Submitted to: Trends in Plant Science
Publication Type: Peer reviewed journal
Publication Acceptance Date: 2/3/1998
Publication Date: N/A
Citation: Interpretive Summary: Nitrogen is the second most abundant element in plants. Nitrogen acquisition and use are critical to plant growth and yield. Improvement in nitrogen use by plants requires a thorough knowledge of the genes that control nitrogen assimilation. One of the key steps in nitrogen metabolism and assimilation is controlled by the gene that makes the enzyme (protein catalyst) glutamate synthase: GOGAT. The different forms of GOGAT and their importance in plant N metabolism are identified and discussed. Reports documenting the isolation of GOGAT genes are summarized. The evolution of the GOGAT genes is defined and the relationships between GOGAT genes are identified. This report is important because it provides a comprehensive overview of the GOGAT enzymes and genes that function in plants. It points out major advances and identifies further research areas to be pursued.
Technical Abstract: The assimilation of ammonia by a wide variety of organisms is the primary route for the introduction of nitrogen into the biosphere. The assimilatory enzymes glutamine synthetase and glutamate synthase catalyze reactions that convert alpha-ketoglutarate and ammonia to glutamate, which is then used in a wide variety of biosynthetic reactions. These enzymes also play a major role in the reassimilation of ammonia derived from photorespiration in C3 plants. This review summarizes recent biochemical, molecular, and genetic studies that are leading to a better understanding of the factors that determine the activity and function of glutamate synthase.