Proteins alterations associated with salinity, desiccation, high and low temperature stresses and abscisic acid application in seedlings of Pusa 169,a high-yielding rice (Oryza sativa L.) cultivar

Abiotic stresses (such as salinity, water stress and low and high temperatu res) adversely affect growth of rice. The objectives of the present study w ere to make a comparative assessment of various polypeptides which are alte red in response to different abiotic stresses and to see the utility of str ess proteins in distinguishing between the stress response of stress-sensit ive and tolerant cultivars in rice. We have identified nearly 73 steady-sta te high and low molecular weight proteins which are up- or down-accumulated in shoot and root tissues of an indica rice cultivar (Pusa 169) when intac t seedlings are subjected to salinity (NaCl), air drying and high and low t emperatures. A set of five polypeptides ranging in molecular weight from 80 to 100 kDa was found to be co-regulated in response to various stresses st udied here. Exogenous application of abscisic acid mimicked several, but no t all, of the protein perturbations caused by the imposition of stresses. C omparison of salt-sensitive (Basmati 370 and Pusa 169) and tolerant (CSR 10 and CSR 19) rice cultivars revealed that most stress proteins appear to ac cumulate in a similar pattern in the contrasting types; however, differenti al pattern of accumulation of two specific stress proteins with molecular w eights of 104 and 90 kDa was noted by Western blotting in CSR 19 as against CSR 10, Pusa 169 and Basmati 370 cultivars.