Studies On The Screening Of Elicitors And Metabolic Regulation In The Adventitious Root Culture Of Panax Ginseng And Panax Notoginseng

In this study,on the basis of established adventitious roots culture of Panax ginseng and Panax notoginseng,the studies about the application of elicitors in adventitious roots,verification of UGTPgX function to improve the content of ginsenosides and perfect the ginsenosides biosynthesis pathway,respectively,were conducted.Firstly,it investigated the effects of Aspergillus niger,Aspergillus flavus and Aspergillus oryzae as elicitors prepared from mycelium or fermentation broth?FM or FFB?on roots growth and ginsenosides production in roots.It found that the content of ginsenosides(29.90±4.67mg·g^-1)was significantly increased at 200mg·L^-11 A.niger challenged adventitious roots resulting in 3.52-fold increase over control roots compared with the other groups.In order to find the effective component of A.niger FM,it investigated the effects of polysaccharide and proteins separated from A.niger FM and the result showed that the highest ginsenosides content(20.37±0.98 mg·g^-1)was obtained upon elicitation with 100 mg·L^-1 protein,which was 2.83-fold of control group.Therefore,the effects of different fractions of protein on ginsenosides content were investigated.It found that 150 mg·L^-1 protein fragment more than 30 kDa significantly increased the ginsenosides contents(18.78±0.55 mg·g^-1),which was 1.90-fold of control group.The studies about the effects of the elicitors on the changes of ginsenosides and induction mechanism were also conducted,it found that the elicitor can significantly elevate the activities of signal molecules(PLA₂,Ca²⁺,SA,JA,NO and ABA)and the expression of defensive genes?PR10,PAL?and functional genes?GPS,FPS,SS,SE,DS,CYP716A47,CYP716A53v2,UGTAE2,UGT94Q2,UGTPg100 and UGTPg1?in the ginsenosides biosynthesis pathways,and induce the changes of the ginsenosides in the adventitious roots of P.ginseng.The culture of P.notoginseng was established and the study of elicitor was conducted.In order to enhance the content of bioactive compounds,the elicitors jasmonic acid?JA?and methyl dihydrojasmonate?MDJ?)in adventitious root culture were applied.It was observed that the highest total saponin content(71.94 mg·g^-1)was achieved after treatment with 5mg·L^-1 jasmonic acid,which was 2.09-fold and8.45-fold of native roots and control group respectively.ESI-MSⁿ analysis was performed,showing that six new compounds were present after treatment with the elicitors.Then the induction mechanism was investigated.It was found that the elicitor was able to enhance the autoimmunity through the peroxidase system in plant cells,and induced the change of the functional gene in the saponin synthesis pathway to increase the saponin content.In addition,the function of UGTPgX was verified and found that it can transfer Rd,Rh₁ to Rb₁,Rg₁ respectively.The above studies provide theoretical and technical support for the large-scale cultivation of P.ginseng and P.notoginseng adventitious roots and the industrialization of saponin.