论文部分内容阅读
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.
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 for 1 d before and 2, 4, 6, 8 and 10 d after the start of waterlogging treatment. Through the activities of superoxide dismutase (SOD), ascorbate peroxidase (APX), glutathione reductase (GR), catalase (CAT) and guaiacol peroxidase (POD) between waterlogging-tolerant and waterlogging sensitive 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. Lip id 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 indicate 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.