Investigation of the Ability of Lepidium draba L. Seedlings in Zinc and Silver Ions Absorption and Effect of the Ions on Morphological and Biochemical Characteristics of the Seedlings

The aim of this study was to investigate the ability of Lepidium draba L. seedlings to eliminate zinc and silver ions from the medium. The seeds of L. draba were cultured on MS solid medium for 15 days in the presence of different concentrations of both silver and zinc ions. The bioaccumulation of these ions in L. draba tissues were measured by atomic absorption. Furthermore, biochemical and morphological properties of the seedlings such as catalase and superoxide dismutase activities, total flavonoid content, germination percentage, root and stem lengths were analyzed. Results revealed that L. draba seedlings were able to absorb high level of zinc and silver ions and a direct relationship between the level of absorption and the amount of ions in media was seen. On the other hand, total flavonoid contents, catalase and superoxide dismutase activities were elevated by increasing concentrations of the ions in media. Silver ion increased the germination, while the seed germination did not show significant different in treatment with zinc ion in compared to the control. Upon the treatment seedlings with silver ion, the stem growth was significantly increased, while the root growth was decreased. Significant decrease in the stem and root growth were occurred upon seedlings treatment with high level concentrations of zinc ion. Based on the results, it seems that L. draba could be introduced an appropriate option for refining of the aforementioned metals from contaminated area.