Accumulation potential of Atriplex halimus to zinc and lead combined with NaCl: Effects on physiological parameters and antioxidant enzymes activities

Abstract An experiment in this study was designed to investigate the effect of different concentrations of Zn 2+ or Pb 2+ (0, 200, 400 and 600 μM) with NaCl (0, 200 mM), on the morphological and physiological parameters as well as the antioxidative response of the halophytic species Atriplex halimus . Results showed that Pb 2+ had no significant impact on biomass production while Zn 2+ significantly affected plant development mainly at high concentration, 600 μM. Total chlorophyll content did not change significantly under elevation concentrations of Zn 2+ when compared to control. However, there was a modest decrease in total chlorophyll concentration in the leaves of A. halimus grown in a medium supplemented with 600 μM Pb 2+ and with combined stress Pb 2+ /NaCl. Zn 2+ and Pb 2+ contents in tissues were higher in the belowground organs of this halophyte. Overall results pointed out that application of different concentrations of Zn 2+ or Pb 2+ disturbed status of nutrients in A. halimus . Analysis of antioxidant enzymes [ascorbate peroxidase (APX), guaiacol peroxidase (GPX), and catalase (CAT)] showed that the activity was diminished by increasing Zn 2+ concentrations in the medium. Whereas, the addition of Pb 2+ in the medium increased CAT activity and decreased APX activity.