Institute of Plant Sciences, University of Bern, CH-3013 Bern, Switzerland.
Plant Physiol. 2012 Apr;158(4):1514-22. doi: 10.1104/pp.111.191460. Epub 2012 Feb 21.
Although growth and morphogenesis are controlled by genetics, physical shape change in plant tissue results from a balance between cell wall loosening and intracellular pressure. Despite recent work demonstrating a role for mechanical signals in morphogenesis, precise measurement of mechanical properties at the individual cell level remains a technical challenge. To address this challenge, we have developed cellular force microscopy (CFM), which combines the versatility of classical microindentation techniques with the high automation and resolution approaching that of atomic force microscopy. CFM's large range of forces provides the possibility to map the apparent stiffness of both plasmolyzed and turgid tissue as well as to perform micropuncture of cells using very high stresses. CFM experiments reveal that, within a tissue, local stiffness measurements can vary with the level of turgor pressure in an unexpected way. Altogether, our results highlight the importance of detailed physically based simulations for the interpretation of microindentation results. CFM's ability to be used both to assess and manipulate tissue mechanics makes it a method of choice to unravel the feedbacks between mechanics, genetics, and morphogenesis.
虽然生长和形态发生受遗传控制，但植物组织的物理形状变化是细胞壁松弛和细胞内压力平衡的结果。尽管最近的研究表明机械信号在形态发生中起作用，但在单个细胞水平上精确测量力学性能仍然是一个技术挑战。为了解决这一挑战，我们开发了细胞力显微镜（CFM），它结合了经典微压痕技术的多功能性和接近原子力显微镜的高自动化和分辨率。CFM 的大力范围提供了绘制质壁分离和膨胀组织表观硬度的可能性，以及使用非常高的应力对细胞进行微穿刺的可能性。CFM 实验表明，在组织内，局部硬度测量值可能会以出人意料的方式随膨压水平而变化。总之，我们的结果强调了详细的物理基础模拟对于解释微压痕结果的重要性。CFM 既可以用于评估又可以用于操纵组织力学，使其成为揭示力学、遗传学和形态发生之间反馈的首选方法。
