Changes of Antioxidative Enzymes and Lipid Peroxidation in Leaves and Roots of Waterlogging-Tolerant and Waterlogging-Sensitive Maize Genotypes at Seedling Stage

To better understand the physiological and biochemical mechanisms of waterlogging tolerance, waterlogging effects on lipid peroxidation and the activity of antioxidative enzymes were investigated in leaves and roots of two maize genotypes, HZ32 （waterlogging-tolerant） and K12 （waterlogging-sensitive）. Potted maize plants were waterlogged at the second leaf stage under glasshouse conditions. Leaves and roots were harvested 1 d before and 2, 4, 6, 8 and 10 d after the start of waterlogging treatment. Through comparing the activities of superoxide dismutase （SOD）, ascorbate peroxidase （APX）, glutathione reductase （GR）, catalase （CAT） and guaiacol peroxidase （POD） between waterlogging-tolerant and waterloggingsensitive genotype, we deduced that CAT was the most important H2O2 scavenging enzyme in leaves, while APX seemed to play a key role in roots. POD, APX, GR and CAT activities in conjunction with SOD seem to play an essential protective role in the O2^- and H2O2 scavenging process. Lipid peroxidation was enhanced significantly only in K12 （P 〈 0.001） and there was no difference （P 〉 0.05） in HZ32 up to 6 d after waterlogging stress. These results indicated that oxidative stress may play an important role in waterlogging-stressed maize plants and that the greater protection of HZ32 leaves and roots from waterlogging-induced oxidative damage results, at least in part, through the maintenance of increased antioxidant enzyme activity.

模拟厌氧胁迫对薏苡和玉米抗氧化酶活性及膜脂过氧化物的作用

研究了模拟厌氧胁迫下薏苡(Coix lacrymajobi L.)和玉米(zea may L.)的丙醛(MDA)和过氧化脂质(LPO)含量及超氧物歧化酶(SOD)和过氧化物酶(POD)活性的变化。结果表明:厌氧胁迫处理增加薏苡、玉米根系和叶片的MDA的含量,同时导致膜脂过氧化物的生成;但在根系中,薏苡膜脂过氧化物含量低于玉米,MDA含量与处理前比较处于较低水平,此外,薏苡根系中SOD维持较高的活性,而玉米则在叶片中有较高的POD和SOD活性。