title: Mechanical stress acts via katanin to amplify differences in growth rate between adjacent cells in Arabidopsis.
abstract: The presence of diffuse morphogen gradients in tissues supports a view in which growth is locally homogenous. Here we challenge this view: we used a high-resolution quantitative approach to reveal significant growth variability among neighboring cells in the shoot apical meristem, the plant stem cell niche. This variability was strongly decreased in a mutant impaired in the microtubule-severing protein katanin. Major shape defects in the mutant could be related to a local decrease in growth heterogeneity. We show that katanin is required for the cell's competence to respond to the mechanical forces generated by growth. This provides the basis for a model in which microtubule dynamics allow the cell to respond efficiently to mechanical forces. This in turn can amplify local growth-rate gradients, yielding more heterogeneous growth and supporting morphogenesis.
authors.affiliation: Laboratoire de Reproduction et Développement des Plantes, INRA, CNRS, ENS, UCB Lyon 1, 46 Allée d'Italie, 69364 Lyon Cedex 07, France.
authors.forename: Magalie
authors.initials: M
authors.lastname: Uyttewaal
authors.forename: Agata
authors.initials: A
authors.lastname: Burian
authors.forename: Karen
authors.initials: K
authors.lastname: Alim
authors.forename: Benoît
authors.initials: B
authors.lastname: Landrein
authors.forename: Dorota
authors.initials: D
authors.lastname: Borowska-Wykręt
authors.forename: Annick
authors.initials: A
authors.lastname: Dedieu
authors.forename: Alexis
authors.initials: A
authors.lastname: Peaucelle
authors.forename: Michał
authors.initials: M
authors.lastname: Ludynia
authors.forename: Jan
authors.initials: J
authors.lastname: Traas
authors.forename: Arezki
authors.initials: A
authors.lastname: Boudaoud
authors.forename: Dorota
authors.initials: D
authors.lastname: Kwiatkowska
authors.forename: Olivier
authors.initials: O
authors.lastname: Hamant
mesh_terms: D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism*; D017360:Arabidopsis / Q000166:cytology* / Q000254:growth & development / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D006706:Homeostasis; D000074201:Katanin; D018519:Meristem / Q000166:cytology* / Q000254:growth & development / Q000378:metabolism; D008870:Microtubules / Q000378:metabolism; D008954:Models, Biological; D009024:Morphogenesis; D009154:Mutation; D059828:Plant Cells / Q000502:physiology; D018520:Plant Shoots / Q000166:cytology / Q000254:growth & development; D013314:Stress, Mechanical
chemical_list: D029681:Arabidopsis Proteins; D000251:Adenosine Triphosphatases; C436244:KTN1 protein, Arabidopsis; D000074201:Katanin