镍对紫丁香离体叶片衰老的延缓作用

Retardation of Senescence in Detached Leaves of Syringa oblata by Nickel Treatment

用10、30、50、70μmol·L-1的Ni2+处理紫丁香离体叶片,研究了镍对紫丁香离体叶片衰老的作用效果。结果表明:紫丁香离体叶片在衰老过程中,可溶性蛋白质、叶绿素、抗坏血酸(AsA)和还原型谷光苷肽(GSH)含量显著降低;超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性明显下降;过氧化物酶(POD)活性增强;阴离子超氧自由基(O2-)产生速率、丙二醛(MDA)含量和外渗电导率明显升高,脂质过氧化作用加剧。Ni2+处理能显著地延缓可溶性蛋白质和叶绿素的降解,提高SOD和CAT活性,增加抗氧化剂AsA和GSH含量,使POD活性降低,O2-产生速率、MDA含量和外渗电导率下降,从而能减轻细胞膜脂过氧化作用。因此,镍能延缓紫丁香离体叶片的衰老进程。

Effects of nickel （10, 30, 50, 70 μmol · L^-1） on the senescence of detached Syringa oblata leaves were studied. Results showed that in the process of senescence, the contents of protein, chlorophyll , AsA and GSH decreased significantly, and the activities of superoxide dismurase （SOD） and catalase （CAT） also reduced significantly. However the activities of peroxidase （POD）, the generative rate of superoxide radical（ O2^- ）, the malondialdehyde （MDA） content and electric conductivity of the leaves increased significantly. Ni^2＋ treatment can significantly retard the degradation of protein and chlorophyll, enhance the activities of SOD and CAT, and increase the contents of antioxidant AsA and GSH. Ni^2＋ treatment can also decrease the activities of POD, generative rate of O2^-, MDA content and electric conductivity of the leaves, alleviate the membrane lipid peroxidation, and protect chloroplast. Therefore, it can slow down the senescence of detached Syringa oblata leaves.