外源NO和ABA对杨树气孔运动和SOD及POD活性的影响

Effect of Exogenous NO and ABA on the Leaf Stomatal Movement and Enzyme Activities of Scavenging Free Radical of Populus

研究了外源NO和脱落酸(ABA)对杨树气孔运动和SOD、POD活性的影响。结果表明 :NO和ABA均可诱导杨树叶片气孔关闭 ,且NO有加强ABA诱导气孔关闭的作用。NO清除剂(C -PTIO)能显著抑制NO和ABA对气孔关闭的诱导效应。不同浓度硝普钠(SNP)和ABA处理杨树离体叶片 ,SOD活性变化不明显 ,POD活性受到显著抑制。粗酶液的体外实验结果表明 ,不同浓度SNP对POD活性的抑制呈明显的浓度及时间效应 ;而ABA对POD活性则几乎没有影响。说明在ABA调控气孔运动的过程中需要NO的参与 ,由此推测ABA对杨树叶片气孔运动的调节与NO对POD的抑制有关。

The effect of exogenous NO and ABA on the leaf stomatal movement and enzyme activities of scavenging free radical of populus was studied.Results showed that different concentrations of SNP and ABA induced stomatal closure of detached populus leaves.Besides,the inductions of stomatal closure by ABA were enhanced by NO.PTIO,a specific NO scavenger,had the effect of alleviating the role of NO and ABA on the leaf stomatal closure.With different concentrations of SNP and ABA,the activities of POD were dramatically inhibited while the activities of SOD hardly decreased.In vitro experiments,however,the activities of POD were dramatically inhibited by NO not ABA.Therefore,NO,which perhaps played a role in regulating H 2 O 2 levels by inhibiting POD,was a signal component of ABA-induced stomatal closure.