Molecular mechanisms of ABA biosynthesis under drought stress

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。研究员：Jianhua Zhu jhzhu@umd.edu（首席研究员）提案编号：0919745提案标题：干旱胁迫下阿坝生物合成的分子机制摘要土壤水分亏缺导致的干旱是全球范围内导致作物生产力大幅损失的最常见的环境因素之一。植物激素脱落酸（阿坝）是控制植物非生物胁迫反应的重要因子。因此，阿坝被称为应激激素。虽然阿坝积累本身是一个众所周知的响应干旱胁迫，控制阿坝积累和阿坝下游响应连接的分子因子在很大程度上是未知的。 本项目通过对干旱胁迫诱导的阿坝积累和耐旱性缺陷的拟南芥突变体进行正向遗传分析，研究干旱胁迫下阿坝生物合成的分子调控机制。这些突变体最初是基于9-顺式-环氧类胡萝卜素双加氧酶3（NCED 3）基因的表达改变而分离的。在拟南芥中，NCED 3是干旱胁迫诱导的阿坝合成的限速酶，控制该基因表达的蛋白质可能在调节阿坝生物合成的传感和信号通路的早期事件中发挥重要作用。作为该项目的一部分进行的研究将显着推进我们的阿坝生物合成是如何在分子水平上进行调节的理解，并可能导致额外的阿坝传感器的识别。这将有助于设计和实施新的抗旱作物工程战略，并将对教育和宣传产生重要影响。教育和推广由两部分组成：a）向研究生和高级本科生提供功能基因组学知识，主要研究员目前在马里兰州大学教授课程; B）每年向一名在历史上黑人本科院校就读的学生提供一次暑期实习。教育和推广的目标是为当前和未来的科学家提供植物非生物胁迫反应分子遗传学方面的理解和研究专长。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).Investigator (s): Jianhua Zhu jhzhu@umd.edu (principal investigator)Proposal number: 0919745Proposal title: Molecular mechanisms of ABA biosynthesis under drought stressAbstractDrought resulting from soil water deficit is one of the most common environmental factors that lead to substantial losses in productivity of crops worldwide. The phytohormone abscisic acid (ABA) is a very important factor in controlling abiotic stress responses in plants. Therefore, ABA is referred to as a stress hormone. While ABA accumulation itself is a well known response to drought stress, the molecular factors that control ABA accumulation and connect ABA to downstream responses are largely unknown. This project includes work that aims to understand the molecular mechanisms regulating ABA biosynthesis under drought stress by using forward genetic analysis of Arabidopsis mutants defective in drought stress-induced ABA accumulation and drought tolerance. These mutants were originally isolated based on altered expression of the 9-cis-epoxycarotenoid dioxygenase 3 (NCED3) gene. In Arabidopsis, NCED3 is a rate limiting enzyme in drought stress-induced ABA synthesis and proteins that control expression of this gene are likely to play important roles in early events of the sensing and signaling pathways that regulate ABA biosynthesis. The research undertaken as part of this project will significantly advance our understanding of how ABA biosynthesis is regulated at the molecular level, and perhaps lead to the identification of additional ABA sensors. This could assist in designing and implementing new strategies for engineering drought tolerant crops.The project will have important impacts on education and outreach. The education and outreach is composed of two parts: a) Delivery of knowledge of functional genomics to graduate and advanced undergraduate students in courses which the Principal Investigator is currently teaching at the University of Maryland; b) Offering one summer internship per year to a student enrolled at a historically black undergraduate institution. The goal of education and outreach is to provide current and future scientists with understanding and research expertise in molecular genetics of plant abiotic stress responses.