SfgA Renders Aspergillus flavus More Stable to the External Environment

Journal of Fungi

Yan-Feng Luo¹  Sheng-Da Chi²  Zhu-Mei He²  Su Qu²  Jie-Ying Li²  Xiao-Yu Yuan²  Qing-Qing Zhi² 

[1] Guangdong Jinyinshan Environmental Protection Technology Co., Ltd., Guangzhou 510705, China;The Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Science, Sun Yat-sen University, Guangzhou 510275, China;

关键词: Aspergillus flavus;    sfgA;    sclerotia;    aflatoxin;    conidiation;    secondary metabolism;   

DOI  :  10.3390/jof8060638

来源: DOAJ

【 摘 要 】

sfgA is known as a key negative transcriptional regulator gene of asexual sporulation and sterigmatocystin production in Aspergillus nidulans. However, here, we found that the homolog sfgA gene shows a broad and complex regulatory role in governing growth, conidiation, sclerotia formation, secondary metabolism, and environmental stress responses in Aspergillus flavus. When sfgA was deleted in A. flavus, 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, sfgA regulated aflatoxin biosynthesis in a complex way that was associated with the changes in cultured conditions, and the increased production of aflatoxin in the ∆sfgA mutant was associated with a decrease in sclerotia size. Furthermore, the ∆sfgA 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 sfgA was deleted. Additionally, we also found that sfgA functions downstream of fluG in A. flavus, which is consistent with the genetic position in FluG-mediated conidiation in A. nidulans. Collectively, sfgA plays a critical role in the development, secondary metabolism, and stress responses of A. flavus, and sfgA renders A. flavus more stable to the external environment.

【 授权许可】

Unknown