Management of pests and diseases of crops in sustainable and safe manner is imperative to meet the target of reduction in pesticide emissions. The discovery of RNA interference as a natural regulatory mechanism has proved to be a powerful strategy to engineer disease resistance against viruses, viroids, nematodes, insect pests and fungi in plants. RNA based biopesticides or ‘RNA sprays’ for plants as a next generation crop protection platform without the need for genetic modification is gaining momentum globally, with pests and pathogens targeted with accuracy and specificity.
The instability and short protection window of topically applied naked double stranded RNA as trigger molecule of RNAi on plants may offer some challenges. We have developed BioClay platform to deliver RNA as biological active using clay (Layered Double Hydroxide, LDH) particles as carriers towards a non-GM, residue free, specific, and environmentally sustainable crop protection alternative to chemical pesticides. The clay degrades on the surface of the leaf alleviating concerns about residues. We have shown that BioClay can provide protection against plant viruses, multiple life cycle stages of whitefly, a pest with a very wide host range and Botrytis cinerea, a fungus that infects both horticultural and broad acre crops. BioClay platform is being progressed to target multiple viruses, insect pests and fungi. Real world application of RNA based biopesticides with sustainable credentials for the global consumer will be governed by factors such as cost-effective production of dsRNA, the regulatory landscape and social acceptance.