飞蝗两种群羧酸酯酶及谷胱甘肽S-转移酶活性与马拉硫磷敏感性关系的研究

对飞蝗天津北大港种群及河北沧州种群进行了生物测定与生化水平的比较分析,生物测定结果显示,天津北大港种群对马拉硫磷的LD50值为河北沧州种群的13.2倍,显示天津北大港种群已对马拉硫磷产生了耐药性.两种群羧酸酯酶比活力分析表明,以α-醋酸萘酯(α-NA)为底物时,两种群羧酸酯酶比活力无显著差异；以α-丁酸萘酯(α-NB)和β-醋酸萘酯(β-NA)为底物时,飞蝗天津北大港种群较河北沧州种群羧酸酯酶比活力为低,且具有显著差异.以1氯-2,4-二硝基苯(CDNB)为底物对两种群谷胱甘肽S-转移酶活性进行检测,结果表明,河北沧州种群谷胱甘肽S-转移酶比活力高于天津北大港种群.以上结果显示,天津北大港种群对马拉硫磷的耐药性,可能与羧酸酯酶和谷胱甘肽S-转移酶没有直接的相关性,而与靶标敏感性的下降有关.

Activities of Carboxylesterases and Glutathione S-transferases Related to Malathion Susceptibility in two Populations of Locusta migratoria

A series of comparative analysis including bioassay,biochemical studies to the locust collected from Tianjin beidagang and Hebei cangzhou were conducted.The bioassay indicated that Tianjin Beidagang population was tolerance to malathion(tolerance ratio=13.2).The carboxylesterases(CarEs) specific activity with α-naphthyl butyrate(α-NB) and β-naphthyl acetate(β-NA) substrates of the Hebei Cangzhou population was significantly higher compared with Tianjin Beidagang population.While the α-naphthyl acetate(α-NA) was used as substrate,the significant difference of CarEs specific activity between two populations was not detected.The specific activity of glutathione S-transferases(GSTs) of Hebei Cangzhou population was significantly higher than these of Tianjin Beidagang population when 1-chloro-2,4-dinitrobenzene(CDNB) was used as substrate.All these results suggested that the observed tolerance to malathion in the Tianjin Beidagang population was not conferred by the CarEs and GSTs,but possibly related to the reduction of the target sensitivity.