[Regulation of the synthesis of plastid proteins in Euglena gracilis].

The multiplication of chloroplasts in synchronized Euglena gracilis, strain Z, requires the existence of a regulating system which coordinates both the synthesis of plastid proteins coded in the plastom and the synthesis of plastid proteins coded in the genom. At 27°C this system can not be influenced by external factors, such as chloramphenicol and cycloheximide. At 35°C, however, the inhibition of the synthesis of plastom-coded proteins by chloramphenicol increases the synthesis of certain plastid proteins coded in the genom. The inhibitor cycloheximide acts vice versa. These results are in favour of the hypothesis that the synthesis of plastid proteins is coordinated by regulator proteins.