Effect of chloramphenicol on the development of proplastids in Euglena gracilis: II. The Synthesis of Carotenoids

Abstract

Summary Dark-grown cells of Euglena gracilis contain carotenoids, which are localized in the proplastids. By contrast with greening cells, dark-grown cells are able to synthesize carotenoids in the presence of chloramphenicol. In greening cells chloramphenicol is reported to inhibit the formation of thylakoids. In the dark chloramphenicol has no effect upon the synthesis of the prolamellar bodies, where possible carotenoids are stored. The results signify that the enzymes involved in the synthesis of carotenoids and the proteins of the prolamellar body are most likely synthesized in the cytoplasm. The different effects of chloramphenicol upon the synthesis of carotenoids in light and in darkness are explained in terms of available sites for the accomodation of the pigments.