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通过水培试验,研究Cd2+胁迫对萝卜幼苗活性氧的产生、脂质过氧化和抗氧化酶活性的影响。超氧 阴离子(O 2)的产生速率和丙二醛(MDA)的含量与对照相比有不同程度的增加,表明Cd2+胁迫能导致萝卜体 内的氧化胁迫;超氧化物歧化酶(SOD)的活性,随着Cd2+浓度提高,首先明显上升,然后逐渐下降,甚至低于 对照,叶片过氧化氢酶(CAT)的活性明显增加,根系CAT活性则减少,根系以及较高浓度Cd2+处理后期叶片 谷胱甘肽还原酶(GR)的活性均显著增加。推测:胁迫初期可能主要由SOD和CAT发挥抗氧化作用;后期由 于抗坏血酸—谷胱甘肽(AsA GsH)循环途径的激活,以及还原型谷胱甘肽(GSH)和植物络合素(Phytochela tins,PCs)的合成,可能在清除活性氧或者直接鏊合Cd2+中起作用。
The effects of Cd2 + stress on reactive oxygen species production, lipid peroxidation and antioxidant enzyme activities in radish seedlings were studied through hydroponics. The generation rate of superoxide anion (O 2) and the content of malondialdehyde (MDA) increased to some extent compared with the control, indicating that Cd 2+ stress can lead to oxidative stress in radish; the activity of superoxide dismutase (SOD) , As the concentration of Cd2 + increased, the content of CAT increased firstly and then decreased gradually, even lower than that of the control, the activity of catalase (CAT) and the activity of CAT decreased in the root system and the higher concentration of Cd2 + Glycopeptide reductase (GR) activity were significantly increased. It is speculated that SOD and CAT may play an antioxidant role in the early stage of stress, that in the late stage due to the activation of the AsA GsH cycle pathway, and the reduction of GSH and Phytochela tins , PCs) may play a role in the removal of reactive oxygen species or direct Cd 2+ binding.