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.