汞对慈姑活性氧代谢和染色体的影响  

Effects of Mercury on Active Oxygen Metabolism and Chromosome in Sagittaria trifolia

作　　者：曾晓敏[1] 施国新[1] 徐楠[1] 徐勤松[1] 张小兰[1] 周红卫[1] 陈源[1] 

机构地区：[1]南京师范大学生命科学学院,南京210097

出　　处：《植物生理与分子生物学学报》2003年第3期227-232,共6页Journal Of Plant Physiology and Molecular Biology

基　　金：国家自然科学基金项目 (No:3 9770 0 46);教育部科学技术研究重要项目 (No :0 10 43 )资助~~

摘　　要：研究了不同浓度Hg2 + 以及处理时间对慈姑叶和根的活性氧 (reactiveoxygenspecies,ROS)和染色体的影响。结果显示 :汞能诱导慈姑叶和根大量产生ROS ,其中H2 O2 的突发早于O- ·2 。 0 .5～ 5mg/L处理组染色体畸变率 (chromosomalaberrantfrequency ,CAF)和微核率 (mi cronucleusfrequency ,MCNF)在 72h内与处理浓度、时间呈正相关。CAF、MCNF所反映的细胞遗传毒性的大小主要取决于汞处理浓度 ,而ROS则起次要作用。H2 O2很可能在慈姑抵御汞胁迫中起信号传导作用 ;慈姑通过促进根部部分细胞死亡提高抗汞能力。Effects of mercury on active oxygen metabolism and choromosome in Sagittaria trifolia at different concentrations and for different time were studied. As a matter of fact, aquatic mercury concentration is becoming higher and higher with the development of industry and agriculture. So, studies of the effects of mercury on aquatic plants are needed. Few studies on the changes and roles of ROS of plant in mercury stress and on the cytogenetical toxicity of mercury in aquatic plants were reported. In an attempt to know whether active oxygen metabolism was affected by mercury conducted signal or not, and to get the messages of resistance to mercury stress. Sagittaria trifolia was treated with different Hg 2+ concentrations for 0 to 10 mg/L. O -· 2 formation rates and H 2O 2 contents were measured. The mitosis and the chromosome abnormality were observed and the number was reported. The toxic reactions of root tip cells induced by mercury were scored by the method of systemic analysis with IM, CAF and MCNF. The degree of correlation was analyzed with the grey systems theory. The results indicated that O -· 2 formation rates and H 2O 2 content in leaves and roots of Sagittaria trifolia were changed by mercury, and the inducement to H 2O 2 was earlier than that to O -· 2(Figs.3,4). In the groups treated with 0.5-5 mg/L mercury concentrations, the frequency of chromosomal aberrations(CAF) and the frequency of micronucleus (MCNF) were positive correlated with the concentration and time during 72 h(Fig.6). The major responsibility for the cytogenetical toxicity was Hg 2+ ; while the role of ROS was secondary. The role of H 2O 2 is possibly signal conduction in resistance against mercury toxicing. Sagittaria trifolia enhanced its resistantance to mercury stress by inducing root death.

关 键 词：汞 慈姑 活性氧 信号传导 遗传毒性 

分 类 号：X173[环境科学与工程—环境科学]