Changes Of Main Detoxification Enzyme And Tissue Proteins Of Silkworm (Bombyx Mori) Induced By Fenvalerate And Dimehypo

In recent years, a large number of new pesticides have been widely used in pest control because of the growing resistance of agricultural pests. Pesticide poisoning of silkworm occurs often due to mulberry pesticide contamination. This brings hidden dangers to the healthy development of sericulture. The results of relative researches show that pest resistance mainly due to the enhancement of detoxification enzymes and the production of some functional proteins. In order to find out the changes of main detoxification enzymes and tissue proteins in silkworm induced by fenvalerate and dimehypo, we added the 2 pesticides to the fifth instar larvae of silkworm and determined the main detoxification enzyme activities and enzyme gene expression using enzyme activity determination and fluorescence quantitative PCR technique (qRT-PCR) and also studied differential expression of blood proteins and midgut proteins using two dimensional electrophoresis ( 2-DE ) and ESI mass (electro spray ionization mass).The results are as follows:(1) Main detoxification enzyme activity and gene expression induced by pesticidesThe activities of carboxylesterase (CarE) and glutathione-S-transferase (GSTs) were detected using enzyme activity determination. We found that activities of most CarEs in different tissues at different times are restrained and GSTs'are also restrained before 24h in pesticide groups and enhanced after 24h. In order to test the expression changes of the two kinds of enzymes in gene level we analyzed relative expression amount of CarE-16 and Gst-delta using fluorescence quantitative PCR technique (qRT-PCR). The results show that CarE-16 and Gst-delta are expressed in most tissues and the amount of them in pesticide groups at different times are lower than control group's. But Gst-delta in fat body in pesticide groups are higher than control group's.(2) Expression changes of blood proteins and midgut proteins induced by pesticidesWe separated the heamolymph and midgut proteins using two dimensional electrophoresis ( 2-DE ) and identified spots with significant difference which have over two repetitive through ESI mass (electro spray ionization mass). The results show that Fibrillin-like protein,Fructose-1,6-bisphosphate aldolase and BCP inhibitor were induced by fenvalerate and Serpin-13 were induced by dimehypo in blood, and the amount of Apolipophorin-â…¢was reduced in both pesticide groups in blood after eating mulberries which have pesticides. AGAP005134-PA and the ribosomal protein S21 were induced by dimehypo in midgut. We analyzed the functions of these proteins and found most of them are related to immune or resistance.