SO_2对大蒜根尖细胞遗传损伤作用的研究  

Cytogenetic Damage of A. sativum Root Cells Induced by Sulfur Dioxide

作　　者：仪慧兰[1] 孟紫强[1] 

机构地区：[1]山西大学环境医学与毒理学研究所,生命科学与技术学院太原030006

出　　处：《生态学报》2002年第5期709-714,共6页Acta Ecologica Sinica

基　　金：国家自然科学基金资助项目 ( 39770 6 34 ) ;山西省自然科学基金资助项目

摘　　要：研究 SO2 ( 1 4 ,35 ,84 mg/m3 )对大蒜幼根细胞的遗传损伤效应。结果表明 :大蒜幼苗短时间暴露于高浓度 SO2 环境中 ,或者长时间生长在低浓度 SO2 环境中 ,均可导致根尖细胞微核和双核频率明显增高 ,并引起根尖部分细胞核固缩。SO2 的上述效应具有明显的时间 -效应和剂量 -效应关系 ,细胞中的微核、双核及核固缩率与 SO2 浓度间呈线性相关。研究结果表明 :SO2 可引起植物细胞遗传物质的损伤 ,大蒜根尖细胞有可能用作监测 SO2 污染的生物计量计。Human exposure to the environmental pollutant sulfur dioxide (SO 2) has become increasingly widespread due to the combustion of fossil fuels. Consequently, it has become important to study the toxic effects of SO 2 in the environment to human. The plant micronucleus (MCN) assays, which are considerably less expensive and simplicity, have been validated in the international collaborative study and proven to be efficient tests for genotoxicity monitoring of environmental pollutants. For these reasons, the MCN induced by SO 2 in A. sativum root tips were investigated, meanwhile binucleate cells and pycnosis in the root tips were also observed. Garlic bulbs, after removing old roots and scales, were suspended over a container of tap water and kept in an incubator at 25℃±1℃. After 2 days, roots had reached 1.0～2.0 cm in length. Garlic bulbs divided into five groups. One group for positive control, one group for negative control, other three groups used for SO 2 exposure with different concentrations (14, 35, 84mg/m 3)and various duration (4, 8, 12, 16 h). Cyclophosphamide (CP) was used for the positive control at the concentration of 5μg/ml. The garlic bulbs, which were incubated in tap water and unexposed to SO 2, were used for negative controls. For SO 2 groups, monitoring plants were kept in pots during the exposure time and watered daily with tap water. The SO 2 duration was 4h daily, afterwards the plants were left for 20h recovery. The roots after treatment (only for MCN) or a recovery period (24h) were fixed overnight in freshly prepared 1:3 aceto-ethanol solution, and then transferred to 70% ethanol for storage. They were hydrolyzed in 1N HCl at 60℃ for 8～10 min and stained with Schiff reagent for 40～60 min, 1 mm of the mitotic zone from well-stained root tip were immersed in a drop of distilled water on a clean slide and squashed under a cover glass. About 4000 cells were examined from 10 separate A.sativum seedlings per experimental group. MCN, binucleate cells and pycnosis were expre

关 键 词：SO2 大蒜根尖细胞 遗传损伤作用 微核 双核 核固缩 大气污染 

分 类 号：S633.4[农业科学—蔬菜学]