Patent ID: 8841511
Filing Date: 2014-09-23
Classification: C12N

Abstract:
1. A site specific recombination method for removal of heterologous nucleic acid sequences from the plastid genome, said method comprising: a) providing a transplastomic plant cell, said plastids of said cell comprising a heterologous nucleic acid sequence flanked by excision sites and a nucleic acid sequence encoding at least one foreign gene of interest which is not flanked by excision sites; b) providing a DNA construct, said construct comprising a promoter operably linked to a nucleic acid encoding a protein having excision activity on the excision sites of step a) said construct comprising a sequence encoding a plastid transit peptide sequence and a selectable marker gene flanked by plant specific 5′ and 3′ regulatory regions; c) introducing the construct of step b) into the plant cell of step a) such that said DNA construct enters said cell, but does not integrate into the nuclear genome of a plant cell, whereby the proteins encoded thereby are transiently expressed in said plant cell for a suitable time period, said proteins catalyzing the excision of the heterologous sequence from the plastids in the plant cell of step a), thereby removing said heterologous sequence; and d) regenerating a plant from the cell of step c) without previously selecting for the excision of the heterologous sequence, said plant lacking both said heterologous nucleic acid sequence and said protein having excising activity.