以‘贵农5号’刺梨为材料,研究了果实和叶片发育过程中主要保护酶和抗坏血酸(AsA)的变化.结果表明,刺梨果实和叶片内都具有较高的SOD活性,并在发育过程中呈基本相似的变化模式;总体上看,刺梨叶片中具有较高的POD和CAT等抗氧化酶活性,并呈‘初期升高后期降低’的变化趋势,但AsA含量及其氧化还原态(AsA与AsA库的比值)较低.在果实中,SOD活性和AsA含量高,而POD活性很低,并且在果实发育中、后期降至检测不到的水平,整个生育期都未能检测到CAT活性.这表明刺梨果实和叶片中存在着不同的自由基清除协作机制.
Rosa roxburghii Tratt‘Guinong 5’was used to investigate the co-changes of antioxidant enzymes activity and ascorbic acid contents in fruits and leaves during the development. The results showed that the high activity of SOD presented in both fruits and leaves, and basically with a parallel pattern during the development. The high activities of POD and CAT and low ascorbate content, which increased at the early developmental stage but decreased later in leaves. By comparison, the fruit had a remarkable characteristics of extreme richness of both SOD and ascorbic acid although transitory and weak POD and no CAT activity was detected during the fruit development. These data revealed that different ROS-scavenging mechanisms co-operating in the fruits and leaves of this plant.