title: [Effect of endophytic fungi on expression amount of key enzyme genes in saponins biosynthesis and Eleutherococcus senticosus saponins content].
abstract: OBJECTIVE
  To analyze the effect of endophytic fungi on expression amount of key enzyme genes SS (squalene synthase gene), SE (squalene epoxidase gene) and bAS (beta-amyrin synthase gene) in saponin biosynthesis and saponins content in Eleutherococcus senticosus.
  
  
  METHODS
  Wound method was used for back meeting the endophytic fungi to E. senticosus. With GAPDH as internal control gene, the expression of key enzyme genes was detected by real time PCR method. E. senticosus saponins content was measured by spectrophotometry method.
  
  
  RESULTS
  When wound method back meeting P116-1a and P116-1b after 30 d, the expression content of SS improved significantly (P < 0.05), however the back meeting of P109-4 and P312-1 didnt change the expression of SS. After that SS expression showed reduction-equality-reduction varying trend. Thirty days after back meeting P312-1, the expression content of SE improved significantly (P < 0.05). Ninty days after back meeting P116-1b and P312-1, the expression content of SE improved significantly to 130%,161%, respectively (P < 0.05). After 120 d, back meeting four endophytic fungi, the expression of SE were significantly higher than the control (P < 0.05). Back meeting four endophytic fungi form 60 d to 120 d, the expression of bAS was significantly higher than the control (P < 0.05). The back meeting four endophytic fungi improved E. senticosus saponins content significantly (P < 0.05).
  
  
  CONCLUSIONS
  Endophytic fungi P116-1a, P116-1b, P1094 and P312-1 significantly effected the expression of key enzyme genes SS, SE and bAS and then affected E. senticosus saponins content. Among the genes, bAS was key target gene.
authors.affiliation: College of Life Science, Hebei United University, Tangshan 063000, China. xingzhaobin@yahoo.com.cn
authors.forename: Zhaobin
authors.initials: Z
authors.lastname: Xing
authors.forename: Yuehong
authors.initials: Y
authors.lastname: Long
authors.forename: Fengyun
authors.initials: F
authors.lastname: Lao
authors.forename: Shan
authors.initials: S
authors.lastname: He
authors.forename: Nengsong
authors.initials: N
authors.lastname: Liang
authors.forename: Baocai
authors.initials: B
authors.lastname: Li
mesh_terms: D028001:Eleutherococcus / Q000737:chemistry / Q000378:metabolism / Q000382:microbiology*; D060026:Endophytes / Q000502:physiology*; D013186:Farnesyl-Diphosphate Farnesyltransferase / Q000235:genetics; D005658:Fungi / Q000502:physiology*; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D019751:Intramolecular Transferases / Q000235:genetics; D012503:Saponins / Q000032:analysis* / Q000096:biosynthesis; D050603:Squalene Monooxygenase / Q000235:genetics
chemical_list: D012503:Saponins; D050603:Squalene Monooxygenase; D013186:Farnesyl-Diphosphate Farnesyltransferase; D019751:Intramolecular Transferases; C039924:2,3-oxidosqualene-beta-amyrin-cyclase