UV-B photoreceptors, their role in photosignaling, physiological responses, and abiotic stress in plants

Abstract

Light is a major developmental cue that infl uences critical aspects of the development, morphology, and metabolism in plants. Hence, the need arose for the evolution of a class of molecule solely responsible for “sensing” light. Photoreceptors are commonly classifi ed based on their chemical nature and photochemistry of their chromophore, and at present, six distinct classes of the photoreceptors are known in the nature. Two putative families have been identifi ed more recently. The electromagnetic spectrum reaching the earth’s surface also comprises of ultraviolet radiation, a form of abiotic stress, in the wavelength range from 100 to 400 nm. This chapter mainly deals with the various classes of plant photoreceptors known, the evolution of a UV-B-specifi c photoreceptor, and the signaling pathways involved to effectively bring about the UV-B-specifi c stress responses in plants. Importance of “omics”-based approaches would also be discussed for deciphering photoreceptormediated cellular signaling and its relevance to stress response in plants