Stress responses of Zea mays to cadmium and mercury
Stress responses of Zea mays to cadmium and mercury
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DOI：
10.1007/s11104-005-3900-1
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发表时间：
2006-02-01
期刊：
影响因子：
4.9
通讯作者：
Hernández, LE
中科院分区：
文献类型：
--
作者：
Rellán-Alvarez, R;Ortega-Villasante, C;Hernández, LE
采用水培试验研究了玉米幼苗对氧化胁迫的反应。CV. Dekalb DK604）对镉（Cd）和汞（Hg）的影响。植物水培生长7天的营养液中补充了几个浓度的镉和汞：0.0（对照），6或30 μ M。两种金属均抑制生长。这种影响在接触汞的植物中更为严重。氧化应激是由于暴露于金属，量化的丙二醛和羰基积累，脂质过氧化和蛋白质氧化的副产品，分别。抗坏血酸过氧化物酶（APX）和超氧化物歧化酶（SOD）的活性，参与清除活性氧的酶，测定金属处理后。我们发现了一个激活的胞质APX亚型，通过使用特定的多克隆抗血清。SOD活性变化不大。巯基肽的分析表明，在6 μ M镉显着增加根还原型谷胱甘肽（GSH）的含量发生，氧化型谷胱甘肽（GSSG）的相对含量的影响不大。然而，在30亩M镉和植物暴露于6和30亩M的汞，GSH根含量保持稳定或显着下降，而GSSG的比例增加。此外，只有镉能够诱导积累的植物螯合素在两个测定浓度。显然，汞的毒性比镉，推断的幅度的变化发现在测试的生理参数。
A hydroponic experiment was carried out to characterize the oxidative stress responses of maize seedlings (Zea mays L. cv. Dekalb DK604) to cadmium (Cd) and mercury (Hg). Plants were grown hydroponically for 7 days in a nutrient solution supplemented with several concentrations of Cd and Hg: 0.0 (control), 6 or 30 mu M. Growth was inhibited by both metals. The effect was more severe in plants exposed to Hg. Oxidative stress was caused by the exposure to the metals, as quantified by malondialdehyde and carbonyl accumulation, by-products of lipid peroxidation and protein oxidation, respectively. The activity of ascorbate peroxidase (APX) and superoxide dismutase (SOD), enzymes involved in the scavenging of reactive oxygen species, were measured upon metal treatment. We found an activation of a cytosolic APX isoform, as identified by using a specific polyclonal antiserum. However, there were negligible changes in SOD activity. Analysis of thiol-peptides revealed that at 6 mu M Cd a remarkable increase in root reduced glutathione (GSH) content occurred, and little effect on the relative content of oxidised glutathione (GSSG) was observed. However, at 30 mu M Cd and in plants exposed to 6 and 30 mu M of Hg, GSH root content either remained stable or decreased significantly, while the proportion of GSSG increased. Moreover, only Cd was able to induce accumulation of phytochelatins at both assayed concentrations. Apparently, Hg was more toxic than Cd, as inferred from the magnitude of the changes found in the physiological parameters tested.