Mitochondria associate with plastid stromules in hypocotyl epidermis Tobacco expressing plastid-targeted CFP and mitochondrial-targeted GFP were imaged with confocal microscopy in light-grown (A) and dark-grown (B-E) seedlings. CFP-labeled plastids are false-colored green. GFP-labeled mitochondria are false-colored red. DIC images are false-colored blue. Mitochondria appear yellow due to bleed through of GFP into the CFP detector. A) Mitochondria line up along stromules (arrows) and plastid bodies (arrowheads). B-E) Time-lapse images of a mitochondrion moving along a stromule (arrows). Images were collected at 19.5 second intervals. Bars: 5 μm.