Knock-down of the methyltransferase Kmt6 reliefs H3K27me3 and induces expression of cryptic otherwise silent secondary metabolite gene clusters in Fusarium fujikuroi [gene expression]
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ABSTRACT: Filamentous fungi produce a vast array of secondary metabolites (SMs) and some of them are applied in agriculture or pharmacology. Recent sequencing of the rice pathogen Fusarium fujikuroi revealed the presence of far more SM-encoding genes than known products. SM production is energy-consuming and thus tightly regulated, leaving the majority of SM gene clusters silent under laboratory conditions. It is now well established that one important regulatory layer in SM biosynthesis involves histone modifications that render the genes either silent or poised for transcription. In this study, we show that the majority of the putative SM gene clusters in F. fujikuroi are located within facultative heterochromatin marked by H3K27me3. In this study, we performed comparative transcriptomics of a knock-down mutant of the responsible methyltransferase Kmt6 involved in H3K27 methylation grown on either solid complete medium or solid synthetic ICI medium. Overall four so far cryptic and otherwise silent putative SM gene clusters were significantly induced in the KMT6kd strain accompanied by reduced H3K27me3 levels at the respective gene loci and accumulation of novel metabolites. One of the four putative SM gene clusters, the STC5 gene cluster, was analysed in detail and heterologous expression of the key enzyme allowed for the identification of the first pathway-specific intermediate (1R,4R,5S)-guaia-6,10(14)-diene.
ORGANISM(S): Fusarium fujikuroi
PROVIDER: GSE80477 | GEO | 2016/07/04
SECONDARY ACCESSION(S): PRJNA319026
REPOSITORIES: GEO
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