Ameliorative effects of proline on salt stress-induced lipid peroxidation in cell lines of groundnut (Arachis hypogaea L.)

Cell lines of a salt-sensitive cultivar of groundnut (Arachis hypogaea L. c v. JL24) were selected on media amended with high NaCl concentrations. Comp arative analyses of the water status and ionic relations of salt-sensitive and salt-tolerant cell lines showed a decrease in the water potential (psi (w)) and solute potential (psi (pi)) with increases in salt stress. However , the maintenance of cellular turgor indicated active osmotic adjustments i n response to salinity stress. In addition to the extrusion of Na+ in the N aCl-selected cell lines, a significant accumulation of proline was observed , which was probably associated with osmotic adjustments and the protection of membrane integrity. The addition of proline to the culture medium allev iated the salt stress-induced decline in fresh weight accumulation and redu ced peroxidative damage to the lipid membranes, both in a concentration-dep endent manner.