Lysine catabolism: a stress and development super-regulated metabolic pathway.

Lysine is a nutritionally important essential amino acid whose level in plants is largely regulated by the rate of its synthesis. In some plant tissues and under some stress conditions, however, lysine is also efficiently catabolized into glutamate and several other stress-related metabolites by novel mechanisms of metabolic regulation. Lysine catabolism is important for mammalian brain function; it is possible that the generation of glutamate regulates nerve transmission signals via glutamate receptors. Plants also possess homologues of animal glutamate receptors. It is thus likely that lysine catabolism also regulates various plant processes via these receptors.