Establishment of a Cell Suspension Culture of Kalopanax Septemblobus and Biosynthesis of Saponin Enhanced by Elicitation
Background : Even though Kalopanax septemlobus has been used as a traditional crude drug and a dietary health supplement, the wild or cultivated sources of this plant are not economically feasible. Methods and Results : In this study, a cell suspension culture of K. septemlobus using friable calli was established to make source sustainable. A cell suspension culture of K. septemlobus was incubated during 15th day and reached the maximum capacity of saponin production after day 6 (0.42㎍/㎎ of fresh weight). To investigate the effect of elicitors on the product yield of saponins in the K. septemlobus suspension culture, we treated methyl-jasmonic acid and coronatine (COR), which are known as signal molecules. COR positively regulates the total saponin production in the cell suspension of K. septemlobus at a concentration of 1 μM compared with the mock-treated control. Furthermore, the expression of beta-amyrin synthase (KsbAS) was induced by elicitation of COR. Consequently, oleanane-type triterpene saponins, oleanolic acid (2.369 ± 0.98 ㎍/㎎ of extract) were accumulated by only COR. Conclusion : From the above results, COR is an efficient elicitor for inducing saponin biosynthesis in a K. septemlobus suspension culture. Gene expression pattern and analysing precursor of triterpenoid saponin indicate that major target gene of COR in K. septemlobus suspension culture is KsbAS.