Effect of 1-MCP treatment on cellulase activity and its gene expression to improve postharvest quality of custard apple fruit

The custard apple fruit is a respiratory climacteric fruit. Cell wall polysaccharide metabolism causes it to soften and decay rapidly during postharvest storage, which lowers its quality and shortens its shelf life. The objective of this work was to investigate the effect of 24-hour treatment with 1-MCP (1.8 mu L L-1) on the cellulase activity and its gene expression, evaluating the changes on postharvest quality of harvested custard apple fruit. The results showed that compared with the control group, 1-MCP treatment can depress the activity of cellulase and its gene expression level, by 11.37% and 25.25%, respectively. Furthermore, 1-MCP treatment could successfully preserve the firmness and prevent browning in appearance of the fruit, but had no discernible impact on the content of soluble solids (p < 0.05). Although the total amount of volatile compounds in treated custard apple fruits increased by 10 species compared with the control, 1-MCP treatment inhibited the production of esters and the degradation of aldehydes. After 1-MCP treatment, the activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) increased by 34.88%, 29.19%, and 16.97%, respectively. These results indicate that 1MCP treatment is a potentially effective method to improve postharvest quality, and enhance storage efficiency of custard apple fruit.