The effect of glucose on the biochemical and ultrastructural characteristics of developing Euglena chloroplasts.
Chloroplast development is inhibited in Euglena gracilis strain Z, when greened in a medium containing glucose. This inhibition is reflected not only in the pattern of chlorophyll accumulation but also in the chloroplast ultrastructure and activities of the 2 light reactions of photosynthesis. Chloroplasts of cells greening in the presence of glucose are delayed in developing certain structures. Photosystem I activity develops at about the same rate as that of the controls during the first 48 h of greening, after which it develops at a slower rate. The rate of development of photosystem II activity in cells greening in a glucose medium lags considerably behing that of the controls until the later hours of greening. There are similarities between glucose inhibition and chloramphenicol inhibition of chloroplast development. Glucose may inhibit a step in chloroplast development ultimately controlled by the chloroplast genome.
D002734:Chlorophyll / Q000378:metabolism; D002736:Chloroplasts / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D005056:Euglena gracilis / Q000648:ultrastructure*; D005947:Glucose / Q000494:pharmacology*; D008027:Light; D010788:Photosynthesis
D002734:Chlorophyll; D005947:Glucose