Effects of iron and cupper ions on sulforaphane content and peroxidase activity in Lepidium draba seedlings

Sulforaphane is an isothiocyanate which is produced through glucoraphanin hydrolysis via myrosinase activity. In the present study, Sulforaphane content and peroxidase activity has been assessed in Lepidium draba seedlings which treated with different concentrations of iron and copper ions for 8 and 16 hours. The results showed that the Sulforaphane content drastically elevated around two-fold compared to control when the seedlings treated with 1 mg/L Fe2+for 8 hours. But, the Sulforaphane content decreased in treated seedlings with higher Fe2+concentrations and any concentrations of Cu2+. Furthermore, promotion of peroxidase activity was observed in the treated seedlings with the both metals. The data revealed that, not only the inhibitory effect of Cu2+ on Sulforaphane production was stronger than Fe2+, but its stimulatory effect on peroxidase activity was also remarkable especially after 16 hours treatment. It seems that at low Fe2+ concentration reactive oxygen species induced by these metals resulted in inducing of glucoraphanin biosynthesis pathway. While, produced reactive oxygen species in treated seedlings with higher Fe2+concentration and Cu2+ led to induce more enzym