The Effect of Red and Far Red Light on Carotenoid and Chlorophyll Formation in Pea Seedlings

Treatment of etiolated pea seedlings with a short exposure to red light caused a stimulation of growth (size and dry wt production) and carotenoid synthesis during the following 48 hr compared with seedlings kept entirely in darkness.The effect is nullified by a following dose of far red light and thus the phenomenon is probably phytochrome‐controlled. Similar treatment with red light one hour before continuous illumination with white light tended to reduce the lag period for chlorophyll synthesis.Again a following dose of far red light reversed this response.