Impact of Olfactory Genes in Management of Lepidopteran Pest Spodoptera Litura by dsRNA Mediated RNAi

Abstract

RNAi mediated by dsRNA is widely used for management of agriculturally important insect’s pests. But, the screening of candidate gene of interest to be targeted in RNAi study is crucial for efficient RNAi. The aim of our study is to know the impact of olfactory genes, as potential target for dsRNA mediated RNAi, for management of Lepidopteran pest, Spodoptera litura F. (Noctuidae). We have targeted three genes in our present investigation, GOBP1 encoding General odorant binding proteins, OR1 and OR83b encoding olfactory receptors and olfactory co-receptor respectively. These genes belongs to insect chemoreceptor super family, involved in transmission of external environmental signals (chemicals) by transporters designated as binding proteins, and conversion of chemical signals into electrical signals that are perceived by insect nervous system, interprets and decides insect behavior, communication and interaction with host species. Inhibition of such interactions is targeted through dsRNA for designing effective management strategies. The results suggested, substantial decrease in larval feeding, inturn resulted in larval body weight ranges from 46 % to 100% and fecal pellet weight ranges from 50 % to 80% in targeted genes as compared to the control. OR1 had shown higher reduction in both larval weight (82%) and pellet weight (80%). Thus, indicated the alteration in feeding behavior in S. litura larvae by silencing olfactory receptors. Hence, the targeted gene (OR1) can be used as a good candidate gene for dsRNA mediated RNAi based insect pest management.