Biochemical responses of Hyacinth bean (Lablab purpureus) to salinity stress

Effect of salinity on Hyacinth bean, Lablab purpureus (HA-4 cultivar) was evaluated in 10-day old seedlings with 100-500 mM NaCl over 72 h of exposure. The stress reduced dry and fresh weight, leaf surface area, root and shoot length, total chlorophyll, and RWC. Oxidative stress markers, H2O2, glutathione, TBARS, proline, ascorbic acid, total phenols, and total soluble sugar contents were significantly elevated. Salinity enhanced antioxidant enzymes, POX, and GR activities and reduced that of CAT in concentration and time dependent manner in leaves. Antioxidant enzymes in roots showed inverse relationship with concentration and time of exposure. Metabolic enzyme beta-amylase activity increased in both leaves and roots. Acid phosphatase decreased in leaves and elevated in roots. Intensity of constitutive isozymes correlated with in vitro levels under stress, but the protein band patterns differed from controls. Lablab showed reasonable tolerance up to 300 mM NaCl, but leaves and roots differed in their response.