auxin biosynthesis indole-3-acetic acid biosynthesis indole-3-acetate biosynthesis Biosynthesis of auxins. Auxins are natural plant hormone involved in several stages of plant growth and development such as cell elongation, cell division, tissue differentiation, and apical dominance. The biosynthesis and the underlying mechanism of auxins (and cytokinins) action are subjects of intense investigation. Diverse bacterial species possess the ability to produce the auxin phytohormone indole-3-acetic acid (IAA). PMID:12758033 indoleacetate biosynthesis UPa:UPA00151 IAA biosynthesis GO:0009851 pathway PMID:17509086 PMID:7576148 plant hormone metabolism auxin metabolism