Regulation of plant cell wall stiffness by mechanical stress: a mesoscale physical model
Regulation of plant cell wall stiffness by mechanical stress: a mesoscale physical model
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DOI：
10.1007/s00285-018-1286-y
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发表时间：
2019-02-01
影响因子：
1.9
通讯作者：
Ali, Olivier
中科院分区：
文献类型：
--
作者：
Oliveri, Hadrien;Traas, Jan;Ali, Olivier
发育生物学中的一个关键问题是细胞生长如何在活组织中协调以产生复杂且可重复的形状。我们在这里解决这个问题，在植物中，僵硬的细胞外壁阻止细胞迁移和形态发生主要是由膨压驱动的生长结果。细胞如何响应压力而生长部分取决于其壁的机械性质，这些性质通常是异质的、各向异性的和动态的。因此，这些特性的主动控制是植物形态建成的基石。在这里，我们专注于壁刚度，这是下的分子和机械信号的控制。事实上，在植物组织中，膨压和细胞壁弹性之间的平衡产生了组织范围的应力场。在细胞内，机械敏感结构，如皮质微管，相应地调整其行为，并局部影响细胞壁重塑动力学。为了充分理解这个反馈回路的性质，建模方法是必不可少的。为此，已经开发了几种虚拟组织形式的建模工具。然而，这些模型通常以相对抽象的方式将机械应力和细胞壁刚度联系起来，其中各种演员的分子特异性没有完全捕获。在本文中，我们建议完善这种方法，包括简约的生化和生物力学特性的主要分子演员参与。通过粗粒度的方法，并通过有限元模拟，我们研究了器官尺度力学的应力传感微管的作用。
A crucial question in developmental biology is how cell growth is coordinated in living tissue to generate complex and reproducible shapes. We address this issue here in plants, where stiff extracellular walls prevent cell migration and morphogenesis mostly results from growth driven by turgor pressure. How cells grow in response to pressure partly depends on the mechanical properties of their walls, which are generally heterogeneous, anisotropic and dynamic. The active control of these properties is therefore a cornerstone of plant morphogenesis. Here, we focus on wall stiffness, which is under the control of both molecular and mechanical signaling. Indeed, in plant tissues, the balance between turgor and cell wall elasticity generates a tissue-wide stress field. Within cells, mechano-sensitive structures, such as cortical microtubules, adapt their behavior accordingly and locally influence cell wall remodeling dynamics. To fully apprehend the properties of this feedback loop, modeling approaches are indispensable. To that end, several modeling tools in the form of virtual tissues have been developed. However, these models often relate mechanical stress and cell wall stiffness in relatively abstract manners, where the molecular specificities of the various actors are not fully captured. In this paper, we propose to refine this approach by including parsimonious biochemical and biomechanical properties of the main molecular actors involved. Through a coarse-grained approach and through finite element simulations, we study the role of stress-sensing microtubules on organ-scale mechanics.