Comparative tracking and effectiveness of positively and negatively charged dsRNA zein nanoparticles to suppress the potato virus Y (PVY)

• Grant number: 25/00937-0
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• Start date: July 01, 2025
• End date: June 30, 2026
• Field of knowledge: Biological Sciences - Biochemistry - Chemistry of Macromolecules
• Principal Investigator: Leonardo Fernandes Fraceto
• Grantee: Felipe Franco de Oliveira
• Supervisor: Jason C White
• Host Institution: Instituto de Ciência e Tecnologia. Universidade Estadual Paulista (UNESP). Campus de Sorocaba. Sorocaba , SP, Brazil
• Institution abroad: Connecticut Agricultural Experiment Station (CAES), United States
• Associated to the scholarship: 23/07905-0 - Development of a multicomplex nanostructured system associated with the use of RNAi to control tomato chlorosis virus (ToCV), BP.PD

Abstract

Potato (Solanum tuberosum L.) is a staple crop and ranks sixth in global production. However, biotic factors significantly impact its cultivation, notably the potato virus Y (PVY), which causes substantial economic losses in solanaceous crops. PVY management remains challenging due to limited and expensive control measures. RNA interference (RNAi) is a natural gene regulatory mechanism present in eukaryotic cells that has emerged as a promising strategy for plant virus control. However, challenges such as efficient delivery of RNAi inducers, dsRNA or siRNA, to plant cells and environmental instability of such molecules persist. Nanocarriers, such as zein-based nanoparticles, can offer a sustainable solution by enhancing dsRNA or siRNA stability, absorption, and controlled release of these molecules to plants. This proposed project aims to characterize zein nanoparticles for efficient dsRNA delivery to plants for plant virus control. We will evaluate distinctly charged nanoparticle behavior in plants, determine dsRNA encapsulation efficiency and release dynamics, and assess the efficacy of the nanocomplex (Zein_dsRNA) synthesized in controlling PVY infections. The nanoparticles will be synthesized via the nanoprecipitation method using Poloxamer-127 or lignin as stabilizing agents. Established protocols to estimate encapsulation efficiency and release kinetics for other nanopesticides will be tested for the Zein-dsRNA nanoformulations. The efficacy of the Zein-dsRNA nanocomplex in controlling PVY will be tested in Nicotiana tabacum, as a model plant, using mechanical and vector-mediated inoculations of the virus. Cy3-labeled dsRNA and FITC-labeled zein will be employed to track the nanocomplex behavior in planta. Fluorescent microscopy will shed light on the nanoparticle distribution and accumulation in treated tissues with quantified fluorescence intensity. This comprehensive approach will provide insights into nanoparticle-based dsRNA delivery systems for sustainable plant virus management, and it will help us accomplish our long-term goal of developing a novel platform to address critical gaps in RNAi and nanotechnology integration for practical agricultural applications.