title: Introgression of Swertia mussotii gene into Bupleurum scorzonerifolium via somatic hybridization.
abstract: BACKGROUND
  The wild herb Swertia mussotii is a source of the anti-hepatitis compounds swertiamarin, mangiferin and gentiopicroside. Its over-exploitation has raised the priority of producing these compounds heterologously. Somatic hybridization represents a novel approach for introgressing Swertia mussotii genes into a less endangered species.
  
  
  RESULTS
  Protoplasts derived from calli of Bupleurum scorzonerifolium and S. mussotii were fused to produce 194 putative hybrid cell lines, of which three (all derived from fusions where the S. mussotii protoplasts were pre-treated for 30 s with UV light) later differentiated into green plants. The hybridity of the calli was confirmed by a combination of isozyme, RAPD and chromosomal analysis. The hybrid calli genomes were predominantly B. scorzonerifolium. GISH analysis of mitotic chromosomes confirmed that the irradiation of donor protoplasts increased the frequency of chromosome elimination and fragmentation. RFLP analysis of organellar DNA revealed that mitochondrial and chloroplast DNA of both parents coexisted and recombined in some hybrid cell lines. Some of the hybrid calli contained SmG10H from donor, and produced swertiamarin, mangiferin and certain volatile compounds characteristic of S. mussotii. The expression of SmG10H (geraniol 10-hydroxylase) was associated with the heterologous accumulation of swertiamarin.
  
  
  CONCLUSIONS
  Somatic hybrids between B. scorzonerifolium and S. mussotii were obtained, hybrids selected all contained introgressed nuclear and cytoplasmic DNA from S. mussotii; and some produced more mangiferin than the donor itself. The introgression of SmG10H was necessary for the accumulation of swertiamarin.
authors.affiliation: The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Sciences, Shandong University, Shanda Nanlu 27#, Jinan 250100, China.
authors.forename: Junfeng
authors.initials: J
authors.lastname: Wang
authors.forename: Cuizhu
authors.initials: C
authors.lastname: Zhao
authors.forename: Chang
authors.initials: C
authors.lastname: Liu
authors.forename: Guangmin
authors.initials: G
authors.lastname: Xia
authors.forename: Fengning
authors.initials: F
authors.lastname: Xiang
mesh_terms: D001483:Base Sequence; D029972:Bupleurum / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D003577:Cytochrome P-450 Enzyme System / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism; D006822:Hybrid Cells / Q000378:metabolism / Q000502:physiology; D006824:Hybridization, Genetic; D057888:Iridoid Glucosides / Q000378:metabolism; D008969:Molecular Sequence Data; D010946:Plants, Medicinal / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011753:Pyrones / Q000378:metabolism; D029967:Swertia / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D018609:Tibet; D015854:Up-Regulation; D044004:Xanthones / Q000378:metabolism
chemical_list: D057888:Iridoid Glucosides; D011753:Pyrones; D044004:Xanthones; C012997:gentiopicroside; C013592:mangiferin; C013270:swertiamarin; D003577:Cytochrome P-450 Enzyme System; C081675:geraniol 10-hydroxylase