Cd-Phytoextraction Potential of Atriplex nummularia Lindl.

Due to its wide industrial use, cadmium (Cd) is considered a serious environmental pollutant. Halophytes, such as Atripex species, are model candidates to remediate heavy metal-contaminated saline soils. In the present study Atriplex nummularia Lindl. (Amaranthaceae) was grown in hydroponic conditions to investigate the effect of Cd on growth, tissue water content, leaf chlorophyll pigments, proline and ion accumulation. Treatments were prepared by adding 0, 100, 200 and 300 mu M CdCl2 (cadmium chloride) to the medium. Ion concentrations were determined using the X-ray florescence spectroscopy (EDXRF). The results showed that plant growth (FW and DW) was significantly (P < 0.001) affected by high Cd treatments. Photosynthetic pigments (chlorophyll a and chlorophyll b), calcium (Ca), potassium (K), and iron (Fe) contents decreased significantly (P < 0.001) with elevated CdCl2 concentrations, whereas the proline content was exceptionally higher only in shoot part. Most of the Cd uptake by plant was translocated to shoot (146.59 mu g g(-1) DW of Cd at 300 mu M CdCl2), this was confirmed by the high translocation index (TI > 1), which indicated the suitability potential of this halophyte to Cd-phytoextraction. The findings of the present study imply that coordinated regulation between Cd translocated pathways and proline accumulation process empower the xerohalophyte A. nummularia to grow in Cd-contaminated soil.