Chen Yingya, Zhang Zhen, Ma Jie, Pan Ke
Shenzhen Key Laboratory of Marine Microbiome Engineering Institute for Advanced Study, Shenzhen University, Shenzhen, China.
Shenzhen Key Laboratory of Marine Microbiome Engineering Institute for Advanced Study, Shenzhen University, Shenzhen, China; Department of Ocean Science, The Hong Kong University of Science and Technology, SAR, China; SZU-HKUST Joint PhD Program in Marine Environmental Science, Shenzhen University, Shenzhen, China.
Mar Environ Res. 2025 Feb;204:106928. doi: 10.1016/j.marenvres.2024.106928. Epub 2024 Dec 20.
The ongoing decline in seawater pH, driven by the absorption of excess atmospheric CO, represents a major environmental issue. This reduction in pH can interact with metal pollution, resulting in complex effects on marine phytoplankton. In this study, we examined the combined impacts of seawater acidification and copper (Cu) exposure on the marine diatom Phaeodactylum tricornutum. Our data indicate that elevated pCO had a minor effect on the growth and photochemistry and overall performance of P. tricornutum. However, seawater acidification significantly influenced cell size, surface roughness, and adhesion. Higher pCO levels led to increased Cu accumulation in P. tricornutum under low ambient Cu concentrations, while significantly reducing Cu accumulation. The smaller cell size and reduced negative charge on the cell surface may explain the decreased Cu accumulation and toxicity. In response to metal stress, P. tricornutum upregulated Cu efflux to mitigate the increased Cu stress in acidified seawater. The expression of the metal transporter gene CTR1 and the reductase gene FRE1 were significantly downregulated, while ATPase5-1B was upregulated in cells exposed to elevated Cu concentrations at 1200 μatm pCO. Our study provides useful insights into the interactions between metals and diatoms in an increasingly acidified ocean.
由过量大气二氧化碳吸收导致的海水pH值持续下降是一个重大环境问题。pH值的降低会与金属污染相互作用，对海洋浮游植物产生复杂影响。在本研究中，我们考察了海水酸化和铜（Cu）暴露对海洋硅藻三角褐指藻的综合影响。我们的数据表明，升高的pCO₂对三角褐指藻的生长、光化学及整体性能影响较小。然而，海水酸化显著影响了细胞大小、表面粗糙度和附着力。在低环境铜浓度下，较高的pCO₂水平导致三角褐指藻中铜积累增加，而在高pCO₂水平下则显著降低铜积累。较小的细胞大小和细胞表面负电荷减少可能解释了铜积累和毒性的降低。为应对金属胁迫，三角褐指藻上调铜外排以减轻酸化海水中增加的铜胁迫。在1200 μatm pCO₂下暴露于高浓度铜的细胞中，金属转运蛋白基因CTR1和还原酶基因FRE1的表达显著下调，而ATPase5-1B上调。我们的研究为日益酸化的海洋中金属与硅藻之间的相互作用提供了有用的见解。
