Assistant Professor UC San Diego La Jolla, California
Body of Abstract: Small molecules are critical cues that coordinate complex, multicellular behaviors, such as tissue patterning. However, many small molecule-based mechanisms remain poorly characterized due to inherent challenges in measuring their production, localization, and function in situ. These problems are amplified when considering small-molecule activity in rare cellular subpopulations, such as stem cells. My lab performs precise measurements of small molecules in developing tissue using mass spectrometry imaging (MSI), a technique that combines the power of chemical fingerprinting with high spatial resolution. Specifically, we utilize desorption electrospray ionization mass spectrometry imaging (DESI-MSI) to map the small molecule chemistry of plant roots. Plant roots are organized along a well-characterized developmental gradient with proliferating cells localized to the tip of the root (the meristem). As cells exit the meristem, they differentiate, creating a gradient of “stem-ness.” DESI-MSI profiling of this gradient has revealed dozens of molecules with developmentally specific enrichment patterns. By investigating the developmental logic of these patterns using exogenous metabolite treatments and stem cell specific overexpression lines, we are exploring new functions of primary and secondary metabolites in development.