Functional Morphology and Biomechanics, Institute of Zoology, Kiel University, Kiel, Germany.
Functional Morphology and Biomechanics, Institute of Zoology, Kiel University, Kiel, Germany.
Acta Biomater. 2024 Sep 15;186:330-341. doi: 10.1016/j.actbio.2024.07.041. Epub 2024 Aug 2.
Most of the plants using epizoochory show adaptations to this diaspore dispersal strategy by having the diaspores covered by barbs, hooks, spines or viscid outgrowths, which allow diaspores to easily attach to an animal surface. Many previous studies have been mainly focused on the dispersal distances and efficiency, or effectiveness of diverse attachment structures depending on their size, anatomy, and morphology. However, the knowledge about the mechanical properties of these structures remains rather poor. In this study, we use a combination of scanning electron microscopy, energy dispersive X-ray element analysis and nanoindentation, to examine the microstructure, biomineralization and mechanical properties of single hooks in Arctium minus, Cynoglossum officinale and Galium aparine. Both the biomineralization and mechanical properties of the hooks strongly differ in examined plant species; mechanical properties depend on the biomineralization pattern, such as the accumulation of silicon and calcium. Elastic modulus and hardness decrease in the series C. officinaleG. aparineA. minus. Anisotropic mechanical properties are found between the radial and longitudinal directions in each single hook. By characterizing the mechanical properties and biomineralization of plant hooks, this paper contributes to the understanding of attachment biomechanics related to seed dispersal. STATEMENT OF SIGNIFICANCE: The dispersal of seeds is essential for plant survival. Many of the plants that use the outside surface of animals to transport the seeds show adaptations to this dispersal strategy by having the seeds covered with hooks. Although these hooks have various sizes, morphologies and anatomical structures, all of them provide mechanical interlocking to animal surfaces. To reduce the risk of interlocking failure, the hooks are usually reinforced by mineralization. However, the relationship between mineralization, mechanical properties and specialized function of plant hooks has been largely overlooked. Here we perform a characterization study on the hooks of three plant species. Our results deepen the current understanding of the mineralization-material-function relationship in specialized hooks of plant seeds.
大多数利用体外动物传播的植物都通过在种皮上覆盖倒刺、钩、刺或粘性突起来适应这种传播策略，这使得种皮能够轻易地附着在动物表面上。许多之前的研究主要集中在不同附着结构的传播距离和效率，或有效性上，这取决于它们的大小、解剖结构和形态。然而，关于这些结构的力学性能的知识仍然相当匮乏。在这项研究中，我们使用扫描电子显微镜、能量色散 X 射线元素分析和纳米压痕法，来检查苍耳、牛舌草和筋骨草中单钩的微观结构、生物矿化和力学性能。所研究的植物物种中的钩的生物矿化和力学性能有很大的不同；力学性能取决于生物矿化模式，如硅和钙的积累。弹性模量和硬度在 C. officinale、G. aparine 和 A. minus 中依次降低。在每个单钩中，都可以发现径向和纵向之间的各向异性力学性能。通过对植物钩的力学性能和生物矿化进行表征，本文有助于理解与种子传播相关的附着生物力学。意义声明：种子的传播对于植物的生存至关重要。许多利用动物外部表面来运输种子的植物通过在种子上覆盖钩来适应这种传播策略。尽管这些钩具有不同的大小、形态和解剖结构，但它们都为动物表面提供了机械互锁。为了降低互锁失效的风险，钩通常通过矿化来加固。然而，矿化、力学性能和植物钩的特殊功能之间的关系在很大程度上被忽视了。在这里，我们对三种植物的钩进行了特征描述研究。我们的研究结果加深了对植物种子特殊钩的矿化-材料-功能关系的理解。
