Transcriptome analysis reveals the mechanism of polyethylene atmosphere packaging delaying browning of postharvest Pleurotus eryngii

To elucidate the mechanism of low-density polyethylene(LDPE) atmosphere packaging on delaying browning of Pleurotus eryngii under a postharvest low-temperature storage, this study focused on exploring the effects of two thicknesses (0.02 and 0.05 mm) LDPE packaging on some antioxidant enzymes, and stress markers in P. eryngii. The results showed that LDPE atmosphere packaging maintained the phenolic content and higher superoxide dismutase (SOD), ascorbate peroxidase (APX) and catalase (CAT) levels, reduced malondialdehyde (MDA) content, electrolyte leakage rate and polyphenol oxidase (PPO) levels in the mushroom. Also, transcriptome analyses showed that LDPE atmosphere packaging regulated the expression of enzymes PPO, POD, CAT and APX-related genes, inhibited the expression of lipoxygenases (LOX) and phospholipase D (PLD)-related genes and regulated the l-glutathione (GSH) antioxidant system. Overall, LDPE atmosphere packaging delayed the reduction of unsaturated fatty acids and energy loss by maintaining the integrity of cell membranes and regulating important genes involved in membrane lipid metabolism, energy metabolism, and respiratory metabolism of P. eryngii. In addition, it activated the expression of genes related to GSH synthesis and metabolism, thus enhancing the antioxidant capacity of mushroom body, reducing the accumulation of ROS and delaying browning.