保护酶系在小菜蛾对阿维菌素抗性中的作用
The defending enzymes in abamectin resistant Plutella xylostella
吴青君1**，张友军1，徐宝云1，张文吉2
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作者单位：1中国农业科学院蔬菜花卉研究所北京100081；2中国农业大学北京100193
中文关键词：小菜蛾，阿维菌素，抗药性，保护酶系
英文关键词：Plutella xylostella, abamectin, resistance, defending enzymes
中文摘要： 对小菜蛾Plutella xylostella (L.)阿维菌素敏感（ABM-S）和抗性（ABM-R）种群的保护酶系（超氧化物歧化酶SOD、过氧化物酶POD和过氧化氢酶CAT）进行了活性比较。以单头虫表示酶活力，上述3种酶的活性与虫龄正相关，老熟幼虫期酶活性最高。总体上，ABM-S种群的3种酶活性高于ABM-R种群，SOD活性的种群差异随虫龄的增长而减小，1~2龄幼虫ABM-S种群的SOD活性是ABM-R种群的14.27倍。POD活性在3龄幼虫期性差异最大，为4.80倍。CAT活性在4龄末期幼虫无种群差异，其它龄期的活性差异约1~2倍。上述结果表明，阿维菌素抗性并未导致小菜蛾保护酶系统活性增加，这也暗示了昆虫酶系统的能量保守性。
英文摘要： The endogenous enzymes of the immune systems of abamectin susceptible (ABM-S) and resistant (ABM-R)
Plutella xylostella (L.), including superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT), were examined to determine whether their activities were affected by insecticide resistance. These three enzymes′ activities were positively correlated with larval stage in terms of enzyme activity per larva. On the whole, SOD, POD and CAT activity was lower in the ABM-R strain than in the ABM-S strain. Differences in SOD activity between the two strains decreased with each developmental stage. In the first to second instars, SOD activity in the ABM-S strain was 14.27fold higher than in the ABM-R strain. The biggest difference in POD activity was observed in the third instar, in which there was 4.28fold difference between strains. There was no significant difference in CAT activity between the late fourth instars of each strain but 1 to 2 fold difference in the activity of this enzyme was found in other developmental stages. These results indicate that pesticide resistance does not induce an increase in antioxidant enzyme activity, which suggests that there is a kind of energy conservation in the insect enzyme system.