The use of the PMI/mannose selection system to recover transgenic sweet orange plants (Citrus sinensis L. Osbeck)

Author(s)

Boscariol‚ RL ; Almeida‚ WAB ; Derbyshire‚ M. ; Mourao Filho‚ FAA ; Mendes‚ BMJ

• Document type: Journal article
• Source: Plant Cell Reports; v. 22, n. 2, p. 122-128, 2003.

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. (AU)

• FAPESP's process: 99/04073-3 - Optimization of in vitro regeneration systems and establishment of a genetic transformation protocol for Citrus sp.
• Grantee: Beatriz Madalena Januzzi Mendes
• Support Opportunities: Genome Research Grants