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Qin L, Gong X, Nong J, Tang X, Cui K, Zhao Y, Xia S. Histone Methyltransferase SsDim5 Regulates Fungal Virulence through H3K9 Trimethylation in Sclerotinia sclerotiorum. J Fungi (Basel) 2024; 10:271. [PMID: 38667942 PMCID: PMC11051235 DOI: 10.3390/jof10040271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Revised: 04/02/2024] [Accepted: 04/04/2024] [Indexed: 04/28/2024] Open
Abstract
Histone post-translational modification is one of the main mechanisms of epigenetic regulation, which plays a crucial role in the control of gene expression and various biological processes. However, whether or not it affects fungal virulence in Sclerotinia sclerotiorum is not clear. In this study, we identified and cloned the histone methyltransferase Defective in methylation 5 (Dim5) in S. sclerotiorum, which encodes a protein containing a typical SET domain. SsDim5 was found to be dynamically expressed during infection. Knockout experiment demonstrated that deletion of SsDim5 reduced the virulence in Ssdim5-1/Ssdim5-2 mutant strains, accompanied by a significant decrease in H3K9 trimethylation levels. Transcriptomic analysis further revealed the downregulation of genes associated with mycotoxins biosynthesis in SsDim5 deletion mutants. Additionally, the absence of SsDim5 affected the fungus's response to oxidative and osmotic, as well as cellular integrity. Together, our results indicate that the H3K9 methyltransferase SsDim5 is essential for H3K9 trimethylation, regulating fungal virulence throug mycotoxins biosynthesis, and the response to environmental stresses in S. sclerotiorum.
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Affiliation(s)
- Lei Qin
- Hunan Provincial Key Laboratory of Phytohormones and Growth Development, Hunan Agricultural University, Changsha 410128, China; (L.Q.); (X.G.); (J.N.); (X.T.); (Y.Z.)
| | - Xin Gong
- Hunan Provincial Key Laboratory of Phytohormones and Growth Development, Hunan Agricultural University, Changsha 410128, China; (L.Q.); (X.G.); (J.N.); (X.T.); (Y.Z.)
| | - Jieying Nong
- Hunan Provincial Key Laboratory of Phytohormones and Growth Development, Hunan Agricultural University, Changsha 410128, China; (L.Q.); (X.G.); (J.N.); (X.T.); (Y.Z.)
| | - Xianyu Tang
- Hunan Provincial Key Laboratory of Phytohormones and Growth Development, Hunan Agricultural University, Changsha 410128, China; (L.Q.); (X.G.); (J.N.); (X.T.); (Y.Z.)
| | - Kan Cui
- Institute of Plant Protection, Hunan Academy of Agricultural Sciences, Changsha 410125, China;
| | - Yan Zhao
- Hunan Provincial Key Laboratory of Phytohormones and Growth Development, Hunan Agricultural University, Changsha 410128, China; (L.Q.); (X.G.); (J.N.); (X.T.); (Y.Z.)
| | - Shitou Xia
- Hunan Provincial Key Laboratory of Phytohormones and Growth Development, Hunan Agricultural University, Changsha 410128, China; (L.Q.); (X.G.); (J.N.); (X.T.); (Y.Z.)
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Kramer HM, Cook DE, Seidl MF, Thomma BP. Epigenetic regulation of nuclear processes in fungal plant pathogens. PLoS Pathog 2023; 19:e1011525. [PMID: 37535497 PMCID: PMC10399791 DOI: 10.1371/journal.ppat.1011525] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/05/2023] Open
Abstract
Through the association of protein complexes to DNA, the eukaryotic nuclear genome is broadly organized into open euchromatin that is accessible for enzymes acting on DNA and condensed heterochromatin that is inaccessible. Chemical and physical alterations to chromatin may impact its organization and functionality and are therefore important regulators of nuclear processes. Studies in various fungal plant pathogens have uncovered an association between chromatin organization and expression of in planta-induced genes that are important for pathogenicity. This review discusses chromatin-based regulation mechanisms as determined in the fungal plant pathogen Verticillium dahliae and relates the importance of epigenetic transcriptional regulation and other nuclear processes more broadly in fungal plant pathogens.
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Affiliation(s)
- H. Martin Kramer
- Laboratory of Phytopathology, Wageningen University and Research, Wageningen, the Netherlands
| | - David E. Cook
- Laboratory of Phytopathology, Wageningen University and Research, Wageningen, the Netherlands
- Department of Plant Pathology, Kansas State University, Manhattan, Kansas, United States of America
| | - Michael F. Seidl
- Laboratory of Phytopathology, Wageningen University and Research, Wageningen, the Netherlands
- Theoretical Biology & Bioinformatics, Department of Biology, Utrecht University, Utrecht, the Netherlands
| | - Bart P.H.J. Thomma
- Laboratory of Phytopathology, Wageningen University and Research, Wageningen, the Netherlands
- University of Cologne, Institute for Plant Sciences, Cluster of Excellence on Plant Sciences (CEPLAS), Cologne, Germany
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Chen H, Fang Y, Song W, Shu H, Li X, Ye W, Wang Y, Dong S. The SET domain protein PsKMT3 regulates histone H3K36 trimethylation and modulates effector gene expression in the soybean pathogen Phytophthora sojae. MOLECULAR PLANT PATHOLOGY 2023; 24:346-358. [PMID: 36748674 PMCID: PMC10013772 DOI: 10.1111/mpp.13301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/20/2022] [Revised: 01/10/2023] [Accepted: 01/10/2023] [Indexed: 06/18/2023]
Abstract
Plant pathogens secrete effector proteins to overcome host immunity and promote colonization. In oomycete plant pathogens, the expression of many effector genes is altered upon infection; however, the regulatory mechanisms are unclear. In this study, we identified a su(var)3-9, enhancer of zeste, and trithorax (SET) domain protein-encoding gene, PsKMT3, that was highly induced at early infection stages in Phytophthora sojae. Deletion of PsKMT3 led to asexual development and pathogenicity defects. Chromatin immunoprecipitation followed by sequencing (ChIP-seq) and western blot analyses demonstrated that histone H3K36 trimethylation (H3K36me3) was significantly reduced genome-wide in mutants. RNA-seq analysis identified 374 genes encoding secreted proteins that were differentially expressed in pskmt3 at the mycelium stage. The significantly altered genes encompassed the RxLR (Arg-x-Lys-Arg) effector gene family, including the essential effector genes Avh23, Avh181, Avh240, and Avh241. Transcriptome analysis at early infection stages showed misregulation of effector gene expression waves in pskmt3. H3K36me3 was directly and indirectly associated with RxLR effector gene activation. Our results reveal a role of a SET domain protein in regulating effector gene expression and modulating histone methylation in P. sojae.
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Affiliation(s)
- Han Chen
- Department of Plant Pathology, the Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, the Key Laboratory of Plant ImmunityNanjing Agricultural UniversityNanjingChina
| | - Yujie Fang
- Department of Plant Pathology, the Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, the Key Laboratory of Plant ImmunityNanjing Agricultural UniversityNanjingChina
| | - Wenrui Song
- Department of Plant Pathology, the Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, the Key Laboratory of Plant ImmunityNanjing Agricultural UniversityNanjingChina
| | - Haidong Shu
- Department of Plant Pathology, the Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, the Key Laboratory of Plant ImmunityNanjing Agricultural UniversityNanjingChina
| | - Xi Li
- Department of Plant Pathology, the Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, the Key Laboratory of Plant ImmunityNanjing Agricultural UniversityNanjingChina
| | - Wenwu Ye
- Department of Plant Pathology, the Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, the Key Laboratory of Plant ImmunityNanjing Agricultural UniversityNanjingChina
| | - Yuanchao Wang
- Department of Plant Pathology, the Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, the Key Laboratory of Plant ImmunityNanjing Agricultural UniversityNanjingChina
| | - Suomeng Dong
- Department of Plant Pathology, the Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, the Key Laboratory of Plant ImmunityNanjing Agricultural UniversityNanjingChina
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Miller TA, Hudson DA, Johnson RD, Singh JS, Mace WJ, Forester NT, Maclean PH, Voisey CR, Johnson LJ. Dissection of the epoxyjanthitrem pathway in Epichloë sp. LpTG-3 strain AR37 by CRISPR gene editing. FRONTIERS IN FUNGAL BIOLOGY 2022; 3:944234. [PMID: 37746172 PMCID: PMC10512260 DOI: 10.3389/ffunb.2022.944234] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/14/2022] [Accepted: 07/18/2022] [Indexed: 09/26/2023]
Abstract
Epichloë festucae var. lolii and Epichloë sp. LpTG-3 are filamentous fungal endophytes of perennial ryegrass (Lolium perenne) that have a substantial impact on New Zealand's agricultural economy by conferring biotic advantages to the host grass. Overall, Epichloë endophytes contribute NZ$200 million to the economy annually, with strain AR37 estimated to contribute NZ$3.6 billion to the New Zealand economy over a 20-year period. This strain produces secondary metabolites, including epoxyjanthitrems, which are a class of indole diterpenes, associated with the observed effects of AR37 on livestock and insect pests. Until very recently, AR37 was intractable to genetic modification but this has changed with the application of CRISPR-Cas9 based gene editing techniques. In this paper, gene inactivation by CRISPR-Cas9 was used to deconvolute the genetic basis for epoxyjanthitrem biosynthesis, including creating an AR37 strain that has been edited to remove the biosynthesis of all indole diterpenes. We show that gene editing of Epichloë can be achieved without off-target events or introduction of foreign DNA (footprint-less) through an AMA1-based plasmid that simultaneously expresses the CRISPR-Cas9 system and selectable marker. Genetic modification events in these transformants were investigated through genome sequencing and in planta chemistry.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Linda J. Johnson
- Grasslands Research Centre, AgResearch, Palmerston North, New Zealand
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Lai Y, Wang L, Zheng W, Wang S. Regulatory Roles of Histone Modifications in Filamentous Fungal Pathogens. J Fungi (Basel) 2022; 8:jof8060565. [PMID: 35736048 PMCID: PMC9224773 DOI: 10.3390/jof8060565] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Revised: 05/23/2022] [Accepted: 05/24/2022] [Indexed: 12/19/2022] Open
Abstract
Filamentous fungal pathogens have evolved diverse strategies to infect a variety of hosts including plants and insects. The dynamic infection process requires rapid and fine-tuning regulation of fungal gene expression programs in response to the changing host environment and defenses. Therefore, transcriptional reprogramming of fungal pathogens is critical for fungal development and pathogenicity. Histone post-translational modification, one of the main mechanisms of epigenetic regulation, has been shown to play an important role in the regulation of gene expressions, and is involved in, e.g., fungal development, infection-related morphogenesis, environmental stress responses, biosynthesis of secondary metabolites, and pathogenicity. This review highlights recent findings and insights into regulatory mechanisms of histone methylation and acetylation in fungal development and pathogenicity, as well as their roles in modulating pathogenic fungi–host interactions.
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Affiliation(s)
- Yiling Lai
- CAS Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences (CAS), Shanghai 200032, China; (L.W.); (W.Z.)
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing 100049, China
- Correspondence: (Y.L.); (S.W.)
| | - Lili Wang
- CAS Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences (CAS), Shanghai 200032, China; (L.W.); (W.Z.)
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Weilu Zheng
- CAS Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences (CAS), Shanghai 200032, China; (L.W.); (W.Z.)
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Sibao Wang
- CAS Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences (CAS), Shanghai 200032, China; (L.W.); (W.Z.)
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing 100049, China
- Correspondence: (Y.L.); (S.W.)
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Local Rather than Global H3K27me3 Dynamics Are Associated with Differential Gene Expression in Verticillium dahliae. mBio 2021; 13:e0356621. [PMID: 35130723 PMCID: PMC8822345 DOI: 10.1128/mbio.03566-21] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Differential growth conditions typically trigger global transcriptional responses in filamentous fungi. Such fungal responses to environmental cues involve epigenetic regulation, including chemical histone modifications. It has been proposed that conditionally expressed genes, such as those that encode secondary metabolites but also effectors in pathogenic species, are often associated with a specific histone modification, lysine27 methylation of H3 (H3K27me3). However, thus far, no analyses on the global H3K27me3 profiles have been reported under differential growth conditions in order to assess if H3K27me3 dynamics govern differential transcription. Using chromatin immunoprecipitation sequencing (ChIP-seq) and RNA sequencing data from the plant-pathogenic fungus Verticillium dahliae grown in three in vitro cultivation media, we now show that a substantial number of the identified H3K27me3 domains globally display stable profiles among these growth conditions. However, we observe local quantitative differences in H3K27me3 ChIP-seq signals that are associated with a subset of differentially transcribed genes between media. Comparing the in vitro results to expression during plant infection suggests that in planta-induced genes may require chromatin remodeling to achieve expression. Overall, our results demonstrate that some loci display H3K27me3 dynamics associated with concomitant transcriptional variation, but many differentially expressed genes are associated with stable H3K27me3 domains. Thus, we conclude that while H3K27me3 is required for transcriptional repression, it does not appear that transcriptional activation requires the global erasure of H3K27me3. We propose that the H3K27me3 domains that do not undergo dynamic methylation may contribute to transcription through other mechanisms or may serve additional genomic regulatory functions. IMPORTANCE In many organisms, including filamentous fungi, epigenetic mechanisms that involve chemical and physical modifications of DNA without changing the genetic sequence have been implicated in transcriptional responses upon developmental or environmental cues. In fungi, facultative heterochromatin that can decondense to allow transcription in response to developmental changes or environmental stimuli is characterized by the trimethylation of lysine 27 on histone H3 (H3K27me3), and H3K27me3 has been implicated in transcriptional regulation, although the precise mechanisms and functions remain enigmatic. Based on ChIP and RNA sequencing data, we show for the soilborne broad-host-range vascular wilt plant-pathogenic fungus Verticillium dahliae that although some loci display H3K27me3 dynamics that can contribute to transcriptional variation, other loci do not show such a dependence. Thus, although we recognize that H3K27me3 is required for transcriptional repression, we also conclude that this mark is not a conditionally responsive global regulator of differential transcription upon responses to environmental cues.
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Wang R, Luo S, Clarke BB, Belanger FC. The Epichloë
festucae Antifungal Protein Efe-AfpA Is also a Possible Effector Protein Required for the Interaction of the Fungus with Its Host Grass Festuca rubra subsp. rubra. Microorganisms 2021; 9:140. [PMID: 33435432 PMCID: PMC7827515 DOI: 10.3390/microorganisms9010140] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 12/18/2020] [Accepted: 01/07/2021] [Indexed: 01/08/2023] Open
Abstract
Strong creeping red fescue (Festuca rubra subsp. rubra) is a commercially important low-maintenance turfgrass and is often naturally infected with the fungal endophyte Epichloë festucae. Epichloë spp. are endophytes of several cool-season grass species, often conferring insect resistance to the grass hosts due to the production of toxic alkaloids. In addition to insect resistance, a unique feature of the strong creeping red fescue/E. festucae symbiosis is the endophyte-mediated disease resistance to the fungal pathogen Clarireedia jacksonii, the causal agent of dollar spot disease. Such disease resistance is not a general feature of other grass/ Epichloë interactions. E. festucae isolates infecting red fescue have an antifungal protein gene Efe-afpA, whereas most other Epichloë spp. do not have a similar gene. The uniqueness of this gene suggests it may, therefore, be a component of the unique disease resistance seen in endophyte-infected red fescue. Here, we report the generation of CRISPR-Cas9 Efe-afpA gene knockouts with the goal of determining if absence of the protein in endophyte-infected Festuca rubra leads to disease susceptibility. However, it was not possible to infect plants with the knockout isolates, although infection was possible with the wild type E. festucae and with complemented isolates. This raises the interesting possibility that, in addition to having antifungal activity, the protein is required for the symbiotic interaction. The antifungal protein is a small secreted protein with high expression in planta relative to its expression in culture, all characteristics consistent with effector proteins. If Efe-AfpA is an effector protein it must be specific to certain interactions, since most Epichloë spp. do not have such a gene in their genomes.
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Affiliation(s)
- Ruying Wang
- Department of Plant Biology, Rutgers University, New Brunswick, NJ 08901, USA; (R.W.); (S.L.); (B.B.C.)
- Department of Horticulture, Oregon State University, Corvallis, OR 97331, USA
| | - Simin Luo
- Department of Plant Biology, Rutgers University, New Brunswick, NJ 08901, USA; (R.W.); (S.L.); (B.B.C.)
- College of Agro-Grassland Science, Nanjing Agricultural University, Nanjing 210095, China
| | - Bruce B. Clarke
- Department of Plant Biology, Rutgers University, New Brunswick, NJ 08901, USA; (R.W.); (S.L.); (B.B.C.)
| | - Faith C. Belanger
- Department of Plant Biology, Rutgers University, New Brunswick, NJ 08901, USA; (R.W.); (S.L.); (B.B.C.)
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