Fig. 6

In vivo pollen germination at 85% relative humidity in the FLA14 knockout mutant (fla14) of Arabidopsis. a, e Alexander staining of dehiscent anthers from wild-type (WT) (a) and FLA14 knockout mutant (fla14) (e) plants. b, f Fluorescence microscopy images of a WT anther (b) and a fla14 anther (f) at the time of dehiscence stained with aniline blue. Pollen tubes germinating and elongating within a fla14 anther (f) are labeled with aniline blue to show callose. c, g Scanning electron micrographs of dehiscent anthers from WT (c) and fla14 (g) plants. d, h Scanning electron micrographs of pollen grains and pollen tubes from WT (d) and fla14 (h) plants. e–h Arrows indicate apparent pollen tubes germinating and elongating within the anthers of fla14 plants grown at 85% relative humidity. Scale bars = 100 μm (a-c, e–g); 20 μm (d, h)