Studies On Somatic Embryogenesis And The Proteins Related Of Eruca Sativa

Somatic embryogenesis (SEM) is one of plant regeneration in vitro, and is very useful for studying the mechanism of plant embryogenesis and cell differentiation, also for screening new valuable crop variety via cell and gene engineering method. E. Sativa Mill is an oil crop of Cruciferae which has high drought-resistance and thin-tolerant. In this study, a system of high-frequence somatic embryogenesis of E. Sativa was established and some proteins related to the somatic embryogenesis of E. Sativa was characterized through SDS-PAGE isolation and then tandem mass spectrometry analysis. The main findings are as follows:1. A plant somatic embryogenesis system with high frequency (72.9%) was established using the cotyledon of E. Sativa Qing Cheng variety as explants. The results showed that the best induction condition of E. Sativa somatic embryogenesis was MS medium with 1.0mg/L 2,4-D. The MS medium with 0.2 mg/L 2, 4-D was suitable for proliferation of embryogenesis callus. The maturation frequency of somatic embryo was significantly increased when 80g/L sucrose were applied to MS medium. Additional 60g/L sucrose to MS medium was effective for the germination of E. Sativa somatic embryo.2. Cytological observation of the paraffin sections of the embryogenic callus revealed that the somatic embryo originated from the cells lying in surface and internal area of embryogenic callus. The somatic embryos were originally produced from one single cell, via repeat division and differentiation, which developed into globular, heart, torpedo and cotyledon embryo.3. The dynamic changes of soluble proteins occurred during somatic embryogenesis of E. Sativa were analyzed, and two specific embryogenesis-related proteins, 34kD and 48kD, were identified by SDS-PAGE. 34kD and 48kD protein were specifically expressed at the 5th and 15th day after the cotyledon explants were induced on MS medium with 1.0mg/L 2, 4-D, respectively. Tandem mass spectrometry analysis and NCBI retrieval analysis found that the 34kD protein showed 39% and 37% homology with the S-adenosyl-L-homocysteine hydrolase (SAHH) of Beta vulgaris and chitinase (EP1) of Arabidopsis thaliana, respectively. And the 48kD protein showed 29% and 36% homology to the catalase of Brassica napus and enloase of Brassica rapa, respectively. So they can be used as the molecular markers of the embryo development-stage or a specific period. It can make a good sense for the further research on the molecular mechanism of somatic embryogenesis of E. Sativa or other plants.