Plant Pigment

Phycobilins are water soluble photosynthetic pigments. They are not present in higher plants, but do occur in red algae and the cyanobacteria, a group of photosynthetic bacteria.

Betalains are red or yellow pigments which are synthesized by plants in ten different families. Interestingly, none of the species which have betalains also produce anthocyanins, even though these two pigments are unrelated.

Flavins are orange-yellow pigments often associated with proteins. Some flavins are specialized for control of phototropism and other developmental responses of plants. Like phytochrome, flavins occur in low concentrations and cannot be seen unless purified.

Rhodopsin is a pigment which controls light-regulated movements, such as phototaxis and photokinesis, in many species of algae. Interestingly, humans and many other animals also use rhodopsin for vision.