Shade avoidance

From Wikipedia, the free encyclopedia

Shade avoidance is a set of responses that plants display when they are subjected to the shade of another plant. It often includes elongation, altered flowering time, increased apical dominance and altered partitioning of resources. This set of responses is collectively called the shade-avoidance syndrome or low fluence response (LFR).

Plants can tell the difference between the shade of an inanimate object (eg a rock) and the shade of another plant, because of the altered balance between red and far-red light in the shade of a plant. In the shade far red light is far more predominant than red light so the phytochrome measures the ratio of far-red to red light to detect if its in the shade or not so it can alter its strategy accordingly (photomorphogenesis). This LFR is also used by seeds to detect if there is enough light to germinate.