Transcriptome Sequencing Revealed an Inhibitory Mechanism of Aspergillus flavus Asexual Development and Aflatoxin Metabolism by Soy-Fermenting Non-Aflatoxigenic Aspergillus

Aflatoxins (AFs) have always been regarded as the most effective carcinogens, posing a great threat to agriculture, food safety, and human health. is the major producer of aflatoxin contamination in crops. The prevention and control of and aflatoxin continues to be a global problem. In this study, we demonstrated that the cell-free culture filtrate of and a non-aflatoxigenic can effectively inhibit the production of AFB1 and the growth and reproduction of , indicating that both of the non-aflatoxigenic strains secrete inhibitory compounds. Further transcriptome sequencing was performed to analyze the inhibitory mechanism of treated with fermenting cultures, and the results revealed that genes involved in the AF biosynthesis pathway and other biosynthetic gene clusters were significantly downregulated, which might be caused by the reduced expression of specific regulators, such as AflS, FarB, and MtfA. The WGCNA results further revealed that genes involved in the TCA cycle and glycolysis were potentially involved in aflatoxin biosynthesis. Our comparative transcriptomics also revealed that two conidia transcriptional factors, and , were found to be significantly downregulated, which might lead to the downregulation of conidiation-specific genes, such as the conidial hydrophobins genes and . In summary, our research provides new insights for the molecular mechanism of controlling AF synthesis to control the proliferation of and AF pollution.