Studies On Metabolism Regulation Of Adventitious Root In Glycyrrhiza Uralensis Fisch And Panax Ginseng C.A. Mey As Well As Functional Study Of Glycosyltransferase UGT71A29

Both Glycyrrhiza uralensis and Panax ginseng are widely used medicinal materials.In this thesis,the root system of G.uralensis and P.ginseng was established.The methods of adding non-biological and biological elicitors were used to regulate the metabolism and mechanism of glycyrrhizic acid and ginsenside in the cultures,and the content of active ingredients was significantly improved.In addition,the study of glycosyltransferase function in ginseng further reveals the ginsenoside biosynthesis pathway.1.The RAPD method was used to confirm that the adventitious roots of G.uralensis had high genetic stability.Four kinds of G.uralensis adventitious roots were established.Histological analysis showed that the fibers,ducts,calcium oxalate and cork cells of adventitious roots of G.uralensis were smaller than those of cultivated G.uralensis.The content of glycyrrhizic acid,glycyrrhetinic acid and total flavonoids was the highest in cultivated G.uralensis,followed by indirect induced G.uralensis adventitious roots.Principal component analysis divided cultivated G.uralensis and G.uralensis adventitious root into two categories.Correlation analysis showed that glycyrrhizic acid content was significantly positively correlated with HMGR andβ-AS expression.The study also found that adventitious roots of G.uralensis have better anti-inflammatory activity.2.Abiotic elicitors were used to regulation the adventitious roots of G.uralensis.Compared with single induction,mixed induction of methyl jasmonate（MJ）and phenylalanine（PHE）can significantly increase glycyrrhizic acid(0.36 mg·g^-1)and glycyrrhetinic acid(0.22 mg·g^-1)in adventitious roots of G.uralensis.Through transcriptome sequencing and correlation analysis,it was speculated that MJ interacts with the AP2-EREBP family transcription factor Cluster-30944.55070,and finally regulates the content of glycyrrhizic acid and glycyrrhetinic acid by regulating FPS,SE and UGT（Cluster-30944.25725）genes.3.The biological elicitor is used to regulate the adventitious roots of G.uralensis.responsive protein LSP1 that isolated and purificated from Meyerozyma guilliermondii can significantly increase the content of active ingredients in G.uralensis,total flavonoids(3.46 mg·g^-1),glycyrrhizic acid(0.41 mg·g^-1),glycyrrhetinic acid(0.41 mg·g^-1)and polysaccharide(94.49 mg·g^-1)were 1.6,3.4,2.4,and 2.0 times of the control group,respectively.LSP1 significantly increased the content of triterpenoid saponins in G.uralensis by stimulation signal molecules,MAPK,resistance proteins and functional genes.4.Metabolic regulation of ginseng adventitious roots was carried out by using ginseng pathogens and their resistant bacteria.The study found that 200 mg·g^-1Penicillium sp.YJM-2013 can significantly increase the ginsenoside content of ginseng adventitious roots(48.95 mg·g^-1),which is 2.59 times that of the control group.Penicillium sp.YJM-2013 increased the content of ginsenosides in the adventitious roots of ginseng ginseng by activating the signaling molecules,transcription factors PgWRKY 1,2,3,5,7,9 and the expression of functional genes.5.The function of the glycosyltransferase UGT71A29 isolated from ginseng was verified.Through in vitro by Saccharomyces cerevisiae and in vivo in ginseng cells found that UGTPg71A29 can catalyze the glycosylation of Rh₁ at position 20 to form Rg₁,and can also catalyze the glycosylation of Rd to form Rb₁.Homology modeling,molecular dynamics,and mutation analysis revealed that glutamine 283 is a key catalytic site for UGTPg71A29.This study laid the foundation for the production of glycyrrhizic acid and ginsenoside by biotechnology.