Phytochrome - Development of plant
You know that plants capture light energy during photosynthesis, now you are familiarised with another important and interesting role of light in developmental' phenomena. Just as for photosynthesis lie is absorbed by pigments chlorophylls and carotenoids, similarly to bring about developmental response light has to be absorbed by some pigments. One of the pigments that detects the quality of light in the range of 600-800 nm region is phytochrome. It may also be mentioned that some developmental changes do exist even in total darkness. These processes would be independent of active form of phytochrome. Such changes are called skotomorphogenetic as against photomorphogenesis change that occur in light. There also exists an unidentified blue light absorbing pigment which brings about phototropism and nastic movements.