水花生愈伤组织对Pb^(2+)胁迫的响应  

Response of callus of Alternanthera philoxeroides to Pb^(2+) stress

作　　者：王娟[1] 施国新[1] 张乐乐[1] 康宜宁[1] 徐小颖[1] 丁春霞[1] 

机构地区：[1]南京师范大学生命科学学院江苏省生物多样性与生物技术重点实验室,南京210046

出　　处：《湖泊科学》2011年第2期281-286,共6页Journal of Lake Sciences

基　　金：国家自然科学基金项目(30870139)资助

摘　　要：利用组织培养技术培养水花生愈伤组织并以此为实验材料,研究不同浓度(0,0.2,0.4,0.8和1.6mmol/L)的Pb2+对水花生愈伤组织光合色素和可溶性蛋白含量、活性氧水平、抗氧化酶活性(CAT、SOD和POD)以及细胞亚显微结构产生的胁迫影响.结果表明,随着Pb2+浓度的增加,水花生愈伤组织光合色素和可溶性蛋白含量逐渐下降;超氧阴离子和过氧化氢含量呈上升趋势,丙二醛含量表现为先升后降;超氧化物歧化酶、过氧化物酶活性同样呈现先升后降趋势,过氧化氢酶活性则为逐渐下降的趋势;电镜观察发现,Pb2+胁迫对愈伤组织细胞的叶绿体、线粒体和细胞核造成不同程度的损伤,0.8-1.6mmol/L浓度对超微结构产生致命性的毒害.Pb2+破坏了水花生愈伤组织进行正常生长代谢所必需的生理和结构基础,且打乱了代谢平衡,最终导致愈伤组织的死亡.Callus of Alternanthera philoxeroides was cultured by tissue culture technique,which was used as experimental material.This paper studied the toxic effects of Pb2＋ gradient concentrations（0,0.2,0.4,0.8 and 1.6 mmol/L） on the contents of photosynthetic pigments and soluble protein,the level of active oxygen,activities of antioxidase（CAT,SOD and POD） and changes of ultrastructure in callus of Alternanthera philoxeroides.The results indicated that,with the increasing of Pb2＋ concentration,the contents of photosynthetic pigments and soluble protein decreased gradually.The contents of O.-2 and H2O2 increased gradually,while the content of MDA increased at first and then decreased.The changes of SOD and POD activities were the same as MDA,but CAT activity decreased gradually.Transmission electron microscopy observation showed that the chloroplast,mitochondria and nucleus suffered serious damages under Pb2＋stress,and the concentration of 0.81.6mmol/L generated the fateful poisons to ultrastructure.It was concluded that Pb2＋ stress induced not only destruction of physiological function and structural foundation of Alternanthera philoxeroides callus,but also the disorder of physiological metabolism,which led to the death of the callus at last.

关 键 词：愈伤组织 水花生 Pb2+胁迫 抗氧化酶 超微结构 

分 类 号：X173[环境科学与工程—环境科学]