Glutathione S-Transferase Activity during Phytoremediation of 2,4-Dichlorophenol (2,4-DCP) in Some Wild Plants

S-transferases (GSTs) play important roles in many different events, including the detoxification of xenobiotics, herbicides, and pesticides, as well as enhancing stress tolerance in plants1. 2,4-Dichlorophenol (2,4-DCP), an extremely toxic chlorophenolic, is one of the toxic environmental pollutants used as a raw material in many industries, including most herbicide and insecticide production2.

This study investigates the response mechanism of GST during phytoremediation of 2,4-DCP in Datura stramonium, Amaranthus retroflexus, and Sinapis arvensis plants with high phytoremediation potential, exposed to different doses of 2,4-DCP. The seedlings growing in a hydroponic system were exposed to the different solutions of 2,4-DCP in a concentration range from 75 to 275 ppm for 4 days. Then, GST activity was evaluated spectrophotometrically in roots and shoots of seedlings. GST activity in roots and leaves of D. stramonium increased up to 125 ppm dose of 2,4-DCP but decreased at its 150 ppm and higher doses, compared to control. Even at 275 ppm, its highest dose, the activity decreases were 13% in leaves and 17% in roots. In A. retroflexus, GST activity increased up to 175 ppm dose of 2,4-DCP in the leaves and 125 ppm in the roots, but after these doses, its activity in both organs generally decreased in parallel with the increasing doses of 2,4-DCP. The highest decreases in GST activity were 20% in the leaves and 28% in the roots. In S. arvensis, on the other hand, all the doses of 2,4-DCP decreased GST activity in parallel with the increasing doses in both leaves and root, compared to their controls. In addition, the highest decreases in GST activity were 44% in the leaves and 80% in the roots. Our results show that of these 3 plants studied, D. stramonium and A. retroflexus plants responded to 2,4-DPC toxicity by stimulating GST activity, especially at low concentrations.

References:

1) Estévez, I.H., Hernández, M.R., 2020. Plant Gene, 23, 100233.

2) Rodriguez-Hernandez, M.C., García De la-Cruz, R.F., Leyva, E., 2017. Navarro-Tovar, G. Chem., 173, 190e198.