南极冰藻Chlorophyceae L4抗氧化酶活性对温度升高的响应

为了阐明南极冰藻Chlorophyceae L4抗氧化酶活性对温度升高的响应以及了解冰藻细胞内抗氧化酶系统对活性氧自由基的清除作用，对不同温度下（包括最适温度6℃、高于最适温度10℃和15℃）Chlorophyceae L4细胞中自由基的产生速率、丙二醛含量的变化和相应的抗氧化酶系统活性的变化进行了测定。结果表明，在环境温度高于最适生长温度的初期（24～72h），Chlorophyceae L4中自由基产生速率、丙二醛含量迅速提高，但随后（96～144h）很快降低，恢复到细胞能容忍的水平。各种抗氧化酶SOD、POD和CAT活性在初期显著降低，但随后响应温度的变化很快升高，明显比对照组的高，而且温度越高酶活性增幅越高。

Response of antioxidant enzymes activity in antarctic ice microalgae Chlorophyceae L4 to temperature increment

In order to understand antioxidant enzymes activities in response to temperature increment and the active oxygen free radical clearing function of antioxidant enzymes in antarctic ice mircoralgae Chlorophyceae L4, the free radical generation rate, the malonaldehyde （MDA） content changes and the corresponding antioxidant enzymes activities changes in Chlorophyceae L4 at different temperatures were determined. The results showed that the free radical generation rate and MDA content in Chlorophyceae L4 increased rapidly in early time （24 to 72 hours） of temperature increment, then decreased rapidly, and could return to tolerable level at the end of time. Under the stress of high temperature, the superoxide dismutase （SOD）, peroxidase （POD） and catalase （CAT） activities in Chlorophyceae L4 slowed down sharply in early time, then increased obviously, which were much higher than those in the control,and their activities became higher at higher temperatures. In a word, the antioxidant enzymes system plays an important role in the adaptation of antarctic ice microalgae to high temperature environment.