Potential of Virus-Mediated RNAi of Insect Genes in Plants to Control Aphids

Expression of double-stranded RNAs (dsRNAs) in plants is an emerging strategy to efficiently control insects. RNA interference (RNAi)-mediated pest control takes advantage of double-stranded RNA that can suppress the expression of one or more insect genes that encode key proteins. Virus-induced gene silencing (VIGS) is a useful tool for plant expression of dsRNAs to control pests without altering the plant's genome. Trehalase (TRE) and chitin synthase (CHS) are very important in insects. In this study, we first demonstrated that spraying dsRNAs targeting <i>CHS</i> and <i>TRE</i> increased the mortality rate of the peach aphid <i>Myzus persicae</i> treated with the pathogenic fungus <i>Metarhizium anisopliae</i>. When dsRNAs targeting <i>mpTRE</i> and <i>mpCHS</i> were expressed in plants via VIGS, the expression of <i>mpTRE</i> and <i>mpCHS</i> was reduced in aphids, and their fertility and survival rates were decreased. These results indicate that VIGS-mediated RNA interference is a powerful approach to effectively control aphids, and aphids had a higher mortality rate when <i>M. anisopliae</i> was sprayed.