The circadian rhythm in photosynthesis in Acetabularia in the presence of actinomycin D, puromycin, and chloramphenicol.
J Gen Physiol
; 50(3): 647-59, 1967 Jan.
Article
em En
| MEDLINE
| ID: mdl-11526851
ABSTRACT
Anucleate Acetabularia crenulata shows a circadian rhythm in photosynthesis. In this study, an oxygen electrode was employed to measure this photosynthetic rhythm in the presence and absence of the inhibitors, actinomycin D, chloramphenicol, and puromycin. High concentrations of the inhibitors were used actinomycin D, 20-40 micrograms ml-1; puromycin, 30 and 100 micrograms ml-1; and chloramphenicol, 250 micrograms ml-1. The effectiveness of these inhibitors on protein synthesis was also measured under the same conditions used for the determination of rhythmicity. In spite of large effects of all three inhibitors on the incorporation of 14C leucine, no effect on the period or the phase of the photosynthetic rhythm was observed. The higher concentration of puromycin and chloramphenicol produced toxic effects which were expressed as a reduction in the amount of photosynthesis, but rhythmicity was still apparent. After 3 or 4 days' exposure to actinomycin, Acetabularia became resistant to its effect. Recovery was also observed in the ability to incorporate leucine. The implications of these results for theories of the basic oscillator responsible for circadian rhythmicity are discussed.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fotossíntese
/
Ritmo Circadiano
/
Dactinomicina
/
Acetabularia
/
Antibacterianos
Idioma:
En
Revista:
J Gen Physiol
Ano de publicação:
1967
Tipo de documento:
Article
País de afiliação:
Estados Unidos