DEFINING THE MOLECULAR DETERMINANTS OF THRIPS VECTOR COMPETENCE TO TRANSMIT ORTHOTOSPOVIRUSES

The majority of plant-pathogenic viruses rely solely on arthropod vectors for transmission to plants. Orthotospoviruses, one of the top ten most devastating groups of plant viruses, are transmitted by thrips vectors, invasive and polyphagous crop pests of worldwide significance. As a means to devise novel strategies to break the transmission cycle to plants, we have used a systems-biology approach to identify thrips proteins of F. occidentalis that interact directly with tomato spotted wilt virus (TSWV) structural proteins and transcriptionally respond to virus infection of larval thrips guts - the gateway to virus entry, replication and transmission to plants.The long-range goal of this project is to develop novel, sustainable, and biologically-based strategies for controlling thrips and orthotospoviruses in agricultural croplands and greenhouses. The project will address the Pests and Beneficial Species in Agricultural Production Systems goal to 'advance knowledge of invasive or established plant pests and associated beneficial species leading to innovative and biologically-based strategies to manage pests.' The aim of this project is to functionally characterize novel thrips proteins and virus-responsive gene networks associated with thrips vector competence. In other words, we plan to identify biotic factors affecting the ability of thrips to transmit TSWV.The specific research objectivesof the project are to:Objective 1. Characterize the fine-scale, co-localization patterns of TSWV-interacting proteins (TIPs) with viral structural proteins in thrips. We will use a combination of protein-protein interaction assays and microscopy to create a physical interaction map for TIPs and TSWV structural proteins.Objective 2. Functionally annotate TSWV-responsive TIPs with regards to cell biology and larval growth and development. We will use RNAi, and supplementary gene-editing, to empirically interrogate gene co-expression network connections of TIPs and their role(s) in thrips physiology.Objective 3. Functionally characterize the biological role(s) of TIPs during TSWV infection of the thrips vector. We will use RNAi, genome-editing, pharmacological inhibition, and competitive binding assays to thoroughly characterize the functional role(s) of TIPs in the virus infection cycle in thrips.