Plant Cortical Microtubule Array Organization.

Indiana University, Bloomington IN

Investigators

Abstract

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). Each individual plant cell forms an outer covering of carbohydrate materials that must be stretched and remodeled over time to create cell shape. The collective integration of those cell shapes gives rise to plant form. The goal of this project is to identify key molecular factors responsible for determining how cell expansion is regulated. Small polymers called microtubules form temporary patterns inside the cell which template the deposition of carbohydrates into the cell wall. Those carbohydrate patterns, in turn, play a significant role in determining how plant cells expand to create tissues, organs, and ultimately plant form. This project uses molecular and cell biological techniques to test hypotheses about how the microtubule polymers become arrayed into specific patterns for plant development. Proteins that act on the polymers to trim them to size or to bundle them into super-structures have been identified and their role in patterning the microtubule array during morphogenesis are being assessed. The successful completion of this project will provide critical insight into the most basic mechanisms of plant growth. Broader impacts: The growth mechanisms under study are directly responsible for the compact axial growth habit of crop plants desirable for efficient conversion of light energy to biomass. This project will provide information both about the role of the microtubules (a common herbicide target) and the organization of cellulose polymers (e.g. biofuels feedstock) in creating the axial plant morphology. This project provides advanced training for a post-doctoral research fellow and a graduate student using state of the art imaging technologies and integrated mathematical modeling approaches for hypothesis testing. Two undergraduate honors students will also participate in this project, gaining valuable research experience toward their stated professional goals. Biological materials developed for this research are being incorporated into an undergraduate honors biology course and a graduate imaging course. Special techniques developed for time-lapse imaging in 3-dimensions and subsequent quantitative analysis are being disseminated through technical publications, lectures, and web based materials.