Antioxidant enzyme activities and protein profiling under salt stress in indica rice genotypes differing in salt tolerance

摘要

The effect of NaCl stress (0-300 mM) was investigated in terms of antioxidant enzymes activity and their isozymatic pattern and SDS-PAGE proteins banding pattern in three rice cultivars (cvs), Panvel-3 (tolerant), Kalarata (moderately tolerant) and Karjat-3 (sensitive). Interestingly, superoxide dismutase activity in roots and glutathione reductase activity in both shoots and roots were decreased significantly under high salinity levels in Karjat-3 and Kalarata, while, a sharp increase was observed in Panvel-3. Catalase and peroxidase activities were increased with salt stress of all cvs, with highest magnitude in Panvel-3. There was an induction of two new POX isoforms in Panvel-3 and Kalarata in stressed plants. Four SOD isoforms were observed in all the genotypes, irrespective of non/saline conditions. Total 33 proteins bands ranging from 17-154.5 kDa were either expressed de novo or up/down-accumulated due to NaCl stress. In Panvel-3, three new bands, one of 32 kDa in shoots while two of 37 and 116.7 kDa appeared in roots under salt stress. A new band of 37 kDa was also observed in roots of Kalarata under salinity stress. Thus, salinity tolerance nature of Panvel-3 may be correlated with higher enzyme activities and expression of some new polypeptides under salt stress.