水杨酸对湖北海棠活性氧代谢及超微弱发光的影响

 以50 μg·mL ^{- 1}水杨酸( SA) 喷施湖北海棠(Malus hupehensis Rehd. ) 幼苗, 结果显示: 超氧阴离子O^·₂ 的产生速率在处理后12～48 h明显高于对照, 而在72 h以后明显低于对照; H₂O₂ 含量在水杨酸处理后, 始终高于对照, 并在处理后第12和48小时出现两次峰值。POD活性在处理12 h后逐渐增加,SOD活性则在处理48 h后才有显著的增加, 而CAT在处理后24 h内活性高于对照, 48 h后明显低于对照。SA还明显促进了脂过氧化产物丙二醛(MDA) 的产生, 也明显促进了叶片的超微弱发光, 超微弱发光值在处理后的120 h内始终高于对照, 但在整个试验过程中超微弱发光的变化趋势与H₂O₂ 含量及O^·₂ 的产生速率的变化趋势明显不同。

Effects of Salicylic Acid on the Active Oxygen Metabolism and Ultraweak Luminescence of Malus hupehensis Rehd

The change of active oxygen and ultraweak luminescence (UWL ) in leaves was studied by spraying Malus hupehensis Rehd. seedlings with 50 μg·mL ^{- 1} exogenous salicylic acid ( SA). The results showed the generation rate of superoxide anion O^·₂ was higher than that of the control between 12 h and 48 h after treatment. H₂O₂ level was significantly increased with two peaks at the 12 h and 48 h. In the meantime, the activity of peroxidase ( POD) was enhanced step by step from 12 h to 120 h, and superoxide dismutases ( SOD) activity was significantly increased after 48 h of treatment. Moreover, catalase (CAT) activity was higher than that of the control within 24 h, but lower from 48 h to 120 h. The content of malondialdehyde (MDA) and ultraweak luminescence in leaves enhanced after SA treatment, and the value of UWL was higher than the control of all the time within 120 h. The change ofUWL is different from one of the H₂O₂ and O_^·2 in the course of whole experiment.