Aromatic amino acid metabolism during organogenesis in rice callus cultures

The activity during root and shoot initiation of key enzymes involved in aromatic amino acid metabolism was examined in rice ( Oryza sativa L. cv. Bala) callus cultures. Increased activities of the enzymes quinate:NAD⁺ oxidoreductase (EC 1.1.1.24), shikimate kinase (EC 2.7.1.71), chorismate mutase (EC 5.4.99.5), anthranilate synthase (EC 4.1.3.27) and tryptophan synthetase (EC 4.2.1.20) were noticed in organ-forming callus compared to proliferating callus of rice, especially prior to the visible manifestation of form. These results suggest a correlation between organogenesis and the aromatic amino acid pathway.