Location: Emerging Pests and Pathogens Research
Project Number: 8062-22000-023-032-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Jul 1, 2026
End Date: Jun 30, 2027
Objective:
The objectives of this project are to further evaluate a nanocarrier-delivered dsRNA system and to develop a beneficial bacterium-mediated dsRNA delivery platform for controlling economically important nematode diseases in potatoes.
Approach:
1) Continue evaluating nanocarrier-encapsulated dsRNA as an effective RNAi-inducer against potato nematodes. We will continue to use the RKN-Arabidopsis pathosystem to evaluate efficacy of a nanocarrier-delivered RNAi system against nematode infection. Biodegradable zeolitic imidazolate framework-8 (ZIF-8) micro- and nanoparticles will be used to encapsulate dsRNA-16D10-Actin4-pas4. In vitro nematode bioassays will be used to assess RNAi efficacy during nematode infection of plants treated with ZIF-8- dsRNA-16D10-Actin4-pas4. Upon confirmation of efficacy, greenhouse bioassays will be conducted to further validate the effectiveness of ZIF-8-dsRNA-16D10-Actin4-pas4 application in reducing potato infection by nematodes.
2) Establish Bacillus velezensis as a stable rhizosphere delivery platform in potato. We will evaluate multiple B. velezensis strains (e.g., BAC03, HN_Q_8, and others) to identify those that exhibit robust and consistent colonization of potato roots. Selected B. velezensis strain(s) will be engineered to express dsRNA-16D10-Actin4-pas4. Production of the dsRNA in the engineered B. velezensis strain(s) will be confirmed using molecular analyses.
3) Evaluate the efficacy of B. velezensis–mediated RNAi in suppressing nematode infection in potato. Greenhouse bioassays will be conducted to evaluate RNAi efficacy during nematode infection of potato plants treated with dsRNA-16D10-Actin4-pas4-producing B. velezensis. The engineered B. velezensis strain will be applied either as a soil drench during potato growth or as a seed-piece treatment prior to nematode inoculation. Plants treated with non-engineered B. velezensis and untreated plants will be included as controls. Each treatment will consist of 10–20 plants.