Transcription Activator Swi6 Interacts with Mbp1 in I Cell Cycle Box-Binding Complex and Regulates Hyphal Differentiation and Virulence in .

Mbp1 protein acts as a DNA-binding protein in I cell cycle box-binding complex (MBF) and plays an essential role in filamentous myco-pathogen .In the current study, BbSwi6 (a homologue of yeast Swi6) was functionally characterized in . Both BbSwi6 and BbMbp1 localize in the nucleus and display a direct interaction relationship which is indicated by a yeast two-hybrid assay. significantly contributes to hyphal growth, asexual sporulation and virulence. On the aerial surface, Δ grew slower on various nutrients and displayed abnormal conidia-producing structures, which hardly produced conidia. In liquid media, loss led to 90% reduction in blastospore yield. Finally, the virulence of the Δ mutant was modestly weakened with a reduction of 20% in median lethal time. Comparative transcriptomics revealed that BbSwi6 mediated different transcriptomes during fungal development into conidia and blastospores. Notably, under the indicated condition, the BbSwi6-mediated transcriptome significantly differed to that mediated by BbMbp1. Our results demonstrate that, in addition to their roles as the interactive components in MBF, BbSwi6 and BbMbp1 mediate divergent genetic pathways during morphological transitions in .