Involved in auxin production. Both TAA1 and TAR2 are required for maintaining proper auxin levels in roots, while TAA1, TAR1 and TAR2 are required for proper embryo patterning. Involved in the maintenance of the root stem cell niches. 2-oxoglutarate + L-tryptophan = indole-3-pyruvate + L-glutamate L-tryptophan + pyruvate = indole-3-pyruvate + L-alanine Inhibited by L-kynurenine. Plant hormone metabolism; auxin biosynthesis. Expressed in roots, cotyledons and in the apical parts of hypocotyls. In roots, restricted to the provasculature of meristematic regions. Detected on the inner side of the apical hooks. In early-stage flowers, expressed in all floral organs. Becomes later restricted to the gynoecia, preferentially to the outer cell layers that give rise to the valves. No expression in flowers at anthesis. Up-regulated by ethylene. No visible phenotype. Belongs to the alliinase family.