Response of Prosopis farcta to copper and cadmium stress and potential for accumulation and translocation of these heavy metals

Few studies have evaluated the effects of various levels of heavy metals on medicinal plants. The impact of gradually increased soil levels of copper (Cu) and cadmium (Cd) on the medicinal plant native to Southwest Asia and North Africa, Prosopis farcta, irrigated with metal-enriched water was determined. The exposure of plants to Cd or Cu decreased plant growth and increased Cd and Cu concentration in their shoots and roots. External Cd or Cu in the soil increased the uptake of both elements. Regression analysis showed that the weight of both shoots and roots decreased linearly with the increase of Cu and Cd contents in roots and shoots. Results showed that Cd was more toxic than Cu. The water content of shoots and roots decreased linearly with increased heavy metal levels. P. farcta could take up Cu and Cd in both Cu- and Cd-contaminated soils, however, it was more capable for transporting Cd from roots to shoots rather than Cu. P. farcta is a natural accumulator for Cu and Cd under gradually increased levels of these metals in the soil.