Fig. 3.

Activity of siRNAs with slice site mutations was consistent with an RNAi mode-of-action. dsRNA (20 μl dsRNA at 1 μg/μl in 0.01% Silwet L77) was applied and evenly spread onto leaves 3 and 4 of 14-day plants followed by abrasion with #600 grit sandpaper (2 plants per treatment). The treated leaves are circled. siRNAs are diagrammed as guide (red) and passenger (blue) strands, and base pairings indicated by grey vertical bars. A loop is shown where an unpaired base is present (GFP 21/22 and CheI 21/22). Green or orange dots indicate mutated bases, and mutations at positions 9–11 or 10–12 target the presumptive slice sites. siRNA sequences are shown in Table 1. a A representative plant treated with GFP-targeting or control siRNAs. The plants were photographed under UV lights at 5 dat. b A representative plant treated with MgCheI-targeting or control siRNAs. The plants were photographed under white LED lights at 5 dat. Control, 24 nt dsRNA from A. palmeri EPSPS