Figure 3.

Green-fluorescent protein-based bioreporting of fructose availability on isolated Populus x canescens cuticles. (A–E) Epifluorescent images of Populus x canescens CMs inoculated with Eh299(pP_fruB-gfp[AAV]). White scale bars represent 20 μm. Images are pseudo-colored merges of DAPI (blue) and GFP (green) channels; when fluorescence occurred in both channels the visible color is yellow. The blue channel mainly shows autofluorescence of the CM and DAPI counterstained, non-fructose reporting bacteria. (A) Area with many bacterial bioreporter cells but none that fluoresce to indicate exposure to fructose; the right-hand panel is a magnification of the photograph shown on the left-hand site, to show individual DAPI-stained bacteria. (B–D) Typical arrangements of bioreporting bacteria on isolated Populus x canescens CMs. (F) Light microscopy image of a Populus x canescens CM. Arrows point to sites with shed-off trichomes.