ESTABLISHMENT OF CELL SUSPENSION CULTURES OF Prosopis laevigata (Humb. & Bonpl. ex Willd) M.C. Johnst TO DETERMINE THE EFFECT OF ZINC ON THE UPTAKE AND ACCUMULATION OF LEAD

 

A. Maldonado-Magaña, J. Orozco-Villafuerte, L. Buendía-González, M.E. Estrada-Zúñiga, A. Bernabé-Antonio and F. Cruz-Sosa

 

 

In vitro studies indicate that Prosopis laevigata can be considered a potential hyperaccumulator of lead. Likewise, lead uptake has been related to protein transporters for zinc. In this work presents a protocol for the establishment of cell suspension culture to determine the effect of zinc on the uptake and accumulation of lead. A bioassay with Pb2+/Zn2+ (0.0, 0.5, and 1.0 mM) was carried out on cell suspension cultures derived from callus induced in half-strength Murashige and Skoog (MS) medium added with 6.8 μM 2,4-dichlorophenoxyacetic acid (2,4-D) with 4.5 μM kinetin (KIN). Cells showed significant tolerance to growth (GR>60%) at all concentrations and combinations of Pb and Zn (0.0, 0.5 and 1.0 mM). When the Pb with or without Zn were added to the culture medium, the cells showed the highest accumulation efficiency for non-essential (lead) metal over essential (zinc) metal (BF values for Pb >> BF values for Zn; 2-33 times). Scanning electron micrographs evidenced the accumulation of Pb in the cells walls. These results provide insights about the tolerance and accumulation mechanisms of Pb occurring in P. laevigata.