Comparative studies on antioxidant enzyme action and ion accumulation in soybean cultivars under salinity stress.

Plant biomass, antioxidant enzymes activity, ions accumulation and proline level in four soybean cultivars were investigated at different NaCl concentrations (20, 40, 60, 80 and 100 mM) applied to plants 15 days after sowing. There was a significant decrease in plant biomass and soluble protein content with each NaCl treatment. Accumulation of Na+ and Cl– was maximum in roots, followed by the stem and leaves in all the treated cultivars; Pusa 9712 being the top accumulator. On the contrary, K+ and Ca2+ ion concentrations were inhibited in all the treated cultivars. Activities of antioxidant enzymes (superoxide dismutase, ascorbate peroxidase and glutathione reductase) and proline content increased significantly in all the cultivars with each NaCl treatment. The maximum increase was found in Pusa 9712. However, catalase activity decreased in all the cultivars except in Pusa 9712. On the whole, Pusa 9712 was most efficient in managing protection against salinity stress.

Effect of calcium against salinity-induced inhibition in growth, ion accumulation and proline contents in Cichorium intybus L.

This study assesses the effect of NaCl (80 and 160 mM) and CaCl2 (10 mM) solutions, alone and in combination, to 30-day-old seedlings of Cichorium intybus L. Observations were made at 30 day intervals from the time of treatment till harvest (180 days after sowing). Application of NaCl resulted in significant decreases in lengths of root and stem, in dry weights of root, stem and leaves and in the leaf area, as compared with control. The reduction was less with the combined application of NaCl and CaCl2 than with the NaCl treatment alone. On the contrary, treatment of CaCl2 alone promoted the above variables. Proline content in the leaves was enhanced with NaCl and CaCl2 alone as well as with the NaCl + CaCl2 treatments; the maximum (six-fold) enhancement was observed with the combined treatments, compared with NaCl (four-fold increase) and CaCl2 (two-fold increase) alone. The sodium (Na+) and Chloride (Cl) contents in different plant parts increased both with NaCl and with NaCl + CaCl2 treatments. The maximum accumulation was observed in leaves, followed by that in stem and root. The potassium (K+) and calcium (Ca2+) contents decreased under NaCl stress, but increased with CaCl2 treatment. Thus, calcium ameliorated the deleterious effects of NaCl stress and stimulated the plant metabolism and growth.