@article{MajdaGronesSintornetal.2017,
  author    = {Majda, Mateusz and Grones, Peter and Sintorn, Ida-Maria and Vain, Thomas and Milani, Pascale and Krupinski, Pawel and Zagorska-Marek, Beata and Viotti, Corrado and Jonsson, Henrik and Mellerowicz, Ewa J. and Hamant, Olivier and Robert, Stephanie},
  title     = {Mechanochemical Polarization of Contiguous Cell Walls Shapes Plant Pavement Cells},
  series = {Developmental cell},
  volume    = {43},
  journal   = {Developmental cell},
  publisher = {Cell Press},
  address   = {Cambridge},
  issn      = {1534-5807},
  doi       = {10.1016/j.devcel.2017.10.017},
  pages     = {290 -- +},
  year      = {2017},
  abstract  = {The epidermis of aerial plant organs is thought to be limiting for growth, because it acts as a continuous load-bearing layer, resisting tension. Leaf epidermis contains jigsaw puzzle piece-shaped pavement cells whose shape has been proposed to be a result of subcellular variations in expansion rate that induce local buckling events. Paradoxically, such local compressive buckling should not occur given the tensile stresses across the epidermis. Using computational modeling, we show that the simplest scenario to explain pavement cell shapes within an epidermis under tension must involve mechanical wall heterogeneities across and along the anticlinal pavement cell walls between adjacent cells. Combining genetics, atomic force microscopy, and immunolabeling, we demonstrate that contiguous cell walls indeed exhibit hybrid mechanochemical properties. Such biochemical wall heterogeneities precede wall bending. Altogether, this provides a possible mechanism for the generation of complex plant cell shapes.},
  language  = {en}
}
@misc{KrupinskiBozorgLarssonetal.2016,
  author    = {Krupinski, Pawel and Bozorg, Behruz and Larsson, Andr{\´e} and Pietra, Stefano and Grebe, Markus and J{\"o}nsson, Henrik},
  title     = {A model analysis of mechanisms for radial microtubular patterns at root hair initiation sites},
  series = {Frontiers in plant science},
  journal   = {Frontiers in plant science},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-407181},
  pages     = {12},
  year      = {2016},
  abstract  = {Plant cells have two main modes of growth generating anisotropic structures. Diffuse growth where whole cell walls extend in specific directions, guided by anisotropically positioned cellulose fibers, and tip growth, with inhomogeneous addition of new cell wall material at the tip of the structure. Cells are known to regulate these processes via molecular signals and the cytoskeleton. Mechanical stress has been proposed to provide an input to the positioning of the cellulose fibers via cortical microtubules in diffuse growth. In particular, a stress feedback model predicts a circumferential pattern of fibers surrounding apical tissues and growing primordia, guided by the anisotropic curvature in such tissues. In contrast, during the initiation of tip growing root hairs, a star-like radial pattern has recently been observed. Here, we use detailed finite element models to analyze how a change in mechanical properties at the root hair initiation site can lead to star-like stress patterns in order to understand whether a stress-based feedback model can also explain the microtubule patterns seen during root hair initiation. We show that two independent mechanisms, individually or combined, can be sufficient to generate radial patterns. In the first, new material is added locally at the position of the root hair. In the second, increased tension in the initiation area provides a mechanism. Finally, we describe how a molecular model of Rho-of-plant (ROP) GTPases activation driven by auxin can position a patch of activated ROP protein basally along a 2D root epidermal cell plasma membrane, paving the way for models where mechanical and molecular mechanisms cooperate in the initial placement and outgrowth of root hairs.},
  language  = {en}
}
@article{KrupinskiBozorgLarssonetal.2016,
  author    = {Krupinski, Pawel and Bozorg, Behruz and Larsson, Andre and Pietra, Stefano and Grebe, Markus and J{\"o}nsson, Henrik},
  title     = {A Model Analysis of Mechanisms for Radial Microtubular Patterns at Root Hair Initiation Sites},
  series = {Frontiers in plant science},
  volume    = {7},
  journal   = {Frontiers in plant science},
  publisher = {Frontiers Research Foundation},
  address   = {Lausanne},
  issn      = {1664-462X},
  doi       = {10.3389/fpls.2016.01560},
  pages     = {12},
  year      = {2016},
  abstract  = {Plant cells have two main modes of growth generating anisotropic structures. Diffuse growth where whole cell walls extend in specific directions, guided by anisotropically positioned cellulose fibers, and tip growth, with inhomogeneous addition of new cell wall material at the tip of the structure. Cells are known to regulate these processes via molecular signals and the cytoskeleton. Mechanical stress has been proposed to provide an input to the positioning of the cellulose fibers via cortical microtubules in diffuse growth. In particular, a stress feedback model predicts a circumferential pattern of fibers surrounding apical tissues and growing primordia, guided by the anisotropic curvature in such tissues. In contrast, during the initiation of tip growing root hairs, a star-like radial pattern has recently been observed. Here, we use detailed finite element models to analyze how a change in mechanical properties at the root hair initiation site can lead to star-like stress patterns in order to understand whether a stress-based feedback model can also explain the microtubule patterns seen during root hair initiation. We show that two independent mechanisms, individually or combined, can be sufficient to generate radial patterns. In the first, new material is added locally at the position of the root hair. In the second, increased tension in the initiation area provides a mechanism. Finally, we describe how a molecular model of Rho-of-plant (ROP) GTPases activation driven by auxin can position a patch of activated ROP protein basally along a 2D root epidermal cell plasma membrane, paving the way for models where mechanical and molecular mechanisms cooperate in the initial placement and outgrowth of root hairs.},
  language  = {en}
}