Disruption of AtOCT1, an organic cation transporter gene, affects root development and carnitine-related responses in Arabidopsis.
In animals, organic cation/carnitine transporters (OCTs) are involved in homeostasis and distribution of various small endogenous amines (e.g. carnitine, choline) and detoxification of xenobiotics such as nicotine. Here, we describe the characterization of AtOCT1, an Arabidopsis protein that shares most of the conserved features of mammalian plasma membrane OCTs. Transient expression of an AtOCT1::GFP fusion protein in onion epidermal cells and Arabidopsis protoplasts supported localization in the plasmalemma. AtOCT1 functionally complemented the Deltacit2/Deltaagp2p yeast strain that is defective in plasma membrane carnitine transport. Disruption of AtOCT1 in an Arabidopsis oct1-1 knockout mutant affected both the expression of carnitine-related genes and the developmental defects induced by exogenous carnitine. RT-PCR and promoter-uidA fusion analysis showed that AtOCT1 was expressed in vascular tissues of various organs and at sites of lateral root formation. Correlating with this expression pattern, oct1-1 seedlings grown in vitro exhibited a higher degree of root branching than the wild-type, showing that the disruption of AtOCT1 affected root development under certain conditions.
Lelandais-Brière
Christine
C
Institut des Sciences Végétales, UPR-CNRS 2355, Bat 23, Avenue de la Terrasse, 91198 Gif/Yvette, France.
Jovanovic
Mariana
M
Torres
Gisèle A M
GA
Perrin
Yolande
Y
Lemoine
Rémi
R
Corre-Menguy
Fabienne
F
Hartmann
Caroline
C
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism*; D002331:Carnitine / Q000378:metabolism*; D003001:Cloning, Molecular; D018506:Gene Expression Regulation, Plant; D008969:Molecular Sequence Data; D009154:Mutation; D027702:Organic Cation Transporter 1 / Q000235:genetics* / Q000378:metabolism*; D010802:Phylogeny; D018517:Plant Roots / Q000235:genetics* / Q000254:growth & development*; D012441:Saccharomyces cerevisiae
D029681:Arabidopsis Proteins; C000614718:OCT1 protein, Arabidopsis; D027702:Organic Cation Transporter 1; D002331:Carnitine