C₂H₂型转录因子AflAZF1在黄曲霉生长发育与毒素合成调控中的作用

The C2H2 zinc finger transcription factor AZF1 in fungi has multiple biological functions such as regulating growth and development, secondary metabolism synthesis, and pathogenicity, however, the functions of this homologous protein in Aspergillus flavus is still unclear. Homology comparison revealed that the protein encoded by AFLA_054800 shares 50% homology with the AZF1 protein in Trichoderma reesei, and it was named AflAZF1. This study found that the colony size of the AflAZF1 gene deletion strain (ΔAflAZF1) was not significantly different from that of the wild type, but the conidiation was significantly reduced, and the sclerotia could not form. The production of aflatoxin AFB1 in the ΔAflAZF1 strain was significantly increased. When glucose, arabinose, mannose, sucrose, and xylose were used as carbon sources, the conidiation ability of the ΔAflAZF1 strain was significantly decreased, but it was significantly increased in lactose and glycerol. Additionally, under pH 5 and pH 11 conditions, the number of conidia in the ΔAflAZF1 strain was significantly lower than that in the wild type. The results indicate that AflAZF1 not only regulates conidiation and sclerotial formation and AFB1 biosynthesis, but also modulates the utilization of different carbon sources and adaptation to extreme pH conditions by affecting conidiation ability. This discovery not only reveals the key role of AflAZF1 in the growth and development and toxin synthesis of A. flavus, but also provides a theoretical basis for the prevention and control of A. flavus contamination and the development of new biological control strategies.