The world will need to increase agricultural yields dramatically to meet the demands of the rapidly growing population for food and renewable fuel. The edible parts of several major food plants, including corn, rice, wheat, beans, and peas, undergo a specialized process called endoreduplication in which their cells enlarge and increase their DNA content several fold. Despite its importance, little is known about how endoreduplication is regulated, and it is difficult to investigate in food plants because the endoreduplicating nutritive tissues are buried deep within their developing seeds. To overcome this difficulty, the research proposed will use genetics, cell biology, and genomics to investigate endoreduplication in exposed cells on the surface of the Arabidopsis flower. In this new system, the cells are accessible for experimentation in growing plants. In particular, the research will address the question of how endoreduplication influences the cell undergoing the process. First, a mutant with increased numbers of endoreduplicated cells will be used to elucidate how endoreduplication is controlled. Second, the mechanism through which endoreduplication turns off one gene will be determined. Normally scientists think of external signals turning on and off genes within a cell. However, exciting recent results suggests that in, at least one case, endoreduplication can turn off a gene. Finally, to find how many genes are turned on or off by endoreduplication, the expression levels of all of the genes in the Arabidopsis genome will be compared between endoreduplicating cells and their non-endoreduplicating neighbors. Findings from this research may show new ways to increase crop yield. In addition, this project will train two graduate students, provide opportunities for summer research for three undergraduate students, and will enable workshops targeted to interest school girls in science.
