Mn^(2+)对菹草活性氧代谢及其亚显微结构的影响  

Effect of Manganese on Reactive Oxygen Species Metabolism and Submicroscopic Structure of Potamogeton crispus

作　　者：徐小颖[1] 施国新[1] 徐勤松[1] 杨海燕[1] 许晔[1] 丁春霞[1] 

机构地区：[1]南京师范大学生命科学学院,江苏南京210046

出　　处：《南京师大学报（自然科学版）》2009年第1期105-109,共5页Journal of Nanjing Normal University(Natural Science Edition)

基　　金：国家自然科学基金(30670121;30870139);高等学校博士学科点专项科研基金(20050319005)资助项目

摘　　要：通过溶液培养试验,研究了不同Mn2+浓度(0、0.09、0.18、0.27、0.36mmol/L)胁迫对菹草抗氧化系统、活性氧产生和亚显微结构的影响.结果表明:随着Mn2+浓度的增加,菹草叶片中的叶绿素a、b和总叶绿素含量都呈现先升后降的趋势;超氧化物歧化酶(SOD)活性逐渐上升,而过氧化物酶(POD)和过氧化氢酶(CAT)活性则呈先升后降趋势,还原型谷胱甘肽(GSH)和抗坏血酸(AsA)含量呈先升后降趋势,同时超氧阴离子(O.2-)产生速率、过氧化氢(H2O2)、丙二醛(MDA)含量均呈逐渐上升趋势;电镜观察发现,Mn2+对叶片细胞器的亚显微结构特别是叶绿体、线粒体和细胞核造成严重损伤.Mn2+破坏了菹草正常生理活动的结构基础和离子平衡,并造成抗氧化系统功能紊乱,这些都是Mn2+对菹草产生毒害的重要原因.The toxic effect of various concentrations of Mn^2＋（0,0.09,0. 18,0.27,0.36 mmol/L） was studied on antioxidant system, active oxygen generation and submicroscopic structure of Potamogeton crispus. The results showed that the content of chlorophyll a, chlorophyll b and total chlorophyll all first increased and then decreased with increasing the concentration of Mn^2＋. Superoxide dismutase （SOD） activity generally increased, peroxydase （POD） and catalase （CAT） activities enhanced a several fold, but with the manganese concentration increased continuously, they all de- creased, which was possibly the reason of accumulation of O2 and H2O2. Glutathione （GSH） and antiscorbic acid （AsA） contents changed at the same trend of POD and CAT. The level of lipid peroxidation was measured as the content of malondialdehyde （MDA）, which was always increased and was the same as the change of O2- and H2O2. Transmission electron microscopy observation indicates that the higher Mn^2＋ concentration, the more serious damages to the leaf cells, especially chloroplast, mitochondrion and nucleus. The conclusion could be reached that the growth declining e- ven death of plant was resulted from destruction of structure foundation of physiological function, interruption of ion and enzymes equilibrium and disorder of antioxidant system. But the influences of those aspects are in different extent in Potamogeton crispus.

关 键 词：菹草 Mn2+ 胁迫 亚显微结构 ROS 

分 类 号：Q944[生物学—植物学]