title: Screening for differentially expressed genes in endophytic fungus strain 39 during co-culture with herbal extract of its host Dioscorea nipponica Makino.
abstract: Strain 39 is an endophytic fungus which was isolated from Dioscorea nipponica Makino (DNM). After Strain 39 co-cultured with ethanol extract of DNM rhizomes for several days, the content of saponins in this culture mixture would be obviously increased. To analyze the mechanism of this microbial transformation, we used the differential display reverse transcription polymerase chain reaction (DDRT-PCR) method to compare the transcriptomes between Strain 39 cultured in normal PD medium and in PD medium which added ethanol extract of DNM rhizomes. We amplified 29 DDRT-PCR bands using 12 primer combinations of three anchored primers and five random primers, and six bands were re-amplified. Analysis of real-time PCR and sequence alignment showed that three clones were up-regulated in sample group: squalene epoxidase, squalene synthase, and catalase, one clone was expressed only in sample group. The possible roles and origins of the above genes were discussed, and the molecular mechanism of Strain 39 biotransformation was speculated. This study is the first report of the molecular biotransformation mechanism of saponins production by endophytic fungus of DNM.
authors.affiliation: Pharmacy College, Heilongjiang University of Chinese Medicine, 24 Heping Road, Harbin, 150040, China, goodluckdd81@126.com.
authors.forename: Chang-Hong
authors.initials: CH
authors.lastname: Ding
authors.forename: Xiao-Wei
authors.initials: XW
authors.lastname: Du
authors.forename: Ying
authors.initials: Y
authors.lastname: Xu
authors.forename: Xiao-Meng
authors.initials: XM
authors.lastname: Xu
authors.forename: Jin-Chao
authors.initials: JC
authors.lastname: Mou
authors.forename: Dan
authors.initials: D
authors.lastname: Yu
authors.forename: Jun-Kai
authors.initials: JK
authors.lastname: Wu
authors.forename: Fan-Jia
authors.initials: FJ
authors.lastname: Meng
authors.forename: Yan
authors.initials: Y
authors.lastname: Liu
authors.forename: Wan-Li
authors.initials: WL
authors.lastname: Wang
authors.forename: Li-Juan
authors.initials: LJ
authors.lastname: Wang
mesh_terms: D027742:Dioscorea / Q000737:chemistry / Q000382:microbiology*; D060026:Endophytes / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics* / Q000378:metabolism; D005658:Fungi / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal; D010936:Plant Extracts / Q000378:metabolism; D012503:Saponins / Q000378:metabolism
chemical_list: D005656:Fungal Proteins; D010936:Plant Extracts; D012503:Saponins