Synergistic effects of a chitosan-pectate composite coating on postharvest preservation and Underlying mechanisms in mango Fruit

This study developed a novel chitosan-pectate (CS-PA) composite coating to enhance the postharvest preservation of ‘ Taimang’ mango. The CS-PA coating demonstrated synergistic effects, significantly outperforming individual CS or PA treatments. It more effectively reduced decay incidence (by 38% compared to CS alone) and weight loss, delayed the respiratory climacteric peak, and better maintained firmness and titratable acidity. Mechanistically, the composite coating synergistically enhanced antioxidant enzymes (SOD, APX) activities, reducing oxidative damage (H 2 O 2 and MDA). It also most effectively suppressed the activities and gene expression of cell wall-degrading enzymes (PG, PME), thereby preserving pectin integrity. Notably, the CS-PA coating uniquely and simultaneously activated key genes in both salicylic acid (MiPR1) and jasmonic acid (MiLOX) signaling pathways, indicating potentiated systemic resistance. The superior performance is attributed to a multi-tiered synergy involving a robust physical barrier, enhanced antioxidant capacity, preserved cell wall integrity, and induced broad-spectrum defense. This composite coating presents a promising, eco-friendly strategy for mango preservation. • A novel chitosan-pectate (CS-PA) composite coating was developed for mango. • CS-PA coating synergistically delayed softening and suppressed postharvest decay. • The composite uniquely activated both salicylic acid and jasmonic acid pathways. • Synergistic suppression of cell wall disassembly enzymes and genes was revealed. • CS-PA enhanced antioxidant system and reduced oxidative damage synergistically.