Influence of structural reinforcements on the twist-to-bend ratio of plant axes: a case study on Carex pendula.
Influence of structural reinforcements on the twist-to-bend ratio of plant axes: a case study on Carex pendula.
复制标题
DOI：
10.1038/s41598-021-00569-z
复制
发表时间：
2021-10-27
影响因子：
4.6
通讯作者：
Dondl PW
中科院分区：
文献类型：
--
作者：
Wolff-Vorbeck S;Speck O;Speck T;Dondl PW
在生物进化过程中，植物形成了各种各样的身体计划和概念，使它们能够适应不断变化的环境条件。弯曲和扭转刚度之间的权衡是有时相互冲突的机械要求的一个重要例子，其适应程度可以通过无因次的扭弯比来量化。我们的研究考虑了垂穗苔草的三角形花柄，它显示了草本植物轴的最高扭曲/弯曲比。为了深入了解这一峰值，我们开发了反映三角形横截面的2D设置的几何模型，该三角形横截面由由表皮包围的血管束组成的实质基质组成。我们分析了数学模型(使用有限元)来测量表皮组织的增强或纤维增强(如厚壁组织和厚壁组织)对扭转/弯曲比的影响。木栓质周皮从表皮到覆盖组织的变化增加了弯曲和扭转的硬度，并降低了扭弯比。此外，位于横截面外围并嵌入薄壁地面组织中的单个纤维增强束导致弯曲强度的显著增加和扭转刚度的较小增加，从而导致扭弯比显著增加。在所开发的模型中，为了获得较高的扭弯比，49根厚壁组织纤维束或24根厚壁组织纤维束的增强是最佳的。根据纤维的机械质量，厚壁组织增强的轴线的扭弯比明显较小，厚壁组织的弹性模数约为硬质组织的20倍。因此，基于我们的数学模型，我们可以得出关于机械要求对植物轴线几何发展的影响的结论，特别是钢筋的位置。
During biological evolution, plants have developed a wide variety of body plans and concepts that enable them to adapt to changing environmental conditions. The trade-off between flexural and torsional rigidity is an important example of sometimes conflicting mechanical requirements, the adaptation to which can be quantified by the dimensionless twist-to-bend ratio. Our study considers the triangular flower stalk of Carex pendula, which shows the highest twist-to-bend ratios ever measured for herbaceous plant axes. For an in-depth understanding of this peak value, we have developed geometric models reflecting the 2D setting of triangular cross-sections comprised of a parenchymatous matrix with vascular bundles surrounded by an epidermis. We analysed the mathematical models (using finite elements) to measure the effect of either reinforcements of the epidermal tissue or fibre reinforcements such as collenchyma and sclerenchyma on the twist-to-bend ratio. The change from an epidermis to a covering tissue of corky periderm increases both the flexural and the torsional rigidity and decreases the twist-to-bend ratio. Furthermore, additional individual fibre reinforcement strands located in the periphery of the cross-section and embedded in a parenchymatous ground tissue lead to a strong increase of the flexural and a weaker increase of the torsional rigidity and thus resulted in a marked increase of the twist-to-bend ratio. Within the developed model, a reinforcement by 49 sclerenchyma fibre strands or 24 collenchyma fibre strands is optimal in order to achieve high twist-to-bend ratios. Dependent on the mechanical quality of the fibres, the twist-to-bend ratio of collenchyma-reinforced axes is noticeably smaller, with collenchyma having an elastic modulus that is approximately 20 times smaller than that of sclerenchyma. Based on our mathematical models, we can thus draw conclusions regarding the influence of mechanical requirements on the development of plant axis geometry, in particular the placement of reinforcements.
登录
查看更多内容
影响因子：
2
作者：
Konrad, Wilfried;Flues, Felix;Speck, Olga
通讯作者：
Speck, Olga
影响因子：
3
作者：
Caliaro, Marco;Schmich, Florian;Speck, Olga
通讯作者：
Speck, Olga
影响因子：
6.9
作者：
HEJNOWICZ, Z;SIEVERS, A
通讯作者：
SIEVERS, A
影响因子：
2
作者：
Klein, Hartmut;Hesse, Linnea;Speck, Olga
通讯作者：
Speck, Olga
影响因子：
1.9
作者：
Rowe, NP;Speck, T
通讯作者：
Speck, T