Fig. 6

IDR2 of BP1 is required for H3K27me3-mediated transcriptional repression of secondary metabolite–related genes. A Scatterplot of differentially expressed genes between the wild-type PH-1 and BP1^ΔIDR2-C F. graminearum as identified by RNA-seq. The red circles represent significantly upregulated genes, and blue circles represent significantly downregulated genes (P value ≤ 0.05 and fold-change ≥ 2 or ≤  − 2, respectively). Genes not differentially expressed are shown in black. B Venn diagram showing the overlap between significantly upregulated genes in BP1^ΔIDR2-C, ΔBP1, and ΔKmt6. C Venn diagram showing the overlap between significantly upregulated genes in BP1^ΔIDR2-C, ΔBP1, and ΔKmt6 strains and genes harboring H3K27me3 (as identified by chromatin immunoprecipitation sequencing, ChIP-seq). D Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis of the overlapping upregulated, H3K27me3-enriched genes in panel C. The top 10 significantly pathways are listed, based on enriched gene counts. E Heatmap representation of the transcriptional changes of selected secondary metabolism biosynthesis genes in BP1^ΔIDR2-C strain compared to those in wild-type F. graminearum. Selected genes included those encoding polyketide synthases (PKSs), non-ribosomal peptide synthases (NRPSs), and cytochrome P450 enzymes. F–H Transcript levels of secondary metabolism biosynthesis genes in BP1^ΔIDR2-C as determined by RT-qPCR. Relative transcript levels were normalized to ACTIN as the internal standard and presented as means ± SD from three independent experiments. Different lowercase letters denote significant differences at P = 0.05 based on one-way ANOVA test