Architecture and material properties of diatom shells provide effective mechanical protection
Architecture and material properties of diatom shells provide effective mechanical protection
复制标题
DOI：
10.1038/nature01416
复制
发表时间：
2003-02-20
期刊：
影响因子：
64.8
通讯作者：
Smetacek, V
中科院分区：
文献类型：
--
作者：
Hamm, CE;Merkel, R;Smetacek, V
硅藻是湖泊和海洋中浮游植物大量繁殖的主要贡献者，因此在水生生态系统和全球碳循环中处于中心地位（1）。所有自由生活的硅藻与其他浮游植物群体的不同之处在于具有硅化的细胞壁，其形式为两个形状多样和结构复杂的“壳”（硅藻壳）（2），其功能和作用（如果有的话）有助于硅藻的进化成功正在争论中（3-5）。我们探讨了防御潜力的硅藻壳作为盔甲对捕食者通过测量他们的力量。对中心硅藻细胞和羽状硅藻细胞进行真实的和虚拟的加载测试（使用校准的玻璃微针和有限元分析）。在这里，我们表明，硅藻壳是非常强大的凭借其架构和硅藻二氧化硅的材料特性。我们的结论是，硅藻硅藻壳已经演变为机械保护的细胞，因为特殊的力量是需要打破他们。硅藻与其专门捕食者之间的进化军备竞赛将对构建远洋食物网和海洋地球化学循环产生重大影响。
Diatoms are the major contributors to phytoplankton blooms in lakes and in the sea and hence are central in aquatic ecosystems and the global carbon cycle(1). All free-living diatoms differ from other phytoplankton groups in having silicified cell walls in the form of two 'shells' (the frustule) of manifold shape and intricate architecture(2) whose function and role, if any, in contributing to the evolutionary success of diatoms is under debate(3-5). We explored the defence potential of the frustules as armour against predators by measuring their strength. Real and virtual loading tests (using calibrated glass microneedles and finite element analysis) were performed on centric and pennate diatom cells. Here we show that the frustules are remarkably strong by virtue of their architecture and the material properties of the diatom silica. We conclude that diatom frustules have evolved as mechanical protection for the cells because exceptional force is required to break them. The evolutionary arms race between diatoms and their specialized predators will have had considerable influence in structuring pelagic food webs and biogeochemical cycles.