Work

BcEaf2 plays a critical role in hyphal growth, asexual reproduction, pathogenic infection, and histone methylation in Botrytis cinerea

Year: 2026

Type: article

Abstract: Histone modifications are central to the regulation of fungal development and pathogenicity, yet the upstream mechanisms modulating these epigenetic marks remain incompletely understood in phytopathogenic fungi. Here, we identify and functionally characterize BcEaf2, a conserved Eaf2/DMAP1 homolog, in the necrotrophic pathogen Botrytis cinerea . BcEaf2 gene exhibits dynamic expression during conidiation and host infection, and its silencing results in impaired hyphal growth, heightened sensitivity to oxidative and osmotic stresses, reduced conidiation, and markedly attenuated virulence. Notably, silencing of BcEaf2 leads to a specific decrease in global H3K36me3 levels, without affecting other major histone modifications, indicating a selective role in chromatin regulation. Mechanistically, we demonstrate that BcEaf2 physically interacts with the H3K36 methyltransferase BcSET2 and significantly enhances its enzymatic activity in vitro . Consistent with this, deletion of BcSET2 phenocopies BcEaf2 -silenced strains, displaying defects in growth, stress adaptation, conidiation, and pathogenicity, alongside reduced H3K36me3 levels. These findings establish BcSET2 as a key regulator of fungal fitness and virulence and reveal BcEaf2 as a cofactor that fine-tunes BcSET2-mediated histone methylation. Collectively, our study uncovers a previously unrecognized regulatory module controlling H3K36me3 deposition in B. cinerea and highlights a functional divergence of Eaf2 proteins from canonical roles in histone acetylation or DNA methylation toward direct modulation of histone methyltransferase activity. These findings reveal a critical role of the BcEaf2/BcSET2 regulatory module in fungal development and pathogenicity and provide a mechanistic framework for exploring this module as a potential target for future antifungal intervention.

Source: Frontiers in Microbiology

DOI: 10.3389/fmicb.2026.1978891