汞对水花生愈伤组织生理及超微结构的毒性效应  

Physiological and ultrastructural responses of Alternanthera philoxeroides callus to mercury

作　　者：康宜宁[1] 吴婷婷[1] 施国新[1] 徐小颖[1] 张乐乐[1] 王娟[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：《环境科学学报》2010年第12期2506-2511,共6页Acta Scientiae Circumstantiae

基　　金：国家自然科学基金(No.30870139)~~

摘　　要：研究了Hg胁迫对水花生致密型愈伤组织叶绿素含量、可溶性蛋白含量、活性氧水平、抗氧化酶活性及细胞超微结构的影响.结果表明,随着Hg施加浓度的增加,总叶绿素、叶绿素a、叶绿素b、可溶性蛋白含量呈先升后降趋势,叶绿素a/叶绿素b逐渐下降;超氧化物歧化酶(SOD)、过氧化物酶(POD)活性先升后降,而过氧化氢酶(CAT)活性呈逐渐下降趋势;同时,超氧阴离子(O2-·)产生速率、丙二醛(MDA)和过氧化氢(H2O2)含量均呈逐渐上升趋势.电镜扫描结果发现,Hg胁迫破坏了细胞膜系统,特别是对线粒体、叶绿体、细胞核造成了较为严重的不可逆的损伤,所观察到的核膜破裂方式主要是超量分泌膜泡.Hg对水花生愈伤组织的致死浓度范围为20～40μmol·L-1.The effects of Hg on contents of chlorophyll,soluble protein,and active oxygen generation,as well as the activities of antioxidases and the ultrastructure of Alternanthera philoxeroides callus were studied.The results showed that,with the increase of Hg concentration,contents of total chlorophyll,chlorophyll a,chlorophyll b and soluble protein increased first and then decreased,while chlorophyll a/chlorophyll b decreased gradually;Superoxide dismutase（SOD） and peroxidase（POD） activities were initially enhanced followed by a decline,while catalase（CAT） activity decreased drastically;Levels of O 2-·,MDA and H2 O2 generally increased.Transmission electron microscope observation indicated that Hg caused irreversible damage to the cell membrane system,especially chloroplasts,mitochondria and nuclei.The nuclear membrane was disrupted by secreting excessive numbers of membrane vesicles.The lethal concentration of Hg to A philoxeroides based on the experimental results was 20 ～ 40 μmol·L-1.

关 键 词：水花生愈伤组织 HG 抗氧化酶 超微结构 

分 类 号：X171.5[环境科学与工程—环境科学]