Linking Reactive Nitrogen Metabolism and Redox Homeostasis in Plants

随着全球气候变化和经济模式的转变改变了水和其他资源的分布，了解植物生长，发育和生产力的控制变得越来越重要。该项目研究了一氧化氮分子如何控制这些过程。一氧化氮在几乎所有生物体中起着重要作用。 最近的数据表明，一氧化氮有助于植物保存水分和产生种子。GSNOR是一种负责分解细胞内过量一氧化氮的蛋白质;此外，缺乏GSNOR的植物对热应激敏感，产生较少的种子，并受到过量一氧化氮的损害。这些观察结果表明，GSNOR调节一氧化氮水平，也可能改变一氧化氮在植物中的感知。该研究项目将采用尖端技术来确定GSNOR如何控制模式植物物种拟南芥中一氧化氮与其他蛋白质的反应。该项目有可能揭示植物适应高温和干旱等胁迫的方式，并将为在不断变化的气候中提高植物生产力的努力提供信息。除了一名博士后研究员和一名研究生外，该项目还将为马萨诸塞州大学本科生和阿默斯特地区高中的高中生和教师提供培训机会。本项目的目标是了解一氧化氮（NO）和氧化还原代谢是如何整合控制植物生长和发育的。最近的数据牵连NO和蛋白质半胱氨酸氧化（氧化还原）的过程中的关键植物的生命周期。几乎所有生物体都利用NO作为调节分子，并且已知半胱氨酸氧化影响真核生物中许多蛋白质的生物学功能。酶S-亚硝基谷胱甘肽还原酶（GSNOR）起着关键作用，在NO稳态催化的NADH依赖性还原的S-亚硝基谷胱甘肽（GSNO），生物活性NO的主要水库。在这项研究中，研究人员将采用分子遗传学，生物化学，代谢组学和蛋白质组学的方法来评估GSNOR在蛋白质氧化还原调节和代谢途径的作用，在模式植物拟南芥。实验将：（1）检验GSNOR活性在植物死亡后通过氧化还原修饰和/或通过与其他蛋白质的相互作用进行调节的假设;（2）确定蛋白质亚硝基化的改变如何控制植物表型;（3）测量GSNOR的突变如何在体内改变GSH氧化还原平衡;以及（4）测量特定代谢途径的通量，其改变的调节可以通过氧化还原修饰来控制。 这项工作将有助于阐明GSNOR在植物形态和分子表型中的作用，这些表型与花发育、育性和胁迫反应等性状相关。

As global climate change and shifting economic patterns alter the distribution of water and other resources, it is increasingly important to understand the control of plant growth, development, and productivity. This project investigates how the molecule, nitric oxide, controls these processes. Nitric oxide plays significant roles in almost every living organism. Recent data show that nitric oxide helps plants to conserve water and produce seeds. GSNOR is a protein responsible for breaking down excess nitric oxide inside of cells; furthermore, plants that lack GSNOR are sensitive to heat stress, make fewer seeds, and suffer damage from excess nitric oxide. These observations suggest that GSNOR regulates nitric oxide levels and may also alter nitric oxide perception in plants. This research project will employ cutting-edge technologies to determine how GSNOR governs the reaction of nitric oxide with other proteins in the model plant species Arabidopsis thaliana. This project has potential to uncover the means by which plants adapt to stresses such as heat and drought, and will inform efforts to improve the productivity of plants in a changing climate. In addition to involving one postdoctoral fellow and a graduate student, the project will also provide training opportunities for University of Massachusetts undergraduates and for high school students and teachers from Amherst Regional High School. The goal of this project is to understand how nitric oxide (NO) and redox metabolism are integrated to control plant growth and development. Recent data implicate NO and protein cysteine oxidation (redox) in processes critical to the plant life cycle. Virtually all organisms utilize NO as a regulatory molecule, and cysteine oxidation is known to influence the biological function of many proteins in eukaryotes. The enzyme S-nitrosoglutathione reductase (GSNOR) plays a key role in NO homeostasis by catalyzing the NADH-dependent reduction of S-nitrosoglutathione (GSNO), the major reservoir of bioactive NO. In this research, investigators will employ molecular genetic, biochemical, metabolomic, and proteomic methods to assess the role of GSNOR in protein redox regulation and metabolic pathways in the model plant Arabidopsis thaliana. Experiments will: (1) test the hypothesis that GSNOR activity is regulated post-translationally by redox modifications and/or by interaction with other proteins; (2) determine how alterations in protein nitrosylation may control plant phenotype; (3) measure how mutation of GSNOR alters GSH redox poise in vivo; and (4) measure flux of specific metabolic pathways whose altered regulation may be controlled by redox modifications. This work will help elucidate the role of GSNOR in morphological and molecular phenotypes of plants associated with traits such as flower development, fertility and response to stress.