In addition to its role in photosynthesis, light provides the plant with important information about the environment. Specific qualities, quantities and combinations of light control specific facets of plant development. For instance, germination, plant stature and the transition to flowering all are dependent upon information contained in various wavelengths of light. The effects of blue and red/far-red light have been well described, and studies over the last decade have defined a suite of photoreceptors and attendant signal transduction pathways. The specific effects of green wavebands have been documented for 50 years. Recent studies in the plant model system Arabidopsis thaliana have shown that green signals frequently antagonize the effects of known photosensory systems that forward developmental responses. These effects include stem growth promotion, inhibition of light-induced stomatal opening and repression of light-induced transcript levels. The goal of the present study is to further characterize these novel responses to green light and study a series of genes with similarity to those of the animal visual-cycle using a reverse-genetic approach. The findings will further define the contribution of a yet uncharacterized light sensor and possibly the role of retinoids in plant systems. This will have broad impacts in understanding how various wavebands of light are sensed, integrated, and in turn modulate plant processes. These activities will provide an outstanding platform for education of postdoctoral scholars, graduate students and undergraduates in photomorphogenesis and plant development. These studies also have the potential to profoundly affect agriculture, as green-light contributions to applied light-regulated processes are realized.
