title: Proline-rich protein-like PRPL1 controls elongation of root hairs in Arabidopsis thaliana.
abstract: The synthesis and composition of cell walls is dynamically adapted in response to many developmental and environmental signals. In this respect, cell wall proteins involved in controlling cell elongation are critical for cell development. Transcriptome analysis identified a gene in Arabidopsis thaliana, which was named proline-rich protein-like, AtPRPL1, based on sequence similarities from a phylogenetic analysis. The most resemblance was found to AtPRP1 and AtPRP3 from Arabidopsis, which are known to be involved in root hair growth and development. In A. thaliana four proline-rich cell wall protein genes, playing a role in building up the cross-connections between cell wall components, can be distinguished. AtPRPL1 is a small gene that in promoter::GUS (β-glucuronidase) analysis has high expression in trichoblast cells and in the collet. Chemical or mutational interference with root hair formation inhibited this expression. Altered expression levels in knock-out or overexpression lines interfered with normal root hair growth and etiolated hypocotyl development, but Fourier transform-infrared (FT-IR) analysis did not identify consistent changes in cell wall composition of root hairs and hypocotyl. Co-localization analysis of the AtPRPL1-green fluorescent protein (GFP) fusion protein and different red fluorescent protein (RFP)-labelled markers confirmed the presence of AtPRPL1-GFP in small vesicles moving over the endoplasmic reticulum. Together, these data indicate that the AtPRPL1 protein is involved in the cell's elongation process. How exactly this is achieved remains unclear at present.
authors.affiliation: Department of Biology, Plant Growth and Development, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerpen, Belgium.
authors.forename: Agnieszka Karolina
authors.initials: AK
authors.lastname: Boron
authors.affiliation: Department of Biology, Plant Growth and Development, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerpen, Belgium.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Van Orden
authors.affiliation: Department of Biology, Plant Growth and Development, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerpen, Belgium.
authors.forename: Marios
authors.initials: M
authors.lastname: Nektarios Markakis
authors.affiliation: Institut de Recherche Agronomique, UMR1318, Institut Jean-Pierre Bourgin, Saclay Plant Sciences, F-78000 Versailles, France AgroParisTech, Institut Jean-Pierre Bourgin, RD10, F-78000 Versailles, France.
authors.forename: Grégory
authors.initials: G
authors.lastname: Mouille
authors.affiliation: Laboratory of Cell Biology and Histology, Veterinary Sciences Department, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerpen, Belgium.
authors.forename: Dirk
authors.initials: D
authors.lastname: Adriaensen
authors.affiliation: Department of Biology, Plant Growth and Development, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerpen, Belgium.
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Verbelen
authors.affiliation: Institut de Recherche Agronomique, UMR1318, Institut Jean-Pierre Bourgin, Saclay Plant Sciences, F-78000 Versailles, France AgroParisTech, Institut Jean-Pierre Bourgin, RD10, F-78000 Versailles, France.
authors.forename: Herman
authors.initials: H
authors.lastname: Höfte
authors.affiliation: Department of Biology, Plant Growth and Development, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerpen, Belgium kris.vissenberg@ua.ac.be.
authors.forename: Kris
authors.initials: K
authors.lastname: Vissenberg
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant / Q000235:genetics / Q000502:physiology; D018546:Hypocotyl / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000235:genetics / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins
keywords: Arabidopsis thaliana; cell expansion; hypocotyl; pollen Ole allergen; root hairs.