Advances in mechanistic understanding of light signal transduction derived from plant structural biology.
Abstract:
Light is a pivotal environmental signal regulating diverse plant developmental and physiological processes, including seed germination, hypocotyl elongation, phototropism, metabolite biosynthesis, stress resistance, temperature response, and circadian rhythms. Multiple signal transduction pathways of ultraviolet, blue light, and red/far-red light as well as related protein interaction networks in plants have been identified. Deciphering the mechanisms of light perception and signal transduction is of great significance to crop breeding and optogenetic manipulation. Structural biology has profoundly advanced the studies of light signal transduction by elucidating high-resolution three-dimensional (3D) structures of photoreceptors and their downstream signaling components. These studies uncover the molecular basis underlying perception and transduction of different light signals by plants. This review summarizes key structural findings of plant light signal transduction, highlighting the architectures and molecular functions of photoreceptors and associated signaling factors. We also outline the mechanisms underlying photoreceptor activation, inhibition, and regulatory interactions within light signaling networks and discuss the challenges in this field.
