Histone H3K4 methylation regulates hyphal growth, secondary metabolism and multiple stress responses in Fusarium graminearum
Histone H3 lysine 4 methylation (H3K4me) is generally associated with actively transcribed genes in a variety of eukaryotes. The function of H3K4me in phytopathogenic fungi remains unclear. Here, we report that FgSet1 is predominantly responsible for mono‐, di‐ and trimethylation of H3K4 in Fusarium...
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| Published in | Environmental microbiology Vol. 17; no. 11; pp. 4615 - 4630 |
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| Main Authors | , , , , , |
| Format | Journal Article |
| Language | English |
| Published |
England
Blackwell Science
01.11.2015
Blackwell Publishing Ltd Wiley Subscription Services, Inc |
| Subjects | |
| Online Access | Get full text |
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| Summary: | Histone H3 lysine 4 methylation (H3K4me) is generally associated with actively transcribed genes in a variety of eukaryotes. The function of H3K4me in phytopathogenic fungi remains unclear. Here, we report that FgSet1 is predominantly responsible for mono‐, di‐ and trimethylation of H3K4 in Fusarium graminearum. The FgSET1 deletion mutant (ΔFgSet1) was crippled in hyphal growth and virulence. H3K4me is required for the active transcription of genes involved in deoxynivalenol and aurofusarin biosyntheses. Unexpectedly, FgSet1 plays an important role in the response of F. graminearum to cell wall‐damaging agents via negatively regulating phosphorylation of FgMgv1, a core kinase in the cell wall integrity pathway. In addition, ΔFgSet1 exhibited increased resistance to the transcription elongation inhibitor mycophenolic acid. Yeast two‐hybrid assays showed that FgSet1 physically interacts with multiple proteins including FgBre2, FgSpp1 and FgSwd2. FgBre2 further interacts with FgSdc1. Western blotting analyses showed that FgBre2 and FgSdc1 are associated with H3K4me. Both proteins are also involved in regulating deoxynivalenol biosynthesis and in responses to mycophenolic acid and cell wall‐damaging agents. Taken together, these data indicate that H3K4me plays critical roles not only in regulation of fungal growth and secondary metabolism but also in multiple stress responses in F. graminearum. |
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| Bibliography: | http://dx.doi.org/10.1111/1462-2920.12993 Special Fund for Agro-scientific Research in the Public Interest - No. 201303016 Fig. S1. TRI6 transcript level and H3K4 methylation in F. graminearum incubated in glucose yeast extract peptone (GYEP) and in potato dextrose broth (PDB). A. Transcript level of TRI6 in the wild-type PH-1 cultured in GYEP in comparison with that same strain incubated in PDB. Line bars in each column denote standard errors of three repeated experiments. B. Enrichment level of H3K4me1, H3K4me2 and H3K4me3 at the 5′ region of TRI6 in PH-1 incubated in GYEP in comparison with the same strain cultured in PDB. The enrichment levels of H3K4me1, -me2 and me3 were determined by chromatin immunoprecipitation-quantitative PCR (ChIP-qPCR). Line bars in each column denote standard errors of three repeated experiments. Fig. S2. Schematic representation of gene disruption strategy and Southern blotting analyses of the deletion mutants. A. Schematic representation of the FgSET1 disruption strategy and Southern blotting analyses of FgSET1 deletion mutant (ΔFgSet1) and its complemented strain (ΔFgSet1-C). An upstream fragment of FgSET1 was used as the probe1 in the Southern blotting assays. B. Schematic representation of the disruption strategy for FGSG_02778, FGSG_05558, FGSG_07445 and FGSG_00899, FgBRE2, FgSDC1, FgSPP1 and Southern blotting analysis of their corresponding mutants. A fragment of the hygromycin resistance gene was used as the probe2 in the Southern blotting assays. The restriction enzymes used for digestion of genomic DNA preparation and the size of the resulting hybridization band are indicated for each strain at the bottom of the image. Fig. S3. Essential role of the SET domain in FgSet1. A. Schematic diagram of the SET domain (indicated in red) in FgSet1. B. The defects in mycelial growth of ΔFgSet1 were not restored by genetic complementation with the truncated FgSET1 without the SET domain, but were restored by the full length FgSET1 fused with GFP. C. The defects in H3K4 methylation of ΔFgSet1 were not restored by genetic complementation with the truncated FgSET1, but were restored by the full length FgSET1 fused with GFP. Fig. S4. Comparisons of pigmentation in the wild type (PH-1), ΔFgAurJ and ΔFgAurF grown on potato dextrose agar (PDA). Fig. S5. Determination of FgSET1 transcript level. A. The relative transcript level of FgSET1 in comparison with ACTIN was quantified by quantitative real-time PCR. Line bars indicate standard errors from three repeated experiments. B. Comparisons of the transcript level between FgSET1 and the reference gene ACTIN by reverse transcription quantitative PCR from the same cDNA templates. Lanes 2 and 3 are two repeated samples for ACTIN, and lanes 5 and 6 for FgSET1. Lanes 4 and 7 are the negative controls without cDNA templates. Fig. S6. Subcellular localization of FgMgv1 in F. graminearum. FgMgv1-GFP was mainly localized to the nucleus and nearby areas. Nuclei were stained with 4′6-diamidino-2-phenylindole (DAPI). DIC, differential interference contrast; bar = 2 μm. Table S1. Oligonucleotide primers used in this study. Table S2. Ten proteins were predicted to interact with FgSet1 by using the computer programs fppi and string. National Key Basic Research and Development Program - No. 2013CB127802 ArticleID:EMI12993 National Science Foundation - No. 31272000; No. 31300128 ark:/67375/WNG-494CQ0RC-H China Agriculture Research System - No. CARS-3-1-15 istex:4F51D1EE6B19FA7BA4884347824D50629030A676 ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 14 content type line 23 |
| ISSN: | 1462-2912 1462-2920 1462-2920 |
| DOI: | 10.1111/1462-2920.12993 |