Perillaldehyde-Elicited Inhibition of Ochratoxin A Production by Aspergillus carbonarius

Ochratoxin A (OTA) is a major mycotoxin contaminant in grapes and their products, and Aspergillus carbonarius is its main producer. Controlling the growth of A. carbonarius is therefore critical for mitigating OTA contamination. Plant-derived perillaldehyde, with good antifungal activity and safety, has garnered growing attention. However, current understanding of how perillaldehyde affects A. carbonarius growth and OTA production remains poorly characterized. In this study, we systematically investigated the antifungal and antimycotoxigenic effects of perillaldehyde against A. carbonarius and explored the underlying mechanisms. The results showed that perillaldehyde could alter the mycelial morphology and damage the cell integrity of A. carbonarius. Additionally, perillaldehyde could diminish the total antioxidant capacity and impair the energy metabolism of A. carbonarius. Transcriptome analysis showed that the expressions of all the known conserved OTA biosynthetic genes and two OTA transport-related genes were significantly down-regulated, indicating that perillaldehyde could directly inhibit their expression. In conclusion, perillaldehyde can significantly inhibit OTA production by directly disrupting OTA biosynthesis and transport and inhibiting the growth of A. carbonarius. Thus, perillaldehyde has the potential to be used as a natural fungicide or alternative food preservative in grapes and their products, owing to its strong antifungal and antimycotoxigenic effects on A. carbonarius.