Research Of The Accumulation Secondary Metabolites And Signal Transduction In Synthesis Pathway In Rhodiola Plant Inoculated By Endophytic Fungi

Rhodiola is a rare alpine plant,a China's traditional medicinal plants and that was used as folk medicine by alpine nation for thousands of years.P-tyrosol and salidroside is the main active ingredient in Rhodiola L.,which is the main component of the antioxidant.The main problem that the Rhodiola plants are facing is that the main ingredients need 5-7 years for reaching the required pharmaceutical standard.Using traditional methods can not solve this problem.The study is investigate the effect of anabolic pathways of metabolites in Rhodiola inculated with endophytic fungi in a wild Rhodiola ecological point.Using a experiment which is combined of inoculation,symbiosis and selection,obtaining 2 strains of endophytic fungi?ZPRa-R-1 and ZPRs-R-11?which have the ability of promoting growing from 347 strains endophytic fungi that separated from R.crenulata,R.angusta and R.sachalinensis.The results showed that,when ZPRa-R-1 and ZPRs-R-11 acted on Rhodiola seedings,caused a change in the signal-network pathway?eg,NO,SA and H₂O₂?firstly,Then,it caused the change of key enzyme's activity?eg,PAL,CA4H and TAL?,and ultimately,led to the accumulation of p-tyrosol salidroside and other products.The study had researched the composition of fungal elicitor.Getting mycelium and fermented liquid by fermention from endophytic fungi.Mycelium and fermented liquid which were added into the medium that was used to Rhodiola seedling,respectively.The results showed that that the mycelium can promote the accumulation of active ingredients in Rhodiola seedling effectively.By separating coarse constituents and promote test,determined that mycelia polysaccharide ia an active ingredient.Then,polysaccharides acted on Rhodiola seedling,researching the signal transduction pathway of accumulation of secondary metabolites induced by polysaccharide.The method that endophytic fungi was dissolved in hot water,than ethanol precipitation,was used to extract polysaccharide.The polysaccharide liquids by concentration of 59.2896 mg�L^-1,55.9593 mg�L^-1,respectively,added to the medium which was used to develop Rhodiola seedling.It was used for researching on signal transduction and the function of key enzyme induced by polysaccharides elicitor.By adding exogenous signals?SNP?SA and H₂O₂?and inhibitor?cPTIO?trans-CA and CAT?to research the metabolic pathways induced by fungi and signaling molecules'functions.The results showed that there has a significant changes of the contents of the major signaling molecules.When Rhodiola seedling induced by ZPRa-R-1's polysaccharide liquid,the maximum content of NO,SA and H₂O₂ was detected at 7 d,8 d and 8 d,respectively,and the maximum activity of PAL,CA4H and TAL was detected at 7 d,7 d and 8 d,respectively.Meanwhile,the maximum content of NO,SA and H₂O₂ was detected at 6 d,7 d and 8 d,respectively,and the maximum activity of PAL,CA4H and TAL was detected at 7 d,8 d and 8 d,respectively,in the Rhodiola seedling induced by ZPRs-R-11's polysaccharide liquid.Also found that the inducing effects of by fungus polysaccharide was mediated by NO which depends on the SA and H₂O₂,and NO was the upstream signaling molecule of the SA and H₂O₂.After that fungal elicitor were added,PAL's activity were higher than control group all the time;CA4H's activity was higher than the control group at 2-10 d and 5-10 d;TAL's activity was higher than the control group at 1-8 d and the whole period.This affected the key enzyme's activity of the phenylalanine metabolic pathways and tyrosine metabolism significantly,and showed that phenylalanine metabolic pathways and tyrosine metabolic pathway exist in the synthetic process of salidroside and p-tyrosol.Through this topic's research,reveals the endophytic fungi has causality with the host rhodiola's metabolism.The interactions of fungi and host,first of all,is the cause of metabolic network signal cascade amplifier,resulting in the change of key enzyme expression,eventually lead to the change of the accumulation of host plant's metabolites.This can provide research evidence for mining the endophytic fungi resources,findind out the method of accumulation of active ingredients in Rhodiola.