IMPROVIR · Improved double-stranded RNAs for nanocomposite-driven SIGS in plant virus control

IMPROVIR is an interdisciplinary project combining nanotechnology, plant molecular biology, and plant virology to control twodamaging and emerging plant viruses, Tomato brown rugose fruit virus (ToBRFV) and Cucurbit chlorotic yellows virus (CCVY) via anenvironment-friendly approach called spray-induced gene silencing (SIGS). Currently, these two viruses are threatening production oftomato, pepper and cucurbits across the globe especially in Europe. SIGS approach is based on RNA-interference (RNAi) technologybut it does not involve transgenic manipulation of the plants. The non-transgenic approach of SIGS is an innovative strategy thatrelies on topical spraying of double stranded RNAs (dsRNAs) on plant surface that enter plant cells and tissues and eventually inducegene silencing by the RNAi mechanism against specific plant pathogens and pests. We will improve the dsRNAs molecules for SIGS byusing a tRNAMet tag to enhance dsRNA mobility in the plant. Besides, the enhanced dsRNA molecules will be incorporated into eithercarbon dot or chitosan-derived nanoparticles in the form of nanocomposites to: (1) increase the stability of the dsRNAs on plantsurfaces and (2) increase the delivery of dsRNAs into plants. This approach is fast (compared to time-consuming approaches such asplant breeding, genetic transformation and introduction of resistant varieties), environment-friendly (no residue in products and inenvironment as opposed to chemical pesticides) and publicly acceptable (no need for genetic transformation and modification). Theperformance of the dsRNA:NP nanocomposites in controlling those virus diseases will be assessed by evaluating disease progress,virus titers and siRNA production in treated vs. non-treated infected plants. In a non-academic placement at Kimitec, a private biotechcompany in Spain, the technologies developed at IFAPA (host institution) during the project will be applied to control anotherimportant plant pathogen, Phytophthora sp.