The above-ground parts of flowering plants arise from a few hundred cells, collectively called the shoot apical meristem, found at the tip of each shoot. How these cells divide, change their patterns of gene expression and produce plant tissues is not well understood, other than the recognition that many of the activities of meristem cells depend on messages sent between the cells. What is proposed here is a new way to study communication between the cells of the meristem by using a specialized microscope to follow the individual cells as they divide, change their patterns of gene expression, and differentiate to become stem, leaves and flowers. By simultaneously activating or inactivating the genes that make, or allow response to, cell-cell communication signals, it will be possible to discover the immediate effects of changes in the communication network on patterns of gene expression and of cell growth and division. These studies should help elucidate how cell-cell communication controls plant growth. Additionally the microscope will be used to follow the formation of new meristems in cultured plant tissue, so as to elucidate the steps that lead to organization of a new meristem. The potential impact of gaining a fundamental understanding of plant growth is a better understanding of crops and their breeding and a new understanding of principles of communication networks. Undergraduate students recruited through the Student Undergraduate Research Fellows program, a graduate student, and a postdoctoral fellow will participate in the proposed research.
