Proteomic Analysis of Spring Rapeseed Leaves under Salt Stress

Excess salinity is one of the most important problems of agricultural production. Rapeseed is a superior oilseed due to the high quality of oil, large amounts of polyunsaturated fatty acids and oil yield. Rapeseed is classified as a semi-salt-tolerant plant although yields decrease more than in many other crops when salinity is higher than the threshold. Therefore breeding for increasing salt tolerance would be of interest. Changes of protein expression were investigated in a Safi7 tolerant genotype in order to identify the molecular mechanisms of salinity tolerance in rapeseed. NaCl concentrations of 0 (control), 150 and 300 mM caused a significant increase of Na content in leaves and a decrease of shoot dry weight, shoot height, leaf K content and the leaf Kﳖ ratio. 110 repeatably-appearing protein spots were identified on two-dimensional electrophoresis (2-DE) gels and among them, 37 spots showed significant expression changes based on changes in the induction factor (IF). Among them, 5 spots showed significant statistically changes at the 95% confidence level, with 1 spot being up-regulated and the other four spots down-regulated. Identification of the spots was performed by LC-MS/MS mass spectrometry analysis. The identified proteins play a key role in energy production and photosynthesis. Our results indicated that these proteins can also play a role in rapeseeds tolerance to salt stresses.