A novel strategy combining perillaldehyde with polyamines based on polyamine metabolism in Ceratocystis fimbriata for the postharvest control of sweetpotato black rot

Black rot caused by Ceratocystis fimbriata is a destructive disease affecting sweetpotato, posing a significant threat to both the sweetpotato industry and human health. Perillaldehyde (PAE) is the primary active component of Perilla essential oil. Polyamines (PAs) are universal biological growth factors. There have been no reports on the control of fungal diseases in fruit and vegetables during the postharvest preservation using a combination of PAE and PAs. In our study, we observed differential expression of genes related to PA metabolism in C. fimbriata under PAE stress. We further investigated the impact of both exogenous and endogenous PAs on the growth and response of C. fimbriata under external stress. Our results indicated that both exogenous and endogenous PAs could alter the resistance and growth of C. fimbriata. Additionally, endogenous PAs influenced the growth and virulence of C. fimbriata by affecting the expression of the MAPK pathway. Furthermore, PAs were found to mitigate the damage caused by C. fimbriata under external stress, with their effectiveness closely tied to the concentration of PAs. Notably, the response to the PA concentration differed between sweetpotato and C. fimbriata. Combined treatment with 1 mM PAs and PAE significantly boosted the activities of Superoxide dismutase (SOD), Peroxidase (POD), Polyphenol oxidase (PPO), and other enzymes in postharvest sweetpotato, resulting in a notable reduction in the occurrence of postharvest sweetpotato black rot. These discoveries offer a novel strategy for managing postharvest fungal diseases in fruit and vegetables.