title: The Specification of Geometric Edges by a Plant Rab GTPase Is an Essential Cell-Patterning Principle During Organogenesis in Arabidopsis.
abstract: Plant organogenesis requires control over division planes and anisotropic cell wall growth, which each require spatial patterning of cells. Polyhedral plant cells can display complex patterning in which individual faces are established as biochemically distinct domains by endomembrane trafficking. We now show that, during organogenesis, the Arabidopsis endomembrane system specifies an important additional cellular spatial domain: the geometric edges. Previously unidentified membrane vesicles lying immediately beneath the plasma membrane at cell edges were revealed through localization of RAB-A5c, a plant GTPase of the Rab family of membrane-trafficking regulators. Specific inhibition of RAB-A5c activity grossly perturbed cell geometry in developing lateral organs by interfering independently with growth anisotropy and cytokinesis without disrupting default membrane trafficking. The initial loss of normal cell geometry can be explained by a failure to maintain wall stiffness specifically at geometric edges. RAB-A5c thus meets a requirement to specify this cellular spatial domain during organogenesis.
authors.affiliation: Department of Plant Sciences, University of Oxford, South Parks Road, Oxford OX1 3RB, UK.
authors.forename: Charlotte
authors.initials: C
authors.lastname: Kirchhelle
authors.affiliation: Department of Plant Sciences, University of Oxford, South Parks Road, Oxford OX1 3RB, UK.
authors.forename: Cheung-Ming
authors.initials: CM
authors.lastname: Chow
authors.affiliation: Department of Plant Sciences, University of Oxford, South Parks Road, Oxford OX1 3RB, UK.
authors.forename: Camille
authors.initials: C
authors.lastname: Foucart
authors.affiliation: Department of Plant Sciences, University of Oxford, South Parks Road, Oxford OX1 3RB, UK.
authors.forename: Helia
authors.initials: H
authors.lastname: Neto
authors.affiliation: Center for Plant Molecular Biology, Microscopy, University of Tübingen, Auf der Morgenstelle 32, 72076 Tübingen, Germany.
authors.forename: York-Dieter
authors.initials: YD
authors.lastname: Stierhof
authors.affiliation: Department of Plant Sciences, University of Oxford, South Parks Road, Oxford OX1 3RB, UK.
authors.forename: Monika
authors.initials: M
authors.lastname: Kalde
authors.affiliation: Department of Plant Sciences, University of Oxford, South Parks Road, Oxford OX1 3RB, UK.
authors.forename: Carol
authors.initials: C
authors.lastname: Walton
authors.affiliation: Department of Plant Sciences, University of Oxford, South Parks Road, Oxford OX1 3RB, UK.
authors.forename: Mark
authors.initials: M
authors.lastname: Fricker
authors.affiliation: Department of Comparative and Developmental Genetics, Max Planck Institute for Plant Breeding Research, Carl-von-Linné-Weg 10, Cologne 50829, Germany.
authors.forename: Richard S
authors.initials: RS
authors.lastname: Smith
authors.affiliation: Department of Engineering Science, University of Oxford, Parks Road, Oxford OX1 3PJ, UK.
authors.forename: Antoine
authors.initials: A
authors.lastname: Jérusalem
authors.affiliation: Department of Plant Sciences, University of Oxford, South Parks Road, Oxford OX1 3RB, UK.
authors.forename: Niloufer
authors.initials: N
authors.lastname: Irani
authors.affiliation: Department of Plant Sciences, University of Oxford, South Parks Road, Oxford OX1 3RB, UK. Electronic address: ian.moore@plants.ox.ac.uk.
authors.forename: Ian
authors.initials: I
authors.lastname: Moore
mesh_terms: D017360:Arabidopsis / Q000201:enzymology*; D002462:Cell Membrane / Q000378:metabolism*; D048749:Cytokinesis; D038081:Organogenesis / Q000502:physiology*; D059828:Plant Cells / Q000378:metabolism*; D021381:Protein Transport / Q000502:physiology; D020691:rab GTP-Binding Proteins / Q000378:metabolism*
chemical_list: D020691:rab GTP-Binding Proteins