2-DE method and proteomic map analysis in Cichorium intybus L. leaves under salt stress

To compare the global protein maps of Cichorium intybus L. between normal leaves and leaves under salt stress by means of two-dimensional electrophoresis (2-DE) so as to explore the biochemical mechanisms of salt tolerance of C. intybus. The whole leaf protein was prepared by improved TCA-acetone precipitation method and then separated by 2D-PAGE. The electrophoregrams of C. intybus proteome between normal leaves and salt-stress leaves were evaluated qualitatively and quantitatively with the Image Master 2-DE analyzer. The results showed that total 413 protein spots were detected in 2-DE and the qualitative and quantitative changes in 12 protein expression of salt-stressed versus control leaves were detected, three of which were significantly up-regulated and nine significantly down-regulated in salt-stressed leaves. Furthermore, three new protein spots emerged and one spot missed in electrophoregrams of salt-stressed leaves. The differential displayed protein spots might relate to the salt tolerance.