DAO1 catalyzes temporal and tissue-specific oxidative inactivation of auxin in Arabidopsis thaliana.

ABSTRACT: Tight homeostatic regulation of the phytohormone auxin [indole-3-acetic acid (IAA)] is essential to plant growth. Auxin biosynthetic pathways and the processes that inactivate auxin by conjugation to amino acids and sugars have been thoroughly characterized. However, the enzyme that catalyzes oxidation of IAA to its primary catabolite 2-oxindole-3-acetic acid (oxIAA) remains uncharacterized. Here, we show that DIOXYGENASE FOR AUXIN OXIDATION 1 (DAO1) catalyzes formation of oxIAA in vitro and in vivo and that this mechanism regulates auxin homeostasis and plant growth. Null dao1-1 mutants contain 95% less oxIAA compared with wild type, and complementation of dao1 restores wild-type oxIAA levels, indicating that DAO1 is the primary IAA oxidase in seedlings. Furthermore, dao1 loss of function

SUBMITTER: Zhang J 

PROVIDER: S-EPMC5047167 | biostudies-literature | 2016 Sep

REPOSITORIES: biostudies-literature