Amino Acids

Abstract

Amino acids perform essential functions in both primary and secondary plant metabolism besides their obvious role in protein synthesis. They can be categorised on the basis of their function such as serving to assimilate and transport nitrogen from sources to sinks or serving as precursors for secondary products such as hormones, vitamins, co‐factors and compounds in plant defence. Thus, synthesis of amino acids directly or indirectly controls various aspects of plant growth and development. Recent investigations of genes involved in amino acid biosynthesis reveal that this is a dynamic process controlled by metabolic, environmental and developmental factors including mineral nutrients such as nitrate and sulphate. This chapter intends to provide fundamental knowledge on nitrogen and sulphur metabolism as basis for amino acid biosynthesis and to highlight examples in which combined molecular, biochemical and genetic approaches have helped to define the pathways and uncover regulatory mechanisms of amino acid biosynthesis in plants. These studies have implications for both basic and applied research because amino acid biosynthesis is as well a target for herbicide action as an option to improve the nutritional quality of crops by metabolic engineering and plant breeding.