Patent ID: 7217860
Filing Date: 2007-05-15
Classification: C07K,C12N

Abstract:
1. A site specific recombination method for removal of predetermined nucleic acid sequences from the plastid genome, said method comprising: a) providing a first nucleic acid construct, said construct comprising a promoter being operably linked to a nucleic acid encoding plastid targeting transit sequence which is operably linked to a nucleic acid encoding a site specific recombinase having excision activity, said construct further comprising a first selectable marker encoding nucleic acid having plant specific 5′ and 3′ regulatory nucleic acid sequences; b) providing a second DNA construct, said second construct comprising an second selectable marker encoding nucleic acid sequence which is flanked by excision sites, said second construct optionally containing a gene of interest, said second construct further comprising flanking plastid targeting nucleic acid sequences which facilitate homologous recombination into said plastid genome; c) introducing said second DNA construct into a plant cell; d) culturing said plant cell of step c) in the presence of a selection agent, thereby selecting for those plant cells expressing the proteins encoded by said second DNA construct; e) introducing said first DNA construct into plant cells from step d) in the presence of a selection agent and selecting those plant cells expressing proteins encoded by said first construct, which when present said site specific recombinase acts on said excision sites, thereby removing said sequence flanked by said excision sites from said plastid genome.