苏云金杆菌对淡色库蚊幼虫抗氧化酶的影响

Effects of Bacillus thuringiensis on antioxidant enzymes in Culex pipiens pallens larvae

目的测定苏云金杆菌(Bacillus thuringiensis,Bt)对淡色库蚊幼虫的毒力,以及Bt浸渍后淡色库蚊幼虫体内抗氧化酶浓度的变化。方法采用浸渍法测定Bt溶液对淡色库蚊幼虫的毒力;应用酶联免疫吸附法(ELISA)测定4 mg/ml Bt处理24 h后未致死组(A)、致死组(B)和对照组(C)的抗氧化酶浓度。结果2、4和8 mg/L Bt溶液对淡色库蚊幼虫均有一定的毒力。A组、B组和C组的过氧化氢酶(CAT)浓度分别为(123.75±1.09)、(112.83±1.46)和(108.17±3.26)ng/ml,差异具有统计学意义(F=41.182,df=2,P<0.0001);超氧化物歧化酶(SOD)的浓度分别为(12.10±0.10)、(10.12±0.46)和(10.04±0.62)ng/ml,差异具有统计学意义(F=20.447,df=2,P=0.002);谷胱甘肽过氧化物酶(GSH-PX)浓度分别为(64.33±4.41)、(58.90±4.30)和(55.53±0.72)ng/ml,差异没有统计学意义(F=4.617,df=2,P=0.061)。结论淡色库蚊幼虫体内的抗氧化酶可能在抵抗Bt浸渍的过程中发挥重要作用。

Objective To determine the virulence of Bacillus thuringiensis(Bt)to the larvae of Culex pipiens pallens,and to investigate the changes in the concentrations of antioxidant enzymes in the larvae after Bt application.Methods The toxicity of Bt to the larvae of Culex pipiens pallens was determined by dipping method.Enzyme-linked immunosorbent assay(ELISA)was performed to measure the concentrations of antioxidant enzymes in non-lethal group(A)and lethal group(B)treated with 4 mg/ml Bt 24 h after the application and control group(C,without Bt treatment).Results The 2,4 and 8 mg/L Bt solutions all displayed toxicity to Culex pipiens pallens larvae.Respectively in group A,group B and group C,the concentrations of catalase(CAT)were(123.75±1.09),(112.83±1.46)and(108.17±3.26)ng/ml,with significant difference(F=41.182,df=2,P<0.0001);the concentrations of superoxide dismutase(SOD)were(12.10±0.10),(10.12±0.46)and(10.04±0.62)ng/ml,with significant difference(F=20.447,df=2,P=0.002);and the concentrations of glutathione peroxidase(GSH-PX)were(64.33±4.41),(58.90±4.30)and(55.53±0.72)ng/ml,without significant difference(F=4.617,df=2,P=0.061).Conclusion The antioxidant enzymes in the larvae of Culex pipiens pallens may play an important role in the resistance to Bt infection.