Metabolic Regulation and Engineering
We use a variety of plant systems including the model flowering plant, Arabidopsis thaliana, tobacco, rice, and the model grass, Brachypodium distachyon to characterize homeostasis mechanisms (i.e. how levels are regulated within the cell) for metabolites that function as signaling compounds. For example, we use stable isotope labeling to examine the regulation of growth and development by the signaling molecule indole-3-acetic acid (IAA), also known as auxin. We are developing analytical tools (primarily high throughput sample prep, quantitative metabolite profiling, and fluorescence-based cell sorting) and mutants that are disrupted in some aspect of metabolite regulation in order to characterize IAA homeostasis. Mass spectrometry features prominently in our experimental approach. Our long-term goal is to understand how auxin biosynthetic pathways interact with biosynthetic pathways for other important signaling molecules such as cytokinins, gibberellins, salicylic acid, ethylene, jasmonic acid, abscisic acid and brassinolide and to apply this knowledge to the development and optimization of cellulosic biofuel feedstocks such as Switchgrass.