Unravelling the antifungal mechanism of phytic acid on Aspergillus flavus development and aflatoxin B1 biosynthesis.

Aspergillus flavus (A. flavus) is a plant pathogenic fungus that produces toxic and carcinogenic aflatoxins, posing a threat to food safety and human health. As a kind of food additive, phytic acid (PA) exhibits excellent antimicrobial activity. However, the antifungal effects of PA against A. flavus are not well understood. Here, transcriptomic and biochemical analyses were carried out to investigate the inhibitory effects of PA against A. flavus and potential mechanisms. Our findings demonstrated that PA effectively inhibited the vegetative growth, conidiation and aflatoxin B1 (AFB1) production of A. flavus. In addition, we found that PA also suppressed the pathogenicity of A. flavus on peanut and maize seeds. The transcriptomic analysis confirmed that the differentially expressed genes (DEGs) were involved in development, aflatoxin biosynthesis, oxidative stress, ergosterol biosynthesis, and the MAPK signalling pathway in A. flavus. Biochemical experiments further demonstrated that PA could destroy cell membrane integrity and induce reactive oxygen species (ROS) accumulation, eventually resulting in defects of development and AFB1 biosynthesis in A. flavus. Taken together, this research enhances understanding of the antifungal mechanism of PA, and provides novel insights into its potential as a food additive to prevent and control A. flavus contamination.