Protocol for mapping the variability in cell wall mechanical bending behavior in living leaf pavement cells
Protocol for mapping the variability in cell wall mechanical bending behavior in living leaf pavement cells
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DOI：
10.1093/plphys/kiab588
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发表时间：
2021-12-15
期刊：
影响因子：
7.4
通讯作者：
Turner, Joseph A.
中科院分区：
文献类型：
--
作者：
Li, Wenlong;Keynia, Sedighe;Turner, Joseph A.
细胞的力学性质、大小和几何形状以及内部膨胀压力对细胞的形态发生有很大影响。细胞生长的计算模型需要壁弹性模量和膨胀压力的值，但很少设计实验来验证使用变形整个细胞壁厚度的测量结果。新的壁材料在细胞的内表面合成，因此需要全层变形来量化与细胞发育相关的相关变化。在这里，我们提出了一个综合的，实验计算的方法来定量分析活的拟南芥（拟南芥）路面细胞的原代细胞壁弹性弯曲行为的变化，并测量不同渗透条件下细胞内的膨胀压力。该方法使用激光扫描共聚焦显微镜来测量单个铺面细胞的三维几何形状，并通过压痕实验来探测斜周壁的局部力学响应。利用实验有限元模型对实验结果进行迭代匹配，确定了局部力学性能和膨胀压力。所得到的模量沿叶周壁分布在所研究的叶细胞中是不均匀的。这些结果与植物细胞壁具有异质组织的特点相一致。结果和模型可以定量预测细胞壁应力的大小和方向。这些方法也为今后从细胞壁异质性和各向异性角度分析植物细胞的形态发生行为提供了参考。所描述的结合实验和计算方案允许使用弯曲整个壁厚度的变形来量化活拟南芥表皮细胞的弹性模量和膨胀压力。
Mechanical properties, size and geometry of cells, and internal turgor pressure greatly influence cell morphogenesis. Computational models of cell growth require values for wall elastic modulus and turgor pressure, but very few experiments have been designed to validate the results using measurements that deform the entire thickness of the cell wall. New wall material is synthesized at the inner surface of the cell such that full-thickness deformations are needed to quantify relevant changes associated with cell development. Here, we present an integrated, experimental-computational approach to analyze quantitatively the variation of elastic bending behavior in the primary cell wall of living Arabidopsis (Arabidopsis thaliana) pavement cells and to measure turgor pressure within cells under different osmotic conditions. This approach used laser scanning confocal microscopy to measure the 3D geometry of single pavement cells and indentation experiments to probe the local mechanical responses across the periclinal wall. The experimental results were matched iteratively using a finite element model of the experiment to determine the local mechanical properties and turgor pressure. The resulting modulus distribution along the periclinal wall was nonuniform across the leaf cells studied. These results were consistent with the characteristics of plant cell walls which have a heterogeneous organization. The results and model allowed the magnitude and orientation of cell wall stress to be predicted quantitatively. The methods also serve as a reference for future work to analyze the morphogenetic behaviors of plant cells in terms of the heterogeneity and anisotropy of cell walls.The combined experimental and computational protocol described allows the elastic modulus and turgor pressure of living Arabidopsis epidermis cells to be quantified using deformations that bend the entire thickness of the wall.