Biocompatible antiviral Pickering emulsion‐based formulation for plant root protection from tobamovirus‐infected soil

Abstract

The soil‐borne virus known as tomato brown rugose fruit virus (ToBRFV) has a low rate of around 3% soil‐mediated infection when the soil has root debris from a previous 30–50 day development cycle of tomato plants infected with ToBRFV. This study presents anti‐viral coating formulations based on Pickering emulsion. The coating formulation is based on water‐in‐canola oil emulsions stabilized using commercial hydrophobic silica, with water‐soluble polymer (sodium polyacrylic acid). The structure of the emulsions and their stability were characterized by confocal microscopy, centrifugal analysis using a LUMiSizer®, used to confirm the emulsion stability. We tested a few different silica concentration‐based formulations, which were prepared with or without the addition of various virus disinfectants. We found that under conditions of 100% soil‐mediated ToBRFV infection of uncoated positive control plants, root‐coating with formulations based on silica Pickering emulsion were prepared with the disinfectant chlorinated‐trisodium phosphate (TSP‐Cl) showed low percentages of soil‐mediated ToBRFV infection. These formulations had no adverse effect on plant growth parameters when compared to negative control plants grown under non ToBRFV inoculation conditions.