Recombinant expression of Thermosynechococcus elongatus BP-1 glutathione S-transferase in Arabidopsis thaliana: an efficient tool for phytoremediation of thiocyanate

Large-scale production of thiocyanate (SCN^-) for industrial purposes has led to widespread environmental pollution by this compound. Thiocyanate (SCN^-) is toxic for humans and recalcitrant to biological oxygenation and hydrolysis. Phytoremediation is an effective technique for disposal of SCN^- because thiocyanate (SCN^-) can be assimilated by many plants from contaminated water and soil. In this study, we demonstrate that Thermosynechococcus elongatus BP-1 glutathione S-transferase (TeGST) is a good candidate gene for enhancing phytoremediation of thiocyanate (SCN^-) in the plant. Our study demonstrated that Arabidopsis thaliana introduced with the glutathione S-transferase (GST) gene were able to germinate and grow in a medium containing 5 mmol L⁻¹ thiocyanate (SCN^-), which was lethal for wild-type plants. Moreover, the GST can confer the capacity of plants to remove more thiocyanate in vivo. Our results suggest that grafting the T. elongatus BP-1 glutathione S-transferase (TeGST) gene into plants is a potentially effective strategy to enhance phytoremediation of environmental thiocyanates. To our knowledge, this is the first study on the degradation of guanidine isothiocyanate by transgenic plants.