Fig. 4. Colocalization of VpVAN, the first committed step in vanillin biosynthesis, in chloroplasts and phenyloplasts in 7-month-old Vanilla planifolia pods. Panel (A) shows light microscopy image of transverse section of the vanilla pod localizing chlorophyll containing green chloroplasts (black arrows indicating selected chloroplasts). Panel (B) shows immunolocalization of VpVAN (in green) in either chloroplasts or phenyloplasts. VpVAN was visualized by fluorescence microscopy using specific antibodies raised against VpVAN. Panel (C) shows the localization of VpVAN in chloroplasts (white arrows) and phenyloplasts (white stars) using fluorescence microscopy filter settings for simultaneous detection of both VpVAN (via FITC) and chloroplasts by chlorophyll auto-fluorescence. Chlorophyll (Chl) auto-fluorescence is shown in red indicating the localization of chloroplasts. Re-differentiating chloroplast are observed in yellow as the Chl auto-fluorescence is lower and phenyloplasts display no Chl auto-fluorescence and appear green. Scale bars equal to 100 μm. epi, epicarp. Figure adapted from Gallage et al. 2018, Plant & Cell Physiology.121.