Zhou Weilong, Zheng Haolong, Wu Yingyin, Lin Junyi, Ma Xiaofei, Xing Yixuan, Ou Huilong, Vasquez Hebert Ely, Zheng Xing, Yu Feng, Gu Zhifeng
School of Marine Biology and Fisheries, Hainan University, Haikou 570228, China.
Key Laboratory of Tropical Hydrobiology and Biotechnology of Hainan Province, Haikou 570228, China.
Antioxidants (Basel). 2024 Oct 18;13(10):1268. doi: 10.3390/antiox13101268.
The escalating impact of human activities has led to the accumulation of microplastics (MPs) and heavy metals in marine environments, posing serious threats to marine ecosystems. As essential components of oceanic ecosystems, large seaweeds such as play a crucial role in maintaining ecological balance. This study investigated the effects of MPs and cadmium (Cd) on the growth, physiology, biochemistry, and Cd accumulation in while elucidating the underlying molecular regulatory mechanisms. The results demonstrated that exposure to MPs alone significantly promoted the growth. In contrast, exposure to Cd either alone or in combination with MPs significantly suppressed growth by reducing stem and stolon length, bud count, weight gain, and specific growth rates. Combined exposure to MPs and Cd exhibited the most pronounced inhibitory effect on growth. MPs had negligible impact while Cd exposure either alone or combined with MPs impaired antioxidant defenses and exacerbated oxidative damage; with combined exposure being the most detrimental. Analysis of Cd content revealed that MPs significantly increased Cd accumulation in algae intensifying its toxic effects. Gene expression analysis revealed that Cd exposure down-regulated key genes involved in photosynthesis, impairing both photosynthetic efficiency and energy conversion. The combined exposure of MPs and Cd further exacerbated these effects. In contrast, MPs alone activated the ribosome pathway, supporting ribosomal stability and protein synthesis. Additionally, both Cd exposure alone or in combination with MPs significantly reduced chlorophyll B and soluble sugar content, negatively impacting photosynthesis and nutrient accumulation. In summary, low concentrations of MPs promoted growth, but the presence of Cd hindered it by disrupting photosynthesis and antioxidant mechanisms. Furthermore, the coexistence of MPs intensified the toxic effects of Cd. These findings enhance our understanding of how both MPs and Cd impact large seaweed ecosystems and provide crucial insights for assessing their ecological risks.
人类活动影响的不断升级导致海洋环境中微塑料（MPs）和重金属的积累，对海洋生态系统构成严重威胁。作为海洋生态系统的重要组成部分，大型海藻等在维持生态平衡方面发挥着关键作用。本研究调查了MPs和镉（Cd）对[大型海藻名称未给出]生长、生理、生化及Cd积累的影响，同时阐明其潜在的分子调控机制。结果表明，单独暴露于MPs显著促进生长。相反，单独或与MPs联合暴露于Cd通过降低茎和匍匐茎长度、芽数、体重增加和特定生长率显著抑制生长。MPs和Cd联合暴露对生长的抑制作用最为明显。MPs影响可忽略不计，而单独或与MPs联合暴露于Cd会损害抗氧化防御并加剧氧化损伤；联合暴露最为有害。Cd含量分析表明，MPs显著增加了藻类中Cd的积累，加剧了其毒性作用。基因表达分析表明，Cd暴露下调了参与光合作用的关键基因，损害了光合效率和能量转换。MPs和Cd联合暴露进一步加剧了这些影响。相比之下，单独的MPs激活了核糖体途径，支持核糖体稳定性和蛋白质合成。此外，单独或与MPs联合暴露于Cd均显著降低叶绿素B和可溶性糖含量，对光合作用和养分积累产生负面影响。总之，低浓度的MPs促进了[大型海藻名称未给出]的生长，但Cd的存在通过破坏光合作用和抗氧化机制阻碍了其生长。此外，MPs的共存加剧了Cd的毒性作用。这些发现增进了我们对MPs和Cd如何影响大型海藻生态系统的理解，并为评估其生态风险提供了关键见解。
