PDR-type ABC transporter mediates cellular uptake of the phytohormone abscisic acid.
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.
POSTECH-UZH Global Research Laboratory, Division of Molecular Life Sciences, Pohang University of Science and Technology, Pohang 790-784, Korea.
Joohyun
J
Kang
Jae-Ung
JU
Hwang
Miyoung
M
Lee
Yu-Young
YY
Kim
Sarah M
SM
Assmann
Enrico
E
Martinoia
Youngsook
Y
Lee
D018528:ATP-Binding Cassette Transporters / Q000235:genetics / Q000378:metabolism*; D000040:Abscisic Acid / Q000378:metabolism*; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D002462:Cell Membrane / Q000378:metabolism; D017931:DNA Primers / Q000235:genetics; D055864:Droughts; D017343:Genes, Plant; D005816:Genetic Complementation Test; D009154:Mutation; D010937:Plant Growth Regulators / Q000378:metabolism*; D054046:Plant Stomata / Q000378:metabolism; D030821:Plants, Genetically Modified; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D013312:Stress, Physiological
D018528:ATP-Binding Cassette Transporters; D029681:Arabidopsis Proteins; D017931:DNA Primers; C482841:PDR12 protein, Arabidopsis; D010937:Plant Growth Regulators; D011994:Recombinant Proteins; D000040:Abscisic Acid