NRA, UMR 547 PIAF Clermont-Ferrand, France ; Clermont Université, Université Blaise Pascal, UMR 547 PIAF Clermont-Ferrand, France.
Front Plant Sci. 2015 Feb 23;6:52. doi: 10.3389/fpls.2015.00052. eCollection 2015.
As land plants grow and develop, they encounter complex mechanical challenges, especially from winds and turgor pressure. Mechanosensitive control over growth and morphogenesis is an adaptive trait, reducing the risks of breakage or explosion. This control has been mostly studied through experiments with artificial mechanical loads, often focusing on cellular or molecular mechanotransduction pathway. However, some important aspects of mechanosensing are often neglected. (i) What are the mechanical characteristics of different loads and how are loads distributed within different organs? (ii) What is the relevant mechanical stimulus in the cell? Is it stress, strain, or energy? (iii) How do mechanosensing cells signal to meristematic cells? Without answers to these questions we cannot make progress analyzing the mechanobiological effects of plant size, plant shape, tissue distribution and stiffness, or the magnitude of stimuli. This situation is rapidly changing however, as systems mechanobiology is being developed, using specific biomechanical and/or mechanobiological models. These models are instrumental in comparing loads and responses between experiments and make it possible to quantitatively test biological hypotheses describing the mechanotransduction networks. This review is designed for a general plant science audience and aims to help biologists master the models they need for mechanobiological studies. Analysis and modeling is broken down into four steps looking at how the structure bears the load, how the distributed load is sensed, how the mechanical signal is transduced, and then how the plant responds through growth. Throughout, two examples of adaptive responses are used to illustrate this approach: the thigmorphogenetic syndrome of plant shoots bending and the mechanosensitive control of shoot apical meristem (SAM) morphogenesis. Overall this should provide a generic understanding of systems mechanobiology at work.
随着陆生植物的生长和发育，它们会遇到复杂的机械挑战，尤其是来自风和膨压的挑战。对生长和形态发生的机械敏感性控制是一种适应性特征，可以降低断裂或爆炸的风险。这种控制主要是通过对人工机械负载的实验进行研究，通常侧重于细胞或分子的机械转导途径。然而，机械传感的一些重要方面经常被忽视。（i）不同负载的机械特性是什么，以及不同器官内的负载是如何分布的？（ii）细胞内相关的机械刺激是什么？是应力、应变还是能量？（iii）机械敏感细胞如何向分生细胞发出信号？如果不能回答这些问题，我们就无法分析植物大小、植物形状、组织分布和硬度的机械生物学效应，也无法分析刺激的幅度。然而，随着系统机械生物学的发展，这些问题正在迅速得到解决，该学科使用了特定的生物力学和/或机械生物学模型。这些模型有助于比较实验中的负载和响应，并使定量测试描述机械转导网络的生物学假设成为可能。这篇综述面向一般的植物科学受众，旨在帮助生物学家掌握他们进行机械生物学研究所需的模型。分析和建模分为四个步骤，分别是研究结构如何承受负载、分布式负载如何被感知、机械信号如何转导，以及植物如何通过生长做出响应。在整个过程中，使用了植物茎弯曲的向触性综合征和分生组织顶端（SAM）形态发生的机械敏感性控制两个自适应响应的例子来说明这种方法。总体而言，这应该提供了一个关于系统机械生物学的一般性理解。
