Transcriptional and translational regulation of photosystem I and II genes in light-dark- and continuous-light-grown cultures of the unicellular cyanobacterium Cyanothece sp. strain ATCC 51142.
نویسندگان
چکیده
Cyanothece sp. strain ATCC 51142, a unicellular, diazotrophic cyanobacterium, demonstrated extensive metabolic periodicities of photosynthesis, respiration, and nitrogen fixation when grown under N2-fixing conditions. This report describes the relationship of the biosynthesis of photosynthesis genes to changes in the oligomerization state of the photosystems. Transcripts of the psbA gene family, encoding the photosystem II (PSII) reaction center protein D1, accumulated primarily during the light period, and net transcription reached a peak between 2 to 6 h in the light in light-dark (LD) growth and between 4 to 10 h in the subjective light when grown under continuous light (LL). The relative amount of the D1 protein (form 1 versus form 2) appeared to change during this diurnal cycle, along with changes in the PSII monomer/dimer ratio. D1 form 1 accumulated at approximately equal levels throughout the 24-h cycle, whereas D1 form 2 accumulated at significantly higher levels at approximately 8 to 10 h in the light or subjective light. The psbD gene, encoding the reaction center protein D2, also demonstrated differences between the two copies of this gene, with one copy transcribed more heavily around 6 to 8 h in the light. Accumulation of the PSI reaction center proteins PsaA and PsaB was maximal in the dark or subjective-dark periods, a period during which PSI was primarily in the trimeric form. We conclude that photosystem organization changes during the diurnal cycle to favor either noncyclic electron flow, which leads to O2 evolution and CO2 fixation, or cyclic electron flow, which favors ATP synthesis.
منابع مشابه
Transcriptional and translational regulation of nitrogenase in light-dark- and continuous-light-grown cultures of the unicellular cyanobacterium Cyanothece sp. strain ATCC 51142.
Cyanothece sp. strain ATCC 51142 is a unicellular, diazotrophic cyanobacterium which demonstrated extensive metabolic periodicities of photosynthesis, respiration, and nitrogen fixation when grown under N2-fixing conditions. N2 fixation and respiration peaked at 24-h intervals early in the dark or subjective-dark period, whereas photosynthesis was approximately 12 h out of phase and peaked towa...
متن کاملDifferential transcriptional analysis of the cyanobacterium Cyanothece sp. ATCC 51142 during light-dark and continuous-light growth
Differential transcriptional analysis of the cyanobacterium Cyanothece sp. ATCC 51142 during light-dark and continuous-light growth.Differential transcriptional analysis of the cyanobacterium Cyanothece sp. ATCC 51142 during light-dark and continuous-light growth.
متن کاملTranscriptional Analysis of the Unicellular, Diazotrophic Cyanobacterium Cyanothece ATCC 51142 Grown Under Short Day/Night Cycles
1 Cyanothece sp. strain ATCC 51142 is a unicellular, diazotrophic cyanobacterium that demonstrates 2 extensive metabolic periodicities of photosynthesis, respiration and nitrogen fixation when grown under 3 N2-fixing conditions. We have performed a global transcription analysis of this organism using 6 h 4 light/dark cycles in order to determine the response of the cell to these conditions and ...
متن کاملTranscriptional Analysis of the Unicellular, Diazotrophic Cyanobacterium Cyanothece Sp. Atcc 51142 Grown under Short Day/night Cycles(1).
Cyanothece sp. strain ATCC 51142 is a unicellular, diazotrophic cyanobacterium that demonstrates extensive metabolic periodicities of photosynthesis, respiration, and nitrogen fixation when grown under N2 -fixing conditions. We have performed a global transcription analysis of this organism using 6 h light:dark (L:D) cycles in order to determine the response of the cell to these conditions and ...
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عنوان ژورنال:
- Journal of bacteriology
دوره 180 3 شماره
صفحات -
تاریخ انتشار 1998