Fig. 1.

Generation of transplastomic tobacco plants with a disrupted psaI gene. (A) Physical maps of the wild-type plastid genome (plastome) and the transformed plastome harbouring the selectable marker gene aadA to disrupt the psaI gene (Nt-∆psaI). (B) Confirmation of plastid transformation and integration of the aadA marker via homologous recombination by Southern blotting. Total DNA was digested with the restriction enzymes XhoI and HindIII, generating a restriction fragment of 3371 bp in the wild type and a fragment of 4471 bp in four representative transplastomic psaI knockout lines. (C) Confirmation of homoplasmy of the transplastomic plants by seed assays on antibiotic-free and antibiotic-containing media. Only one example line (Nt-∆psaI-5) is shown. See text for details. (D) Northern blot analysis to examine the expression of psaI and the three other genes in the operon.