My laboratory studies signal transduction in response to abscisic acid (ABA), a hormone that affects many agronomically important features of plant growth: embryo development, seed and bud dormancy, water relations, tolerance of a variety of environmental stresses, and senescence. We have used mutants of Arabidopsis with reduced sensitivity to ABA to identify genes required for response. Characterization of these mutants suggests that the products of the ABA-insensitive (ABI) and other ABA response loci operate in a web of interconnected recognition/response pathways that includes "cross-talk" with signaling in response to other hormones, nutrient status, abiotic stresses, light and developmental cues. By integrating molecular, genetic and physiological data, we are contributing to a coherent model of ABA action that can have applications in modifying seed quality and yield or stress tolerance of plants.
Students participating in this project build recombinant DNA expression and reporter constructs, then analyze their function in yeast or plants; these techniques are directly transferable to studies of many other organisms. Expression and genetic studies focus on the plant physiology side of the project. Students analyze transgenic plants by assaying activity of reporter genes under control of regulatory sequences from proteins implicated in ABA response. In addition, they may create lines with loss or gain of expression for these proteins and assay the effects on growth, stress tolerance and gene expression.
Course prerequisites: Introductory Biology (MCDB 1AB), Genetics (MCDB 101AB, may be taken concurrently with project participation).