We investigated changes in physiology and mechanical properties of diatoms exposed to chemical cues released by copepods Pseudodiaptomus annandalei. Our results showed that the diatoms Phaeodactylum tricornutum, Cylindrotheca closterium, Thalassiosira weissflogii, and Amphora coffeaeformis exhibited elevated growth rates and a substantial 2‐ to 50‐fold increase in biogenic silica (BSi) content increase when exposed to the chemical cues except for Cyclotella sp. Atomic force microscopy and X‐ray photoelectron spectroscopy analyses revealed that diatom frustules exhibited a remarkable 3‐ to 10‐fold increase in modulus and a substantial 2‐ to 5‐fold increase in hardness when they received grazing signals. The increase in the proportion of condensed silicon in the frustules could be the major reason for the more mechanically robust cells. Our results indicate that diatoms simultaneously increase their growth rate and robustness when exposed to copepod chemical cues. This study at the nanoscale enhanced our understanding of how diatoms respond to zooplankton predation in marine ecosystems.

中文翻译：

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吃草引起的硅藻壳机械性能的变化：水军备竞赛的新证据


我们研究了硅藻暴露于桡足类 Pseudodiaptomus annandalei 释放的化学信号后的生理和机械特性的变化。我们的结果表明，硅藻三角褐指藻、新月柱藻、Thalassiosira weissflogii 和 Amphora coffeaeformis 在暴露于除小环藻之外的化学物质时，生长速度加快，生物二氧化硅 (BSi) 含量显着增加 2 至 50 倍。原子力显微镜和 X 射线光电子能谱分析表明，硅藻壳在接收到掠食信号时，模量显着增加 3 至 10 倍，硬度显着增加 2 至 5 倍。硅藻壳中凝聚硅比例的增加可能是电池机械性能更强的主要原因。我们的结果表明，当硅藻暴露于桡足类化学物质时，其生长速度和健壮性会同时提高。这项纳米尺度的研究增强了我们对硅藻如何响应海洋生态系统中浮游动物捕食的理解。