BcTaf14 regulates growth and development, virulence, and stress responses in the phytopathogenic fungus Botrytis cinerea.

TATA box-binding protein (TBP)-associated factor 14 (Taf14), a transcription-associated factor containing a conserved YEATS domain and an extra-terminal (ET) domain, is a multifunctional protein in Saccharomyces cerevisiae. However, the role of Taf14 in filamentous phytopathogenic fungi is not well understood. In this study, the homologue of ScTaf14 in Botrytis cinerea (named BcTaf14), a destructive phytopathogen causing grey mould, was investigated. The BcTaf14 deletion strain (ΔBcTaf14) showed pleiotropic defects, including slow growth, abnormal colony morphology, reduced conidiation, abnormal conidial morphology, reduced virulence, and altered responses to various stresses. The ΔBcTaf14 strain also exhibited differential expression of numerous genes compared to the wild-type strain. BcTaf14 could interact with the crotonylated H3K9 peptide, and mutation of two key sites (G80 and W81) in the YEATS domain disrupted this interaction. The mutation of G80 and W81 affected the regulatory effect of BcTaf14 on mycelial growth and virulence but did not affect the production and morphology of conidia. The absence of the ET domain at the C-terminus rendered BcTaf14 unable to localize to the nucleus, and the defects of ΔBcTaf14 were not recovered to wild-type levels when BcTaf14 without the ET domain was expressed. Our results provide insight into the regulatory roles of BcTaf14 and its two conserved domains in B. cinerea and will be helpful for understanding the function of the Taf14 protein in plant-pathogenic fungi.