title: Atkinesin-13A modulates cell-wall synthesis and cell expansion in Arabidopsis thaliana via the THESEUS1 pathway.
abstract: Growth of plant organs relies on cell proliferation and expansion. While an increasingly detailed picture about the control of cell proliferation is emerging, our knowledge about the control of cell expansion remains more limited. We demonstrate here that the internal-motor kinesin AtKINESIN-13A (AtKIN13A) limits cell expansion and cell size in Arabidopsis thaliana, with loss-of-function atkin13a mutants forming larger petals with larger cells. The homolog, AtKINESIN-13B, also affects cell expansion and double mutants display growth, gametophytic and early embryonic defects, indicating a redundant role of the two genes. AtKIN13A is known to depolymerize microtubules and influence Golgi motility and distribution. Consistent with this function, AtKIN13A interacts genetically with ANGUSTIFOLIA, encoding a regulator of Golgi dynamics. Reduced AtKIN13A activity alters cell wall structure as assessed by Fourier-transformed infrared-spectroscopy and triggers signalling via the THESEUS1-dependent cell-wall integrity pathway, which in turn promotes the excess cell expansion in the atkin13a mutant. Thus, our results indicate that the intracellular activity of AtKIN13A regulates cell expansion and wall architecture via THESEUS1, providing a compelling case of interplay between cell wall integrity sensing and expansion.
authors.affiliation: Institut für Biochemie und Biologie, Universität Potsdam, Potsdam-Golm, Germany.
authors.forename: Ushio
authors.initials: U
authors.lastname: Fujikura
authors.affiliation: BIOSS Centre for Biological Signaling Studies, Faculty of Biology, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany.
authors.forename: Lore
authors.initials: L
authors.lastname: Elsaesser
authors.affiliation: Institut für Biochemie und Biologie, Universität Potsdam, Potsdam-Golm, Germany.
authors.forename: Holger
authors.initials: H
authors.lastname: Breuninger
authors.affiliation: Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam-Golm, Germany.
authors.forename: Clara
authors.initials: C
authors.lastname: Sánchez-Rodríguez
authors.affiliation: Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam-Golm, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Ivakov
authors.affiliation: BIOSS Centre for Biological Signaling Studies, Faculty of Biology, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Laux
authors.affiliation: Cell & Developmental Biology Department, John Innes Centre, Norwich Research Park, Norwich, United Kingdom.
authors.forename: Kim
authors.initials: K
authors.lastname: Findlay
authors.affiliation: Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam-Golm, Germany; ARC Centre of Excellence in Plant Cell Walls, School of Botany, University of Melbourne, Parkville, Victoria, Australia.
authors.forename: Staffan
authors.initials: S
authors.lastname: Persson
authors.affiliation: Institut für Biochemie und Biologie, Universität Potsdam, Potsdam-Golm, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Lenhard
mesh_terms: D017360:Arabidopsis / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D049109:Cell Proliferation; D002473:Cell Wall / Q000737:chemistry / Q000378:metabolism*; D004843:Epistasis, Genetic; D018506:Gene Expression Regulation, Plant; D009154:Mutation; D010641:Phenotype; D011494:Protein Kinases / Q000378:metabolism*; D011956:Receptors, Cell Surface / Q000378:metabolism*; D015398:Signal Transduction
chemical_list: D029681:Arabidopsis Proteins; D011956:Receptors, Cell Surface; D011494:Protein Kinases; C522441:THESEUS1 protein, Arabidopsis