TY - JOUR
T1 - UUAT1 is a golgi-localized UDP-uronic acid transporter that modulates the polysaccharide composition of arabidopsis seed mucilage
AU - Saez-Aguayo, Susana
AU - Rautengarten, Carsten
AU - Temple, Henry
AU - Sanhueza, Dayan
AU - Ejsmentewicz, Troy
AU - Sandoval-Ibañez, Omar
AU - Doñas, Daniela
AU - Parra-Rojas, Juan Pablo
AU - Ebert, Berit
AU - Lehner, Arnaud
AU - Mollet, Jean Claude
AU - Dupree, Paul
AU - Scheller, Henrik V.
AU - Heazlewood, Joshua L.
AU - Reyes, Francisca C.
AU - Orellana, Ariel
N1 - Funding Information:
This work was supported by FONDECYT 11130498 (to F.C.R.), FONDECYT 3140415 (to S.S.-A.), FONDECYT 1151335, Fondo de Areas Prioritarias-Centro de Regulacion del Genoma-15090007, ECOS-CONICYT C14B02 and PFB-16 (to A.O.), and aCONICYT fellowship to H.T.Work conducted by the Joint BioEnergy Institute was supported by the U.S. Department of Energy, Office of Science, Office of Biological and Environmental Research, through contract DE-AC02-05CH11231 between Lawrence Berkeley National Laboratory and the U. S. Department of Energy. J.L.H. is supported by an Australian Research Council Future Fellowship (FT130101165). Work conducted by Glyco-MEV (J.-C.M. and A.L.) was in part supported by the VASI research network from the Upper Normandy region and the French ministry of research.We thank MiriamBarros for her advice and expertise in confocal microscopy. We also thank Hernan Salinas and Alvaro Miquel for technicalassistancewithHPAECanalysis,andFlavienDardelleandFranasois Le Mauff for technical assistance with gas chromatography analyses of pollen tube cell walls.
PY - 2017/1
Y1 - 2017/1
N2 - UDP-glucuronic acid (UDP-GlcA) is the precursor of many plant cell wall polysaccharides and is required for production of seed mucilage. Following synthesis in the cytosol, it is transported into the lumen of the Golgi apparatus, where it is converted to UDP-galacturonic acid (UDP-GalA), UDP-arabinose, and UDP-xylose. To identify the Golgi-localized UDP-GlcA transporter, we screened Arabidopsis thaliana mutants in genes coding for putative nucleotide sugar transporters for altered seed mucilage, a structure rich in the GalA-containing polysaccharide rhamnogalacturonan I. As a result, we identified UUAT1, which encodes a Golgi-localized protein that transports UDP-GlcA and UDP-GalA in vitro. The seed coat of uuat1 mutants had less GalA, rhamnose, and xylose in the soluble mucilage, and the distal cell walls had decreased arabinan content. Cell walls of other organs and cells had lower arabinose levels in roots and pollen tubes, but no differences were observed in GalA or xylose contents. Furthermore, the GlcA content of glucuronoxylan in the stem was not affected in the mutant. Interestingly, the degree of homogalacturonan methylation increased in uuat1. These results suggest that this UDP-GlcA transporter plays a key role defining the seed mucilage sugar composition and that its absence produces pleiotropic effects in this component of the plant extracellular matrix.
AB - UDP-glucuronic acid (UDP-GlcA) is the precursor of many plant cell wall polysaccharides and is required for production of seed mucilage. Following synthesis in the cytosol, it is transported into the lumen of the Golgi apparatus, where it is converted to UDP-galacturonic acid (UDP-GalA), UDP-arabinose, and UDP-xylose. To identify the Golgi-localized UDP-GlcA transporter, we screened Arabidopsis thaliana mutants in genes coding for putative nucleotide sugar transporters for altered seed mucilage, a structure rich in the GalA-containing polysaccharide rhamnogalacturonan I. As a result, we identified UUAT1, which encodes a Golgi-localized protein that transports UDP-GlcA and UDP-GalA in vitro. The seed coat of uuat1 mutants had less GalA, rhamnose, and xylose in the soluble mucilage, and the distal cell walls had decreased arabinan content. Cell walls of other organs and cells had lower arabinose levels in roots and pollen tubes, but no differences were observed in GalA or xylose contents. Furthermore, the GlcA content of glucuronoxylan in the stem was not affected in the mutant. Interestingly, the degree of homogalacturonan methylation increased in uuat1. These results suggest that this UDP-GlcA transporter plays a key role defining the seed mucilage sugar composition and that its absence produces pleiotropic effects in this component of the plant extracellular matrix.
UR - http://www.scopus.com/inward/record.url?scp=85012216683&partnerID=8YFLogxK
U2 - 10.1105/tpc.16.00465
DO - 10.1105/tpc.16.00465
M3 - Article
AN - SCOPUS:85012216683
VL - 29
SP - 129
EP - 143
JO - Plant Cell
JF - Plant Cell
SN - 1040-4651
IS - 1
ER -