Comparison of transcriptomes of an orthotospovirus vector and non-vector thrips species.

Abstract

Thrips transmit one of the most devastating plant viruses worldwide-tomato spotted wilt tospovirus (TSWV). Tomato spotted wilt tospovirus is a type species in the genus Orthotospovirus and family Tospoviridae. Although there are more than 7,000 thrips species, only nine thrips species are known to transmit TSWV. In this study, we investigated the molecular factors that could affect thrips ability to transmit TSWV. We assembled transcriptomes of a vector, Frankliniella fusca [Hinds], and a non-vector, Frankliniella tritici [Fitch], and performed qualitative comparisons of contigs associated with virus reception, virus infection, and innate immunity. Annotations of F. fusca and F. tritici contigs revealed slight differences across biological process and molecular functional groups. Comparison of virus cell surface receptors revealed that homologs of integrin were present in both species. However, homologs of another receptor, heperan sulfate, were present in F. fusca alone. Contigs associated with virus replication were identified in both species, but a contig involved in inhibition of virus replication (radical s-adenosylmethionine) was only present in the non-vector, F. tritici. Additionally, some differences in immune signaling pathways were identified between vector and non-vector thrips. Detailed investigations are necessary to functionally characterize these differences between vector and non-vector thrips and assess their relevance in orthotospovirus transmission.