科研之友
微信
新浪微博
Facebook
分享链接
摘要
The susceplibililies to three organophosphate (OP) insecticides (malathion, chlorpyrifos, and phoxim), responses to three metabolic synergists [triphenyl phosphate (TPP), piperonyl butoxide (PBO), and diethyl maleate (DEM)], activities of major detoxification enzymes [general esterases (ESTs), glutathione S-transferases (GSTs), and cytochrome P450 monooxygenases (P450s)], and sensitivity of the larget enzyme actylcholinesterase (AChE) were, compared between a laboratory-susceptible strain, (LS) and a field-resistant population (FR) of the oriental migratory locust, Locusta migratoria manilensis (Meyen). The FR was significantly resistant to malathion (57.5-fold), but marginally resistant to chlorpyrifos (5.4) and phoxim. (2.9). The malathion. resistance of the FR was significantly diminished by TPP (synergism ratio: 16.2) and DEM (3.3), but, was unchanged by PBO. In. contrast, none of these synergists significantly affected the toxicity of malathion in the LS. Biochemical studies indicated that EST and GST activities in the FR were 2.1- to 3.2-fold and 1.2- to 2.0-fiold, respectively, higher than those in the LS, but there was no significant difference in P450 activity between the LS and FR. Furthermore, A ChE from the FR showed 4.0-fold, higher activity but was 3.2-, 2.2-, and 1.1-fold less sensitive to inhibition by malaoxon, chlorpyrifos-oxon, and phoxim, respectively, than that from the LS. All these results clearly indicated that the observed malathion resistance in the FR was conferred by multiple mechanisms, including increased detoxification by EST and GSTs, and increased activity and reduced sensitivity of A ChE to OP inhibition.
- 出版日期2009-5
- 单位山西大学
