Location: Corn, Soybean and Wheat Quality Research
Project Number: 5082-22000-002-014-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Aug 31, 2025
End Date: Aug 30, 2026
Objective:
The overall goal of this research is to identify and elucidate the mechanisms of disease resistance conferred by the wsm3 resistance gene. This research will facilitate the development of corn varieties with elite disease resistance leading to improved crop yields for farmers. Preliminary evidence indicates this gene confers resistance to at least four different corn virus species and may also be involved in fungal disease resistance pathways including northern corn leaf blight and head smut. Objective 1 will confirm the identity of the wsm3 resistance gene using gene editing/overexpression techniques. Objective 2 will elucidate mechanisms of disease resistance and pathogenesis by investigating gene expression, protein-protein interactions, and/or cellular localization of host and pathogen protein factors. This objective will identify additional putative targets for improving disease resistance in corn and other crops.
Approach:
Objective 1: Identifying the wsm3 resistance gene in corn. Leveraging agrobacterium transformation and CRISPR/Cas9 gene editing technologies, the wsm3 candidate gene will be knocked-out or overexpressed in resistant and susceptible corn lines. Gene edited lines will be inoculated with wheat streak mosaic virus (WSMV) and the effect on disease resistance will be evaluated visually and using quantitative reverse transcription polymerase chain reaction (qRT-PCR) to quantify virus titer and host target gene expression.
Objective 2: Elucidating the wsm3 resistance pathway and pathogenesis. To identify protein-protein interactions between wsm3, WSMV, and/or other host factors in the resistance pathway, methods such as pull-downs and western blotting will be utilized. This data, along with prior RNA-seq results from a time course infection study with WSMV, will be used to identify wsm3 protein-interaction candidates for further validation in planta using co-immunoprecipitation (Co-IP) or bi-molecular fluorescence complementation (BiFC). Cellular localization of host and pathogen proteins may be explored using fluorescently tagged host and/or pathogen proteins to further determine mechanisms of disease resistance.