RIBONUCLEIC-ACID POLYMERASE AND PROTEIN-KINASE ACTIVITIES IN PREPARATIONS OF CHROMATIN, NUCLEI, AND SOLUBILIZED CHLOROPLAST RNA-POLYMERASE IN RELATION TO LIGHT-INTENSITY DURING PLANT-GROWTH

We studied changes of RNA polymerase and protein kinase activities in preparations of chromatin nuclei, and solubilized RNA polymerase of ch loroplasts from leaves of bean plants (Vicia faba L.) grown at differe nt light intensities (10, 50, 80, and 125 W.m-2 PAR) and during variat ion of illumination conditions. Chromatin-associated RNA polymerase I was most sensitive to changes of light intensity. Such changes affecte d the activities of RNA polymerase II and solubilized chloroplast RNA polymerase to a lesser extent. Changes of protein kinase activity in p reparations of chromatin, nuclei, and solubilized chloroplast RNA poly merase were for the most part correlated with changes of their RNA pol ymerase activity. Such unidirectional changes of RNA polymerase and pr otein kinase activities were observed both during prolonged growth und er light of different intensities and during variation of illumination conditions. Possible involvement of phosphorylation in light regulati on of nuclear and chloroplast RNA polymerase activity is discussed in the paper.