Physiological Responses and Comparison of Protein Changes in the Leaves of Two Wheat (Triticum aestivum L.) Genotypes by 2-D Electrophoresis Under NaCl Salinity Stress

A pot experiment was conducted to investigate salinity stress related physiological responses and comparison of protein changes in the leaves of two wheat genotypes at CRI (Crown Root Initiation) and booting stages. Physiological approach is a preliminary marker to know the effect of salinity amelioration. MSI (Membrane Stability Index) and RWC (Relative Water Content) of wheat leaves were reduced in salinity susceptible genotype GW-496 than in salinity tolerant genotype GW-173 at both the stages. The results also revealed that MSI and RWC were recorded highest at control condition and lowest @160 mM NaCl treatment at booting stage. In proteomics investigation, gel analysis of the resulting protein patterns revealed genotype specific and salt stress responsive protein expression. Total 419 of protein spots were found under match Id in control as well as in treated tolerant and susceptible genotypes at CRI and booting stage. More number of protein expressions was noticed in the tolerant genotype than in the susceptible genotype at both the stages. The change in physiological parameters varied with genotypes and the crop growth stages. Proteomics results indicate that tolerance to salt stress is associated with changes of protein levels in wheat genotypes. In particular, comparative proteomic investigations of plants before and after specific or interactive stresses allow us to obtain information on how defensive mechanisms are adopted from plants which might be helpful in the development of future strategies against salinity stress.