Regier Nicole, Cosio Claudia, von Moos Nadia, Slaveykova Vera I
Environmental Biogeochemistry and Ecotoxicology, Institute F.-A. Forel, Earth and Environmental Sciences, Faculty of Sciences, University of Geneva, 10, route de Suisse, CH-1290 Versoix, Switzerland.
Environmental Biogeochemistry and Ecotoxicology, Institute F.-A. Forel, Earth and Environmental Sciences, Faculty of Sciences, University of Geneva, 10, route de Suisse, CH-1290 Versoix, Switzerland.
Chemosphere. 2015 Jun;128:56-61. doi: 10.1016/j.chemosphere.2014.12.078. Epub 2015 Feb 2.
In this study, the uptake and sub-toxic effects of CuO nanoparticles (CuO-NPs), dissolved Cu(II) alone or in combination with UV radiation on the aquatic macrophyte Elodea nuttallii were studied. Emphasis was on Cu accumulation, growth, photosynthesis and the oxidative stress related enzymes peroxidase (POD) and superoxide dismutase (SOD). The results showed stronger Cu accumulation in plants exposed to 10 mg L(-1) CuO-NPs, corresponding to 1.4-2 mg L(-1) dissolved Cu(II), than to 256 μg L(-1) Cu(II). However, the ratio between the accumulated Cu and dissolved Cu in CuO treatments was lower than in Cu(II) treatments. Additional UV exposure increased accumulation in both treatments, with the effect being stronger for Cu accumulation from CuO-NPs than for dissolved Cu(II). Photosynthetic capacity was strongly reduced by UV treatment, whereas remained unaffected by Cu(II) or CuO-NP treatments. Similarly, the increase of SOD activity was more pronounced in the UV treatments. On the other hand, POD activity enhancement was strongest in the plants exposed to CuO-NPs for 24 h. Expression of the copper transporter COPT1 as revealed by RT-qPCR was inhibited by Cu(II) and CuO-NP treatment, limiting the uptake of excess Cu into the cells. Overall, the combined exposure of E. nuttallii to UV radiation with CuO-NPs or Cu(II) has a higher impact than exposure to CuO-NPs or Cu(II) alone. The results imply that heavy pollution of natural water with CuO-NPs or dissolved Cu might have stronger effects in combination with natural UV irradiation on organisms in situ.
在本研究中，我们研究了氧化铜纳米颗粒（CuO-NPs）、单独的溶解态Cu(II) 或其与紫外线辐射联合作用对水生大型植物伊乐藻的吸收及亚毒性效应。重点关注了铜的积累、生长、光合作用以及与氧化应激相关的酶过氧化物酶（POD）和超氧化物歧化酶（SOD）。结果表明，暴露于10 mg L(-1) CuO-NPs（相当于1.4 - 2 mg L(-1) 溶解态Cu(II)）的植物中铜的积累量比暴露于256 μg L(-1) Cu(II) 的植物更强。然而，CuO处理中积累的铜与溶解态铜的比例低于Cu(II) 处理。额外的紫外线照射增加了两种处理中的铜积累量，且对CuO-NPs中铜积累的影响比对溶解态Cu(II) 的影响更强。紫外线处理强烈降低了光合能力，而Cu(II) 或CuO-NP处理对其没有影响。同样，紫外线处理中SOD活性的增加更为明显。另一方面，暴露于CuO-NPs 24小时的植物中POD活性增强最为显著。RT-qPCR显示，铜转运蛋白COPT1的表达受到Cu(II) 和CuO-NP处理的抑制，限制了过量铜进入细胞。总体而言，伊乐藻同时暴露于紫外线辐射与CuO-NPs或Cu(II) 比单独暴露于CuO-NPs或Cu(II) 的影响更大。结果表明，天然水体被CuO-NPs或溶解态铜严重污染，再加上自然紫外线照射，可能会对原位生物产生更强的影响。
