Signals from Sunlight

This chapter discusses the primary signaling mechanisms involved in light regulated growth and development, focusing primarily on the red-light (600–700 nm), far-red light (700–750 nm), blue light (400–500 nm), and UV-B radiation (290–320 nm) receptors. It highlights photoreceptors, phytochromes, and cryptochromes, and phototropins that help plants regulate developmental processes over their lifetimes by sensitizing plants to incident light. It also points out how photoreceptors initiate protective processes in response to harmful radiation. The chapter examines the association of phytochrome with changes in lipid composition and membrane potentials. It analyzes phototropins located in the plasma membrane and has two flavin mononucleotide (FMN) chromophores that can induce conformational changes.