Characterization of a LATD-dependent ABA signaling pathway in Medicago truncatula roots.

University Of Vermont & State Agricultural College, Burlington VT

Investigators

Abstract

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). The plant hormone Abscisic Acid (ABA) is essential for coordinating the response of plants to environmental stresses, such as drought, salinity and cold. In response to drying soil conditions, ABA is rapidly mobilized through the plant, triggering physiological changes in the leaves that will reduce water loss and stimulating roots to grow deeper into the soil. Although the importance of ABA as a rapid root-to-shoot warning system has been known for years the events that follow the exit of ABA from the vasculature are largely unknown. Medicago truncatula plants that lack a functional LATD protein are unable to maintain growing regions at the tips of plant roots unless extra ABA is added to the growth medium. In addition, movement of ABA through these plants is altered suggesting that the LATD protein might be involved in transporting ABA into or out of plant cells. This project proposes to examine ABA transport more closely. As a part of this project, the location of the LATD protein in plant cells will be determined. In addition, this project proposes to identify regulatory proteins that function before or after the LATD protein in the plant ABA response. Finally, the function of LATD-like proteins in the model plant, Arabidopsis, will be elucidated. Together, these experiments will increase our understanding of how plants use ABA to modulate plant developmental processes, such as root growth and the formation of nitrogen-fixing nodules. This project will provide scientific training for undergraduate and graduate students. In addition, this project also contains an outreach component that involves the design of inquiry-based science projects for middle schools in Vermont.