The Exocyst and Vesicle Trafficking In Plant Development

Oregon State University, Corvallis OR

Investigators

Abstract

PI: John E. Fowler NSF Proposal # IOS-0920747: "The Exocyst and Vesicle Trafficking In Plant Development" Inside each plant cell, tiny membrane-bound vesicles carry a variety of materials essential for plant growth and development to the plasma membrane, which helps form the cell?s boundary. The mechanism by which these vesicles are delivered to the correct location on the plasma membrane at precisely the right time is not well understood, even though this tight regulation is fundamental to such processes as cell division, cell wall elongation, defense against pathogens, and intercellular communication (e.g., plant hormone signaling). This project will study the role of a particular complex of eight proteins, the exocyst, in such vesicle trafficking. Based upon work in yeast and mammalian systems, the exocyst is hypothesized to work as a tether between a vesicle and its intended location at the plasma membrane, helping to target vesicles to specific sites at developmentally appropriate times. The importance of the exocyst in plants is demonstrated by mutations in exocyst proteins, which cause defective pollen tube growth, reduced stem elongation in the dark, and dwarfism (including short roots). This project will utilize genetic, biochemical, and cell biological methods to more specifically investigate the exocyst?s possible roles in vesicle trafficking, phytohormone signaling, and cytokinesis (cell division), and will examine both pollen tube elongation and primary root growth in the model plant, Arabidopsis thaliana. This work is likely to have broader impacts by informing applied work that seeks to modify plant growth, cell walls (e.g., for biofuels), or pathogen response in agricultural crops. This project will train a postdoctoral researcher and a graduate student, foster a productive collaboration with researchers in the Czech Republic, and provide science outreach to local elementary and high school students.