text_1: taa1 tar1 tar2 triple mutants in Arabidopsis do not make root meristem during embryogenesis.
text_2: Biochemical studies revealed that WEI8 encodes a long-anticipated tryptophan aminotransferase, TAA1, in the essential, yet genetically uncharacterized, indole-3-pyruvic acid (IPA) branch of the auxin biosynthetic pathway.