Brachypodium BdABCG25 is a homolog of Arabidopsis AtABCG25 involved in the transport of abscisic acid.

Abscisic acid (ABA), a stress hormone produced by plants to cope with various environmental stresses, has potential as a mobile molecule. Recently, several types of ABA transporters have been described. We previously found a membrane transporter, AtABCG25, that is involved in intercellular ABA transport in Arabidopsis thaliana. However, it is not yet known whether there are any homologs of AtABCG25 in different plant species. Here, we identified a homolog of AtABCG25 in Brachypodium distachyon, named BdABCG25, and characterized its function. We examined the ABA transport activity of BdABCG25 and the physiological properties of BdABCG25 expression in Arabidopsis. The results suggest that BdABCG25 is a putative functional homolog of AtABCG25. Regulating intercellular ABA transport may be a novel strategy for breeding stress-tolerant monocot crops.