Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: February 12, 2002
Publication Date: N/A
Technical Abstract: The major classes of visible plant pigments are chlorophylls, carotenoids, flavonoids (including anthocyanins), and batalains. Each of these classes of pigments is comprised of several individual compounds. For example, there are two major chlorophylls in higher plants, while it is estimated that there are over four hundred carotenoids and three thousand flavonoids which occur in nature. Phytochrome is a blue-green plant pigment which is not plentiful enough to be visible, but it serves as an important sensor of light which stimulates plant growth and development. All plants contain chlorophyll and carotenoids in their leaves and other green plant parts. The chlorophylls are green and central to the process of photosynthesis. They capture light energy and convert it to chemical energy to be used not only by plants but by all animals. The carotenoids and related xanthophylls are red, orange, or yellow and occur along with chlorophylls in plastids where they capture oxidizing compounds generated during photosynthesis. Without the protection they offer, photosynthesis cannot occur, so all photosynthetic tissue contains both the visible green chlorophylls as well as the masked orange carotenoids. Carotenoids serve another function as accessory light-harvesting pigments and photoreceptors which make photosynthesis more efficient. The flavonoids include the red and blue anthocynanins which attract the human and higher animal eye. Other flavonoids are the yellow and white flavonols, flavones, aurones, and chalcones.