Expression patterns of the PPV-NK-GFP amplicon in transgenic 10.1.7 (A) and 10.6.1 (B) plants. Leaf positions (from the bottom of the plant) are indicated. Pictures were taken under UV light at 42 dpt (10.1.7, and leaves 8-10 of 10.6.1) and 50 dpt (leaves 11-16 of 10.6.1). Scale bar: 0.5 cm. Panel C summarizes data about the initiation of amplicon expression in 10.6.1 plants. Plants were classified in different groups according to their number of leaves at the time amplicon expression was detected. Bars represent the average and standard deviation of the positions of the first GFP-expressing leaves. The number of plants of each group is shown on top of the bars.