Fig. 8. Periodic `trafficking events' at the tip of BFA-treated (1 hour, 3.6 µM) L. longiflorum pollen tubes. (A-A') DIC bright field image sequence and corresponding plot recording movement of material along the pollen tube axis as pixel intensity changes in a `sampling window' (highlighted in A). A single trafficking event is indicated in red. (B) As in A but with FM4-64 labelling. (B') Periodic movements of FM4-64-stained material along the pollen tube axis plotted as pixel intensity changes (gray circles) in a `sampling window' highlighted in the insert (white rectangle) over time, each movement event is marked with a vertical bar. The insert image is false-coloured to reveal the pattern of relative staining intensity: red, high fluorescence; blue, low fluorescence intensity. FM4-64 signal intensity within the BIA (black rectangle in insert image) is also plotted (black squares). The two plots were aligned by a -2.5 second shift in the BIA intensity plot. Bars, 15 µm.