Comparative Proteomic Analysis of Differentially Expressed Proteins in Shoots of Salicornia europaea under Different Salinity

Soil salinity is a major abiotic stress that limits agriculture productivity worldwide. Salicornia europaea is a succulent annual euhalophyte and one of the most salt tolerant plant species. The elucidation of its salt tolerance mechanism is of significance for generating salt-tolerant crops. In this study, we provided high resolution of proteome reference maps of S. europaea shoot and obtained evidence on the salt tolerance mechanism by analyzing the proteomic responses of this plant to high salinity. Our results demonstrated significant variations existed in 196 out of 1880 protein spots detected on CBB stained 2-DE gels. Of these, 111 proteins were identified by mass spectrometry. Among them, the majority was energy production and conversion related proteins, followed by photosynthesis and carbohydrate metabolism associated enzymes. Analysis of protein expression patters revealed that energy production and ion homeostasis associated proteins played important roles for this plant salt tolerance ability. Hierarchical clustering results revealed many proteins were involved in S. europaea salt tolerance mechanism as a dynamic network. Finally, based on our proteomic results, we brought forward a possible schematic representation of mechanism associated with the systematic salt tolerance phenotype in S. europaea.