The Etioplast–chloroplast Transformation in Tobacco: Correlation of Ultrastructure, Replication, and Chlorophyll Synthesis

Plastid ultrastructure was correlated with plastid replication and growth during the greening of etiolated tobacco tissue. The plastids grow rapidly, and this growth is correlated with a period of rapid chlorophyll synthesis. Chlorophyll synthesis is correlated with the formation of grana. The plastids divide by constriction and continue to do so after most of the grana have been formed. They contain single membrane‐bound bodies, which are observed less frequently in the last stages of chloroplast maturation. No internal morphological features of the plastids appear to be related to causal aspects of replication.