A Putative CH Transcription Factor CgTF6, Controlled by CgTF1, Negatively Regulates Chaetoglobosin A Biosynthesis in .

Gα signaling pathway as well as the global regulator LaeA were demonstrated to positively regulate the biosynthesis of chaetoglobosin A (ChA), a promising biotic pesticide produced by . Recently, the regulatory function of ZnCys binuclear finger transcription factor that lies within the ChA biosynthesis gene cluster has been confirmed. However, was not merely a pathway specific regulator. In this study, we showed that the homologs gene of (designated as ) regulate ChA biosynthesis and sporulation in NK102. More importantly, RNA-seq profiling demonstrated that 1,388 genes were significant differentially expressed as deleted. Among them, a putative CH transcription factor, named , showed the highest gene expression variation in zinc-binding proteins encoding genes as deleted. qRT-PCR analysis confirmed that expression of was significantly reduced in CgTF1 null mutants. Whereas, deletion of resulted in the transcriptional activation and consequent increase in the expression of ChA biosynthesis gene cluster and ChA production in . These data suggested that CgTF6 probably acted as an end product feedback effector, and interacted with CgTF1 to maintain a tolerable concentration of ChA for cell survival.