The H4K20 methyltransferase Kmt5 is involved in secondary metabolism and stress response in phytopathogenic Fusarium species

•Kmt5 is solely responsible for H4K20me3 in F.fujikuroi and F.graminearum.•Imbalanced H4K20me3 levels affect hyphal growth in F.graminearum.•FgKMT5 deletion strains are hypovirulent on wheat in F.graminearum.•H4K20me3 is required for wild type-like secondary metabolism in both fusaria.•Mutants lacking Kmt5 are more tolerant to oxidative and osmotic stress.