Methyl jasmonate delays postharvest ripening and senescence in the non-climacteric eggplant (Solanum melongena L.) fruit

• Methyl jasmonate (MeJA) at 1 μM exerted the best preservation in eggplant.
• MeJA delays calyx browning in eggplant.
• MeJA induces enzyme activity and gene expression of POD and CAT.

Physiological disorders in harvested eggplant (Solanum melongena L.) fruit result in quality deterioration, short postharvest life and significant economic losses. In this study, the effects of methyl jasmonate (MeJA) on senescence in eggplant fruit were investigated. The results indicated that, compared to control, MeJA at 5 μM depressed ethylene production and effectively delayed fruit senescence. MeJA treatment was beneficial for maintaining fruit quality during storage, inhibiting increase of the calyx browning and weight loss, and retarding decline of sensorial quality, firmness and the anthocyanin content in peel. Moreover, MeJA effectively reduced the total phenolics content and the activity of the polyphenol oxidase (PPO) in calyx and pulp. MeJA also inhibited relative gene expression of PPO in pulp. The activities and gene expression of peroxidase and catalase were significantly induced by MeJA treatment. These findings indicate that the delayed senescence in eggplant fruit by MeJA is related with the decrease of enzymes associated with phenolics metabolism and antioxidant system. Our results suggest that MeJA has potential effect on maintaining the quality and extending postharvest life of eggplant fruit.