Abstract

Alternative splicing of pre-mRNA is a crucial mechanism in gene expression regulation. As a core component of the spliceosome, the biological function of the Skip protein inAspergillus flavusremains unknown. Quantitative real-time PCR (qPCR) analysis revealed the presence of twoskipgene copies inA. flavus. Single-copy deletion of Skip resulted in slowed growth, reduced conidiation, abolished sclerotial formation, increased aflatoxin biosynthesis, and diminished crop colonization. Meanwhile, Skip was found to regulate the oxidative stress response by modulating the alternative splicing ofyapA. Subsequently, immunoprecipitation and Western blot analyses identified lysine 325 (K325) as the benzoylated site on the Skip protein, which catalyzed by the acyltransferase EsaA. Mutation of benzoylated site K325 directly impaired fungal morphogenesis, pathogenicity, and stress adaptation. These findings established the crucial role of Skip and its benzoylation inA. flavusand suggested a potential target for controlling its infection in important crops.