Inhibitory Effects and Mechanisms of Perilla Essential Oil and Perillaldehyde against Chestnut Pathogen Botryosphaeria dothidea

Botryosphaeria dothidea, a notorious plant pathogen, is responsible for causing chestnut rot during postharvest storage. This research aimed to assess the antifungal properties of perilla essential oil (PEO) and perillaldehyde (PAE) against B. dothidea. PEO’s and PAE’s inhibitory effects on B. dothidea were investigated using an agar dilution method, a fumigation method, and an in vivo assay in chestnuts and shell buckets. Based on the results of gas chromatography-mass spectrometry, it was confirmed that the main component of PEO was elemicin. The antifungal mechanism of PEO and PAE against B. dothidea was investigated by conducting staining experiments of the fungal cell wall and cell membrane. PEO and PAE strongly inhibit the mycelial growth of B. dothidea in a dose-dependent manner. The inhibitory mechanism is mainly related to the destruction of the integrity of the fungal cell wall and plasma membrane. Notably, PEO retains its antifungal efficacy against B. dothidea in chestnuts, effectively prolonging their storage life. These findings indicate that PEO and PAE are nontoxic, eco-friendly botanical fungicides, holding promise for controlling postharvest chestnut rot.