Abstract

During postharvest life, floret yellowing confines broccoli’s economic and nutritional worth. This study aimed to investigate the mechanisms activated by octapeptide NOP-1 (LKRYKRRL-NH2) treatment at 0, 250, 500, 750, or 1000 μM for retarding floret yellowing in broccoli during storage at 4 ◦C for 28 d. Our results revealed that the 750 μM NOP-1 treatment retarded chlorophyll degradation by suppressing pheophytinase (PPH) and pheophorbide a oxygenase (PaO) genes expression along with inhibiting Mg2+ dechelatase (MDC), and PPH enzymes activity. Besides, 750 μM NOP-1 treatment prevented jasmonic acid (JA) biosynthesis by suppressing phospholipase A (PLA), 13-lipoxygenase (13-LOX), allene oxide synthase (AOS), allene oxide cyclase (AOC), and OPDA reductase (OPR3) genes expression. Interestingly, 750 μM NOP-1 treatment maintained the membrane integrity in broccoli floret, evaluated by malondialdehyde (MDA) accumulation, which could be ascribed to the suppressing phosphatidylinositol 3-kinase (PI3K), phospholipase D (PLD), and 9-lipoxygenase (9-LOX) genes expression. Our results demonstrated that NOP-1, as an innovative, safe, and eco-friendly antisenescence octapeptide, significantly advances our technological proficiency to delay floret yellowing in broccoli during low temperature storage.