Comparison of PPV HC-Pro and BMYV-IPP P0 suppressor efficiency. Overlay capture of a plain black/white photograph and the overlaid efficiency image from GFP-transgenic leaf samples agroinoculated with pBinGFP/pBin (control, left side of leaf midrib) and pBinGFP/pBinHCPro or pBinGFP/pBinP0, respectively (right side of leaf midrib). Samples are taken on 3, 5, 7, 13 and 21 dpi. Colour bars show the average efficiency and min. and max. values between different time points are different but always identical for samples at the same time point. The white arrow indicates an area of completely GFP-silenced tissue (silencing ring) characteristic for P0 suppressor activity.