PDR-type ABC transporter mediates cellular uptake of the phytohormone abscisic acid

• Published in: Proceedings of the National Academy of Sciences - PNAS 2010-02, Vol.107 (5), p.2355-2360
• Main Authors: Kang, Joohyun, Hwang, Jae-Ung, Lee, Miyoung, Kim, Yu-Young, Assmann, Sarah M, Martinoia, Enrico, Lee, Youngsook
• Format: Article
• Language: English
• Subjects: ABC transporters; abscisic acid; Abscisic Acid - metabolism; Adenosine triphosphatase; Arabidopsis - genetics; Arabidopsis - metabolism; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Arabidopsis thaliana; ATP binding cassette transporters; ATP-Binding Cassette Transporters - genetics; ATP-Binding Cassette Transporters - metabolism; Auxins; Base Sequence; Binding sites; Biological Sciences; Cell Membrane - metabolism; Cell membranes; DNA Primers - genetics; drought tolerance; Droughts; Flowers & plants; gene expression regulation; Genes, Plant; Genetic Complementation Test; Guard cells; Hormones; Leaves; mutants; Mutation; phenotype; physiological transport; Plant cells; Plant growth regulators; Plant Growth Regulators - metabolism; Plant roots; Plant Stomata - metabolism; Plants; Plants, Genetically Modified; Plasma; Pleiotropic drug resistance transporter 12; protoplast fusion; Protoplasts; Recombinant Proteins - genetics; Recombinant Proteins - metabolism; Saccharomyces cerevisiae - genetics; Saccharomyces cerevisiae - metabolism; stomatal movement; Stress, Physiological
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.0909222107

Abscisic acid (ABA) is a ubiquitous phytohormone involved in many developmental processes and stress responses of plants. ABA moves within the plant, and intracellular receptors for ABA have been recently identified; however, no ABA transporter has been described to date. Here, we report the identification of the ATP-binding cassette (ABC) transporter Arabidopsis thaliana Pleiotropic drug resistance transporter PDR12 (AtPDR12)/ABCG40 as a plasma membrane ABA uptake transporter. Uptake of ABA into yeast and BY2 cells expressing AtABCG40 was increased, whereas ABA uptake into protoplasts of atabcg40 plants was decreased compared with control cells. In response to exogenous ABA, the up-regulation of ABA responsive genes was strongly delayed in atabcg40 plants, indicating that ABCG40 is necessary for timely responses to ABA. Stomata of loss-of-function atabcg40 mutants closed more slowly in response to ABA, resulting in reduced drought tolerance. Our results integrate ABA-dependent signaling and transport processes and open another avenue for the engineering of drought-tolerant plants.