Facultative heterochromatin mediated by core and accessory chromosome-encoded H3K27-specific methyltransferases controls virulence in a fungal phytopathogen.

ABSTRACT: In many fungal phytopathogens, infection is regulated by accessory genomic regions enriched in facultative heterochromatin, but the precise role of this chromatin state in virulence is poorly understood. Here we examined the two facultative heterochromatic marks H3K27me and H3K36me in the tomato-pathogenic Fusarium oxysporum isolate Fol 4287, by genetically analyzing the corresponding histone methyltransferases Kmt6 and Ash1. Fol has three KMT6 homologs, two of which, KMTB/C, are encoded on an accessory chromosome. Loss of the core gene KMT6A resulted in strongly reduced but not abolished H3K27me, revealing that methylation of subtelomeres can be taken over by the accessory copy Kmt6b. To the best of our knowledge, this demonstrates for the first time that accessory fungal histone modifier

SUBMITTER: Janevska S 

PROVIDER: S-EPMC12774646 | biostudies-literature | 2026 Jan

REPOSITORIES: biostudies-literature