锌胁迫下水车前叶细胞自由基过氧化损伤与超微结构变化之间关系的研究

主要研究了模拟锌污染对水车前叶细胞的自由基过氧化损伤和超微结构的变化，并对二者之间的关系作了初步探讨，随锌胁迫程度的增大，叶绿素含量，SOD（超氧化物歧化酶）活性和可溶性蛋白含量呈下降趋势；而POD（过氧化物酶）和CAT（过氧化氢酶）活性则先升后降；MDA（丙二醛）含量上升，超微结构的变化也呈现加重趋势，低浓度处理的变化为细胞核变形，叶绿体膨胀，类囊体排列紊乱，严重的超微结构的损伤是核仁散开，染色质凝集，细胞核几乎成为空核和核膜破裂，核质散出；线粒体脊突膨胀和部分溶解；叶绿体膜断裂，消失和部分类囊体溶解和散到细胞质中，实验结果表明，锌胁迫下叶细胞超微结构的变化反映了内膜系统遭到严重伤害，这可能是自由基过氧化损伤的结果。

Studies on Correlation between Peroxidation Damage by Free Radicals and Ultrastructural Changes of Mesophyll Cells in Ottelia alismoides (L.) Pers Induced by Zn Pollution

The correlation between peroxidation damage of free radicals and ultrastructural changes of mesophyll cells under the condition of simulated Zn pollution was studied with Ottelia alismoides (L.) Pers. With the increace of Zn Stress,the content of chlorophyll,superoxide dismutase (SOD) activity and soluble protein content dropped significantly, peroxidase(POD) and catalase(CAT) activities rised at first and lowered later, and malonyl dialdehyde(MDA) content increased drastically. At low concentration of Zn, the changes in ultrastructure were nuclei deformation, chloroplast swelling and disorder of thylakoid arrangement;serious damages in ultrastructure caused by greater Zn stress were indicated by scattered nucleoli,condensed chromatin,almost empty nuclei with nuclear membrane disrupted and nucleoplasm flowing into cytoplasm,swollen and partly dissolved cristae of mitochondria, disrupted and collapsed chloroplast envelopes,and some dissolved thylakoids that flew into cytoplasm.The results indicated that the changes of the ultrastructure of mesophyll cells were consistent with the damage of their membrane systems, which may be caused by the peroxidation damage of free radicals.