Abstract：Abstract 3-Hydroxy-3-methylglutaryl-CoA reductase (HMGR) and 1-deoxy-D-xylulose 5-phosphate reductoisomerase (DXR) catalyse the reaction of 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) to mevalonic acid (MVA) which is the first committed enzyme in the MVA pathway in the cytosol, and the reaction of 1-deoxy-D-xylulose 5-phosphate (DXP) to 2-C-methyl-D-erythritol 4-phosphate (MEP) which is the first committed enzyme in the MEP pathway in the plastid, respectively. For the study of the effect of over-expressing TwHMGR(KU246037.1) and TwDXR(KJ174341.1) genes on the production of secondary metabolites in Tripterygium wilfordfii, the expressing vector of TwHMGR and TwDXR was constructed and integrated into the genome of T. wilfordfii via Agrobacterium-mediated transformation methods. Three transgenic hairy roots were screened and confirmed respectively. The results of qRT-PCR showed that the expressing level of target genes in transgenic hairy roots were significantly higher than those in non-transgenic control, with highest levels at 4.73 times and 5.81 times, respectively. According to the results of high-performance liquid chromatography (HPLC), the contents of wilforgine, wilforine and triptolide of transgenic hairy roots significantly higher than controls. The results showed that the increase of TwHMGR gene and TwDXR gene expression could improve the yield of terpenoids secondary metabolites of T. wilfordii. This study provides the basis for the further use of metabolic engineering methods to improve the content of secondary metabolites and to elucidate of terpenoid biosynthetic pathway in T. wilfordii.
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