Figure 1.

Construction of a plastid transformation vector for targeted disruption of the ycf9 open reading frame. A, Physical and restriction map of the region of the tobacco chloroplast genome containing ycf9. Genes above the line are transcribed from the left to the right, genes below the line are transcribed in the opposite direction. Restriction sites relevant for cloning and RFLP analysis are indicated. B, Map of the plastid DNA targeting fragment in the transformation vector pIycf9. The selectable marker gene, a chimeric aadA, was inserted downstream of the ycf9 initiation codon and is transcribed in the same direction as ycf9 in the wild type. Restriction sites destroyed during construction by ligation of heterologous ends are shown in parentheses.