硝酸铊对浮萍(Lemna gibba L.)的生长抑制及其氧自由基损伤作用  

Growth Inhibition of Thallium( I)- nitrate on Duckweed( Lemna gibba L. )with Relation to Its Oxidative Stress

作　　者：刘涛[1] 邓红梅[2] 王耀龙[2,3] 陈永亨[2] 陈敏婵 巫贵明[2] 曾冬媚[2] 杜建莹 顾颖诗[2] 许旭超 

机构地区：[1]广州大学土木工程学院,广州510006 [2]广州大学环境科学与工程学院,广州510006 [3]华南师范大学化学与环境学院,广州510006

出　　处：《生态毒理学报》2014年第6期1112-1117,共6页Asian Journal of Ecotoxicology

基　　金：国家自然科学基金资助项目(No.41170399);国家级大学生创新训练项目(No.201211078017)

摘　　要：为了探讨硝酸铊(Tl(I)-nitrate)对浮萍(Lemna gibba L.)的生长抑制作用及其可能的氧化损伤机制,设置了Tl(I)-nitrate的8个处理组(0.005、0.01、0.02、0.04、0.08、0.1、0.5和1.0 mg·L-1)和对照组(0.0 mg·L-1),进行96 h急性毒性实验,测定96 h内超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性及丙二醛含量。结果表明:96 h暴露时间下,浮萍生长受抑制程度与Tl(I)浓度之间呈正相关,Tl(I)-nitrate对浮萍的96 h EC50为0.076 mg·L-1,NOEC为0.01 mg·L-1。CAT活性随着Tl(I)-nitrate浓度升高逐渐降低,在0.5和1 mg·L-1时,有极显著差异(p<0.01)产生,SOD活性在0.1 mg·L-1时显著升高(>46%),POD活性和MDA含量在Tl(I)浓度0.5 mg·L-1时明显上升。当Tl(I)-nitrate胁迫超出浮萍抗氧化酶系统清除活性氧的能力时,活性氧积累导致浮萍受到不可逆转的氧化损伤。Tl(I)Abstract： To evaluate the growth inhibition of thalhum（I）-nltrate on possible oxidative damage mechanism, nine Tl（I）-nitrate concentration levels （0, 0.005, 0.01, 0.02, 0.04, 0.08, 0.1,0.5, 1.0 mg· L-1） were set for 96 hours＇ acute toxicity test . The activities of SOD, POD, CATand MDA were measured. Results showed that the growth inhibition of L. gibba was positively correlated with the concentrations of Tl（I）-nitrate, and the 96 h EC50 and NOEC of were 0.076 mg· L-1and 0.01 mg· L-1, respectively. As Tl（I）-nitrate concentration increased, CAT activities in L. gibba gradually decreased, the statistically significant differences （p 〈0.01）were observed at the concentrations of 0.5 and 1 mg· L-1, SOD activity increased significantly （the increasement ratio 〉 46% ） at 0.1 mg· L-1. While the POD activities and the MDA contents significantly increased at 0.5 mg· L-1, compared with the control. With Tl（I）-nitrate concentration increasing, antioxidant enzymes were unable to eliminate the increased concentration of reactive oxygen species （ROS）, which resulted in irreversible oxidative damage. TI（I）- nitrate could obviously inhibit the growth ofL. gibba.

关 键 词：Tl(Ⅰ) 浮萍 抗氧化酶 丙二醛 

分 类 号：X171.5[环境科学与工程—环境科学]