Lipid metabolism regulated by superoxide scavenger trypsin in Hylocereus undatus through multi-omics analyses

To analyze the mechanism of the effect of trypsin on the preservation of Hylocereus undatus, the transcriptomic and widely targeted metabolomic profiles of H. undatus after trypsin treatment were evaluated. Among 477 genes related to lipid metabolism, 32 genes had significant expression differences. GO analysis results showed that the main enriched GO functions include pectinesterase and asparagine esterase activities, and so on. The KEGG metabolic pathway with the highest enrichment rate was fatty acid elongation. The protein-protein interaction (PPI) network analysis results showed that the PPI network of lipid metabolism is a complex biological network of scale-free cells. KCS1, QRT1, and ACC1 acted as hubs to regulate a large number of other proteins and amplify the regulatory role of trypsin to achieve a preservation effect. In addition, three unsaturated fatty acids were upregulated, while eight saturated fatty acids were downregulated. PRACTICAL APPLICATIONS: The postharvest storage of fresh fruits and vegetables brings about bottlenecks to fresh fruits and vegetables. There was also an increasing need for biopreservation techniques. Trypsin could significantly enhance the antioxidant capacity of fruits and vegetables, as a preserver for the storage of fruits and vegetables, which was convenient to operate and more economical. The regulation mechanism of trypsin on lipid metabolism in fruits and vegetables during storage of H. undatus is studied in this paper. The application of trypsin would provide a new strategy for quality control of fruit and vegetable storage.