Significance of Apyrase Activity for Plant Growth and Development

University Of Texas At Austin, Austin TX

Investigators

Abstract

The main objective of this project is to learn more about how the activity of enzymes called apyrases exert their dramatic effects on plant growth and development. Apyrases remove the terminal phosphate from nucleoside triphosphates (e.g., ATP) and nucleoside diphosphates. Their key role in controlling the growth of plants is revealed by two recent discoveries: plants that cannot make two closely related apyrases, APY1 and APY2, are dwarf, and the highest expression of APY1 and APY2 is in tissues that are rapidly growing. To better understand the implications of these findings, this project proposes to investigate the molecular bases underlying them, using genetic, biochemical and cell biological approaches. APY1 and APY2 function both in cell nuclei and in the cell periphery. In the latter location they can reduce the concentration of extracellular ATP. Although virtually all ATP is made inside of cells, some of it moves to the outside of cells where it can serve as a hormone-like substance that can influence many cellular activities. This project tests how the ability of apyrases to regulate the concentration of extracellular and nuclear ATP relates to its ability to regulate plant growth. Learning more about the unexpected role of apyrases in growth processes will significantly expand and deepen knowledge about factors that regulate plant growth, and thus help develop new strategies for increasing crop yields and plant biomass for biofuels. The P.I. and co P.I. have a strong record of mentoring high school and undergraduate students in original research projects, and both are now serving as principle instructors in a new Freshman Research Initiative project on campus, which has the goal of introducing large numbers of entering students to the challenge and joy of research during their first year. This activity is in accord with NSF's goal to foster integration of research and education through formal programs, and may serve as a model program for other such efforts in other Universities.