Figure 2.

ECR in RuvC-expressing plants. (Top) A schematic representation of the constructs used for the ECR assay is shown. Homologous recombination between two defective GUS genes, one of which is deleted in the 3′ region (3′ΔGUS) and one in the 5′ region (5′ΔGUS), gives rise to a GUS active gene (the blue box on the Top Right and the blue spots in the Middle and Bottom). (Middle and Bottom) Pictures of tobacco leaves (cv. Samsun-NN) that underwent bombardment and staining for GUS activity are shown, together with the average number of blue spots per leaf and the SEM in parenthesis. (A–C) Bombardment of the 3′ΔGUS or of the 5′ΔGUS plasmid alone (A) and of the 35S-GUS gene (B), and cotransformation of the 3′ΔGUS and 5′ΔGUS-containing plasmids into WT tobacco (C). (D) Cotransformation of the 3′ΔGUS and 5′ΔGUS plasmids in transgenic plants expressing RuvC.