The Interaction Effect Of Endophytic Fungi And Host Tripterygium On The Triptolide Biosynthesis

Tripterygium wilfordii Hook.f.is a traditional medicinal plant.Triptolide,a diterpenoid metabolite,is the most noteworthy component of this herb,with a range of pharmacological functions such as anti-flammatory,immunomodulatory,anti-neoplastic and anti-angiogenic.However,this bioactive compound is usually produced in extremely small quantity in normal T.wilfordii plant,which has been a major obstacle to the clinical use.In this study,the interaction mechanism between the endophytic fungus and T.wilfordii was studied by the methods of biotic elicitation,synergistic effect and biotransformation in order to reveal their respective triptolide biosynthesis characteristics in the symbiont.The results are listed as follows:1.To screen the triptolide-producing endophytic fungi,a total of 22 strains of fungi were isolated from the medicinal plant Tripterygium wilfordii.The fermentation productions of all fungal isolates were preliminary analyzed by HPLC.A potential triptolide-producing fungus,NS-12 was further analyzed by HPLC-MS/MS,and the results showed that this stain possessed of a retention time and ion peaks identical with the authentic triptolide standards.The isolate NS-12 was classified as Penicillium Steckii based on the molecular phylogenetics inferred from ITS-rDNA sequence analysis with the sequence similarity values of 99%.2.When the NS-12 endophyte hosted in the tissue culture of Tripteiygium Wilfordii,the experiment results proved that this strain not only promoted the growth of Tripterygium Wilfordii but also increased the Triptolide content of host plant.Additionally,NS-12 strain was also found to improve the absorption of various nutrient elements(such as N,P,C,K)for the host plant.3.To reveal the inter-induction effects between the NS-12 endophytic fungus elicitation and host Tripterygium Wilfordii,they were both treated as biological elicitors,respectively.For the NS-12 elicitors,it’s effect on cell growth and triptolide production of Tripterygium Wilfordii was Y2>G2>Y3>G3>Y1>G1(G1 is Low concentration of mycelium elicitor 30mg/L,G2 is the mediumconcentration of mycelium elicitor 60mg/L,G3 is the high concentration of mycelium elicitor 100mg/L,Y1 is the low concentration of fungus medium elicitor 30mg/L,Y2 is the concentration of fungus medium elicitor 60mg/L,and Y3 is a high concentration of fungus medium elicitor 100mg/L).For the Tripteiygium Wilfordii elicitors,it’s effect on cell growth and triptolide production of NS-12 endophytic fungus was Y3>G3>Y1>G1>G2>Y2(G1 is induction of callus sub low concentration 30mg/L;G2 is the elicitor concentration in callus 60 mg/L;G3 is high concentration induced callus 100 mg/L.Y1 is low concentration of callus culture liquid elicitors 30 mg/L;Y2 is the medium concentration of callus culture liquid elicitors 60 mg/L;Y3 is the higher the concentration of callus culture liquid elicitors 100 mg/L.4.The biotransformation of interaction of Endophytic fungi and host Tripterygium wilfordii show that:The callus and fungusl’s culture fluid of biotransformation can promote cell growth and the release of Triptolide.