Photomorphogenesis is defined as the ability of light to regulate plant growth and development, independent of photosynthesis. Phytochrome, derived form the Greek words for plant and color, is the pigment that controls photomorphogenesis. This photoreversible pigment system consists of two forms, Pr and Pfr, which have peak absorptions in red (660 nm) and far-red (730 nm) wavelengths of light, respectively. The conversion of the pigment from one form to another influences such aspects of growth and morphology as flowering and germination. Investigations continue, however, in order to more fully understand the mechanism behind this complex, light regulated system and its affects on plant development. These findings are essential for the further advancement of this sector of our horticultural industry.
The photomorphogenesis research program at Clemson University consists of a group of scientists with diverse backgrounds and interests who share a common goal of learning how manipulation of the light environment can be used to regulate plant development. Many of the research findings have already had an impact on several horticultural industries, including the greenhouse and plastic industries. An important objective of our work that complements our overall goal is to incorporate new knowledge into systems that are more effective in growing horticultural crops. The success of the "light" program at Clemson University is even more noteworthy because much of the early photomorphogenesis research was done with limited financial support. Funding for research came mostly through "in-house" grants and incorporating light-related research objectives into existing projects. The Clemson University photomorphogenesis program continues to evolve and supply information to our horticultural discipline and supporting industries and to provide training to a new generation of research scientists.
Applications of light-regulated plant growth to horticultural plant growing systems