Toxicological and biochemical characterizations of malathion sensitivity in two field populations of Oxya chinensis (Orthoptera: Acridoidea) |
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作者姓名: | MEI-LING YANG HAI-HUA WU YA-PING GUO EN-BO MA |
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作者单位: | College of Life Science and Technology, Shanxi University, Taiyuan, China |
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摘 要: | We evaluate comparative toxicity of malathion in the two populations of the grasshopper Oxya chinensis, collected from Daixian and Fanshi of Shanxi province, China. General esterases and acetylcholinesterase (ACHE) from the two populations were characterized and compared. LD50 of the Daixian population (7.58 μg/g body weight) was 2.02-fold higher than that of the Fanshi population (3.75μg/g body weight). General esterase-specific activities in the Daixian population were 1.91,130 and 1.85-fold higher than those in the Fanshi population, when α-NA, α-NB and β-NA were used as a substrate, respectively. Kinetic studies of general esterase showed that Vmax values of general esterases hydrolyzing α-NA,α-NB and β-NA in the Daixian population were 2.15-, 1.12-, and 1.47-fold, respectively, higher than those in the Fanshi population. The AChE activity of the Fanshi population was 1.54-fold higher than that of the Daixian population. Kinetic analysis of AChE showed that significant differences were presented between the two populations in the Km values; and the Vmax value in the Fanshi population was higher than that in the Daixian population. Inhibition studies of AChE indicated that AChE from the Daixian population was 2.56-, 2.80-, and 2.29-fold less sensitive to inhibition by paraoxon, chlorpyrifos-oxon, and demeton-S-methyl, respectively, than that from the Fanshi population. These biochemical characterizations of general esterases and AChE were consistent with malathion bioassay in the two populations. It is inferred that the reduced sensitivity of altered AChE and increased general esterase activities play an important role in the differences of insusceptibility of Oxya chinensis to malathion between the two populations.
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关 键 词: | 毒物学 生物化学 杀虫剂 直翅目昆虫 |
收稿时间: | 2005-11-22 |
修稿时间: | 2005-11-22 |
Toxicological and biochemical characterizations of malathion sensitivity in two field populations of Oxya chinensis (Orthoptera: Acridoidea) |
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Authors: | MEI-LING YANG HAI-HUA WU YA-PING GUO EN-BO MA |
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Institution: | College of Life Science and Technology, Shanxi University, Taiyuan, China |
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Abstract: | Abstract We evaluate comparative toxicity of malathion in the two populations of the grasshopper Oxya chinensis , collected from Daixian and Fanshi of Shanxi province, China. General esterases and acetylcholinesterase (AChE) from the two populations were characterized and compared. LD50 of the Daixian population (7.58 μg/g body weight) was 2.02-fold higher than that of the Fanshi population (3.75 μg/g body weight). General esterase-specific activities in the Daixian population were 1.91, 1.10 and 1.85-fold higher than those in the Fanshi population, when α-NA, α-NB and β-NA were used as a substrate, respectively. Kinetic studies of general esterase showed that V max values of general esterases hydrolyzing α-NA, α-NB and β-NA in the Daixian population were 2.15-, 1.12-, and 1.47-fold, respectively, higher than those in the Fanshi population. The AChE activity of the Fanshi population was 1.54-fold higher than that of the Daixian population. Kinetic analysis of AChE showed that significant differences were presented between the two populations in the K m values; and the V max value in the Fanshi population was higher than that in the Daixian population. Inhibition studies of AChE indicated that AChE from the Daixian population was 2.56-, 2.80-, and 2.29-fold less sensitive to inhibition by paraoxon, chlorpyrifos-oxon, and demeton- S -methyl, respectively, than that from the Fanshi population. These biochemical characterizations of general esterases and AChE were consistent with malathion bioassay in the two populations. It is inferred that the reduced sensitivity of altered AChE and increased general esterase activities play an important role in the differences of insusceptibility of Oxya chinensis to malathion between the two populations. |
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Keywords: | acetylcholinesterase general esterases malathion susceptibility Oxya chinensis |
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