铯对印度芥菜和菊苣植物螯合肽和金属硫蛋白含量的影响  

Effect of Cs^+ on Phytochelatins and Metallothionein in Seedlings of Brassica juncea and Cichorium intybus

作　　者：何娇[1] 何玉[1] 黄楚乔 韩娜[1] 陶宗娅[1] 吴国[1] 罗学刚[2] 

机构地区：[1]四川师范大学生命科学学院,成都610101 [2]生物质材料教育部工程研究中心,西南科技大学,绵阳621010

出　　处：《生态毒理学报》2016年第3期272-280,共9页Asian Journal of Ecotoxicology

基　　金：国家核设施退役及放射性废物治理重点项目(14ZG6101);四川师范大学校级青年项目(14qn07);四川省教育厅大学生创新创业训练计划项目(201510636076)

摘　　要：以133Cs作为污染源,溶液培养印度芥菜和菊苣幼苗,研究植物螯合肽(phytochelatins,PCs)、金属硫蛋白(metallothionein,MT)等含巯基肽类物质与Cs+胁迫毒理的内在联系。采用改良水培法培养印度芥菜和菊苣长至两片真叶,置于含铯[ρ(Cs^+)0~200 mg·L^(-1)]的营养液中培养一段时间后取样,测定幼苗地上部和根系生物量,采用火焰原子吸收分光光度法测定Cs^+富集量,5,5’-二六硝基苯甲酸(DTNB)比色法测定PCs和MT含量。结果显示:随着Cs^+浓度[ρ(Cs+)25~200 mg·L^(-1)]增加,印度芥菜和菊苣地上部和根系生物量显著降低(P<0.05),印度芥菜的生物量降低幅度小于菊苣;Cs^+的富集量均显著增加,印度芥菜对Cs^+富集量大于菊苣,印度芥菜地上部、菊苣根系分别是Cs^+的主要蓄积部位;非蛋白巯基肽类(non-protein thiol,NPT)、植物螯合肽(PCs)、谷胱甘肽(glutathione,GSH)和金属硫蛋白(MT)含量变化均呈现先升后降的趋势,均表现为根系>地上部,印度芥菜>菊苣。当ρ(Cs^+)100 mg·L^(-1)时NPT、PCs、GSH和MT达最大值。结果表明,菊苣对Cs^+处理敏感,印度芥菜具有较强的吸收和转运Cs^+的能力,Cs^+处理诱导合成PCs、GSH和MT含量显著增加,这是印度芥菜对Cs^+耐性较强的主要原因。This study seeks to investigate the relationship between Cs toxicity and the content of phytochelatins（PCs） and metallothionein（MT） in Brassica juncea and Cichorium intybu. We subjected seedlings at the two-leaf stage to different doses of Cs^＋[ρ（Cs^＋） 0-200 mg·L-（-1）]for two to nine days. Next,we analyzed the dry biomass,and the content of Cs^＋,PCs and MT in the over-ground and the root. The results show that the dry biomass of over-ground and root decreased in both plants when Cs^＋concentration increased（ P〈0. 05）. However,the decrease of dry biomass induced by Cs^＋followed the order as Cichorium intybu 〉Brassica juncea. With the increase in Cs^＋concentration,the accumulation content of Cs in both plants increased significantly（ P〈0. 05）. The capacity for accumulation for Cs^＋showed that： Brassica juncea 〉Cichorium intybu. The root of Cichorium intybu is the main accumulation organ for Cs^＋,but the over-ground is the main accumulation organ in Brassica juncea. With the increase of Cs^＋,the content of non-protein thiol（NPT）,PCs,gultathione（GSH）,and MT first increasd and then decreasd,and the content of both plants maximized when the concentration of Cs^＋reached 100 mg·L^-1. Further analysis shows that the roots had a higher content of NPT,GSH and MT than over-ground in both plants,and Brassica juncea had a higher content than Cichorium intybu. Our findings show that Cs^＋tolerance in Brassica juncea was higher than that in Cichorium intybu. Cs^＋can induce the synthesis of PCs,GSH,and MT in Brassica juncea when the plants have accumulated excessive Cs^＋.

关 键 词：铯(Cs^+) 印度芥菜 菊苣 非蛋白巯基肽类 植物螯合肽 谷胱甘肽 金属硫蛋白 

分 类 号：X171.5[环境科学与工程—环境科学]