Tomato Infected with the Semipersistent Tomato Chlorosis Virus Results in Temporally Altered Gene Expression in Bemisia tabaci

Whitefly transmission of semi-persistent viruses requires specific interactions between the virus and its vector, but little information exists on how host plant infection by semipersistent viruses influences the whitefly or its ability to acquire and retain a plant virus. In order to determine changes in global transcriptional gene regulation in whiteflies resulting from feeding on plants infected with a semipersistent virus, paired-end 151-bp RNA-Seq was performed on whitefly (Bemisia tabaci MEAM1) after 24, 48, and 72 hours of feeding on Tomato chlorosis virus (ToCV)-infected and healthy tomato in three biologically replicated tests. Among a total of 15,668 genes predicted in the whitefly genome, we identified significantly differentially expressed genes in whiteflies fed on ToCV-infected tomato:  447↑543↓ (at 24 h), 4↑ 7↓ (at 48 h), and 50↑160↓ (at 72h), by comparing differential expression based on fold changes no less than 1.5. This indicates temporally influenced gene expression in whiteflies due to the presence of ToCV in host plant phloem, and that gene expression is influenced within the first 24 h of feeding, with fewer and different genes activated after 72 h feeding, corresponding with the time at which ToCV retention in the vector ceases.  Analysis of global differential expression revealed up-regulation of genes related to cathepsin, glucose transporter family members, uric acid pathway and up and down regulation of alpha-glucosidases in whiteflies fed on ToCV infected tomatoes.  Results may reveal pathways associated with whitefly-species specific virus transmission, and will serve as a valuable resource toward effective whitefly and virus control.