Study Of Salt Tolerance In Salicornia Europaea L. Using A Proteomic Approach

Salicornia europaea L. is one of the most salt-tolerant plant species in the world. Proteomic analysis of its salt tolerance is of great significance for us to understand the mechanism of plant salt tolerance and to improve salt tolerance of crops. Two-dimensional electrophoresis (2-DE) is a powerful tool of proteomics. Sample preparation is a critical step and is absolutely essential for good results. As a euhalophyte, S. europaea contains a large amount of salt additional to the various secondary metabolites, and its protein extraction is more difficult. Thus, it is necessary to develop an efficient protein extraction method before performing the proteomic analysis.In this study, we compared three different methods, i.e. trichloroacetic acid/acetone precipitation (TCA), trichloroacetic acid precipitation (E-TCA), and phenol extraction (Phe), to determine their efficiency in extracting total proteins from S. europaea by 2-DE analysis. For plants that were treated with 700 mM NaCl for 2d, 579, 343, and 535 protein spots were generated by the three methods. The 2-DE gels of TCA and E-TCA showed strong horizontal streaks, while that of the Phe method had only a few faint streaks, which indicated effective removal of salt from the protein sample by the Phe method. This was also supported by results from plants that were treated with 200 mM NaCl for 90d. Comparison of different precipitants suggested that methanol couldn't replace the methanol solution of ammonium acetate.