Enhancing Effects of Fluorescent Brightener 28 and Enhancin on Mythimna separata Nucleopolyhedrovirus

The disruptive effects of Fluorescent Brightener 28(FB28) and Heliothis armigera granulovirus enhancing(En-Ha) on the peritrophic membrane(PM) of larvae and enhancing effects on MsNPV in Mythima separata were studied through SDS-PAGE,structural observation and bioassay.The results indicated that proteins could be dissociated from the PM in vitro by FB28.After the larvae were reared with diets containing 1% FB28 for 4 h,bluish fluorescence appeared on the disrupted PM.SDS-PAGE of PM treated with FB28 in vivo showed that some proteins with high molecular weight disappeared.After the PM was treated with En-Ha in vitro,some proteins with high molecular weight disappeared and some with lower molecular weight appeared,which indicated En-Ha could degrade the high-molecular-weight proteins from the PM.The PM became fragile after the larvae were reared with diets containing 9 μg/mL En-Ha for 7 h,and SDS-PAGE showed that some proteins with high molecular weight disappeared similar to the profile treated by FB28.However,the experiments testified that the disruptive effect could be restored after rearing the larvae on the diet without FB28 and EnHa.The bioassay showed that FB28 and En-Ha could enhance the vitality of MsNPV and significantly decreased LC50 by degrading the integrity of PM.