Response of Berberis thunbergii to heavy metals under urban pollution

Increasing pollution of the environment caused by heavy metals is becoming a significant problem in developing cities. Species and cultivars of plants for urban plantings should exhibit tolerance to these pollutants, and what is even more significant, through their absorption they should reduce the level of environmental contamination. The aim of the research was to determine whether Berberis thunbergii (DC.), which was grown in the immediate vicinity of roads, developed mechanisms limiting harmful effects of accumulating heavy metals. The mechanism for heavy metal resistance, involving the generation of phytochelatins (PCs), was investigated in relation to As, Cd, Cr, Co, Cu, Hg, Ni, Pb and Zn accumulation. Levels of thiols, i.e. glutathione (GSH) and phytochelatins (PCs), increased in plants grown in polluted areas in the city of Poznan in comparison to a residential site (control) and it was related to the activity of phytochelatin synthase (PC-synthase) and the accumulation of metals. The results indicate that in Berberis thunbergii growing in the polluted urban environment a defense mechanism adapting the plant to potentially adverse conditions was initiated.