遮荫对牡丹叶片活性氧代谢和抗氧化酶活性的影响

以牡丹品种‘大胡红’为试材,对夏季大田牡丹叶片进行自然光照和遮荫处理(遮光50%),测定牡丹叶片MDA和H2O2含量,活性氧O2.-产生速率,抗氧化酶SOD和CAT的活性,以探讨遮荫对牡丹叶片活性氧代谢和抗氧化酶活性的影响。结果表明:遮荫处理后与自然光照下相比,牡丹叶片MDA和H2O2的含量以及O2.-生成速率的增加幅度均显著减小;SOD、CAT的活性均降低。这说明在夏季自然条件下,牡丹叶片发生了膜脂过氧化作用,而遮荫后叶片的膜脂过氧化程度降低,抗氧化酶活性降低。

Effects of Shading Treatment on Active Oxygen Metabolism and Activities of Antioxidant Enzymes in Tree Peony Leaves

With the tree peony cuhivar ＇Dahuhong＇ as experimental material and the natural light as control, the effects of shading treatment （in 50% shading） on active oxygen metabolism and antioxidant en- zymes activity were studied through detecting the contents of MDA and H2 02, the production rate of O2-, and the activity of SOD and CAT. The results showed that the contents of MDA and H2 02 and the production rate of O2- in tree peony increased continuously, but the increasing levels in shading treatment were lower than those in natural light. Furthermore, the activities of SOD and CAT decreased under shading treatment. In con- clusion, the membrane lipid peroxidation occurred in leaves of tree peony in natural light of summer. Howev- er, membrane lipid peroxidation was alleviated and the activities of SOD and CAT were reduced under shading treatment.