title: Auto-excision of selectable marker genes from transgenic tobacco via a stress inducible FLP/FRT site-specific recombination system.
abstract: Antibiotic resistance marker genes are powerful selection tools for use in plant transformation processes. However, once transformation is accomplished, the presence of these resistance genes is no longer necessary and can even be undesirable. We herein describe the successful excision of antibiotic resistance genes from transgenic plants via the use of an oxidative stress-inducible FLP gene. FLP encodes a recombinase that can eliminate FLP and hpt selection genes flanked by two FRT sites. During a transformation procedure in tobacco, transformants were obtained by selection on hygromycin media. Regenerants of the initial transformants were screened for selective marker excision in hydrogen peroxide supplemented media and both the FLP and hpt genes were found to have been eliminated. About 13-41% of regenerated shoots on hydrogen peroxide media were marker-free. This auto-excision system, mediated by the oxidative stress-inducible FLP/FRT system to eliminate a selectable marker gene can be very readily adopted and used to efficiently generate marker-free transgenic plants.
authors.affiliation: Biosafety Division, National Academy of Agricultural Science, Rural Development Administration, Suwon, South Korea.
authors.forename: Hee-Jong
authors.initials: HJ
authors.lastname: Woo
authors.forename: Hyun-Suk
authors.initials: HS
authors.lastname: Cho
authors.forename: Sun-Hyung
authors.initials: SH
authors.lastname: Lim
authors.forename: Kong-Sik
authors.initials: KS
authors.lastname: Shin
authors.forename: Si-Myung
authors.initials: SM
authors.lastname: Lee
authors.forename: Ki-Jong
authors.initials: KJ
authors.lastname: Lee
authors.forename: Dong-Hern
authors.initials: DH
authors.lastname: Kim
authors.forename: Yong-Gu
authors.initials: YG
authors.lastname: Cho
mesh_terms: D000613:Aminobutyrates / Q000494:pharmacology; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002934:Cinnamates / Q000494:pharmacology; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D005822:Genetic Vectors; D006861:Hydrogen Peroxide / Q000494:pharmacology; D006921:Hygromycin B / Q000031:analogs & derivatives / Q000494:pharmacology; D018384:Oxidative Stress; D030821:Plants, Genetically Modified / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D045522:Recombinases / Q000235:genetics*; D011995:Recombination, Genetic; D014026:Nicotiana / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*
chemical_list: D000613:Aminobutyrates; D000900:Anti-Bacterial Agents; D002934:Cinnamates; D045522:Recombinases; D006921:Hygromycin B; C026273:hygromycin A; C003121:phosphinothricin; D006861:Hydrogen Peroxide