9506192 Marks Very little is known about the mechanisms that control cell fate in plants. The development of hairs (called trichomes) on the leaves of Arabidopsis thaliana plants is being used as a model to study cell fate in plants. Two genes that are required for the commitment of leaf epidermal cells to enter the trichome developmental pathway are TTG and GL1. Mutations in these genes results in a loss of trichome initiation. Both of these genes are thought to function as transcription factors that regulate other genes required for trichome morphogenesis. This proposal will further the study of the role of GL1 in trichome development and also extend the characterization to the TTG gene. The proposed experiments will provide information on how GL1 and TTG are regulated and will identify genes that are regulated by GL1 and TTG. The expected significance of this work is tow fold. first, it provides a convenient system to study cell fate in plants. Second, trichome developments provides a practical model. Trichomes on many plant species serve as a barrier between the plant and a hostile environment. many crop plants such as Canola lack protective trichomes. The ability to manipulate the morphology, density and placement of trichomes on Arabidopsis plants is rapidly evolving. It is hoped that the information learned about Arabidopsis can be applied to Brassica species and other crop plants. ***
