Inhibition of Light-Dependent Development of Chloroplasts by 5-Fluorouracil
| Autor: | Robert M. Smillie, W. R. Evans |
|---|---|
| Rok vydání: | 1971 |
| Předmět: |
chemistry.chemical_classification
Euglena gracilis biology Physiology ved/biology Cytochrome c ved/biology.organism_classification_rank.species Uracil Plant Science biology.organism_classification Euglena Chloroplast chemistry.chemical_compound Enzyme chemistry Biochemistry Cytoplasm biology.protein Ribonuclease |
| Zdroj: | Journal of Experimental Botany. 22:371-381 |
| ISSN: | 1460-2431 0022-0957 |
| DOI: | 10.1093/jxb/22.2.371 |
| Popis: | The uracil analogue, 5-fluorouracil, inhibited the development of chloroplasts in Euglena gracilis, strain Z. Chlorophyll synthesis was inhibited when dark-grown cells were illuminated in the presence of 5-fluorouracil, but only if the 5-fluorouracil was present during the lag phase of chlorophyll synthesis. Ribonuclease showed a similar inhibition. Equimolar con centrations of uracil released inhibition by 5-fluorouracil, but if cells were incubated in the light with 5-fluorouracil before addition of uracil, the ability of uracil to effect rapid reversal of 5-fluorouracil inhibition was decreased. In contrast, prior incubation with 5-fluorouracil in the dark did not affect reversibility by uracil. The synthesis of a chloroplast-localized protein, cytochrome c (552, Euglena), was also inhibited by 5-fluorouracil, whereas the light-stimulated synthesis of a number of cytoplasmic enzymes was enhanced. The results suggest that addi tion of 5-fluorouracil at the beginning of the illumination period preferentially interferes with the synthesis of chloroplast protein compared with the synthesis of cytoplasmic protein by inhibiting the formation of a ribosomal system, presumably localized in the chloroplast, that functions in the synthesis of chloroplast protein. The data also suggest that in uninhibited cells, the formation of this ribosomal system was largely completed within the first 10 to 14 h of illumination and before the main period of synthesis of chloroplastproteins. |
| Databáze: | OpenAIRE |
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