Influence of Visible and Near Infrared Radiant Energy on Organ Development and Pigment Synthesis in Bean and Corn

Abstract

radiant energy have been reported to be an inhibition in growth of hypocotyl when present, an accelerated straightening of the plumular hook, an accelerated leaf expansion, an increased rate of epicotyl development, and a generally increased rate of tissue maturation (7, 10, 13, 15). In the monocotyledons, the most conspicuous response is a reduced growth rate of the first internode (11). The longer wave lengths of the visible spectrum also cause chlorophyll synthesis and photosynthesis. Due principally to the overlapping of the action spectra of these three photochemical reactions, it has been impossible to separate photomorphogenesis from the other two reactions. Consequently, when red radiant energy is used, the biochemical investigation of photomorphogenesis is complicated by the products of three photochemical reactions occurring simultaneously. It, therefore, would be advantageous to be able to separate photomorphogenesis from chlorophyll synthesis and photosynthesis. Attempts to accomplish this separation by the use of albino or chlorophyll-deficient plants have not been successful since all plants so far tested in this laboratory have contained significant quantities of chlorophyll. The curve for chlorophyll synthesis in barley seedlings as reported by