Effects of essential oil decanal on growth and transcriptome of the postharvest fungal pathogen Penicillium expansum

Penicillium expansum is a destructive phytopathogen provoking the blue mold decay of pome fruits and producing a polyketide-derived mycotoxin, patulin. In this study, the effects of exogenous essential oil decanal on development and patulin production of P. expansum were determined. Results indicated that 0.12 g L−1 decanal could significantly inhibit the growth of P. expansum in vitro. 0.24 g L−1 decanal showed a good controlling effect against the blue mold rot on apple and pear fruit. Besides, decanal could inhibit patulin production and the expression of genes involved in patulin biosynthesis. Through RNA sequencing approach, 1703, 3247 and 3963 genes were found which have changed abundantly after 6 h, 12 h and 18 h of incubation in decanal treated samples. Differentially expressed genes (DEGs) mainly participated in metabolism and genetic information processing. The expressions of about two-thirds of the DEGs were down-regulated. Among them, DEGs involved in oxidative phosphorylation, transcription, and translation would be partly responsible for growth inhibition of P. expansum. The findings would provide some new insights for exploring the possible antifungal mechanisms of decanal against P. expansum.