镍对离体玉米叶片衰老的调节作用

Retardation of senescence by nickel treatment in detached maize leaves

本文研究了镍对离体玉米叶片衰老的调节作用。研究结果表明 ,玉米叶片在衰老过程中 ,超氧化物歧化酶 (SOD)、过氧化物酶 (POD)、过氧化氢酶 (CAT)、抗坏血酸过氧化物酶 (AsA—POD)活性和抗坏血酸(AsA)含量显著降低 ,超氧阴离子自由基 (O- ·2 )产生速率显著增加 ,脂质过氧化作用加剧 ,丙二醛 (MDA)含量升高 ,细胞质膜透性增大。而 1 0 - 2 、1 0 - 3 mol·L- 1Ni2 +处理能增强上述保护酶活性和抗氧化剂AsA的含量 ,从而能减轻细胞膜脂过氧化作用。 1 0 - 3 、1 0 - 2 mol·L- 1Ni2 +处理能显著延缓蛋白质和叶绿素的降解。因此镍能延缓离体玉米叶片的衰老 ,尤其是以 1 0 - 2 mol·L- 1Ni2 +对衰老的延缓作用更大。动态测定结果表明 ,1 0 - 2 mol·L- 1Ni2 +处理能使衰老滞后 2— 3天。

The retardation of senescence by nickel treatment in detached maize leaves was studied in this paper .The activies of superoxide dismutase(SOD),catalase(CAT),peroxidase(POD)and ascorbate peroxidase(AsA-POD) and contents of ascorbic acid (AsA) declined significantly during the senescence of detached maize leaves.However the generative rate of superoxide radical(O 2 -·)increased markedly and the contents of malondialdehyde(MDA) increased significantly.10 -3 or 10 -2 mol·L -1 Ni 2+ treatment could significantly enhance the function of the protective systems and increase the contents of antioxidant AsA.So Ni 2+ treatment could alleviate the membrane lipid peroxidation.Ni 2+ treatment could retard the decrease of protein and chlorophyll.So Ni 2+ treatment could retard the senescence of maize leaves,esp.10 -2 mol·L -1 Ni 2+ treatment.The continous observing showed that 10 -2 mol·L -1 Ni 2+ treatment can retard the senescence proceeding for two to three days.