苹果果实发育成熟软化过程中脂氧合酶活性变化及采后乙烯调控

以富士、金冠和嘎拉苹果果实为试材,研究了脂氧合酶（LOX）在果实生长发育至采后软化过程中的变化规律及采后乙烯调控对其活性的影响。结果表明：在果实发育及后熟过程中,富士、金冠和嘎拉3个品种果实的LOX活性呈相似的变化规律,在幼果期均出现较高活性高峰,之后下降,至成熟后果实LOX活性又开始提高。品种间比较结果显示,虽然富士果实LOX在幼果期出现较高峰值,但之后下降迅速直至采收初期,而此间金冠和嘎拉果实LOX活性及增加速率均高于富士,说明LOX活性表达状况可能是衡量果实贮藏特性的一个重要因素。采后乙烯调控后,乙烯抑制剂1-MCP能极显著地抑制苹果果实LOX活性,在贮藏期间其活性基本恒定,而乙烯利对其活性虽有促进作用,但不如1-MCP的作用显著,因品种贮藏性不同而有所差异,其确切机理有待进一步探讨。

Changes of Lipoxygenase Activity of Apple at Softening Stage and Ethylene Regulation after Harvest

Taking three apple cultivars(Fuji,Golden Delicious and Gala) as material,the change of lipoxygenase(LOX) activity during fruit development and softening stages and the effect of ethylene regulation on LOX activity after harvest were studied.The results indicated that the LOX activities showed the similar changes in the three apple cultivars during fruit developing and ripening periods,that was to say,the LOX activity reached the peak at the young fruit stage,then decreased rapidly,and gradually increased after fruit maturation.Among the three different apple cultivars,the LOX activity of Fuji was lower than Golden Delicious and Gala during fruit rapid growing stage,maturation and ripening stages.It dramatically increased at young fruit stage in Fuji apple,therefore,the change of LOX activity was considered to be correlated with the storage characteristic of apple fruit.Ethylene inhibitor 1-Methycyclopene(1-MCP) could significantly inhibit the LOX activity after harvest.During the apple storage stage,the LOX activity was basically constant and it could be promoted by ethylene.However,the effect of ethylene was weaker than 1-MCP,it was different because of the apple storage property,so their regulating mechanism was neeeed more research.