Phototropism: the Phytochrome and Blue-Light Systems
This video presents the same text shown beside it, spoken and on screen. It adds nothing the text does not say.
State
Phototropism, a plant's directional bending toward or away from light, is mediated by blue-light receptors, phototropins, distinct from the red/far-red phytochrome system governing germination and flowering timing.
Show
A windowsill seedling bends toward light as blue-light receptors trigger faster elongation on its shaded side.
Watch for
Phytochrome and phototropin are separate systems — one tracks red/far-red light for timing, the other blue light for direction.