Assessment of changes in protein expression pattern in tolerant and sensitive cultivars of rapeseed under salt stress

To investigate the mechanisms of tolerance and sensitivity to salinity stress in canola (Brassica napus L.), two spring canola cultivars such as SW5001 as tolerant cultivar and Sarigol as sensitive cultivar were evaluated at two levels of salinity in factorial based on randomized complete block design with four replications using a hydroponic culture system into green house. Sampling of leaves was performed in the rosette stage and two weeks after starting of salt stress. Proteins were extracted from leaf tissues and two-dimensional electrophoresis for the study of expression of proteins in both control and salt stressed plants was performed. Staining with commassie brilliant blue and quantitative analysis of protein spot by PDQuest software was performed and protein spots were identified by mass spectrometry using MALDI TOF/TOF MS method. 17 protein spots with significant expression differences between control and treatment plants to salinity, were identified that Of these, 10 protein spots was common between two cultivars and four and three proteins were assigned only to tolerant and sensitive cultivars respectively. Common proteins identified were classified in the functional groups of photo reaction of photosynthesis, Calvin cycle, proteins involved in remove of antioxidant, signal transduction and structural stability of proteins. In generally, in the tolerant cultivar of SW5001, sustainability factors of structure, maintaining of carbon metabolism efficiency and defense against to oxidative stress under stress conditions were effectively creates resistance. The highest strength point tolerant cultivar to rely on the unique proteins was in the light reaction of photosynthesis and the most of damage suffered in sensitive cultivar related to Calvin cycle.