UC San Diego

Pesticide usage in an abusive manner in agriculture causes health problems to society, disease and contamination of livestock, development of pesticide-resistant microorganisms in the soil, and poisoning of water bodies due to leaching. Overuse of pesticides is a critical issue that concerns the health of the environment, plants, animals, and humans – and therefore there is a need for next-generation nanotechnology-driven solutions. Plant virus nanoparticles (VNPs) provide a platform that can be used as nanocarriers for the targeted delivery of pesticides in small and controlled doses while being robust, biodegradable, and versatile. While plant viruses are pathogens to plants – they also evolved to interact with plants and soil because they are plant pathogens. The idea here is to repurpose the biology of plant viruses for precision farming. Previous work showed that plant viruses from tobacco mild green mosaic virus (TMGMV) have good soil mobility. In this work, I addressed structure-function questions: (i) how the soil properties impact plant virus carrier mobility and (ii) how the plant virus surface chemistry impacts its soil mobility – again as a function of soil property. I tested soil mobility in four soil types and assessed soil mobility of native vs. PEGylated plant viral carriers. A combination of chemical synthesis, nanoparticle characterization, and soil mobility assays was used. Data indicate that the soil mobility of the VNPs was greatly enhanced by modifying their surface.