High Levels of Ginsenosides Production Associated with rolC Gene Transcription and Expression in Ginseng Hairy Roots

摘要

Background and Objective: Ginsenosides are considered as key components to mediate the pharmacological activity of the ginseng. It is great significance for obtaining ginseng extract containing high concentration of ginsenosides. This study aimed to investigate the effects of rolC gene on ginsenosides content in ginseng hairy roots. Materials and Methods: Genomic DNA was extracted from ginseng hairy roots of Panax ginseng C.A. Meyer ( P. ginseng ) and rolC gene was cloned for pMD18-T/rolC recombinant plasmid construction. Then Agrobacterium rhizogenes A4 harboring rolC gene was used to infect the ginseng hairy roots obtained after inoculating root of P. ginseng . The mRNA and protein of rolC gene were then detected and the different types of ginsenosides were evaluated. Results: A 543 bp length DNA was cloned from ginseng hairy roots and pMD18-T/rolC recombinant plasmid was successfully constructed for rolC gene introduction. Increased growth ratio was found in rolC gene expressed ginseng hairy roots than 3 years old ginseng roots. Moreover, the highest total ginsenosides level (16.13 mg g^?1) was found in ginseng hairy roots at 4 weeks, which was increased to 355% than 3 years old ginseng (4.54 mg g^?1). Increased levels of both ginsenosides Rb (Rb1, Rb2, Rc, Rd) and Rg (Re, Rf and Rg1) subgroup were found from 2-8 weeks in ginseng hairy roots and 4 week was the optimal time point for the highest ginsenosides content. Conclusion: Introduction of rolC gene could promote ginsenosides content in ginseng hairy roots, which would be beneficial for obtaining ginseng extract containing high concentration of ginsenosides.