Site-specific recombination system to manipulate the plastid genome of higher plants

A method for CRE-mediated inversion of plastid genome segments comprising

• a) providing a moncistronic inversion vector comprising a selectable marker gene operably linked to nucleic acid which functions as a promoter in the plastid of a higher plant, said vector further comprising a heterologous nucleic acid encoding a protein of interest flanked by inverted lox sites, said selectable marker being present and expressed from a first reading frame and said heterologous nucleic acid being in an inverted position relative to said promoter and incapable of expression;
• b) providing CRE recombinase to the plastids of said plant, said CRE acting on said lox sites, thereby inverting said heterologous nucleic acid such that the protein of interest is produced in the plastids of said plant.