大白菜幼苗叶片抗氧化酶系统对黑腐病菌入侵的反应

Response of anti-oxidant system to infection of Xanthomonas campetris pv. campestris in seedling leaf of Chinese cabbage

以大白菜抗病品种秦白2号和感病品种06J31为材料,研究其接种黑腐病菌种YL-17后保护酶活性、超氧阴离子和MDA含量的变化。结果显示:接种后不同抗性的材料总体上表现为超氧阴离子(O2-.)含量先降后升,SOD活性逐步降低,POD活性MDA含量逐步升高,CAT活性则二者变化不一致(抗性材料表现为升-降-升,感性材料表现为先降后升)。由此表明:黑腐病菌侵染大白菜后,抗病材料与感病材料相比,能迸发较多的O2-.并刺激抗氧化物酶SOD和POD活性升高,使MDA含量处于较低的水平,有利于提高秦白2号抗黑腐病和抗氧化能力。

Chinese cabbage cultivars Qinbai No. 2 was used as resistant species and 06J31 as susceptible one. They were infectted by （Xanthomonas campetris pv. campestris） YL-17. The dynamic changes of defensive enzymes activity, O2^-and malondial dehyde （MDA） content in the seedlings were studied. The results showed that,O2^-content declined firstly, and then rose sharply, superoxide dismutase （SOD） activity declined gradually, peroxidase （POD） activity and malondial dehyde （MDA） content rose gradually all the time in the two species after infection. However,the changes of catalase （CAT） activity were different. In the resistant cultivar Qinbai No. 2, it rose firstly, declined then, and finally rose again. Whereas, in the susceptible cultivar 06J31, it declined firstly and then rose. It demonstrated that more O2^- were bursted after infection, and SOD and POD activities were higher in resistant cultivar, which were helpful to improve the resistance to black rot and membrane lipid oxidation.