Transcriptome analysis reveals the underlying mechanism of heptanal against Aspergillus flavus spore germination

Methods of controlling Aspergillus flavus contamination in agro-products have attracted attention because of its impact on global food security. We previously reported that the natural cereal volatile heptanal could effectively inhibit A. flavus growth and showed great potential as a bio-preservative agent. In this study, the minimum inhibitory concentration and minimum fungicide concentration of heptanal could change the surface morphology of A. flavus spores, causing them to wrinkle and collapse. Transcriptomic analysis showed that heptanal treatment significantly changed the expression of several genes involved in cell wall and plasma damage, reactive oxygen species (ROS) accumulation, energy metabolism, AMPK-activated protein kinase, biosynthesis of unsaturated fatty acids, RNA degradation, and DNA replication. Heptanal-induced early apoptosis of A. flavus spores was characterized by decreased mitochondrial membrane potential, increased intracellular ROS production, and DNA fragmentation. This study provides new insight into the inhibitory mechanism of heptanal against A. flavus and points to its potential application as a bio-preservative.

Automated summary

This study reveals the inhibitory mechanism of heptanal against A. flavus by changing the surface morphology of A. flavus spores and affecting the expression of genes related to cell wall and plasma damage, energy metabolism, RNA and DNA synthesis. Heptanal can also induce early apoptosis of A. flavus spores.