
pathogenesis of cotton. Environ Microbiol 2018; 20:1607-1621. [DOI: 10.1111/1462-2920.14101] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Revised: 03/05/2018] [Accepted: 03/11/2018] [Indexed: 11/30/2022]
Affiliation(s)
- Zhidi Feng
- The Key Laboratory of Oasis Eco-Agriculture; College of Agriculture, Shihezi University; Shihezi Xinjiang 832000 China
- State Key Laboratory of Plant Genomic; Institute of Microbiology, Chinese Academy of Sciences; Beijing 100101 China
| | - Juan Tian
- State Key Laboratory of Plant Genomic; Institute of Microbiology, Chinese Academy of Sciences; Beijing 100101 China
| | - Libo Han
- State Key Laboratory of Plant Genomic; Institute of Microbiology, Chinese Academy of Sciences; Beijing 100101 China
| | - Yuan Geng
- State Key Laboratory of Plant Genomic; Institute of Microbiology, Chinese Academy of Sciences; Beijing 100101 China
| | - Jie Sun
- The Key Laboratory of Oasis Eco-Agriculture; College of Agriculture, Shihezi University; Shihezi Xinjiang 832000 China
| | - Zhaosheng Kong
- State Key Laboratory of Plant Genomic; Institute of Microbiology, Chinese Academy of Sciences; Beijing 100101 China
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16
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VdPLP, A Patatin-Like Phospholipase in Verticillium dahliae, Is Involved in Cell Wall Integrity and Required for Pathogenicity. Genes (Basel) 2018. [PMID: 29534051 PMCID: PMC5867883 DOI: 10.3390/genes9030162] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The soil-borne ascomycete fungus Verticillium dahliae causes vascular wilt disease and can seriously diminish the yield and quality of important crops. Functional analysis of growth- and pathogenicity-related genes is essential for revealing the pathogenic molecular mechanism of V. dahliae. Phospholipase is an important virulence factor in fungi that hydrolyzes phospholipids into fatty acid and other lipophilic substances and is involved in hyphal development. Thus far, only a few V. dahliae phospholipases have been identified, and their involvement in V. dahliae development and pathogenicity remains unknown. In this study, the function of the patatin-like phospholipase gene in V. dahliae (VdPLP, VDAG_00942) is characterized by generating gene knockout and complementary mutants. Vegetative growth and conidiation of VdPLP deletion mutants (ΔVdPLP) were significantly reduced compared with wild type and complementary strains, but more microsclerotia formed. The ΔVdPLP mutants were very sensitive to the cell-wall-perturbing agents: calcofluor white (CFW) and Congo red (CR). The transcriptional level of genes related to the cell wall integrity (CWI) pathway and chitin synthesis were downregulated, suggesting that VdPLP has a pivotal role in the CWI pathway and chitin synthesis in V. dahliae. ΔVdPLP strains were distinctly impaired in in their virulence and ability to colonize Nicotiana benthamiana roots. Our results demonstrate that VdPLP regulates hyphal growth and conidial production and is involved in stabilizing the cell wall, thus mediating the pathogenicity of V. dahliae.
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17
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Minz-Dub A, Sharon A. The Botrytis cinerea PAK kinase BcCla4 mediates morphogenesis, growth and cell cycle regulating processes downstream of BcRac. Mol Microbiol 2017; 104:487-498. [PMID: 28164413 DOI: 10.1111/mmi.13642] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/31/2017] [Indexed: 12/24/2022]
Abstract
Rac proteins are involved in a variety of cellular processes. Effector proteins that interact with active Rac convey the GTPase-generated signal to downstream developmental cascades and processes. Here we report on the analysis of the main effector and signal cascade downstream of BcRac, the Rac homolog of the grey mold fungus Botrytis cinerea. Several lines of evidence highlighted the p21-activated kinase Cla4 as an important effector of Rac in fungi. Analysis of Δbccla4 strains revealed that the BcCla4 protein was sufficient to mediate all of the examined BcRac-driven processes, including hyphal growth and morphogenesis, conidia production and pathogenicity. In addition, the Δbccla4 strains had altered nuclei content, a phenomenon that was previously observed in Δbcrac isolates, thus connecting the BcRac/BcCla4 module with cell cycle control. Further analyses revealed that BcRac/BcCla4 control mitotic entry through changes in phosphorylation status of the cyclin dependent kinase BcCdk1. The complete cascade includes the kinase BcWee1, which is downstream of BcCla4 and upstream of BcCdk1. These results provide a mechanistic insight on the connection of cell cycle, morphogenesis and pathogenicity in fungi, and position BcCla4 as the most essential effector and central regulator of all of these processes downstream of BcRac.
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Affiliation(s)
- Anna Minz-Dub
- Department of Molecular Biology and Ecology of Plants, Tel Aviv University, Tel Aviv 69978, Israel
| | - Amir Sharon
- Department of Molecular Biology and Ecology of Plants, Tel Aviv University, Tel Aviv 69978, Israel
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18
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Yuan L, Su Y, Zhou S, Feng Y, Guo W, Wang X. A RACK1-like protein regulates hyphal morphogenesis, root entry and in vivo virulence in Verticillium dahliae. Fungal Genet Biol 2017; 99:52-61. [PMID: 28089629 DOI: 10.1016/j.fgb.2017.01.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Revised: 11/28/2016] [Accepted: 01/08/2017] [Indexed: 02/07/2023]
Abstract
To identify key genes expressed in Verticillium dahliae in early stages of infection of cotton roots, spore suspensions of eight V. dahliae isolates with different virulence levels were induced by cotton roots and genes expressed in these isolates during the early stages of infection were profiled. A gene that was differentially expressed between highly and less virulent strains was identified. Cloning and bioinformatics analysis of the gene suggested that it belongs to the putative Gβ-like/RACK1 protein family, and has seven WD40 domains. Targeted deletion of the gene revealed that it controls a number of growth-related phenotypes, including conidia and microsclerotia production, normal spore germination and hyphal development. RACK1 is a component of eukaryotic ribosomes, and here we found by qRT-PCR that disruption of RACK1 in V. dahliae (designated VdRACK1) significantly altered the transcriptional levels of other ribosomal proteins, suggesting possible global effects of VdRACK1 deletion on the protein translation of other genes. VdRACK1-null mutants lost the ability to penetrate intact cotton roots. However, the mutant strain was able to infect root-wounded cotton plants and, intriguingly, resulted in a hypervirulent phenotype, implicating a role for VdRACK1 in the restriction of rampant growth within the plant.
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Affiliation(s)
- Lei Yuan
- College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Yaxin Su
- College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Shuai Zhou
- College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Yigao Feng
- State Key Laboratory of Crop Genetics & Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China
| | - Wangzhen Guo
- State Key Laboratory of Crop Genetics & Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China
| | - Xinyu Wang
- College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China.
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19
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Xiong D, Wang Y, Tian L, Tian C. MADS-Box Transcription Factor VdMcm1 Regulates Conidiation, Microsclerotia Formation, Pathogenicity, and Secondary Metabolism of Verticillium dahliae. Front Microbiol 2016; 7:1192. [PMID: 27536281 PMCID: PMC4971026 DOI: 10.3389/fmicb.2016.01192] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Accepted: 07/19/2016] [Indexed: 12/02/2022] Open
Abstract
Verticillium dahliae, a notorious phytopathogenic fungus, causes vascular wilt diseases in many plant species resulting in devastating yield losses worldwide. Due to its ability to colonize plant xylem and form microsclerotia, V. dahliae is highly persistent and difficult to control. In this study, we show that the MADS-box transcription factor VdMcm1 is a key regulator of conidiation, microsclerotia formation, virulence, and secondary metabolism of V. dahliae. In addition, our findings suggest that VdMcm1 is involved in cell wall integrity. Finally, comparative RNA-Seq analysis reveals 823 significantly downregulated genes in the VdMcm1 deletion mutant, with diverse biological functions in transcriptional regulation, plant infection, cell adhesion, secondary metabolism, transmembrane transport activity, and cell secretion. When taken together, these data suggest that VdMcm1 performs pleiotropic functions in V. dahliae.
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Affiliation(s)
- Dianguang Xiong
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University Beijing, China
| | - Yonglin Wang
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University Beijing, China
| | - Longyan Tian
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University Beijing, China
| | - Chengming Tian
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University Beijing, China
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20
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Vargas-Muñiz JM, Renshaw H, Richards AD, Waitt G, Soderblom EJ, Moseley MA, Asfaw Y, Juvvadi PR, Steinbach WJ. Dephosphorylation of the Core Septin, AspB, in a Protein Phosphatase 2A-Dependent Manner Impacts Its Localization and Function in the Fungal Pathogen Aspergillus fumigatus. Front Microbiol 2016; 7:997. [PMID: 27446037 PMCID: PMC4916205 DOI: 10.3389/fmicb.2016.00997] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Accepted: 06/10/2016] [Indexed: 12/24/2022] Open
Abstract
Septins are a conserved family of GTPases that form hetero–oligomeric complexes and perform diverse functions in higher eukaryotes, excluding plants. Our previous studies in the human fungal pathogen Aspergillus fumigatus revealed that the core septin, AspB, a CDC3 ortholog, is required for septation, conidiation, and conidial cell wall organization. Although AspB is important for these cellular functions, nothing is known about the role of kinases or phosphatases in the posttranslational regulation and localization of septins in A. fumigatus. In this study, we assessed the function of the Gin4 and Cla4 kinases and the PP2A regulatory subunit ParA, in the regulation of AspB using genetic and phosphoproteomic approaches. Gene deletion analyses revealed that Cla4 and ParA are indispensable for hyphal extension, and Gin4, Cla4, and ParA are each required for conidiation and normal septation. While deletion of gin4 resulted in larger interseptal distances and hypervirulence, a phenotype mimicking aspB deletion, deletion of cla4 and parA caused hyperseptation without impacting virulence, indicating divergent roles in regulating septation. Phosphoproteomic analyses revealed that AspB is phosphorylated at five residues in the GTPase domain (S134, S137, S247, T297, and T301) and two residues at its C-terminus (S416 and S461) in the wild-type, Δgin4 and Δcla4 strains. However, concomitant with the differential localization pattern of AspB and hyperseptation in the ΔparA strain, AspB remained phosphorylated at two additional residues, T68 in the N-terminal polybasic region and S447 in the coiled-coil domain. Generation of nonphosphorylatable and phosphomimetic strains surrounding each differentially phosphorylated residue revealed that only AspBmt-T68E showed increased interseptal distances, suggesting that dephosphorylation of T68 is important for proper septation. This study highlights the importance of septin phosphorylation/dephosphorylation in the regulation of A. fumigatus hyphal septation.
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Affiliation(s)
- José M Vargas-Muñiz
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham NC, USA
| | - Hilary Renshaw
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham NC, USA
| | - Amber D Richards
- Division of Pediatric Infectious Diseases, Department of Pediatrics, Duke University Medical Center, Durham NC, USA
| | - Greg Waitt
- Duke Proteomics and Metabolomics Core Facility, Center for Genomic and Computational Biology, Duke University, Durham NC, USA
| | - Erik J Soderblom
- Duke Proteomics and Metabolomics Core Facility, Center for Genomic and Computational Biology, Duke University, Durham NC, USA
| | - Martin A Moseley
- Duke Proteomics and Metabolomics Core Facility, Center for Genomic and Computational Biology, Duke University, Durham NC, USA
| | - Yohannes Asfaw
- Department of Laboratory Animal Resources, Duke University Medical Center, Durham NC, USA
| | - Praveen R Juvvadi
- Division of Pediatric Infectious Diseases, Department of Pediatrics, Duke University Medical Center, Durham NC, USA
| | - William J Steinbach
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, DurhamNC, USA; Division of Pediatric Infectious Diseases, Department of Pediatrics, Duke University Medical Center, DurhamNC, USA
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21
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Deng S, Wang CY, Zhang X, Wang Q, Lin L. VdNUC-2, the Key Regulator of Phosphate Responsive Signaling Pathway, Is Required for Verticillium dahliae Infection. PLoS One 2015; 10:e0145190. [PMID: 26670613 PMCID: PMC4682923 DOI: 10.1371/journal.pone.0145190] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Accepted: 12/01/2015] [Indexed: 02/07/2023] Open
Abstract
In fungal cells, a phosphate (Pi) responsive signaling and metabolism (PHO) pathway regulates Pi-homeostasis. NUC-2/PHO81 and its homologs are one of the most important components in the regulation pathway. In soil-borne phytopathogenic fungus Verticillium dahliae, we identified a Neurospora crassa nuc-2 homolog gene VdNUC-2. VdNUC-2 is composed of 1,018 amino acids, and is highly conserved in tested filamentous fungi. Under conditions of Pi-starvation, compared with the wild-type strain and ectopic complementation strains, the VdNUC-2 knocked out mutants exhibited reduced radial growth, decreased production of conidia and microsclerotia, and were more sensitive to hydrogen peroxide stress. The virulence of VdNUC-2 defective mutants was significantly compromised, and that was unable to be restored by exogenous application of extra Pi. Additionally, the deletion mutants of VdNUC-1, a key transcription factor gene positively controlled by VdNUC-2 in the PHO pathway, showed the similar cultural phenotypes as VdNUC-2 mutants when both of them grew in Pi-limited conditions. However, the virulence of VdNUC-1 mutants was comparable to the wild-type strain. These evidences indicated that the virulence reduction in VdNUC-2 mutants is not due to the interruptions in the PHO pathway or the disturbance of Pi-homeostasis in V. dahliae cytoplasm. VdNUC-2 is not only a crucial gene in the PHO pathway in V. dahliae, but also is required for the full virulence during host-infection.
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Affiliation(s)
- Sheng Deng
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Cai-yue Wang
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Xin Zhang
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Qing Wang
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Ling Lin
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, China
- * E-mail:
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