Ectopic expression of the spike protein of Rice Ragged Stunt Oryzavirus in transgenic rice plants inhibits transmission of the virus to insects

Abstract

Rice ragged stunt oryzavirus (RRSV) replicates in both its insect vector, Nilaparvata lugens, and its plant host, rice, and has a complex multi-component particle bearing spikes on its outer surface. Transgenic rice lines expressing the 39 kDa spike protein showed good resistance to infection by RRSV. Furthermore, N. lugens fed on these plants prior to feeding on RRSV-infected plants were significantly protected against RRSV infection. The viral titre in insects initially fed on transgenic plants and then on RRSV-infected plants was inversely proportional to the levels of the 39 kDa protein expressed in the transgenic plants. This suggests that the 39 kDa protein interferes with the interaction between the intact virus particles and insect cell receptors and that the spike protein of RRSV contributes to vector specificity. This approach would probably be a more environment-friendly and sustainable method of virus control than by actual eradication of insect vectors.