In vitro SIMULTANEOUS ACCUMULATION OF MULTIPLE HEAVY METALS BY Prosopis laevigata SEEDLINGS CULTURES

Abstract

Experiments were conducted to investigate the capability of Prosopis laevigata to individually or simultaneously uptake four heavy metals (HM; Cr, Ni, Cd, and Pb). To this end, P. laevigata seedlings were cultured during 50 days on modified MS medium supplemented with 30 g L^-1 of sucrose and added with 50 mg L^-1 of 1, 2, 3 or 4 HM. When the four HM were added simultaneously, the medium was supplemented with or without ethylenediaminetetracetic acid (EDTA). In the MS media contained only one HM, the seedlings tolerance to HM was as follows: Pb≥Cr>Ni≥Cd. The accumulation of HM from higher to lower concentration in shoots was Pb≥Ni>Cd>>Cr and in roots Cr>>Pb>>Ni>Cd. When the media contained more than one HM, the accumulation in shoots was the highest for Ni and the lowest for Pb, whether EDTA was added or not. EDTA supplementation increased 61, 39, 22, and 3 fold uptake of Cr, Ni, Pb, and Cd in roots, respectively.