Use of phosphorus to alleviate stress induced by cadmium and zinc in two submerged macrophytes
Use of phosphorus to alleviate stress induced by cadmium and zinc in two submerged macrophytes
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DOI：
10.4314/ajb.v8i10.60551
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发表时间：
2009
影响因子：
--
通讯作者：
Hao Wang;Pei-fang Wang;Hui Zhang
中科院分区：
文献类型：
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作者：
Hao Wang;Pei-fang Wang;Hui Zhang
为了解P、Cd和Zn污染物之间的相互作用，以伊乐藻和黑藻为材料，研究了P拮抗Zn和Cd毒性的可能机制。以Cd（0.25 mg L-1）、Zn（1.0 mg L-1）和不同浓度的P（0、0.05和5 mg L-1）处理两种沉水植物不同时间（0.5、1、2、4和7 d）。Cd和Zn的毒性效应和氧化胁迫导致总叶绿素（叶绿素a和B）减少，谷胱甘肽（GSH）含量增加。过氧化氢酶（CAT）活性和丙二醛（MDA）含量在第1天均呈上升趋势，第6天又呈下降趋势。愈创木酚过氧化物酶（POD）活性和可溶性蛋白质含量均在第1天下降，第2 ~ 7天上升。Cd、Zn + P处理的植株在7 d内各项指标的变化趋势与单施Cd、Zn处理的相似。然而，不同的指数有不同的反应时间。在各指标的最佳响应时间，施磷均能保护植物免受Cd、Zn的毒害和氧化胁迫，说明施磷可与Cd、Zn产生拮抗效应，减轻植物的氧化胁迫。这些结果表明，Cd和Zn对E. nuttallii和H.至少部分是通过诱导氧化应激和抑制光合作用来抑制轮叶藻的生长。通过比较两种植物对Cd和Zn引起的氧化胁迫的反应，发现E. nuttallii比H.轮生植物。E.因此，欧石莲可作为Cd、Zn污染沃茨的指示植物。
The potential mechanism by which P antagonizes the toxicity of Zn and Cd was investigated in Elodea nuttallii and Hydrilla verticillata to understand the interactions between P, Cd and Zn pollutants. The two submerged macrophytes were treated with a combination of Cd (0.25 mg L-1) and Zn (1.0 mg L-1) and various concentrations of P (0, 0.05 and 5 mg L-1) for different exposure times (0.5, 1, 2, 4 and 7 days). The toxic effects and oxidative stress caused by the Cd and Zn resulted in a reduction of the total chlorophyll (chlorophyll a and b) and an increase in the content of glutathione (GSH). The activity of catalase (CAT) and the contents of malondialdehyde (MDA) both increased in the 1st day, and then reduced during the following 6 days. However, the activity of guaiacol peroxidase (POD) and the contents of soluble protein both decreased in the first day then increased from the 2nd to 7th days. Each index in the plants treated with Cd and Zn containing P showed similar changing trends to those treated with only Cd and Zn during the 7 days. However, different indices had different response times. At the best response time in each index, the result showed that using P can protect plants from the toxicity and oxidative stress caused by Cd and Zn, which suggested that P can produce an antagonistic response with Cd and Zn to mitigate the oxidative stress to plants. Also, these results suggested that Cd and Zn exerted their toxic effects on the growth of E. nuttallii and H. verticillata, at least in part, by the induction of oxidative stress and inhibition of photosynthesis. Through comparing the response of the two plants to oxidative stress caused by Cd and Zn, it was found that E. nuttallii was more sensitive than H. verticillata. E. nuttallii can be regarded as an indicative plant for Cd and Zn polluted waters.