Physiological dissection of cobalt/copper tolerance and hyperaccumulation in the plants of south-central Africa

摘要：

The mechanisms of metal tolerance and hyperaccumulation in plants are of great interest, especially in phytoextraction of valuable metals such as cobalt (Co) and copper (Cu) from contaminated land and mineral wastes. A hydroponic system was used to investigate the tolerance and accumulation capacity of Co and Cu in the Co/Cu hyperaccumulators Haumaniastrum robertii and Crotalaria cobalticola in comparison with the common pasture species Tri folium subterraneum. Elemental distributions in the leaves at the subcellular level were analyzed by NanoSIMS. Resuits showed that both hyperaccumulators could tolerate and hyperaccumulate Co in hydroponics;H. robertii accumulated Co to concentrations greater than 1％ of shoot dry biomass. Both hyperaccumulators exhibited about a 10-fold higher shoot/root Co- concentration quotient than did T. subterraneum, suggesting that these Cohyperaccumulators possess specific mechanisms to translocate large amounts of Co from roots to shoots. H. robertii and C. cobalticola could also tolerate high concentrations of Cu in hydroponics without hyperaccumulating Cu in the shoots. NanoSIMS images suggested that Cu was present predominantly in the cell walls surrounding the epidermal cells in H. robertii. This Cu exclusion from the interior of the cells may be the basis of the extraordinarily high degree of Cu tolerance shown by this species.

关键词： Crotalaria cobalticola Haumaniastrum robertii hyperaccumulation metal tolerance NanoSIMS

作者: Y. D. Wang M Leil S. Crawford J. A. C. Smith M. Schroder K. E. Smart C. R. M.Grovenor A. J. M. Baker

作者单位: Applied Ecology Research Group, School of Botany, The University of Melbourne, Victoria 3010, Austra Applied Ecology Research Group, School of Botany, The University of Melbourne, Victoria 3010, Austra Department of Plant Sciences, University of Oxford, South Parks Road, Oxford, OX1 3RB, UK Department of Materials, University of Oxford, Parks Road, Oxford, OX1 3PH, UK

会议类型: 国际会议

会议名称: 第九届痕量元素生物地球化学国际会议(9th International Conference on the Biogeochemistry of Trace Elements)

会议地点: 北京

会议语种:英文

页码: 744-745

在线出版日期: 2007-07-15（万方平台首次上网日期，不代表论文的发表时间）