The Methyltransferase VdPRMT4 Regulates Verticillium dahliae via Regulation of Primary Metabolic Processes

Cotton Verticillium wilt (VW), caused by the soil-borne fungus Verticillium dahliae (V. dahliae), is a devastating disease that poses a serious threat to sustainable cotton production worldwide. Protein methylation plays a critical role in fungal adaptation to the host environment and manipulation of plant immunity. Protein arginine methyltransferases (PRMTs) are key enzymes catalyzing arginine methylation, yet their functions in V. dahliae pathogenicity remain largely unexplored. In this study, we identified VdPRMT4 in V. dahliae through homology-based screening. qRT-PCR analysis revealed that VdPRMT4 transcript levels were significantly increased during the early stages of V. dahliae infection in cotton. HIGS assays showed that silencing VdPRMT4 markedly alleviated cotton VW symptoms and reduced fungal biomass in cotton plants. Gene knockout and complementation experiments demonstrated that deletion of VdPRMT4 did not affect hyphal growth but significantly impaired sporulation capacity and severely attenuated pathogenicity on cotton. Transcriptomic analysis further indicated that loss of VdPRMT4 profoundly affected the metabolic pathways of V. dahliae, including protein processing in the endoplasmic reticulum, purine metabolism, and glycerolipid metabolism. Collectively, this study provides the first evidence that VdPRMT4 plays a critical role in stress adaptation and pathogenicity of V. dahliae, offering new insights into fungal pathogenesis and identifying potential targets for VW control.