Effect of different concentrations of molybdenum on some physiological and biochemical parameters in Hypericum perforatum L

Hypericum perforatum L. is a valuable medicinal species. The plant geneus includes 17 species in Iran, but H. perforatum is the only valuable species.The species plays an essential role in the treatment of depression. In this study, Hypericum perforatum was treated with different concentrations of molybdenum including (control, 0.1, 0.4, 0.8, 1.6 µΜ) in Hoagland solution at 6.8 pH and then samples were used to measure biochemical parameters. Molybdenum significantly increased proline content. The shoot catalase and ascorbate peroxidase activities increased in all treatments of molybdenum, but in root, it was reduced in higher concentrations. Shoot peroxidase activities increased by treatments of molybdenum, except at a concentration of 0.8µΜ. The increase in peroxidase activity was also observed in roots but it was reduced at higher concentrations. The malondealdehyde and molybdenum content increased in higher concentrations of molybdenum. Molybdenum content increased by increasing treated molybdenum. Therefore, molybdenum stress increased the proline content and peroxidase, catalase and ascorbate peroxidase activities, and toxicity symptoms were observed in high concentrations of molybdenum as lipid peroxidation. Data were analyzed by SPSS and mean comparisons was performed by Duncan's multiple range test. In each experiment, 3 replications were used.