Thylakoid differentiation in endocyanelles |
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Authors: | Sabine Marten Reinhard Stamm Peter Brandt |
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Institution: | Pflanzenphysiologisches Inst., Georg-August-Univ., Untere Karspüle 2, D-3400 Göttingen, F.R.G. |
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Abstract: | Cyanophora paradoxa Korshikov synchronized autotrophically in a light-dark regime of 14 h light and 10 h dark divides in the last two hours of the dark period. The division rate of the free-living blue-green alga, Synechococcus leopoliensis Raciborski, at identical culture conditions (24°C; 32 W m?2) is only slightly lowered in the light period. The comparison of thylakoid differentiation in the endocyanelles of Cyanophora paradoxa and in Synechococcus leopoliensis during the light-dark regime yields (1) the same ensemble of pigment-protein complexes in both organisms, (2) comparable syntheses of chlorophyll and phycobilins of Cyanophora paradoxa grown under 32 W m?2 and of Synechococcus leopoliensis grown under light intensities below 9.2 W m?2, and (3) identical photosynthetic oxygen evolution during the light period of the light-dark regime with minima at the beginning, in the middle (6th–7th h), and at the end of the light period. In both organisms this stage-specific oxygen evolution is inhibited by treatment with chloroamphenicol. Cycloheximide, however, causes no significant alterations. Results are discussed in view of the endosymbiotic theory. |
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Keywords: | Cyanophora paradoxa endosymbiotic theory Synechococcus leopoliensis |
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