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作 者 ：梁胜伟, 胡新文, 段瑞军, 符少萍, 郭建春

期 刊 ：植物生态学报 2009年 33卷 4期 页码：638-645

关键词：海马齿；无机汞；生长；耐性；吸附积累；

Keywords:Sesuvium portulacastrum, abiomercury, growth, tolerance, accumulation,

摘 要 ：该文报道了海马齿(Sesuvium portulacastrum)对重金属汞的耐性和吸附特性。 在10 μmol·L^–1汞胁迫时, 海马齿中脯氨酸含量明显低于对照; 丙二醛(MDA)含量、根的电解质外渗率(Electrolyte leakage rate, ELR)无明显变化; 叶绿素含量增加; 植物生长良好, 形态、生长速率、鲜重和根的长度与对照无区别, 且有新的须根形成。结果表明: 低浓度汞对海马齿的生长发育起着促进作用。海马齿能大量吸附积累汞离子, 主要积累在根组织中。当培养液中汞浓度为50 μmol·L^–1时, 海马齿根中汞含量最高可达到33.9 μg·g^–1 DW, 是相同处理下地上部分的70倍。培养液中汞浓度为10 μmol·L^–1时, 植物并未受到伤害, 且能快速生长, 此时根部的汞含量可达到12.02 μg·g^–1 DW。由此可见, 海马齿植物表现为很强的耐汞和吸收汞特性。

Abstract:Aims Mercury pollution is a global environmental problem, and heavy metal hyperaccumulator and plant detoxicity is a promising method and current research area. Our objective was to study the halophyte Sesuvium portulacastrum to determine its Hg tolerance and accumulation in order to find a new phytoremediation plant.
Methods Cuttings of S. portulacastrum with one node and two opposite leaves were cultivated on 1/10 Hoagland nutrient solution supplemented with HgCl2 (0, 5, 10, 25, 50 μmol·L^–1). After 30 d of treatment, we measured growth phenotype and physiological changes such as proline, chlorophyll, electrolyte leakage and Hg²⁺ concentration.
Important findings Under low Hg²⁺ concentration stress (10 μmol·L^–1), plants showed vigorous growth. The levels of proline, malondialdehyde and electrolyte leakage were similar to those in the untreated plants, but the chlorophyll content was increased. The species could accumulate Hg²⁺, especially in roots, which reached 33.9 μg·g^–1 DW with 50 μmol·L^–1 Hg²⁺ stress. The plants that accumulated 12.02 μg·g^–1 DW Hg²⁺ in roots grew well. Thus, S. portulacastrum shows strong Hg²⁺ tolerance and accumulation.

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