Study of the acquisition, replication and transmission of rice stripe virus in vector and non-vector planthoppers...

Rice stripe virus (RSV) naturally infects rice plants through its insect vector during feeding. The small brown planthopper (SBPH) serves as the primary vector to transmit the viruses. The physical barriers preventing virus transmission in non-vectors have remained largely unexplored. In this study, we employed a hemocoel microinjection (MI) method to inoculate RSV into planthoppers and investigated viral infection progression in vector and non-vector species.

Following microinjected into SBPHs, RSV successfully established infection across multiple tissues. Immunofluorescence analysis revealed progressive viral invasion, beginning with hemocytes and fat bodies, followed by salivary glands and gut tissues, achieving infection levels comparable to naturally viruliferous insects by 8 days. RSV-MI SBPHs demonstrated both horizontal transmission to rice plants and vertical transmission to offspring, effectively mimicking natural transmission patterns. When microinjected into two non-vector planthopper species, the white-backed planthopper and brown planthopper, RSV replicated only in hemolymph and established limited infection in hemocytes and fat bodies. This replication and accumulation did not affect insect survival. However, RSV failed to accumulate efficiently in salivary glands, preventing subsequent horizontal transmission to plants.

MI-inoculated RSV could infect planthoppers, with different infection levels in vector and non-vector planthoppers. By comparing RSV infection in vector and non-vector species, our work offers novel insights into study of vector-virus specificity mechanisms. © 2025 Society of Chemical Industry.