Toxic effects, oxidative stress and ultrastructural changes in moss Taxithelium nepalense (Schwaegr.) Broth.: Under chromium and lead phytotoxicity
Toxic effects, oxidative stress and ultrastructural changes in moss Taxithelium nepalense (Schwaegr.) Broth.: Under chromium and lead phytotoxicity
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DOI：
10.1007/s11270-005-8682-9
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发表时间：
2005-10-01
影响因子：
2.9
通讯作者：
Panda, SK
中科院分区：
文献类型：
--
作者：
Choudhury, S;Panda, SK
研究了铅和铬（0、100和1000 μ M）短期胁迫对藓类植物Taxitheliumnepalense（Schwaelium.）肉汤，研究了氧化胁迫的产生、抗氧化代谢以及叶绿体和细胞膜超微结构的变化。在苔藓细胞中，铅和铬处理12和24小时，降低干物质和总叶绿素含量，铅下的抑制作用显着。Pb和Cr在处理24 h后均有积累，其中Pb的积累量最高，Cr次之。在1000 μ M的铅和铬的超微结构的研究表明扭曲的类囊体，扭曲的叶绿体膜和叶绿体结构的变化。铅胁迫下叶绿体的畸变比铬胁迫下更为明显。在高浓度的铅，而在铬，轻微的变化是可见的，与对照相比，在细胞膜的变形是明显的。Pb和Cr均显著增加了H2 O2和O-2（-）自由基等活性氧的产生，Pb处理24 h后活性氧的产生量显著高于Cr处理。苔藓细胞中的活性氧代谢的改变，证明了在苔藓细胞中的脂质过氧化作用的增加，与铅和铬处理后的12 h后，24 h后的效果明显。SOD活性在12和24 h后呈上升趋势，CAT、POX和GR活性在12 h和24 h后呈下降趋势。抗坏血酸和谷胱甘肽表现出较高的积累下铅其次是铬。结果表明，在高浓度金属胁迫下，藓类植物细胞出现氧化应激，表现为ROS的产生和脂质过氧化反应，抑制了主要的抗氧化代谢。生理和超微结构的研究表明，可能诱导氧化应激的Taxitheliumnepalense（Schwaelium）。Broth.铅和铬的毒性。
The effect of short-term Pb and Cr (0, 100 and 1000 mu M) stress in moss Taxithelium nepalense (Schwaegr.) Broth., the possible generation of oxidative stress, antioxidant metabolism and changes in the chloroplast and cell membrane ultrastructure were investigated. In moss cells, treatment of Pb and Cr for 12 and 24 h decreased the dry mass and total chlorophyll content with marked inhibition under Pb. Both Pb and Cr accumulated after 24 h of their treatment where highest accumulation of Pb was visible than that of Cr. The ultrastructural studies at 1000 mu M of Pb and Cr showed distortion of the thylakoid, distortion of chloroplast membrane and changes in the chloroplast structure. Chloroplast distortion was highly visible under Pb than that of Cr. The distortion in the cell membrane was evident at high concentration of Pb, while under Cr, minor changes were visible as compared to controls. Both Pb and Cr significantly increased the production of ROS like H2O2 and O-2(-) radical with marked production after 24 h under Pb than that of Cr. The alteration in metabolism of activated oxygen in moss cells was evidenced by the increase in the lipid peroxidation in moss cells, with pronounced effect after 24 h than that of 12 h after Pb and Cr treatment. The SOD activity showed an increasing trend followed by decrease in CAT, POX and GR activity after 12 and 24 h. Both ascorbate and glutathione showed higher accumulation under Pb followed by Cr. The results showed that at high concentration of metals, oxidative stress could be induced in moss cells characterized by the generation of ROS and initiation lipid peroxidation that inhibited the major antioxidant metabolism. Both physiological and ultrastructural studies suggested the possible induction of oxidative stress in Taxithelium nepalense (Schwaegr.) Broth. under Pb and Cr toxicity.