TY - JOUR T1 - Mechanical stress initiates and sustains the morphogenesis of wavy leaf epidermal cells JF - bioRxiv DO - 10.1101/563403 SP - 563403 AU - Amir J Bidhendi AU - Bara Altartouri AU - Frédérick P. Gosselin AU - Anja Geitmann Y1 - 2019/01/01 UR - http://biorxiv.org/content/early/2019/03/04/563403.abstract N2 - Plant cell shape is governed by the mechanical properties of the cell wall and is intimately related to the specific function of the cell. Pavement cells covering the surface of plant leaves form wavy interlocking patterns in many plants. We use computational mechanics to simulate the morphogenetic process based on experimentally assessed cell shapes, growth dynamics, and cell wall chemistry. The simulations suggest a multistep process underlying the morphogenesis of pavement cells during tissue differentiation. The mechanical shaping process relies on spatially confined, feedback-augmented stiffening of the cell wall in the periclinal walls, an effect that correlates with experimentally observed deposition patterns of cellulose and de-esterified pectin. We provide evidence for mechanical buckling of the pavement cell walls that can robustly initiate patterns and may precede chemical and geometrical anisotropy.HighlightsA multistep morphogenetic process shapes wavy pavement cells.Stress/strain stiffening following the buckling of the cell walls forms a feedback loop shaping wavy pavement cells.Mechanical modeling predicts spatial variations in the mechanical properties of leaf epidermal cells.Bundled cortical microtubules, cellulose microfibrils, and de-esterified pectin locate in necks of wavy pavement cells.Microtubule polarization is preceded by a mechanical anisotropy breaking. ER -