A Zn(II)2Cys6 transcription factor VdRgt1 affects microsclerotia development, virulence, and glucose utilization in the smoke tree wilt fungus Verticillium dahliae

Abstract Verticillium dahliae is a soil-borne vascular pathogen with a broad host range and the ability to survive in soil for extended periods through the formation of stress-resistant microsclerotia. It poses a major challenge to disease management and frequently causes severe Verticillium wilt in smoke tree ( Cotinus coggygria ) in China. Zn(II) 2 Cys 6 transcription factors (TFs) represent a major class of fungal regulators and are involved in various biological processes, including primary and secondary metabolism, stress adaptation, and pathogenesis. In this study, we found that the deletion of VdRgt1 , which belongs to Zn(II) 2 Cys 6 TF, led to abnormal hyphal morphology, reduced vegetative growth, markedly decreased conidial production, and altered timing of microsclerotia development and melanin accumulation. Additionally, the Δ VdRgt1 mutant exhibited significantly reduced virulence and impaired colonization of C. coggygria . Transcriptome analysis indicated that VdRgt1 is involved in the regulation of carbohydrate and energy metabolism. Consistently, the Δ VdRgt1 mutant exhibited reduced ATP levels, and RT-qPCR supported a role for VdRgt1 in glucose-responsive gene regulation. Collectively, these results indicate that VdRgt1 is an important regulator in V. dahliae , coordinating hyphal development, the timing of microsclerotia development and melanin accumulation, carbon and energy metabolism, stress adaptation, and virulence.