Methyl jasmonate maintained higher esters content of ‘Nanguo’ pear on shelf life by regulating unsaturated fatty acid and reactive oxygen metabolisms

Cold storage is a widely employed technique for prolonging the post-harvest shelf life of ‘Nanguo’ pear. Nonetheless, this method has been observed to diminish the fruit’s aromatic properties. Given the significance of aroma in determining the volatile quality, this research endeavors to examine the impact of methyl jasmonate (MeJA) in preserving aroma content, while also delving into the underlying molecular mechanisms that contribute to its efficacy. Upon observing the metabolic changes, it was found that the pear, sprayed MeJA, could keep higher the content of aroma, ascorbic acid, polyphenol, oleic acid, linoleic acid, and linolenic acid than the control, but stearic acid and H₂O₂ were decreased. The enzyme activities of lipoxygenase (LOX), alcohol acyl transferase (AAT), and catalase (CAT) were enhanced by MeJA treatment, but the polyphenol oxidase (PPO) was inhibited. Moreover, the gene expression levels of LOX, AAT, CAT, stearoyl-ACP desaturase (SAD), and fatty acid desaturase 2 (FAD2) were promoted by MeJA. It is reasonable that sprayed MeJA was a reliable method for inhibiting aroma loss and triggered unsaturated fatty acid and reactive oxygen metabolisms.