ABSTRACT
RNA mediated silencing technology (RNAi) has become the tool of choice for induction of virus resistance in many organisms. A significant feature of this technology is the double stranded RNA (dsRNA), the potent triggers of RNAi. In this study, E. coli are engineered to produce dsRNA of the cloned genes from a plasmid (L4440) containing gene of interest under the control of double T7 promoter which efficiently produces dsRNA once it is transformed into E.coli HT115 host strain and upon induction with IPTG. In this study, lef-1(late expression factor-1) involved in BmNPV DNA replication was targeted against which dsRNA was produced. The RT-PCR analysis revealed that larva fed with 30µg of E.coli expressing lef-1 dsRNA showed significant decrease in the expression of viral genes involved in the BmNPV multiplication and showed in-crease in survivability of infected silkworms upto 50%. These results prove the successful use of E.coli expressing dsRNA as an efficient way of delivering dsRNA in silkworms as well as inducing resistance against BmNPV.
