A Model Analysis of Mechanisms for Radial Microtubular Patterns at Root Hair Initiation Sites.
A Model Analysis of Mechanisms for Radial Microtubular Patterns at Root Hair Initiation Sites.
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DOI：
10.3389/fpls.2016.01560
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发表时间：
2016
影响因子：
5.6
通讯作者：
Jönsson H
中科院分区：
文献类型：
--
作者：
Krupinski P;Bozorg B;Larsson A;Pietra S;Grebe M;Jönsson H
植物细胞有两种主要的生长模式，产生各向异性结构。在各向异性定位的纤维素纤维的引导下，整个细胞壁向特定方向延伸的扩散生长，以及尖端的生长，结构的顶端不均匀地添加了新的细胞壁材料。众所周知，细胞通过分子信号和细胞骨架来调节这些过程。在弥漫性生长过程中，机械应力通过皮质微管为纤维素纤维的定位提供了输入。特别是，应力反馈模型预测了根尖组织和生长原基周围纤维的周向模式，这些组织中的各向异性曲率指导着这些组织。相反，在顶端生长根毛的起始过程中，最近观察到了一种星形的放射状图案。在这里，我们使用详细的有限元模型来分析根毛起始部位机械性能的变化如何导致星形应力模式，以了解基于应力的反馈模型是否也可以解释在根毛起始期间看到的微管模式。我们证明，两个独立的机构，单独或组合，足以产生径向模式。在第一种方法中，在根毛的位置局部添加新材质。在第二种情况下，起始区的张力增加提供了一种机制。最后，我们描述了生长素驱动的植物Rho-of-Plants(ROP)GTP酶激活的分子模型如何沿着2D根表皮细胞质膜定位激活的ROP蛋白斑块，为机械和分子机制在根毛的初始放置和生长中协同作用的模型铺平了道路。
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.
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DOI：
10.1016/j.cub.2009.08.052
发表时间：
2009-11-17
期刊：
Current biology : CB
影响因子：
--
作者：
Fu Y;Xu T;Zhu L;Wen M;Yang Z
通讯作者：
Yang Z
影响因子：
3.7
作者：
Hill AE;Shachar-Hill B;Skepper JN;Powell J;Shachar-Hill Y
通讯作者：
Shachar-Hill Y
影响因子：
4.3
作者：
HOGETSU, T
通讯作者：
HOGETSU, T
影响因子：
56.9
作者：
Hamant, Olivier;Heisler, Marcus G.;Traas, Jan
通讯作者：
Traas, Jan
影响因子：
2.1
作者：
Brena-Medina, V.;Champneys, A. R.;Ward, M. J.
通讯作者：
Ward, M. J.