---

作 者 ：柯文山,熊治廷,金则新,柯世省

期 刊 ：生态学报 2007年 27卷 8期 页码：3172~3181

关键词：海州香薷；铜积累；酸性磷酸酶；MDA；伤流液；

Keywords:Elsholtzia haichowensis Sun, Cu accumulation, MDA, acid phosphatases, root pressure exudates,

摘 要 ：以海州香薷铜矿区种群（大冶铜绿山）和非矿区种群（红安）为对象，通过水培实验，比较分析了两个种群根中铜的吸收、MDA含量、根伤流液量和酸性磷酸酶活性变化的差异。结果显示, 红安非矿区种群根中的MDA含量随处理浓度的增加而显著升高，铜绿山矿区种群则没有明显的变化；在≥20 μmol/L Cu处理时，非矿区种群根伤流液量急剧下降而矿区种群反而增大。红安种群根中的Cu吸收量明显比铜绿山种群的高，如20 μmol/L Cu处理时，红安种群根中的铜含量在处理后的第1天和第5天分别是铜绿山种群的3倍和4倍；80 μmol/L Cu处理时，第1天和第5天的Cu含量则分别是铜绿山种群的20倍和5倍。然而，铜绿山种群根分泌的和组织内的酸性磷酸酶活性则明显高于红安种群，如在80 μmol/L Cu处理的第3天和第5天，铜绿山种群根组织内的酸性磷酸酶活性都约为红安种群的3倍，根系分泌的酶活性则分别为红安种群的1.6倍和1.8倍。两个种群也表现出不同的变化趋势：铜绿山种群在低浓度处理时，根分泌的和组织内的酸性磷酸酶活性有所增强，高浓度处理时下降，而红安随处理浓度的增加则显著下降。总之，铜胁迫下，海州香薷红安种群根系过氧化损伤明显，而铜绿山种群根系没有产生明显的过氧化损伤；铜绿山种群根系增强酸性磷酸酶的分泌以及保持组织内的高活性，可能分别在减少其铜的吸收及胁迫条件下维持体内正常的磷生理代谢方面具有重要作用。

Abstract:Two Elsholtzia haichouensis Sun populations, one from Cu mine sites (Tonglushan) and the other from uncontaminated sites (Hongan) in Hubei province, were investigated in hydroponic experiments for the differences of Cu accumulation and ecophysiological responses to Cu under Cu treatment. The results showed that a significant increase of malondialdehyde (MDA) concentration in roots was observed in Hongan population, whereas no significant change was observed in Tonglushan population. The root pressure exudates (ml) decreased significantly in Hongan population, but increased significantly in Tonglushan population at high Cu concentration (≥20 μmol/L) treatment. Cu concentration in roots of Hongan population was significantly higher than that in Tonglushan population. For example, Cu concentration in Hongan population was 3 times and 4 times higher than that in Tonglushan population after 20 μmol/L Cu treatment for one day and three days, respectively. Cu concentration in Hongan population was 20 times and 5 times higher than that in Tonglushan population after 80 μmol/L Cu treatment for one day and three days, respectively. The intracellular and secreted acid phosphatase activities (APase) in roots were significantly higher in Tonglushan population than in Hongan one. The intracellular APase activities in Tonglushan population were 3 times higher than that in Hongan population after 80 μmol/L Cu treatment for three days and five days; The root secreted APase activities in Tonglushan population were 1.6 times and 1.8 times higher than that in Hongan population after 80 μmol/L Cu treatment for three days and five days. In conclusion, excess Cu caused serious oxidative damage in roots of Hongan population, but not in Tonglushan population. The high activities of intracellular and root-excreted APases in Tonglushan population might play an important role in reducing Cu accumulation in roots and maintaining normal phosphorus physiology metabolism in root cells under Cu stress.

---