Over-expressing root-specific β-amyrin synthase gene increases glycyrrhizic acid content in hairy roots of glycyrrhiza uralensis / 中草药·英文版

ABSTRACT

Objsective: Glycyrrhizia uralensis, one of the most widely-used traditional Chinese medicines, is mainly cropped in China. However, many cultivars are less in glycyrrhizic acid than Chinese Pharmacopoeia requires. In this paper, we improved glycyrrhizic acid by regulating β-amyrin synthase gene (GuBAS). Methods: Tobacco root-specific promoter TobRB7 and GuBAS cDNA were obtained and combined with linearized pCAMBIA1305.1 to construct root-specific plant expression vector which was later transformed into Agrobacterium rhizogenes ACCC10060 by electrotransformation. The cotyledons and hypocotyls of G. uralensis were infected by the recombinant A. rhizogenes ACCC10060 to induce hairy roots. The GA content was quantified by HPLC. Results: The PCR and sequencing results both showed that three transgenic hairy root lines were obtained. The copy number of GuBAS in these transgenic hairy roots was intended by qRT-PCR to be 3, 7, and 4. GA was detected by HPLC, and the results showed that GA was present in the three transgenic hairy roots, while absent in wild hairy roots. Conclusion: Over-expressing GuBAS root-specifically in hairy roots of G. uralensis enhanced GA accumulation.