Student Research

Isolating and Identifying a Molecule Responsible for Plant Resistance to Powdery Mildew Disease

Powdery white mildew is a fungal disease that infects crops, decreasing quality of growth and yield. Interestingly, there is a plant that contains a mutation in a pectate-lyase family of genes that appears to enable resistance to powdery mildew disease and acts through a single molecule. Using different separation techniques, we are in the process of isolating and identifying the targeted analyte. Plant extracts containing the metabolite are first processed through C18 solid phase extraction (SPE) to remove the hydrophobic components followed by weak anion exchange (WAX) to isolate the target molecule. The extraction is further purified in hydrophilic interaction liquid chromatography in two primary fractions. In conjunction with a novel bioassay performed at UC Riverside, nuclear magnetic resonance (NMR) is used to try and identify the molecule and a resonance of interest has been identified at 4.9 ppm. Currently, we are exploring size exclusion chromatography to further isolate the molecule. The mixture collected as 12 distinct fractions, and the targeted resonances eluted last, suggesting that the molecule is a small compound. Additional bioassays will be performed on the fractions to help identify the analyte.