SBIR Phase I: Control of Lesion Nematodes by Transgenic RNA Interference

This Small Business Innovation Reserach (SBIR) Phase I research will generate transgenic crops with resistance to plant parasitic nematodes with a focus on the lesion nematode (Pratylenchus). Plant parasitic nematodes annually cause damage of $8 billion in the U.S. and are among the most difficult plant pathogens to control. Transgenic crops have a significant opportunity to provide economic benefit to growers through improved yields and decreased input costs and to replace toxic nematicidal pesticides. This project will use RNA interference (RNAi) to control the lesion nematode by silencing nematode genes. We will test the efficacy of specific double-stranded RNAs (dsRNAs) to inhibit essential parasite genes. Divergence has established an efficient transgenic hairy root in planta expression system to screen candidate dsRNAs. Promising results controlling other plant parasitic nematodes have been achieved and the same system can be utilized for lesion nematode. Objective I will include the selection, cloning, and sequencing of gene targets from Pratylenchus scribneri that are likely to be essential in all lesion nematodes. In objective II, the RNAi potency of target genes will be assayed in the hairy root system. At the conclusion of Phase I, it is anticipated that several target genes demonstrating reduction in lesion nematode reproduction will be selected for Phase II whole plant transformation. A likely crop for the first introduction of transgenic lesion nematode resistance is corn, one of the largest acreage and most valuable crops in the U.S. The broader impact of this project will be to reduce the need for extensive use of pesticides in US agriculture and to counter an aggressive parasite that affects the production of corn.