美国宾州州立大学Daniel J. Cosgrove团队建立植物表皮细胞壁复杂力学的模型。相关论文于2021年5月14日发表于国际学术期刊《科学》。

研究人员试图通过开发基于聚合物物理学的粗粒度模型来阐明纤维素和基质多糖的机械作用，该模型概括了表皮细胞壁的组装和拉伸力学等方面。在模型中，简单的非共价结合相互作用产生类似于原代细胞壁的捆绑纤维素网络，并具有超过弯曲阈值的应力依赖性弹性、刚度和可塑性。可塑性源自在对齐的纤维素网络中的原纤维-原纤维滑动。该物理模型提供了对植物力学生物学基本问题的定量见解，并揭示了将刚度与弯曲和可扩展性相结合的生物材料设计原理。

据介绍，植物已经进化出了复杂的基于纳米原纤维的细胞壁，用于满足各种生物学和物理上的限制。长期以来，如何解决强度和可扩展性如何从不断增长的细胞壁的纳米尺度到中尺度尺度的组织中出现的问题。

附：英文原文

Title: Molecular insights into the complex mechanics of plant epidermal cell walls

Author: Yao Zhang, Jingyi Yu, Xuan Wang, Daniel M. Durachko, Sulin Zhang, Daniel J. Cosgrove

Issue&Volume: 2021/05/14

Abstract: Plants have evolved complex nanofibril-based cell walls to meet diverse biological and physical constraints. How strength and extensibility emerge from the nanoscale-to-mesoscale organization of growing cell walls has long been unresolved. We sought to clarify the mechanical roles of cellulose and matrix polysaccharides by developing a coarse-grained model based on polymer physics that recapitulates aspects of assembly and tensile mechanics of epidermal cell walls. Simple noncovalent binding interactions in the model generate bundled cellulose networks resembling that of primary cell walls and possessing stress-dependent elasticity, stiffening, and plasticity beyond a yield threshold. Plasticity originates from fibril-fibril sliding in aligned cellulose networks. This physical model provides quantitative insight into fundamental questions of plant mechanobiology and reveals design principles of biomaterials that combine stiffness with yielding and extensibility.

DOI: 10.1126/science.abf2824

Source: https://science.sciencemag.org/content/372/6543/706