Response of Prosopis farcta to gradually increased soil copper and cadmium levels based on an integrated investigation

The impact of gradually increased soil levels of copper (Cu) and cadmium (Cd) on the medicinal plant, Prosopis farcta, irrigated with metal-enriched water was determined. Plants were treated with 2.54, 5.08, 10.16, and 20.32 µg mL⁻¹ for Cu²⁺ and 6.13, 12.26, 24.52, and 49 µg mL⁻¹ for Cd²⁺. The rate of phytoremediation was measured by bioconcentration factor (BCF) and the relative bioconcentration factor (RBCF). The movement of metal ions from roots to shoots was calculated as the Translocation Factor (TF). The exposure of plants to Cd or Cu decreased plant growth and increased Cd and Cu concentration in their shoots and roots. The weight of both shoots and roots decreased linearly with the increase of Cu and Cd contents in roots and shoots. Cd was more toxic than Cu as expected. The water content of shoots and roots decreased linearly as heavy metal levels increased. Prosopis farcta can take up Cu and Cd in both Cu- and Cd-contaminated soils but was more capable for transporting Cd from roots to shoots rather than Cu although more Cu is taken up by roots. Prosopis farcta is a natural accumulator of Cu and Cd and can be used in phytoremediation.CONCISE NOVEL ASPECTS OF THIS STUDY This is the first report to show that the medicinal plant Prosopis farcta is an accumulator for Cu and Cd. This was determined by gradual addition of the metals to the soil via irrigation by heavy metal-polluted water which can provide an opportunity for the plant to develop a metal-resistance mechanism. Choosing suitable plant species for heavy metal accumulation is a critical step for successful phytoremediation of heavy metal pollutants. CORE IDEAS Prosopis farcta is of interest as a medicinal plant. P. farcta can take up Cu and Cd in both Cu- and Cd-contaminated soils. P. farcta transports more Cd from roots to shoots but more Cu is taken up.