My research interests lie in improving mass spectrometry and separation strategies and applying them to perform global profiling of metabolites. This approach, known as metabolomics, probes the influence of genetics and environment on rates of biosynthesis and degradation of metabolites. Such measurements lie at the heart of systems biology approaches for engineering plants and microorganisms for improved productivity, as biosensors, and as valuable sources of an assortment of bioactive chemicals. Furthermore, the information in the metabolome can be used as biomarkers of stress, toxicity, and disease.

The diversity of metabolites produced by plants, fungi, and bacteria has been minimally explored, yet many of these compounds have potent biological activities that influence interactions involving plants, microbes, and insects. In several interdisciplinary collaborations, my research group has developed sensitive analytical schemes for characterizing, quantifying, and sorting these unknown metabolites according to chemical classes based on information contained in their mass spectra.

Our ongoing efforts are exploring the boundaries of fast-scanning high-resolution time-of-flight mass spectrometry and other MS/MS approaches to improve characterization of the metabolome using an assortment of plant and animal model systems. Plants appear to distinguish different modes of wounding (e.g. mechanical wounding from insect herbivory and pathogen infections), and their chemistry changes in distinct ways as a response to different environmental stresses. Precursor ion MS/MS scans have shown that different insect species deposit different phospholipids profiles onto plants while feeding, and these lipids may play important signaling roles that allow plants to distinguish stresses and respond with different defensive chemicals.

More targeted analyses of electrophilic signaling lipids are achieved through chemical derivatization that can be used for selective metabolite enrichment. Our group is also developing chiral monolithic capillary columns for sensitive HPLC and capillary electrochromatographic separations of metabolite enantiomers that will allow for improved metabolite localization and analysis of less abundant metabolites.