热空气处理对杨梅果实采后活性氧代谢和热激蛋白合成的影响

研究热空气处理对杨梅果实采后活性氧代谢以及热激蛋白合成的影响。以48℃热空气处理杨梅果实3h，随后于(1±1)℃贮藏12d，并每隔3d测定果实腐烂率，膜脂氧化指标脂氧合酶(LOX)活性，活性氧代谢相关酶超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和抗坏血酸过氧化物酶(APX)活性以及超氧阴离子自由基(O2－ ·)和羟自由基( ·OH)生成量，并同时检测热激蛋白(HSP)合成水平。结果表明，热处理可显著延缓果实贮藏期间SOD、CAT和APX活性的下降，诱导HSP的合成，从而抑制O2－ ·和 ·OH的积累和LOX活性的上升，减轻了过量活性氧自由基对细胞膜的损害。热空气处理延缓杨梅果实采后衰老并减少腐烂的机制与其平衡活性氧代谢和诱导热激蛋白的合成密切相关。

Effect of Hot Air Treatment on Active Oxygen Metabolism and Heat-shock Protein Biosynthesis in Chinese Bayberry

The effects of hot air treatment on active oxygen metabolism and heat-shock protein (HSP) biosynthesis in harvested Chinese bayberry were investigated in this study. The fruit were pretreated with hot air at 48 ℃ for 3 h, then stored at (1 ± 1) ℃ for 12 d. Decay incidence, the activities of superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX) and lipoxygenases (LOX), and the production of superoxide anion and hydroxyl radicals as well as HSP level were determined at 2-day intervals during storage. Hot air treatment significantly delayed the decrease in the activities of SOD, CAT and APX and induced HSP biosynthesis, resulting in inhibition of the accumulation of superoxide anion and hydroxyl radicals and the increase in LOX activity and alleviation of the oxidative damage to plasma membrane. These results suggest that the mechanism of delaying fruit senescence and inhibiting fruit decay by hot air treatment may be closely associated with maintenance of the balance between active oxygen metabolism and the induction of HSP biosynthesis.