Sunflower Germination

This movie shows germination and early growth of sunflower seedlings. As the seedlings emerge from the soil, they are already beginning to make chlorophyll and turn green. The cotyledons and apical hook quickly unfold as the plant emerges into the light. As the seedlings elongate, nutational movement (rotation of the stem) becomes more apparent. In darkness, the nutational movement is present but less robust (see photomorphogenesis movie for comparison). The time between images in this movie was 10 min and they are shown at 15 frames per sec.