Evidence for a general light-dependent negative control of NADPH-protochlorophyllide oxidoreductase in angiosperms

The effect of light on NADPH-protochlorophyllide oxidoreductase and its mRNA has been studied in five different species of dicotyledonous plants, bean (Phaseolus vulgaris L.), pea (Pisum sativum L.), tomato (Lycopersicon esculentum Mill.), sunflower (Helianthus annuns L.) and mustard (Sinapis alba L.), and in two monocotyledonous plant species, maize (Zea mays L.) and barley (Hordeum vulgare L.). In all these species, illumination of etiolated seedlings led to a rapid decline of both the activity and the content of the enzyme protein. These results indicate that there may be a general light-dependent regulation of the enzyme common to higher plants.Abbreviation Pchlide reductase NADPH-protochlorophyllide oxidoreductaseDidicated to Professor H. Mohr on the occasion of his 60th birthdayWe are grateful to P. Westhoff and H. Schrubar (Botanisches Institut, Universität Düsseldorf, FRG) for making available to us their data on the Pchlide reductase of Sorghum bicolor prior to publication and for sending us seeds of this plant species. This work has been supported by the Deutsche Forschungsgemeinschaft.