SfgA Renders More Stable to the External Environment.

is known as a key negative transcriptional regulator gene of asexual sporulation and sterigmatocystin production in . However, here, we found that the homolog gene shows a broad and complex regulatory role in governing growth, conidiation, sclerotia formation, secondary metabolism, and environmental stress responses in . When was deleted in the fungal growth was slowed, but the conidiation was significantly increased, and the sclerotia formation displayed different behavior at different temperatures, which increased at 30 °C but decreased at 36 °C. In addition, regulated aflatoxin biosynthesis in a complex way that was associated with the changes in cultured conditions, and the increased production of aflatoxin in the ∆ mutant was associated with a decrease in sclerotia size. Furthermore, the ∆ mutant exhibited sensitivity to osmotic, oxidative, and cell wall stresses but still produced dense conidia. Transcriptome data indicated that numerous development- and secondary-metabolism-related genes were expressed differently when was deleted. Additionally, we also found that functions downstream of in , which is consistent with the genetic position in FluG-mediated conidiation in . Collectively, plays a critical role in the development, secondary metabolism, and stress responses of and renders more stable to the external environment.