Trace copper-mediated asexual development a superoxide dismutase and induction of in .

The filamentous fungus , in which sexual reproduction remains to be discovered, proliferates mainly asexual spores (conidia). Therefore, despite its industrial importance in food fermentation and recombinant protein production, breeding beneficial strains by genetic crosses is difficult. In , which is genetically close to . , structures known as sclerotia are formed asexually, but they are also related to sexual development. Sclerotia are observed in some . strains, although no sclerotia formation has been reported in most strains. A better understanding of the regulatory mechanisms underlying sclerotia formation in . may contribute to discover its sexual development. Some factors involved in sclerotia formation have been previously identified, but their regulatory mechanisms have not been well studied in . . In this study, we found that copper strongly inhibited sclerotia formation and induced conidiation. Deletion of encoding a core regulator of conidiation and involved in transcriptional induction of suppressed the copper-mediated inhibition of sclerotia formation, suggesting that induction in response to copper leads not only to conidiation but also to inhibition of sclerotia formation. In addition, deletion of the copper-dependent superoxide dismutase (SOD) gene and its copper chaperone gene partially suppressed such copper-mediated induction of conidiation and inhibition of sclerotia formation, indicating that copper regulates asexual development the copper-dependent SOD. Taken together, our results demonstrate that copper regulates asexual development, such as sclerotia formation and conidiation, the copper-dependent SOD and transcriptional induction of in . .