| 轮叶黑藻和穗花狐尾藻对铜的吸收机制研究 |
| 摘要点击 4136 全文点击 2048 投稿时间：2013-09-02 修订日期：2013-10-25 |
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| 中文关键词 轮叶黑藻 穗花狐尾藻 铜 亚细胞 吸收机制 |
| 英文关键词 Hydrilla verticillata Myriophyllum spicatum copper subcellular uptake mechanism |
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| 中文摘要 |
| 应用室内模拟试验，通过对铜（Cu）的短期吸收动力学、各亚细胞组分吸收动力学以及Cu的释放研究，探讨了两种沉水植物轮叶黑藻[Hydrilla verticillata （L. f.） Royle]和穗花狐尾藻（Myriophyllum spicatum L.）对Cu的吸收机制. 结果表明：1轮叶黑藻和穗花狐尾藻均对Cu具有较高的吸收速率，且两种植物最高吸收速率差异不显著[Vmax（DW）为2 μmol·（g·min）-1，P>0.05]；2在2 μmol·L-1 Cu溶液中暴露不同时间（0~96 h），两种沉水植物叶片和茎中各亚细胞组分的Cu含量均迅速增加并约在12 h后达到平衡. 各时间处理下，两种植物叶片富集的Cu含量均显著高于茎（P<0.05），并且叶片中的Cu均主要分布在细胞壁（>60%），其次是可溶部分和细胞器；3两种植物相比，黑藻叶片细胞壁中富集的Cu含量显著高于狐尾藻，而细胞内富集的Cu含量差异不显著. 轮叶黑藻对Cu的富集和释放能力均高于穗花狐尾藻. |
| 英文摘要 |
| Cultivation experiments, including short-term copper uptake kinetics, uptake kinetics of Cu by different subcellular fractions and efflux of Cu, were carried out to investigate mechanisms of copper uptake by two species of submerged macrophyte, Hydrilla verticillata (L. f.) Royle and Myriophyllum spicatum L. The results showed that: ① Both H. verticillata and M. spicatum showed high influx rates for copper ions with no statistically significant differences [Vmax(DW) is 2 μmol·(g·min)-1]; ② Both leaf and stem Cu concentrations of two strains of plants showed sharp increase with the external medium, and the equilibrium was reached for about 12 h after being exposed to solution with 2 μmol·L-1 Cu. Leaves of these two plants accumulated much higher concentrations of Cu than stems. Furthermore, Cu in leaves concentrated predominantly in cell walls (>60%), followed by soluble and organell fractions; ③ Copper accumulated in cell wall of H. verticillata leaf was considerably higher than that of M. spicatum, and Cu concentrated in intracellular fractions of leaves showed no statistically significant difference between these two plants. Moreover, ability of Cu accumulation and efflux by H. verticillata was higher than that by M. spicatum. |
