Comparison of transcriptomes of vector and non-vector thrips species of tomato spotted wilt virus

Tomato spotted wilt virus (TSWV) is one of the most devastating plant viruses, causing billions in yield losses each year. The virus is transmitted exclusively by thrips (Thysanoptera: Thripidae) in a persistent propagative manner. Although there are more than 7000 thrips species, only 9 have been implicated in TSWV transmission. Despite a number of hypotheses on TSWV transmission by thrips, several aspects of TSWV transmission by thrips remain unclear. The main objectives of this study are to identify differences between vector and non-vector thrips species and to determine factors that influence TSWV transmission. To investigate this, transcriptomes of two vectors (tobacco thrips, Frankliniella fusca [Hinds] and onion thrips, Thrips tabaci [Lindeman]) and two non-vector thrips species (poinsettia thrips, Echinothrips americanus  [Morgan] and flower thrips, Frankliniella tritici [Fitch]) will be compared. We will identify genes that are differentially expressed between vector and non-vector species in both quantitative and quantitative manner. Transcriptomic analysis will focus on genes that are potentially involved in TSWV transmission, in particular viral replication and virus receptor homologs. Further, we will also identify genes that are associated with innate immune mechanisms. Our preliminary data on thrips transcriptomes revealed the presence of genes involved in viral reproduction and immune response such as defensins, Toll-like receptors, and elements of the RISC complex including Argonaut. We are currently in the process of characterizing and annotating genes. Findings from this study will provide important insights into the differences between vector and non-vector thrips and may lead to better understanding of thrips-tospovirus interactions.