Proteomic Analysis of Frankliniella occidentalis and Differentially Expressed Proteins in Response toTomato Spotted Wilt VirusInfection

Abstract

<jats:p><jats:italic>Tomato spotted wilt virus</jats:italic>(TSWV) is transmitted by<jats:named-content xmlns:xlink="http://www.w3.org/1999/xlink" content-type="genus-species" xlink:type="simple">Frankliniella occidentalis</jats:named-content>in a persistent propagative manner. Despite the extensive replication of TSWV in midgut and salivary glands, there is little to no pathogenic effect on<jats:named-content xmlns:xlink="http://www.w3.org/1999/xlink" content-type="genus-species" xlink:type="simple">F. occidentalis</jats:named-content>. We hypothesize that the first-instar larva (L1) of<jats:named-content xmlns:xlink="http://www.w3.org/1999/xlink" content-type="genus-species" xlink:type="simple">F. occidentalis</jats:named-content>mounts a response to TSWV that protects it from pathogenic effects caused by virus infection and replication in various insect tissues. A partial thrips transcriptome was generated using 454-Titanium sequencing of cDNA generated from<jats:named-content xmlns:xlink="http://www.w3.org/1999/xlink" content-type="genus-species" xlink:type="simple">F. occidentalis</jats:named-content>exposed to TSWV. Using these sequences, the L1 thrips proteome that resolved on a two-dimensional gel was characterized. Forty-seven percent of the resolved protein spots were identified using the thrips transcriptome. Real-time quantitative reverse transcriptase PCR (RT-PCR) analysis of virus titer in L1 thrips revealed a significant increase in the normalized abundance of TSWV nucleocapsid RNA from 2 to 21 h after a 3-h acquisition access period on virus-infected plant tissue, indicative of infection and accumulation of virus. We compared the proteomes of infected and noninfected L1s to identify proteins that display differential abundances in response to virus. Using four biological replicates, 26 spots containing 37 proteins were significantly altered in response to TSWV. Gene ontology assignments for 32 of these proteins revealed biological roles associated with the infection cycle of other plant- and animal-infecting viruses and antiviral defense responses. Our findings support the hypothesis that L1 thrips display a complex reaction to TSWV infection and provide new insights toward unraveling the molecular basis of this interaction.</jats:p>

Integrated pest management in western flower thrips: past, present and future

“…Alternatively, symbiont‐mediated RNAi, downregulating an essential tubulin gene, resulted in high mortality of WFT larvae . For transmission of TSWV, a suite of WFT candidate proteins reacting to viral infection has been identified, but no RNAi approach for disruption has yet been developed . Sequencing the salivary gland transcriptome of TSWV‐infected and non‐infected WFT led to the putative annotation of genes involved in detoxification and inhibition of plant defence responses .…”

The NSs Protein of Tomato spotted wilt virus Is Required for Persistent Infection and Transmission by Frankliniella occidentalis

“…The lack of silencing suppression activity can be speculated also for the thrips vector, although a different NSs molecular mechanism cannot be ruled out. This topic presents an interesting research subject to understand the molecular mechanisms involved in this virus-vector interaction, given that TSWV activates the thrips vector immune system (52), and specific transcripts and proteins associated with antiviral defense in insects have been reported to be expressed in infected thrips (46,53). In this context, we cannot exclude for NSs a role different from silencing suppressor in evading a not-yet-defined antiviral defense system, such as Jak-STAT, Toll, immunodeficiency, and apoptosis signaling pathways (46), or alternatively, a truly active role in pathogenesis that implies not antiviral defense but other vectorspecific steps, such as determining tissue tropism in the insect.…”

Plant Virus–Insect Vector Interactions: Current and Potential Future Research Directions

“…Despite these findings, little is known about host factors or receptors that may be required for acquisition of TSWV by thrips. However, recent availability of thrips genome, transcriptome and proteome data can be expected to assist identification of thrips factors involved in successful tospovirus acquisition and transmission [66,67]. …”

“…The CRISPR/Cas9 system may serve as a tool for thrips genome editing [172]. A draft genome, and transcriptome and proteome data for whole body and different developmental stages of F. occidentalis are available, and differentially expressed (DE) genes in response to TSWV infection including antiviral defense are being annotated [66]. Global gene expression in response to TSWV infection identified DE genes in cellular processes and innate immune response [173].…”