To test the effect of the inhibition of chloroplast translation on the
organization of the thylakoid membranes, these membranes were puri-
fied at different stages of the vitamin treatment. At time zero a very
intense green band containing the thylakoid membrane was visible in
the discontinuous sucrose density gradient. However, already after
48 h of vitamin treatment the intensity of this band was strongly
reduced and after 72 h the band had almost disappeared