Chloroplast proteins of cytoplasmic origin. Effect of chloramphenicol on their synthesis, transport and intraplastidial localization. Ultrastructural autoradiographic studies.
Ultrastructural autoradiographic studies after application of 3H-lysine indicate that during the transformation of the etioplasts into chlorplasts in the bean (Phaseolus vulgaris) the protein synthesis in plastids occurs mainly near the thylakoid membranes and the prolamellar bodies: most of the autoradiographic grains are placed over the structures. After 24 h postincubation in nonradioactive medium the ratio of the number of silver grains associated with thylakoids to those over stroma increases more than 2.5 times in control plants, whereas in cells treated with chloramphenicol only 1.5 times. Simultaneously in chloramphenicol-treated plants an increase in plastid envelope labelling is observed. It has been assumed that chloramphenicol, having no inhibitory effect on the synthesis and transport of proteins imported from the cytoplasm to the plastid, lowers their penetration inside the plastid as well as their incorporation into the thylakoid membrane.
Kwiatkowska
M
M
Laboratory of Cytophysiology, University of Lódz, Poland.
Strzałka
K
K
D001345:Autoradiography; D002701:Chloramphenicol / Q000494:pharmacology*; D002736:Chloroplasts / Q000187:drug effects / Q000502:physiology*; D003593:Cytoplasm / Q000502:physiology; D007887:Fabaceae; D010940:Plant Proteins / Q000096:biosynthesis*; D010946:Plants, Medicinal
D010940:Plant Proteins; D002701:Chloramphenicol