Fig. 3

Optical sections of 4 day old Arabidopsis seedling roots incubated for 24 h with azido-monosaccharides. Seedlings were incubated with 25 μM Ac₄GlcNAz (a), followed by labeling through a copper-catalyzed click reaction with Alexa Fluor® 488 alkyne. Seedling roots treated with Alexa Fluor® 488 alkyne-labeled Ac₄GlcNAz (25 μM, 24 h) (b, d) were counterstained; Propidium Iodide (PI, 0.05 %) to visualize cell walls (c, d). Yellow color indicates overlap of the two dyes (d). Scale bars = 50 μm. As a control, seedlings were treated with 0.01 % DMSO (e). Alternatively, seedlings were incubated with 25 μM Ac₄FucAz (f), 100 μM Ac₃ArabAz (g), or 25 μM Ac₄ManNAz (h) (see Additional file 14 for high resolution)