Studies On The Bioreactor Culture And Elicitor Treatment Of Adventitious Roots Of Glycyrrhiza Uralensis

Glycyrrhiza uralensis is a kind of perennial leguminous caudex herb,the roots and rhizomes of it are widely used in the traditional Chinese medincine and it has been ‘Nine to ten grass’ said.Morever,Glycyrrhiza uralensis is also a homologous plant for food and medicine,the glycyrrhizic acid,as its main active components,is a widely used sweetening agent in food industry and is 250 times sweeter than the sugar.Furthermore,the extracts of the licorice also can be used in the chemical industry and other fields.So,they have a great market demand in domestic and international.In this study,taking advantage of the established systems for cultivating adventitious roots of Glycyrrhiza uralensis,we conducted studies about adventitious roots culture in bubble bioreactor system.In order to further elevate the contents of bioactive compounds in the adventitious roots,we also conduct the studies about the effects of the elicitors.We optimized the bubble bioreactor with three different angles(60 °,90 °,180 °)and the culture conditions of Glycyrrhiza uralensis adventious roots in bubble bioreactor culture.The results showed that,the most efficient bioreactor for cultivation of the Glycyrrhiza uralensis adventitious roots was the cone-type bioreactors(with the 90 °),and the optimal culture conditions we obtained in experiments were 0.4-0.6-0.4 vvm aeration rate,4% sucrose,1 MS salt strength.In order to further elevate the contents of bioactive compounds in the adventitious roots,we also conduct the studies about the effects of the elicitors.We investigate the effects of salicylic acid,Aspergillus niger,α-linolenic,linoleic,Pichia pastoris,Meyerozyma guilliermondii on the biomass and metabolites accumulation in the adventitious roots of Glycyrrhiza uralensis.The results indicate that Meyerozyma guilliermondii can effectively increase the contents of metabolites in the adventitious roots of Glycyrrhiza uralensis,and the content of total flavonoid(9.89 mg·g-1)、 glycyrrhizic acid(0.92 mg·g-1)、 glycyrrhetinic acid(0.64 mg·g-1)and polysaccharide(89.95 mg·g-1)at 200 mg·L-1 Meyerozyma guilliermondii treatment was 3.76,5.41,4.57 and 2.58-fold higher than the control group.We also conduct the studies about the effects of the elicitors on the changes of bioactive compounds,the accumulation of signal molecules,the activities of anti-oxidative enzymes,the expression of defensive genes and functional genes in the glycyrrhizic acid biosynthesis pathways,the results indicate that the elicitor can significantly elevate the activities of signal molecules(PLA2,Ca2+,SA,JA,NO and ET)and the activities of antioxidant enzymes(SOD,POD and CAT),also the expression of defensive genes(PDF1.2,NOS,PR1,PAL,LOX,ABA8)and functional genes(HMGR,GPS,FPS,SQS,SE,β-AS,CYP88D6 and CYP72A154)in the glycyrrhizic acid biosynthesis pathways,and induce the changes in the bioactive compounds in the adventitious roots of Glycyrrhiza uralensis.