Metal accumulation potential and tolerance responses in Alternanthera dentata grown under multi metal treatment

Abstract Present study investigates metal accumulation potential, enzymatic and non-enzymatic tolerance responses of a tropical perennial plant Alternanthera dentata grown under multi metal (Cr, Cd, As and Ni) treatment at different concentration i.e. 0, 5, 20 and 50 ppm for 60 d in pot culture with garden soil as control. Results revealed accumulation of appreciable amount of toxic metals in the root of Alternanthera dentata, as maximum concentration of Cr (2402.65 μ g g−1 dw), As (1485.81 μ g g−1 dw), Cd (1258.9 μ g g−1 dw) and Ni (1215 μ g g−1 dw) recorded at 50 ppm of multi metal treatment. High concentration of toxic metals in the biomass of Alternanthera dentata indicates its high potential for metal accumulation. Biochemical changes particularly increase in synthesis and concentration of phenol, carotenoid and cysteine in metal treated plant provide non-enzymatic tolerance. Similarly, increased antioxidant activities of Ascorbate Peroxidase (APX) and Guaiacol Peroxidase (GPX) provide better tolerance for growth and survival at higher concentration of toxic metals. The plant Alternanthera dentata grown worldwide, thrive in humid condition, has heat and metal tolerance, thus it could be efficiently used for metal removal globally. Therefore, Alternanthera dentata has emerged as an efficient metal accumulator plant with better tolerance to toxic metals and may be exploited as a bioresource in developing innovative and sustainable technology to remove toxic metals from soil, contaminated due to industrial discharge or geological processes for ecological restoration, environmental cleanup and health safety