Certain plant viruses induce changes in volatile organic compounds from infected plants and thereby affect the behavior of the virus vector. This helps the virus to spread and survive. Genetic basis of these changes is unknown. The overall focus of the proposal - to find virus-encoded gene or genes responsible for induction of volatiles affecting aphid behavior. We will address our objectives through site-directed mutagenesis of virus genes in the PLRV vector construct, and through generation of transgenic plants carrying PLRV genes, coupled with VOC analysis and behavioral bioassay with aphids.