Department of Biomaterials, Max-Planck-Institute of Colloids and Interfaces, Research Campus Golm, 14424 Potsdam, Germany.
Integr Comp Biol. 2009 Jul;49(1):69-79. doi: 10.1093/icb/icp026. Epub 2009 May 22.
Plants use the orientation of cellulose microfibrils to create cell walls with anisotropic properties related to specific functions. This enables organisms to control the shape and size of cells during growth, to adjust the mechanical performance of tissues, and to perform bending movements of organs. We review the key function of cellulose orientation in defining structural-functional relationships in cell walls from a biomechanics perspective, and illustrate this by examples mainly from our own work. First, primary cell-wall expansion largely depends on the organization of cellulose microfibrils in newly deposited tissue and model calculations allow an estimate of how their passive re-orientation may influence the growth of cells. Moreover, mechanical properties of secondary cell walls depend to a large extent on the orientation of cellulose fibrils and we discuss strategies whereby plants utilize this interrelationship for adaptation. Lastly, we address the question of how plants regulate complex organ movements by designing appropriate supramolecular architectures at the level of the cell wall. Several examples, from trees to grasses, show that the cellulose architecture in the cell wall may be used to direct the swelling or shrinking of cell walls and thereby generate internal growth stress or movement of organs.
植物利用纤维素微纤维的取向来构建具有各向异性特性的细胞壁，这些特性与特定功能有关。这使生物体能够在生长过程中控制细胞的形状和大小，调整组织的机械性能，并进行器官的弯曲运动。我们从生物力学的角度回顾了纤维素取向在定义细胞壁结构-功能关系中的关键作用，并通过主要来自我们自己工作的例子来说明这一点。首先，初生细胞壁的扩张在很大程度上取决于新沉积组织中纤维素微纤维的组织，模型计算可以估计它们的被动重取向如何影响细胞的生长。此外，次生细胞壁的机械性能在很大程度上取决于纤维素纤维的取向，我们讨论了植物如何利用这种相互关系进行适应的策略。最后，我们通过在细胞壁水平上设计适当的超分子结构来解决植物如何调节复杂器官运动的问题。从树木到草类的几个例子表明，细胞壁中的纤维素结构可用于指导细胞壁的膨胀或收缩，从而产生内部生长应力或器官运动。
