Abstract An excessive ROS accumulation in harvested longan (Dimocarpus longan Lour.) fruit could promote the pulp breakdown and lower the fruit quality. To solve this problem, the influence of propyl gallate, one kind of ROS scavenger, on the ROS metabolism in pulp of postharvest longans and its connection with the breakdown occurrence of longan pulp were investigated. Contrasted to control samples, the propyl gallate-treated group manifested a lower index of pulp breakdown, MDA content, and production rate of O2−., but higher gene expression levels of DlSOD, DlCAT and DlAPX, higher SOD, CAT and APX activities, higher levels of AsA, flavonoid, GSH and total phenolics, and higher ability of scavenging free radicals. These results revealed that propyl gallate inhibited longan pulp breakdown occurrence, which was because propyl gallate enhanced the ROS scavenging ability and reduced ROS generation and accumulation in longan pulp. These activities involved alleviating the oxidative damage of cell membrane and the peroxidation of membrane lipid in longan pulp, which maintained the structural integrity of longan pulp cell membrane and suppressed the pulp breakdown occurrence in postharvest longan fruit.

中文翻译：

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没食子酸丙酯对龙眼果肉分解的抑制作用及其与ROS代谢的关系

摘要 采摘的龙眼（Dimocarpus longan Lour.）果实中过量的ROS积累会促进果肉分解，降低果实品质。为解决这一问题，研究了一种ROS清除剂没食子酸丙酯对采后龙眼果肉中ROS代谢的影响及其与龙眼果肉分解发生的关系。与对照样品相比，没食子酸丙酯处理组的纸浆分解指数、MDA 含量和 O2− 产生率较低，但 DlSOD、DlCAT 和 DlAPX 的基因表达水平较高，SOD、CAT 和 APX 活性较高，较高水平的 AsA、黄酮类化合物、GSH 和总酚类物质，以及较高的清除自由基能力。这些结果表明没食子酸丙酯抑制了龙眼果肉分解的发生，这是因为没食子酸丙酯增强了 ROS 清除能力，减少了龙眼果肉中 ROS 的产生和积累。这些活动涉及减轻细胞膜的氧化损伤和龙眼果肉中膜脂的过氧化，从而保持了龙眼果肉细胞膜的结构完整性并抑制了采后龙眼果肉的果肉破裂的发生。