PHOTOTRANSFORMATIONS OF PHYTOCHROME

Abstract
Abstract— –Phytochrome is the photoreversible chromoprotein that controls many aspects of plant growth and development Phototransformations of the red absorbing form (Pr) and the far red absorbing form (Pfr) involve initial photoreactions followed by dark relaxation reactions. Techniques for the study of intermediates of phototransformation and the present picture of intermediates involved in the phototransformations of Pr and Pfr are outlined. The molecular natures of the phototransformations are reviewed in relationship to knowledge of the chemistry of the chromophore and apoprotein. The significance of phytochrome intermediates in understanding the physiology of phytochrome controlled responses is discussed.