Cloning And Characterization Of Glycosyltransferases CDNA From Rhodiola Sachalinensis And Establishment Of Transgenic Hairy Root Cultures

Salidroside has been identified as the most potent ingredient of the Chinese medicine herb, Rhodiola sachalinensis. A lot of modern pharmacological study show that salidroside were proved to be effect for treating patients suffering tumor, anoxia, microwave, virus, radiation or fatigue, the same time, it can improve immunity of human-being and prevent cardiovascular disease. So it has very high economic value and wide prospect of development for application. Now, the Rhodiola sachalinensis have been admitted by Chinese government as source of health care products and food. However, the resource of wild R. sachalinensis A. Bor has become less and less due to over-exploitation in order to meet the increasing demand. Extensive field cultivation is not successful. The cultivated plants, however, often contain less salidroside and are very sensitive to root rot diseases. These factors result in the price of salidroside is very expensive (5000RMB/g, 98%) , and the same time the amount of salidroside can't be satisfied with the demand of market.Therefore, in order to reduce the salidroside cost, a effective method of modern biotechnology can be adopted, such as genetic engineering, enzyme engineering or fermentation engineering and so on. The glycosylation reaction is the last step of biosynthesis salidroside from tyrosol. The reaction was catalyzed by glycosyltransferases. So if we increase the glycosyltransferase gene expression, the content of salidroside would have been raised in the following. In this study, after the plant materials were induced by methyl jasmonate, two glycosyltransferases complete cDNA gene was cloned by the method of CODEHOP and RACE, the two new glycosyltransferase named UGTC2 and UGTR were obtained from the callus and root of Rhodiola sachalinensis. Then the two gene and UGT1(cloned by my colleage) were heterogeneous expression and analysis in E. coli. The study show that all of the three enzymes can synthesis salidroside from tyrosol. And we can draw same conclusion in vitro and vivo proved by transgenic plants which were transformed by Agrobacterium rhizogenes. The content of salidroside is highest in UGTR transgenic plant detected by HPLC.In conclusion, cloning, expression and characterization the key gene in salidroside biosynthesis was studied. Then the transgenic hairy root of Rhodiola sachalinensis was established, which will lead a new perspective in produce salidroside in large-scale by bioreactor.