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 < .05) to stimulate the aflatoxin synthesis to complete the infection on the surface. During the postinfection period, the upregulation of aflS and other toxin‐producing regulatory genes accelerated aflatoxin synthesis and completed the internal infection. At the same time, the upregulation of vitamin B6 and allysine involved in amino acid metabolism, and galactose 1‐phosphate involved in energy metabolism ensured the production of acetyl‐CoA and the energy supply for A. flavus infection. The research findings highlight the underlying mechanisms of A. flavus infection at the transcriptome–metabolomics levels, which is important for developing effective strategies to prevent postharvest contamination.

p‐Anisaldehyde suppresses Aspergillus flavus infection and aflatoxin biosynthesis via targeting cell structure and Ap1‐regulatory antioxidant system

“…flavus is widely distributed in soil, decaying vegetation, postharvest crop products, and indoor environments (Amaike & Keller, 2011;Ding et, al., 2023). A. flavus is notorious for its affinity of invading lipidrich seed crops and produce a variety of aflatoxins (AFs) (Fu et al, 2023), among which AFB1 is considered one of the most significant health risks for its carcinogenic and teratogenic properties to humans.…”

The Autophagy-Related Protein ATG8 Orchestrates Asexual Development and AFB1 Biosynthesis in Aspergillus flavus

“…Aspergillus flavus, a saprophytic soil fungus, infects insects and contaminates both preharvest and postharvest seed crops such as maize and peanuts, while also producing potent aflatoxins (AFs) [1,2]. Among the AFs, aflatoxins B1, B2, G1, and G2 are the major four and aflatoxin B1 (AFB1), the most toxic and potent hepatocarcinogenic compound among them, primarily targets the liver [3,4]. Chronic low-level exposure to AFB1 can lead to immunosuppression and hepatocellular carcinoma, while a single acute exposure could be fatal [5,6].…”

Peanut Rhizosphere Achromobacter xylosoxidans Inhibits Aspergillus flavus Development and Aflatoxin Synthesis by Inducing Apoptosis through Targeting the Cell Membrane

“…Aspergillus flavus, a ubiquitous soil-borne saprophyte, presents a significant public health threat due to its ability to contaminate essential crops like peanuts, corn, and cotton, , and its potential to cause invasive aspergillosis in immunocompromised individuals. , This fungus attacks crops at both preharvest and postharvest stages, leading to substantial global economic losses . A particularly concerning aspect of A.…”