Perillaldehyde-Elicited Inhibition of Ochratoxin A Production by Aspergillus carbonarius

Ochratoxin A (OTA) is a major mycotoxin contaminant in grapes and their products, and <i>Aspergillus carbonarius</i> is its main producer. Controlling the growth of <i>A. carbonarius</i> 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 <i>A. carbonarius</i> growth and OTA production remains poorly characterized. In this study, we systematically investigated the antifungal and antimycotoxigenic effects of perillaldehyde against <i>A. carbonarius</i> and explored the underlying mechanisms. The results showed that perillaldehyde could alter the mycelial morphology and damage the cell integrity of <i>A. carbonarius</i>. Additionally, perillaldehyde could diminish the total antioxidant capacity and impair the energy metabolism of <i>A. carbonarius</i>. 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 <i>A. carbonarius</i>. 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 <i>A. carbonarius</i>.