Unformatted text preview: gravitropism. Homeowners have often experienced consequences of root growth towards moisture, when roots “invade” water or sewer pipes. Phototropism, Photomorphogenesis and Photoperiodism The primary response to light by plants is the bending of shoots through differential growth towards a light source, as shown by Charles Darwin and his son in 1880. The hormone, auxin, migrates towards cells away from the light source. Auxin moves from cells in the light side of the plant to cells on the dark side. The differential distribution of auxin promotes elongation of the cells away from the light, causing a curvature or bending of the plant towards the light source. The pattern of development of tissues in response to light is called photomorphogenesis. But how do plants detect light?...
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- Fall '09
- Plants, light source, Plant Environmental Regulators, Paraheliotropism