A Plant Virus Supramolecular NanoSponge for Delivery of Agricultural Pesticides to the Rhizosphere

Managing parasitic plant pests is a significant burden on the global agricultural industry. Endoparasitic plant nematodes and phytopathogenic bacteria target and infect the plant rhizosphere, forming galls and reducing crop yields. Pesticide treatment is often inefficient because the pest-lethal pesticide dose must reach the root level, where pests infect the plants. We previously demonstrated that some plant viruses exhibit excellent soil mobility, and building on this, we here developed a viral NanoSponge formulation that enables the noncovalent loading of agrochemicals but prevents premature release through metal-phenolic network (MPN) coatings. Through optimized molecular interactions, the viral NanoSponge stabilized cargo binding and soil transport. Targeted cargo release and pest treatment were enabled through a pH-responsive cargo release mechanism. The NanoSponge demonstrated superior efficacy against nematodes (<i>Caenorhabditis elegans</i>) and against bacteria and biofilms thereof (<i>Agrobacterium tumefaciens</i>); efficacy was also demonstrated in bacteria-infected plants (<i>Nicotiana benthamiana</i>). The NanoSponge platform represents a sustainable and effective strategy for precision farming, effectively addressing deep soil pests.