Physiological and transcriptomic analysis provide new insights into the mechanisms regulating the maintenance of postharvest quality of goji berry fruit in response to 1-MCP

The physiological indices, reactive oxygen species (ROS) metabolism, and mitochondrial redox metabolism were investigated during 15 days of storage to assess the impact of 1-methylcyclopropene (1-MCP) on the postharvest quality of goji berries in both control and treated groups. The results demonstrated that 1-MCP maintained the physiological qualities of postharvest goji berry fruits, including delaying the appearance of respiratory peak, increasing titratable acid content, and decreasing weight loss. Transcriptome analysis indicated that 1-MCP activated the transcription of genes related to ROS and mitochondrial redox metabolism in goji berry fruits. 1MCP suppressed the increase in conductivity and membrane lipid peroxidation, and reduced the generation rate of O-2(center dot-) (112.7 mmol min(-1) g(-1)) and the content of H2O2 (0.75 mu mol g(-1)). Meanwhile, 1-MCP activated the activities of superoxide dismutase (SOD) (2.4 U g(-1)), catalase (CAT) (46.4 U g(-1)), peroxidase (POD) (3.6 U g(-1)), ascorbate peroxidase (APX) (1.9 U g(-1)) and glutathione reductase (GR). Besides, the amount of ascorbic acid (AsA) and glutathione (GSH) was promoted by 1-MCP, while the opposite was noted in the glutathione disulfide (GSSG) content. 1-MCP treatment enhanced the NAD(P)+ content, decreased the NAD(P)H content, and increased the NAD(P)+/NAD(P)H ratio in mitochondrial. Results suggest that postharvest storage quality of goji berry could be promoted by 1-MCP via regulation of ROS metabolism and mitochondrial redox metabolism.