茉莉酸甲酯处理对采后葡萄离区膜脂过氧化及果实落粒的影响

Effects of methyl jasmonate treatment on membrane-lipid peroxidation in bunch abscission zone and fruit abscission in postharvest grape berries

分析了外源10μmol/L茉莉酸甲酯(M ethyl jasm on ate,MeJA)熏蒸处理对"巨峰"葡萄果穗在1℃贮藏期间离区膜脂过氧化及果实落粒的影响。结果表明,10μmol/LMeJA处理可显著降低葡萄果实冷藏期间落粒率、腐烂率和褐变指数,维持果实感官品质,同时显著诱导贮藏期间葡萄果穗离区组织中活性氧代谢酶(SOD、CAT、APX和POD)活性的上升并抑制超氧阴离子和羟基自由基生成量的增加。经MeJA处理的离区细胞膜中不饱和脂肪酸亚油酸和亚麻酸含量明显高于对照水平,而饱和脂肪酸棕榈酸和硬脂酸含量、相对电导率和MDA含量却显著低于对照水平。这些结果说明,MeJA处理可通过提高葡萄离区组织中活性氧代谢酶活性来减慢离区膜脂过氧化进程并维持离区细胞结构,从而降低了贮藏期间葡萄果实落粒率,改善了果实品质。

The effects of 10 IJmol/L methyl jasmonate on membrane lipid peroxidation in bunch abscission zone and fruit abscission in grape bunches cv. ＇Kyoho＇ during the storage at 1 ~C were investigated in the present study. The results showed that 10 IJmol/L MeJA treatment could significantly reduce the abscission rate, decay incidence and browning index, and maintain fruit sensory quality in grape berries during the cold storage, and induce SOD, CAT, APX and POD activities involved in active oxygen metabolism, and delay the increase in production of superoxide anions and hydroxyl radicals. Meanwhile, the MeJA-treated bunch abscission zone exhibited significantly higher unsaturated fatty acid of Linoleic acid and linolenic acid contents, but lower saturated fatty acid of palmitic acid and stearic acid and MDA contents as well as electrolyte leakage compared to the controls. Thus, these results implied that MeJA treatment markedly reduced the abscission rate in harvested grape berries during the storage and finally improved fruit quality possibly by the regulation of activities of active oxygen metabolism enzyme, which decelerated the process of membrane-lipid peroxidation in bunch abscission zone.