Selenium-oxidizing Agrobacterium sp.T3F4 decreases arsenic uptake by Brassica rapa L.under a native polluted soil  

作　　者：Lijin An Chunzhi Zhou Lipeng Zhao Ao Wei Yiting Wang Huimin Cui Shixue Zheng 

机构地区：[1]State Key Laboratory of Agricultural Microbiology,College of Life Science and Technology,Huazhong Agricultural University,Wuhan 430070,China

出　　处：《Journal of Environmental Sciences》2024年第4期506-515,共10页环境科学学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(No.41771283);"Longyun Program"of the College of Life Science and Technology of Huazhong Agricultural University。

摘　　要：Toxic arsenic(As)and trace element selenium(Se)are transformed by microorganisms but their complex interactions in soil-plant systems have not been fully understood.An Asand Se-oxidizing bacterium,Agrobacterium sp.T3F4,was applied to a native seleniferous As-polluted soil to investigate As/Se uptake by the vegetable Brassica rapa L.and As-Se interaction as mediated by strain T3F4.The Se content in the aboveground plants was significantly enhanced by 34.1%,but the As content was significantly decreased by 20.5% in the T3F4-inoculated pot culture compared to the control(P<0.05).Similar result was shown in treatment with additional 5 mg/kg of Se(IV)in soil.In addition,the As contents in roots were significantly decreased by more than 35% under T3F4 or Se(IV)treatments(P<0.05).Analysis of As-Se-bacterium interaction in a soil simulation experiment showed that the bioavailability of Se significantly increased and As was immobilized with the addition of the T3F4strain(P<0.05).Furthermore,an As/Se co-exposure hydroponic experiment demonstrated that As uptake and accumulation in plants was reduced by increasing Se(IV)concentrations.The 50% growth inhibition concentration(IC50)values for As in plants were increased about one-fold and two-fold under co-exposure with 5 and 10μmol/L Se(IV),respectively.In conclusion,strain T3F4 improves Se uptake but decreases As uptake by plants via oxidation of As and Se,resulting in decrease of soil As bioavailability and As/Se competitive absorption by plants.This provides a potential bioremediation strategy for Se biofortification and As immobilization in As-polluted soil.

关 键 词：Selenium oxidation Selenium biofortification Arsenite-oxidizing bacteria Arsenic immobilization Brassica rapa L 

分 类 号：X17[环境科学与工程—环境科学] X53