What are the pigments found in plants called?

Answer 1

That depends on which color you're asking about. The green color present in plants is actually the result of photosynthesis. It is chlorophyll produced by chloroplasts under the right conditions (i.e. light, temperature, nutrients.) The two main pigments present in leaves are the yellow(xanthophyll) and orange (carotene). Throughout the green season those pigments are always there. However the production of chlorophyll "drowns" them out. Once the days start to get shorter (less light) and the temperature drops (45 degrees), then the onset of the plant's dormancy will occur. There will be a lower rate of photosynthesis allowing the pigments to show through on the leaves.

The red and purple colors that are present in the fall occur under special circumstances. Not only does the plant have to be genetically predisposed to produce anthocyanin (the name of the red/purple pigment), but there must also be special conditions to enable the production of this pigment. First, there must be a large sugar build-up within the leaf. This is caused by lots of warm, sunny days at the begginning of the fall season that are then followed by crisp cool nights (40-45 degrees.) The low temperature at night leads to low levels of respiration causing the abscission layer to form at the node where the leaf connects to a stem. So the following day, when you have more warmth and sun, the leaf will continue to produce sugar. However, there will now be the formation of the abscission layer causing the flow of sugar out of the leaf to be minimized. This in turn results in the large sugar pool mentioned previously. And this large sugar pool enables the leaf to produce the pigment anthocyanin leading to beautiful fall colors. Hope that helps. Sorry if it was TMI.