Exogenous Melatonin Attenuates Post-harvest Decay by Increasing the Antioxidant Activity of Wax Apple (Syzygium samarangense)

Our experiments show that exogenous MT treatment can effectively delay the decay and water loss rate of post-harvest wax apples, which may be related to reducing the degree of membrane lipid peroxidation and inhibiting enzymatic browning. MT treatment also maintains the quality of post-harvest wax apple by enhancing the activity of antioxidant enzymes. At the same time, it can reduce the incidence of post-harvest diseases of wax apple by increasing the JA and SA contents. MT can down-regulate the expression of genes related to oxidation, and up-regulate the expression of related genes in antioxidant enzymes and non-enzymatic antioxidant pathways, suggesting that exogenous melatonin can reduce the production of excess ROS and maintain the redox homeostasis of post-harvest wax apple. Therefore, melatonin, as a strong and effective free radical scavenger and antioxidant, plays an important role in delaying the decay of post-harvest wax apples and prolonging the shelf life. Using IlluminaHiseq4000, de novo transcriptome sequencing was performed on the 5th day of wax apple samples, including control group and 800µM melatonin (MT) treatment group, including 3 biological repeats.