Figure 1.

Amino acid biosynthesis in plants. The carbon skeletons of amino acids are derived from different intermediates of the central carbon metabolism (boxed in blue). According to their respective precursors, the amino acids are grouped into five families derived from glutamate, serine, pyruvate, aspartate, or chorismate. The nine amino acids that cannot be synthesized in animals are shown in dark-green boxes, while those that can be synthesized but additionally need to be taken up with the diet are in brighter boxes. Proteinogenic amino acids that can be sufficiently synthesized in animals are in pale green boxes and non-proteinogenic amino acids and other important intermediates are boxed in white. DAHP, 3-deoxy-D-arabinoheptulosonate-7-phosphate.