水土保持学报2018，Vol.32Issue(2)：335-342,8.DOI:10.13870/j.cnki.stbcxb.2018.02.049
重金属Cd2+、Pb2+胁迫对小白菜生理及其BcMT2a基因表达的影响
Effects of Heavy Metal Cd2+ and Pb2+ Stress on Physiology and the Expression of BcMT2a Gene in Brassica campestris L.
摘要
Abstract
In order to explore the response mechanism of Brassica campestris to the Cd2+,Pb2+ single and combined stress (Cd2+-Pb2+),a culture room experiment was conducted,where the Brassica campestris seedlings were treated with different concentrations of Cd2+ and Pb2+.The biomass,the content of antioxidant defense enzyme activities [i.e.,peroxidase (POD),superoxide dismutase (SOD),catalase (CAT) activities] and malondialdehyde (MDA),and the enrichment of heavy metal ions were measured.In addition,the metallothionein gene BcMT2a which was associated with heavy metal enrichment was cloned and its expression was also analyzed.The results were as follows:except the low concentration of Cd2+ (10 mg/L),which could promote the root length and aboveground growth of Brassica campestris,both the Cd2+ and Pb2+ single and combined stress could inhibit the development of root length and the growth of aboveground of Brassica campestris.And with the increasing concentrations of heavy metal ion,the inhibition effects were gradually strengthened.The order of inhibition effects of heavy metal ions was Pb2+ ＞Cd2+ Pb2+ ＞Cd2+.In the antioxidant enzyme system,POD and SOD activity were higher,and showed a trend of increasing first and decreasing then,as well as CAT activity.MDA content reached the maximum when Cd2+ concentration was 40 mg/L.The order of heavy metal ions accumulation in the organs of Brassica campestris was root＞stem＞ leaf.The protein encoded by BcMT2a gene is a hydropathy and mutant protein predominantly present in the nucleus.In a certain concentration rage,the relative expression of BcMT2a increased with the increase of Cd2+,Pb2+ and both combined concentrations,and the trend of relative expression was consistent with the result of the antioxidant enzyme system.These findings indicate that the antioxidant enzyme system and BcMT2a have a clear response under the different concentrations of Cd2+,Pb2+ and Cd2+-pb2+ in Brassica campestris,and they can increase the tolerance of Brassica campestris to Cd2+ and Pb2+ stress.关键词
小白菜/Cd2+/Pb2+/富集/基因克隆/相对表达量Key words
Brassica campestris/Cd2+/Pb2+/accumulation/clone/relative expression分类
农业科技引用本文复制引用
齐世静,于星宇,温友伟,吴秀菊,孙彦坤,王丽娟..重金属Cd2+、Pb2+胁迫对小白菜生理及其BcMT2a基因表达的影响[J].水土保持学报,2018,32(2):335-342,8.基金项目
博士后落户黑龙江科研启动基金项目(LBH-Q11153) （LBH-Q11153）
黑龙江省教育厅科学技术研究项目(12531030) （12531030）
