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

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。植物激素脱落酸（ABA）在协调植物对干旱、盐度和寒冷等环境胁迫的反应中起着至关重要的作用。在干燥的土壤条件下，ABA通过植物迅速调动，引发叶片的生理变化，减少水分流失，刺激根系向土壤深处生长。尽管多年来人们已经知道ABA作为一种快速的从根到茎的预警系统的重要性，但ABA从脉管系统中退出后发生的事件在很大程度上是未知的。缺少功能性LATD蛋白的短尾紫花苜蓿植株无法维持根部尖端的生长区，除非在生长培养基中添加额外的ABA。此外，ABA在这些植物中的运动发生了改变，这表明LATD蛋白可能参与了ABA进出植物细胞的运输。本项目建议更密切地研究ABA的转运。作为该项目的一部分，将确定LATD蛋白在植物细胞中的位置。此外，本项目拟鉴定在植物ABA响应中，在LATD蛋白之前或之后起作用的调节蛋白。最后，将阐明latd样蛋白在模式植物拟南芥中的功能。总之，这些实验将增加我们对植物如何利用ABA调节植物发育过程的理解，如根系生长和固氮根瘤的形成。本项目将为本科生和研究生提供科学培训。此外，该项目还包含一个扩展组件，涉及为佛蒙特州的中学设计基于探究的科学项目。

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.