Calcium interaction with salinity-induced effects on growth and metabolism of soybean (Glycine max L.) cultivars

In the present work, hydroponic culture of JS-335 and Bragg cultivars of soybean (Glycine max) were raised to analyze changes in growth, reactive oxygen metabolism in terms of H 2 O 2 content, lipid peroxidation (TBARS), free radical quenching systems (non- enzymatic and enzymatic antioxidants) and ion accumulation in different plant parts under NaCl and CaCl 2 stress. Fifteen-day-old seedlings were treated with solutions of 25 mM (T 1 ), 50 mM (T 2 ) and 100 mM (T 3 ) NaCl alone and in combination of 10 mM CaCl 2 i.e., 25 mM + 10 mM (T 4 ), 50 mM + 10 mM (T 5 ) and 100 mM + 10 mM (T 6 ). Observations recorded at 30 days after sowing displayed significant decreases in plant biomass, leaf water potential, leaf area, chlorophyll content and the contents of glutathione (GSH) and ascorbate (AsC) on application of NaCl alone. However, H 2 O 2 content and lipid peroxidation (TBARS) in leaves were enhanced, consequently invoking the activities of SOD, APX, GR and CAT. Application of NaCl + CaCl 2 alleviated adverse effects of NaCl stress. The Na + and Cl - contents in different plant parts increased with NaCl as well as with NaCl + CaCl 2 treatments. The maximum accumulation occurred in roots, followed by the stem and the leaves. The K + and Ca 2+ contents decreased under NaCl stress; but NaCl + CaCl 2 treatment reduced the extent of decrease caused by NaCl. Thus, calcium ameliorated the deleterious effects of NaCl stress and stimulated plant metabolism and growth.