Biochemical and Genetical Responses of Phoenix dactylifera L. to Cadmium Stress.

The cadmium (Cd), a heavy metal, causes toxicity, which leads to hampering the growth and development of the plant. The molecular and biochemical approaches were used for the investigation of antioxidant system response and genotoxicity in date palm ( Phoenix dactylifera L.) cv. Sagai in pot experiment having Cd. The root length was more affected than the shoot length as more accumulation of Cd occurs in roots. Fresh weights of root and shoot were reduced significantly in treated plants as compared to the control. The proline content was increased at low concentration of Cd (300  µ M-CdCl2 ) than the medium and high concentrations (600 and 900  µ M-CdCl2 ), respectively. The thiobarbituric acid reactive substances (TBARS) content was increased at 600 and 900  µ M-CdCl2 compared to the plants treated at 300  µ M-CdCl2 and controls. Antioxidant enzymatic assay was performed under Cd stress and compared with control plants. The catalase (CAT) and superoxide dismutase (SOD) activities were found to be high in plants treated with CdCl2 at 300  µ M compared to at 600 and 900  µ M-CdCl2 , respectively. The genotoxicity of Cd was assessed using the inter-simple sequence repeat (ISSR) marker where all treated and control plants were clustered into three main groups based on genetic similarity. P. dactylifera plants were found to be more divergent at high Cd stress as compared to control and plants treated at low concentration of Cd.