Evaluation of the Cd2+ phytoextraction potential in the xerohalophyte Salsola kali L. and the impact of EDTA on this process

The application of the phytoextraction in saline soil contaminated with heavy metals requires the identification of appropriate plant species showing high salinity tolerance concomitant with an important ability of heavy metal accumulation. The objective of this works is to evaluate the capacity of the xerohalophyte, Salsola kali, to extract Cd2+ from an artificially contaminated soil (100 μg Cd2+ g−1 soil) in the presence of NaCl (100 mM) and/or EDTA (1 mmol kg−1 soil). Results showed that in the absence of NaCl or EDTA, Cd2+ was essentially accumulated in the roots reaching 400 μg Cd2+ g−1 DW, while in the shoots Cd2+ concentration did not exceed 85 μg Cd2+ g−1 DW. Addition of NaCl to the soil significantly reduced root Cd2+ concentration, but had no impact on Cd2+ concentration in the shoots. The addition of the EDTA results in a twofold increase of Cd2+ concentration in shoots. This is due to the improvement of Cd2+ absorption efficiency by the EDTA concomitant with an increase of Cd2+ translocation to the shoots. These data suggest that S. kali is very promising species for the decontamination of Cd2+ contaminated salty soil. Its phytoextraction potential was significantly enhanced by the addition of EDTA.