title: The use of the PMI/mannose selection system to recover transgenic sweet orange plants (Citrus sinensis L. Osbeck).
abstract: A new method for obtaining transgenic sweet orange plants was developed in which positive selection (Positech) based on the Escherichia coli phosphomannose-isomerase (PMI) gene as the selectable marker gene and mannose as the selective agent was used. Epicotyl segments from in vitro-germinated plants of Valencia, Hamlin, Natal and Pera sweet oranges were inoculated with Agrobacterium tumefaciens EHA101-pNOV2116 and subsequently selected on medium supplemented with different concentrations of mannose or with a combination of mannose and sucrose as a carbon source. Genetic transformation was confirmed by PCR and Southern blot. The transgene expression was evaluated using a chlorophenol red assay and isoenzymes. The transformation efficiency rate ranged from 3% to 23.8%, depending on cultivar. This system provides an efficient manner for selecting transgenic sweet orange plants without using antibiotics or herbicides.
authors.affiliation: Laboratório de Biotecnologia Vegetal, Centro de Energia Nuclear na Agricultura, Universidade de São Paulo, Piracicaba 13 400-970 São Paulo, Brazil.
authors.forename: R L
authors.initials: RL
authors.lastname: Boscariol
authors.forename: W A B
authors.initials: WA
authors.lastname: Almeida
authors.forename: M T V C
authors.initials: MT
authors.lastname: Derbyshire
authors.forename: F A A
authors.initials: FA
authors.lastname: Mourão Filho
authors.forename: B M J
authors.initials: BM
authors.lastname: Mendes
mesh_terms: D032084:Citrus sinensis / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development; D046508:Culture Techniques; D005632:Fructose / Q000494:pharmacology; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D005819:Genetic Markers / Q000235:genetics; D008358:Mannose / Q000494:pharmacology*; D008359:Mannose-6-Phosphate Isomerase / Q000235:genetics* / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development; D013395:Sucrose / Q000494:pharmacology
chemical_list: D005819:Genetic Markers; D005632:Fructose; D013395:Sucrose; D008359:Mannose-6-Phosphate Isomerase; D008358:Mannose