外源ABA对黄瓜幼苗抗低温胁迫的作用

在光照下对黄瓜(Cucuntis sativus L.)离体子叶圆片和幼苗分别使用10~(-6)mol/l 与10~(-4)mol/l ABA 处理,有防御低温伤害的作用,表现为降低子叶圆片的电解质渗漏,阻抑幼苗子叶的谷胱甘肽含量的下降和膜脂过氧化产物丙二醛(MDA)的累积,减缓叶片的光合作用的下降和叶绿素荧光的猝灭,提高幼苗的存活率。但这种作用可被黑暗和光合抑制剂(DCMU)所限制。

THE EFFECT OF EXOGENOUS ABA ON THE RESISTANCE TO THE CHILLING STRESS IN CUCUMBER SEEDLINGS

In the cucumber seedlings pretreated with ABA under light and dark or additional photo- synthetic inhibitor(DCMU)before chilling,the effect and the regulative role of ABA on the chilling resistance of cucumber seedlings were investigated.After the excised cotyledonary discs were floated on 10~(-6)mol/l ABA solution for 24h and the seedlings were sprayed by 10~(-4)mol/l ABA in light,it has been found that ABA has an effect of the protection against low temperature injury in cucumber seedlings.The results showed that the leakage of ele- ctrolytes in cucumber cotyledory discs was decreased.The content of glutathione and the ac- cumulation of MDA content in cotyledon of cucumber seedlings were decreased,and decline of the photosynthesis of the leaves or the quenching of chlorophyll fluorescence were slowed, thus the rate of survival in cucumber seedlings was raised.The effect of these regulation was able to be limited by dark or DCMU.