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.
