Investigation molecular mechanism of sensitive and tolerant barley cultivars under different times of salinity stress exposure using proteome analysis

To evaluate the protein response of barley cultivars under salinity stress, leaf samples were prepared 0, 3, 6, 9, 12, and 15 days after the tillering stage. Following two-dimensional electrophoresis, 153 and 141 protein spots were identified in tolerant (Afzal) and sensitive cultivars (Macouei), respectively. In total, 21 and 17 spots with significant induction factor (IF) were revealed in Afzal and Macouei, respectively. The most common proteins between two cultivars were involved in the removal of antioxidants (five proteins), and for each protein group including heat shock, proton transfer, Calvin cycle and photosynthesis optical reaction proteins, a protein was detected. Also, 12 protein spots were exclusively present in the tolerant cultivar (Afzal), most of them being involved in the elimination of antioxidants, and eight protein spots were found exclusively in the sensitive cultivar (Macouei), which was also largely involved in the removal of antioxidants. Lower expression of these proteins in the susceptible cultivar compared to the tolerant one resulted in a decreased homeostasis in susceptible cultivar under salinity stress. Also, for most proteins, the highest and lowest protein expression levels occurred in tolerant and susceptible cultivars, 12 and 9 days after initiation of salinity stress.