Arabidopsis germination - dark
This short movie shows Arabidopsis thaliana seeds germinating in darkness on a vertical agar surface and growing over a period of a few days (1 image captured each hour). Arabidopsis seeds are very small, less than 1 mm long. Typical of most plants, the root emerges from the seed first. Once the root has emerged, the shoot begins to grow.
Small seeds like Arabidopsis have a rather limited food supply stored in the seeds so it is critical for the shoot to elongate rapidly to ensure that the shoot can escape the soil and reach the light where the seedling can produce its own food by photosynthesis. The dark growth is called etiolation. Once the shoot is exposed to light, the plants undergo a process called photomorphogenesis during which shoot elongation slows down, the leaves develop and root growth increases.
See an Arabidopsis seedling germinate in the light for comparison.