Molecular and physiological analysis of indole-3-acetic acid degradation in Bradyrhizobium japonicum E109

Bradyrhizobium japonicum E109 is a bacterium widely used for inoculants production in Argentina. It known its ability to produce several phytohormones and degrade indole-3-acetic acid (IAA). The genome sequence of B. was recently analyzed it showed the presence genes related synthesis IAA by indole-3-acetonitrile, indole-3-acetamide tryptamine pathways. Nevertheless, not able instead has this hormone under saprophytic culture conditions. This work aimed study molecular physiological features degradation identify responsible activity. In we identified two sequences coding putative 3-phenylpropionate dioxygenase (subunits ? ?) that were homologous canonical cluster iacC iacD Pseudomonas putida 1290. These form separate together with three additional unknown functions. activity found be constitutively expressed E109. As products degradation, compounds, 3-indoleacetic 2,3-oxide 2-(2-hydroperoxy-3-hydroxyindolin-3-yl) acetic acid. Our report proposes, first time, model Bradyrhizobium.