Phytochrome

Phytochrome is a plant photoreceptor pigment that regulates growth and development in response to red and far-red light. It exists in two interconvertible forms, allowing plants to detect day length, shade, and light quality, and thereby control germination, stem elongation, flowering, and other developmental processes. In crop science and horticulture, understanding phytochrome responses guides decisions on planting density, greenhouse lighting spectra, and photoperiod manipulation to optimize yield and quality. Post-harvest physiology is also light-influenced in some commodities. Although phytochrome is not a food component, its role in plant development directly affects the productivity and characteristics of the crops that supply the food industry.