Fig. 2. Movement of material into and through the BIA of L. longiflorum pollen tubes followed by confocal FRAP of FM4-64. (A) Bleaching within the BIA; (B) bleaching of the apical region. Sites of photobleaching indicated on bright field images. Time is in seconds after bleaching. (A') Fluorescence intensity at the original location of the bleach site and `following' the displaced region of bleached fluorescence (see insert diagrams). (B') Fluorescence intensity at an apical bleach site and within the BIA. Bars, 15 µm.