Blue-Light Receptors and their Signal Transduction Pathways in Higher Plants.

Two kinds of blue-light receptors, cryptochrome and phototropin, have been found in higher plants. Cryptochrome mediates the inhibition of hypocotyl elongation and anthocyanin accumulation, and controls the timing of flowering and the circadian clock. Phototropin mediates phototropism, light-dependent chloroplast movement, stomata opening and leaf expansion. Here we review the characteristics of these photoreceptors and the signal transduction mechanisms downstream of the blue-light receptors.