title: O-glycosylated cell wall proteins are essential in root hair growth.
abstract: Root hairs are single cells that develop by tip growth and are specialized in the absorption of nutrients. Their cell walls are composed of polysaccharides and hydroxyproline-rich glycoproteins (HRGPs) that include extensins (EXTs) and arabinogalactan-proteins (AGPs). Proline hydroxylation, an early posttranslational modification of HRGPs that is catalyzed by prolyl 4-hydroxylases (P4Hs), defines the subsequent O-glycosylation sites in EXTs (which are mainly arabinosylated) and AGPs (which are mainly arabinogalactosylated). We explored the biological function of P4Hs, arabinosyltransferases, and EXTs in root hair cell growth. Biochemical inhibition or genetic disruption resulted in the blockage of polarized growth in root hairs and reduced arabinosylation of EXTs. Our results demonstrate that correct O-glycosylation on EXTs is essential for cell-wall self-assembly and, hence, root hair elongation in Arabidopsis thaliana.
authors.affiliation: Instituto de Fisiología, Biología Molecular y Neurociencias-Consejo Nacional de Investigaciones Científicas y Técnicas (IFIByNE-CONICET), Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires C1428EGA, Argentina.
authors.forename: Silvia M
authors.initials: SM
authors.lastname: Velasquez
authors.forename: Martiniano M
authors.initials: MM
authors.lastname: Ricardi
authors.forename: Javier Gloazzo
authors.initials: JG
authors.lastname: Dorosz
authors.forename: Paula V
authors.initials: PV
authors.lastname: Fernandez
authors.forename: Alejandro D
authors.initials: AD
authors.lastname: Nadra
authors.forename: Laercio
authors.initials: L
authors.lastname: Pol-Fachin
authors.forename: Jack
authors.initials: J
authors.lastname: Egelund
authors.forename: Sascha
authors.initials: S
authors.lastname: Gille
authors.forename: Jesper
authors.initials: J
authors.lastname: Harholt
authors.forename: Marina
authors.initials: M
authors.lastname: Ciancia
authors.forename: Hugo
authors.initials: H
authors.lastname: Verli
authors.forename: Markus
authors.initials: M
authors.lastname: Pauly
authors.forename: Antony
authors.initials: A
authors.lastname: Bacic
authors.forename: Carl Erik
authors.initials: CE
authors.lastname: Olsen
authors.forename: Peter
authors.initials: P
authors.lastname: Ulvskov
authors.forename: Bent Larsen
authors.initials: BL
authors.lastname: Petersen
authors.forename: Chris
authors.initials: C
authors.lastname: Somerville
authors.forename: Norberto D
authors.initials: ND
authors.lastname: Iusem
authors.forename: Jose M
authors.initials: JM
authors.lastname: Estevez
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001089:Arabinose / Q000378:metabolism; D002236:Carbohydrate Conformation; D002473:Cell Wall / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D006023:Glycoproteins / Q000737:chemistry / Q000378:metabolism*; D006031:Glycosylation; D016695:Glycosyltransferases / Q000235:genetics / Q000378:metabolism; D006900:Hydroxylation; D006909:Hydroxyproline / Q000378:metabolism*; D008954:Models, Biological; D009154:Mutation; D010430:Pentosyltransferases / Q000737:chemistry / Q000378:metabolism; D010641:Phenotype; D010940:Plant Proteins / Q000737:chemistry / Q000378:metabolism*; D018517:Plant Roots / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism; D011134:Polysaccharides / Q000737:chemistry; D011393:Procollagen-Proline Dioxygenase / Q000235:genetics / Q000378:metabolism*; D011392:Proline / Q000378:metabolism; D011487:Protein Conformation; D011499:Protein Processing, Post-Translational; D017433:Protein Structure, Secondary
chemical_list: D029681:Arabidopsis Proteins; D006023:Glycoproteins; D010940:Plant Proteins; D011134:Polysaccharides; C005488:extensin protein, plant; D011392:Proline; D001089:Arabinose; D011393:Procollagen-Proline Dioxygenase; D016695:Glycosyltransferases; D010430:Pentosyltransferases; C101967:arabinosyltransferase; D006909:Hydroxyproline