Blue light sensing in higher plants

Plants have evolved a range of sophisticated mechanisms to adapt and respond to their natural habitat. For example, plants rely heavily upon the surrounding light environment to direct their growth and development. Several different photoreceptor families are known to mediate the effects of light on plant development (1-3). These include the phytochrome (phy) family of photoreceptors, which monitor the red (600–700 nm) and far-red (700–750 nm) regions of the solar spectrum (4). In addition to the phytochromes, many important aspects of plant development are regulated by specific blue (390–500 nm) and/or UV-A (320–390 nm) light-absorbing receptors (5-7). Currently two classes of blue light receptors have been identified in plants: the cryptochromes and the phototropins. Here we briefly review the most recent advances in our understanding of blue light perception and signaling with an emphasis on the cryptochrome and phototropin photosensory systems