鲜切南瓜组织中乙烯产生及1-氨基环丙烷-1-羧酸(ACC)氧化酶活性的变化

本文以鲜切南瓜为实验材料,研究了切割伤害诱导、外源乙烯和降冰片二烯NBD(2,5-norbonadien)处理对乙烯的产生和ACC氧化酶活性的影响.结果表明,南瓜切割和外源乙烯处理都可诱导乙烯产生和ACC氧化酶活性急速上升,达到高峰后逐渐下降并恢复到接近原来的水平.NBD可有效抑制由伤害诱导的ACC氧化酶活性的增加,进而抑制了乙烯的产生.但当外源乙烯和NBD存在时,ACC氧化酶活性不受NBD抑制,其活性明显增加,然后逐渐下降,72h后恢复到接近原来水平,而乙烯的产生显示了与对照相似的显著增加的结果.实验结果认为切割机械伤害和乙烯处理都可通过诱导ACC氧化酶活性的提高而使乙烯的产生显著增加,NBD对ACC氧化酶的抑制作用可被乙烯所解除.

Changes in Wounding Ethylene Production and ACC Oxidase in Fresh-cut Squash

Effects of cutting,exogenous ethylene and NBD treatments on wounding induced ethylene production and ACC oxidase activity in fresh-cut squash(Cucurbita maxima Duch.)were investigated.It indicated that ACC oxidase and wounded ethylene production increased sharply to reach peak after cutting and then decreased gradually.The increase of ACC oxidase activity induced by wounding was obviously inhibited by NBD and recovered primary level after 72 h.But the ACC oxidase activity increased markedly and decreased gradually,ethylene production also increased significantly same as the control level treated by combination of exogenous ethylene and NBD.It was considered that increases of ACC oxidase and wounded ethylene production were induced by cutting and ethylene,inhibition of NBD to ACC oxidase was counteracted by exogenous ethylene.