Together with ABCG36, regulates auxin homeostasis and responses by playing a dual role in coumarine (and derivatives) and in the auxin precursor indole 3-butyric acid (IBA) efflux transport, thus influencing roots and root hairs development. Mediates coumarin exudation in the rhizosphere, especially in iron (Fe) deficient conditions, with a strong specificity for highly oxygenated compounds such as scopoletin and derivatives, dihydroxyscopoletin, esculetin, fraxin, fraxetin and esculin; these molecules improve plant Fe nutrition. Involved in the cellular detoxification of xenobiotics by promoting the excretion of some auxinic herbicides including 2,4-dichlorophenoxyacetic acid (2,4-D), 4-(2,4-dichlorophenoxy)butyric acid (2,4-DB) and other members of the phenoxyalkanoic acid family as well as the polar auxin transport inhibitor, napthylphthalamic acid (NPA). May be a general defense protein.
