Comparative study of Pb-phytoextraction potential in Sesuvium portulacastrum and Brassica juncea: Tolerance and accumulation

Lead phytoextraction from salty soils is a difficult task because this process needs the use of plants which are able to tolerate salt and accumulate Pb2+ within in their shoots. It has recently been suggested that salt-tolerant plants are more suitable for heavy metals extraction than salt-sensitive ones commonly used in this approach. The aim of this study was to investigate Pb-phytoextraction potential of the halophyte Sesuvium portulacastrum in comparison with Brassica juncea commonly used in Pb-phytoextraction. Seedlings of both species were exposed in nutrient solution to 0,200, 400,800 and 1000 mu M Pb2+. for 21 days. Lead strongly inhibited growth in B. juncea but had no impact on S. portulacastrum. Exogenous Pb2+ reduced nutrients uptake mainly in B. juncea as compared to S. portulacastrum. Lead was preferentially accumulated in roots in both species. S. portulacastrum accumulated more Pb2+ in the shoot than B. juncea. Hence, the amounts of Pb2+ translocated at 1000 mu M Pb2+ were 3400 mu g g(-1) DW and 2200 mu g g(-1) DW in S. portulacastrum and B. juncea, respectively. These results suggest that S. portulacastrum is more efficient to extract Pb2+ than B. juncea. Crown Copyright (c) 2010 Published by Elsevier B.V. All rights reserved.