The Rugulation Of Genes Associated With Triterpene Biosynthesis Of Psammosilene Tunicoides W.C. Wu Et C.Y. Wu

PsammosilenetunicoidesW.C. Wu et C.Y. Wu, a monospecific medical plant which was mainly destributed in Yunnan, Sichuan, Guizhou, Tibet. It is one of the components of "Yunnan Baiyao" and possess high pharmacological and economic value. However, the yield of Psammosilenetunicoides was declined rapidly in recent years for overdevelopment and slow growth as well as hard to artificial breeding. It has been listed as Second Grade conservation status.In this study, the hairy roots of Psammosilene tunicoides were induced by MeJA, Ag+, NaCl to detected change of biomass, transcript level as well as secondary metabolites.1. The expression of Squalene synthase and β-amyrin synthase were dramatically influenced by MeJA, Ag+and NaCl in related to control. Up-regulation of Squanlene Synthase were observed in MeJA, Ag+, NaCl treatments at1day post treatment (DPT), NaCl exerted the most strongest stimulation on hairy roots at1DPT (7.2folds) and Ag+(～5folds), MeJA (～4folds). At the rest cultural period, squalene synthase transcript was decreased sharply to be equal to control, it illuminated that the stimulation of exogenous elicitors is not everlasting. β-amyrin synthase transcript experienced a considerably fluctuated during this period, the expression level were up-regulated remarkably by elicitation of MeJA and NaCl (5.3folds,2.7folds respectively) while no obvious change were detected by Ag+.2. HPLC was employed to detect the change of secondary metabolites.14peaks (P1, P2, P3, P4, P5, P6, P7, P8, P9,P10,P11, P12, P13,P14) which existed both in control and three treatment groups were assigned as common peaks and2peaks (Pa,Pb) were assigned as characteristic peaks. Pa was detected in three treatment groups and fail to tested in control. However, Pb was only observed in MeJA-treated group and correlation analysis showed that it was correlated with the expression of β-amyrin synthase. Subsequently, those peaks which have significance differences compared with control among16peaks were marked by using student’s t-test (p<0.05). P1, P2, P8, P9, P10, P11, P12, P13, P14, Pa, Pb emerged significance difference when induced by MeJA, and P5, P6, P11, P14, Pa revealed significance in Ag+-induced group. Similarly, significance difference of P5, P6, P9were observed among NaCl treatment group.Meanwhile, in this project, we constructed overexpression vector of squalene synthase and β-amyrin synthase then transformed Psammosilene tunicoides via engineered agrobacterium. The culture systems of hairy roots were obtained.