| Spinosad is a novel insecticide which has properties of high efficency, safety, wide insecticide spectrum, and becomes the most potential biological insecticide currently. The mode of insecticidal action of spinosad is unique. According to the studies, spinosad irritates insect neurons by activating nicotinic acetylcholine receptor(nAChR), and also acting at y-aminobutyric acid receptor(GABAR).However, their specific action mechanism is not clear.By feeding leaves with or without spinosad treated to beet armyworm(Spodoptera exigua Hubner),we extracted the total protein of beet armyworms after24h feeding. Through comparison of the protein of beet armyworms treated or untreated with spinosad, the mode of action and receptor for spinosad can be studied preliminary. According to the theory and technique of comparative proteomics, the beet armyworm total proteins were extracted, and the method of two-dimensional gel electrophoresis (2-DE) was used to separate the total proteins of beet armyworm with or without spinosad treated. Then the differential expressed proteins in the2-DE images of total proteins of Spodoptera exigua were checked and analyses by Imagemaster6.0.The target proteins were digested with trypsin. Mass spectrometry and bioinformatics method were employed to identify the differential expressed proteins systematically.According to the experiment, we obtained the normal larval2-DE protein map for spinosad treatment and control. By applying the Imagemaster6.0software to analyse the2-DE map under the same conditions,355spots and329spots were identified from the samples of spinosad treated and control respectively. Through the comparison and significance analysis (P<0.05),we identified25different proteins,13of which expressed more highly in sample treated by spinosad, while the rest of them expressed more highly in control.12spots were identified by MS, including carboxylesterase, cytochrome P450, â…¤-ATPase, ecdysone receptor protein, actin and so on. The functions of identified proteins were analyzed by database searching and bioinformatics. It was found that the differences between spinosad treated and control proteins were mainly related to the transport, metabolism, oxidative phosphorylation and so on. Meanwhile, the virulence of spinosad was enhanced significantly by mixing with bafilomycin A1(inhibitor of â…¤-ATPase).Comparing with the former study, it is a new attempt to study the mode of action of spinosad by using technique of comparative proteomics. The possible functions of the differential proteins were analyzed preliminary. This research provides some new methods and theories for the mechanism study for spinosad. |
