title: Requirement of borate cross-linking of cell wall rhamnogalacturonan II for Arabidopsis growth.
abstract: Turgor-driven plant cell growth depends on wall structure. Two allelic l-fucose-deficient Arabidopsis thaliana mutants (mur1-1 and 1-2) are dwarfed and their rosette leaves do not grow normally. mur1 leaf cell walls contain normal amounts of the cell wall pectic polysaccharide rhamnogalacturonan II (RG-II), but only half exists as a borate cross-linked dimer. The altered structure of mur1 RG-II reduces the rate of formation and stability of this cross-link. Exogenous aqueous borate rescues the defect. The reduced cross-linking of RG-II in dwarf mur1 plants indicates that plant growth depends on wall pectic polysaccharide organization.
authors.affiliation: Complex Carbohydrate Research Center and Department of Biochemistry and Molecular Biology, University of Georgia, 220 Riverbend Road, Athens, GA 30602-4712, USA. mao@ccrc.uga.edu
authors.forename: M A
authors.initials: MA
authors.lastname: O'Neill
authors.forename: S
authors.initials: S
authors.lastname: Eberhard
authors.forename: P
authors.initials: P
authors.lastname: Albersheim
authors.forename: A G
authors.initials: AG
authors.lastname: Darvill
mesh_terms: D000483:Alleles; D017360:Arabidopsis / Q000737:chemistry / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D001881:Borates / Q000378:metabolism* / Q000494:pharmacology; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002473:Cell Wall / Q000737:chemistry* / Q000378:metabolism / Q000648:ultrastructure; D019281:Dimerization; D005643:Fucose / Q000032:analysis / Q000378:metabolism / Q000494:pharmacology; D017343:Genes, Plant; D005936:Glucans; D006836:Hydro-Lyases / Q000235:genetics / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D009154:Mutation; D010368:Pectins / Q000737:chemistry* / Q000378:metabolism*; D018515:Plant Leaves / Q000737:chemistry / Q000254:growth & development / Q000378:metabolism; D011134:Polysaccharides / Q000737:chemistry / Q000378:metabolism; D014990:Xylans
chemical_list: D001881:Borates; D005936:Glucans; D011134:Polysaccharides; D014990:Xylans; C042492:rhamnogalacturonan II; D005643:Fucose; C029353:xyloglucan; D010368:Pectins; D006836:Hydro-Lyases; C044971:GDPmannose 4,6-dehydratase