Effects of phosphatidic acid on strawberry fruit during cold storage: Insights into antioxidant system and lipid metabolism

Quality deterioration during cold storage is tightly associated with cellular membrane dysfunction in postharvest fruits. However, the regulatory role of phosphatidic acid (PA) and its underlying mechanism in non-climacteric commodities remain poorly understood. This study aimed to investigate the protective effects and mechanisms of exogenous PA in modulating postharvest behaviors of strawberry fruits. Harvested strawberries were treated with 100 μmol L −1 PA and stored at 4 °C for 15 d. Quality traits, oxidative damage markers, antioxidant system components, and membrane lipid metabolic enzymes, alongside key gene expressions, were systematically evaluated. Exogenous PA treatment markedly attenuated quality loss by effectively delaying fruit softening, reducing decay incidence and weight loss, suppressing H 2 O 2 and malondialdehyde accumulation, and preserving higher levels of ascorbic acid, total phenolics, and flavonoids. PA treatment significantly activated key antioxidant enzymes, thereby enhancing the ROS scavenging network. On the other hand, PA decreased saturated fatty acid proportions while promoting unsaturated fatty acid accumulation, concurrently maintaining higher pools of phosphatidylcholine (PC) and triacylglycerol (TAG). The alteration was mediated by inhibited enzymatic activities and corresponding transcript levels of genes involved in phospholipid degradation ( FaPLDα1 , FaNPC1 and FaPI-PLC6 ) and peroxidation ( FaLOX1 ), fatty acid desaturation ( FaFAD7 ), and TAG synthesis genes ( FaLPAT2 and FaDGAT1 ). Exogenous PA serves as an upstream signaling molecule to trigger antioxidant defense against oxidative stress, while subsequently maintaining membrane lipid homeostasis and fluidity through activating lipid remodeling. These findings offer novel insights into PA-mediated cold tolerance in non-climacteric fruits and provide a potential strategy for postharvest quality preservation.