Zfp1, A Putative Zn(Ii)(2)Cys(6) Transcription Factor, Influences Ustilago Maydis Pathogenesis At Multiple Stages

As a biotrophic fungus, Ustilago maydis, the causal agent of common smut of maize, must establish and maintain a relationship with the host throughout the pathogenic cycle. Functional characterization of the U. maydis transcription factor Zfp1 suggests a role in modulating pathogenic development. Deletion of zfp1 resulted in attenuated pathogenic hyphal growth, reduced infection frequency, arrested disease symptom development, and decreased anthocyanin production. Complementation with Zfp1 constructs lacking conserved domains indicated it may function with and without DNA binding and suggests a role for the Fungal_trans domain in enabling full virulence. RNA-sequencing revealed the transcription of approximately 30% of U. maydis genes, including those encoding predicted and confirmed effectors, were altered in the zfp1 deletion strain during pathogenic growth. Together, the results suggest that Zfp1 is a Zn(II)(2)Cys(6) transcription factor that is required for the full induction of infection, anthocyanin production, and virulence.