Response of Berberis thunbergii to heavy metals under urban pollution

Increasing pollution of the environment causedby heavy metals is becoming a significant problem in developing cities. Species andcultivars of plants for urban plantings shouldexhibit tolerance to these pollutants, andwhat is even more significant, through their absorption they shouldred uce 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 investigatedin relation to As, Cd, Cr, Co, Cu, Hg, Ni, Pb andZn accumulation. Levels of thiols, i.e. glutathione (GSH) andphytochelatins (PCs), increasedin plants grown in pollutedareas in the city of Poznań in comparison to a residential site (control) and it was related to the activity of phytochelatin synthase (PC-synthase) andthe 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

Effect of urban pollution on 4-coumarate: CoA ligase and flavonoid accumulation in Berberis thunbergii

Flavonoids are polyphenolic compounds commonly found in plants and they play an important role in stress tolerance. They have the capacity to chelate heavy metals andscavenge free radicals. Urban pollution causes oxidative stress in plants and flavonoids may protect cells against the negative effect of free radicals. In this study levels of anthocyanins andflavonols and4-coumarate:CoA ligase (4CL) activity were determinedin Berberis thunbergii (DC.) plants grown in pollutedandresid ential areas in the city of Poznań. The results showedsignificantly higher accumulation of anthocyanins andstimulation of 4CL activity in plants from the contaminatedsites in comparison to the control plants. Probably the activation of the phenylpropanoidpathway was a response to stress caused by urban pollution