The combined use of 1-MCP and laser microporous film packaging maintains the quality of Shine Muscat grapes by inhibiting oxidative stress and cell wall catabolism

Softening is a typical senescence symptom in postharvest Shine Muscat grape ( Vitis labruscana Baily × V. vinifera L.). Laser microporous membrane (LMF) packaging is an innovative preservation techniques for delaying senescence of fruits and vegetables. This study aims to investigate the effects of combining 1-methylcyclopropene (1-MCP) treatment with LMF packaging on the quality of harvested Shine Muscat grapes stored at 4±1 °C. The 1-MCP, LMF, and combined treatments mitigated color changing, and suppressed weight loss and the respiration rate compared to the control. All three treatments retarded the decrease in the pectin content and the increase in the soluble pectin content while maintaining relatively high ascorbic acid, titratable acid, and total soluble phenol contents and low soluble solid and reducing sugar contents. All treatments limited the activities of polyphenol oxidase, peroxidase, and lipoxygenase; maintained high superoxide dismutase, catalase, and ascorbate peroxidase activities; and correspondingly reduced superoxide anion, hydrogen peroxide, and malondialdehyde accumulation. These treatments also suppressed the activities of enzymes responsible for the degradation of pectin and cellulose, including cellulase, β-glucosidase, polygalacturonase, and pectin methylesterase. Quantitative real-time polymerase chain reaction analysis revealed significant downregulation of the expression of genes associated with pectin esterase and polygalacturonase ( VvPE7 , VvPE31 , VvPE53-1 , VvPG2 , and VvPG5 ), and there was notable upregulation of the expression of inhibitors of pectin esterase ( VvPE inhibitor 34 and VvPE inhibitor 36-1 ) and polygalacturonase ( VvPG inhibitor 1 ). In conclusion, the 1-MCP+LMF treatment may delay the deterioration in quality of harvested Shine Muscat grapes by regulating oxidative stress, membrane lipid metabolism, and softening-related genes that regulate cell wall catabolism. These results provide an alternative technology for preservation of postharvest berry fruits during storage. • 1-MCP+LMF inhibited softening and quality deterioration of Shine Muscat grapes; • 1-MCP+LMF limited sugar consumption, ROS production and membrane lipid peroxidation; • VvPE7/31/53-1 and VvPG2/5 may be key genes involved in pectin degradation; • The regulation mechanism of 1-MCP+LMF in pectin degradation were proposed; • 1-MCP+LMF could extend the shelf life of Shine Muscat grapes.