Soil salinity is a major constraint in agricultural production. Although rapeseed is a salt tolerant plant, its oil production is reduced under salinity stress. To identify the mechanisms of salt responsiveness in rapeseed, the protein expression pattern of the roots in two contrasting cultivars were analyzed. Plants were exposed to 0, 175, and 350 mM sodium chloride. An increase in the sodium content and a reduction in growth and K content in both genotypes were observed under salt stress. The content of Na was more in the salt-sensitive compared with the other genotype particular in shoot. We applied a 2-DE based approach coupled with the identification of responsive proteins to analyze root samples. Out of 419 protein spots were detected, 20 and 21 proteins were differentially expressed in the susceptible and tolerant cultivars, respectively. Using MALDI TOF/TOF mass spectrometry analysis, 19 proteins could be identified. These spots had functions related to metabolism, transcription, translation, energy production, photosynthesis and electron transport. Results of this experiment suggest that these protein spots might play roles in adaptation to salinity stress. The roles of these proteins in rapeseed adaptation to salt stress will be discussed.
