An overview of phytochrome: An important light switch and photo-sensory antenna for regulation of vital functioning of plants

Abstract

Plants are the primary source of nutrition and essential to maintain life on earth. They have evolved very delicate and advanced photo-sensory antennae to sense their outer environment and transduce the received information for their growth and development accordingly. This “light switch” phenomenon of plants has slowly being unraveled and various plant photoreceptors, their role in downstream molecular signaling, mutual interaction, response to circadian cycle and light signals have been discovered. The photosensory antennae in plants; phytochromes, cryptochromes and phototropins play a very crucial role in sensing the ambient light intensities. By direct interaction with the environment through these photosensory antennae, plants shift their homeostasis to regulate their growth and development. The phytochrome light receptors of plants are responsive to R/FR light and by inducing signaling pathways, trigger the physiological responses such as germination and flowering. The phytochromes also directly contribute to plant development by affecting its photosynthetic rate. To elucidate the role of phytochromes in plant metabolism, this review will focus on the importance of phytochromes, their mechanism of action and their application as an emerging field in plant biology.

Effects of light on in vitro fiber development and flavonoid biosynthesis in green cotton (Gossypium hirsutum)

“…It is now known that plants contain photoreceptors, such as phototropins, cryptochromes, phytochromes, among others. Absorption of light by these photoreceptors stimulates signaling pathway that ultimately influences the physiology of a plant [18]. Previous studies showed that light affects fiber elongation, cellulose accumulation, fiber development genes expression, fiber quality formation, and fiber color in field planted cotton [5,19,20].…”