Transcriptomics and metabolomic profiling identify molecular mechanism for Aspergillus flavus infection in grain

Abstract

Aspergillus flavus is a ubiquitous saprophyte and opportunistic fungal pathogen with worldwide distribution, which causes diseases commonly in agricultural commodities and seriously threatens food security and human health. In this study, we try to reveal the mechanisms of A. flavus infection in grain from the perspective of apparent changes in physicochemical properties, microscopic structure, and ultrastructural changes at transcriptome–metabolomics levels. The results showed that the A. flavus infection included the preinfection (1–3 days) and postinfection period (4–7 days). The downregulated expression of creA promoted the cellulase expression and initiated infection. The metabolite oleic acid promoted infection as a nutrient carbon source and energy source. Then the entry of acetate units into the aflatoxin synthesis pathway was inhibited, whereas aflH, hypD, and hypB were significantly upregulated (p