Mechanism And Receptor Of Cantharidin In Mythimna Separate

Cantharidin is a defensive toxin from insects of Meloidae(Coleoptera), it has a high insecticidal activity, and we can improve its insecticidal activity through restructure its molecule. Previous researches have proved PPPs and HSF1 are the targets of cantharidin, but we still don’t know the clear mechanism, and we also try to look for other possible targets, which will help us to use the pesticide and improve its insecticidal activity.In this study, we used the armyworm(Mythimna separata) to study the midgut proteins, treated with cantharidin, using proteomics method. We identified the proteins using mass spectrum(MS) and analyse their function. In order to improve the quality of the two-dimensional electrophoresis(2-DE) maps, we compared the parameters including protein extraction, IPG strip, dithiothreitol(DTT) concentration and isoelectric focusing conditions. We established the 2-DE system for midgut proteomic analysis of armyworm. The main results are as follows:1. We proposed a better system: Tris-Phenol extraction method was used to extract the total protein from the midgut of armyworm, separate the proteins with pH 5-8(L) strip with DTT concentration I and isoelectric focusing program II. After optimizing the 2-DE system, the 2-DE maps are obtained with more protein spots, clearer background and higher-resolution.2. The midgut proteins of the armyworm(Mythimna separata) after cantharidin treatment was studied. Combined with mass spectrum(MS), we selected 60 different plots. After identified these proteins, we found 37 different kinds of proteins. From which we obtained eleven proteins related to signal transduction procedures and five of them are stress-regulated proteins. Two of them(heat shock protein 70 and transitional endoplasmic reticulum ATPase TER94) were potential targets: Heat Shock Factor 1(an inhibitor of HSP70) and TER94. We also obtained 5 proteins related to stress-regulation from other groups: Prophenoloxidase 1; Apolipophorins; succinyl-CoA ligase; Methylcrotonoyl-CoA carboxylase; Peroxisomal multifunctional enzyme. We presume that these proteins are used by armyworm to prevent damage after cantharidin treatment. These proteins are involved in different physiological processes and are located in different subcellular compartments.