Observation of the circadian photosynthetic rhythm in cyanobacteria with a dissolved-oxygen meter

Yen, Uan-Chen; Huang, Tan-Chi; Yen, Tsu-Chiang

doi:10.1016/j.plantsci.2003.12.005

Cited by 28 publications

(21 citation statements)

References 8 publications

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“…This non destructive in-situ approach also avoids the convolution of experimental cycles and natural circadian rhythms which have been shown to exist in cyanobacterial communities (Yen et al, 2004). Experiments were undertaken on undisturbed ground in areas away from plants to minimise the likelihood of contributions to CO 2 efflux from roots and mycorrhiza.…”

Section: Experimental Design and Samplingmentioning

confidence: 99%

Carbon dioxide fluxes from biologically-crusted Kalahari Sands after simulated wetting

Thomas

Hoon

2010

Journal of Arid Environments

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Thomas, A. D., Hoon, S. R. (2010). Carbon dioxide fluxes from biologically-crusted Kalahari Sands after simulated wetting. Journal of Arid Environments, 74 (1), 113-139.We report surface CO2 efflux and subsoil CO2 concentrations in biologically-crusted soils from the Kalahari. Fluxes were determined in-situ using a closed chamber coupled to a portable gas chromatograph on dry soils and on soils subject to simulated light and heavy rainfall. Surface efflux was measured in an artificially darkened environment in order to determine by difference, whether photosynthesis was occurring. Dry soil efflux rates were 2.8?14.8 mg Cm2 h1 throughout a diurnal cycle. Light rainfall led to an immediate increase in efflux to a peak of 65.6 mg Cm2 h1. Heavy rainfall resulted in a large pulse of CO2 with efflux rates of 339.2 mg Cm2 h1 over the first hour after wetting. Peak rates remained high over the following 2 days (87.8 and 87.0 mg Cm2 h1). Given sufficient moisture, fluxes increased with temperature. We believe hydration of the subsoil stimulates microorganisms which repsire available C either from extracellular polysaccharide sheaths (EPS) or released into the soil through lysis of microbial cells. Higher fluxes from the soil kept in the dark suggests photosynthesis occurs in wetted crusts during the daytime but net C uptake is masked by respiration from other microorganisms.authorsversionPeer reviewe

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Section: Experimental Design and Samplingmentioning

confidence: 99%

Carbon dioxide fluxes from biologically-crusted Kalahari Sands after simulated wetting

Thomas

Hoon

2010

Journal of Arid Environments

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“…Despite the fact that the expression of genes for a number of photosynthetic proteins (e.g., psbAI) is regulated by the circadian clock in S. elongatus PCC 7942, photosynthesis itself (as monitored by oxygen evolution) is not rhythmic in constant light (Yen et al, 2004). Therefore, the significance of the rhythmic expression of photosynthesis genes in S. elongatus is not known.…”

Section: Rhythmic Clock Outputs In Cyanobacteriamentioning

confidence: 99%

“…On the other hand, in other closely related cyanobacterial species (Synechocystis sp. PCC 6803, Synechococcus RF-1), there are rhythms of oxygen evolution in constant light (Yen et al, 2004 …”

Section: Rhythmic Clock Outputs In Cyanobacteriamentioning

confidence: 99%

No Promoter Left Behind: Global Circadian Gene Expression in Cyanobacteria

Woelfle

Johnson

2006

J Biol Rhythms

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Prokaryotic cyanobacteria express robust circadian (daily) rhythms under the control of a clock system that appears to be similar to those of eukaryotes in many ways. On the other hand, the KaiABC-based core cyanobacterial clockwork is clearly different from the transcriptiontranslation feedback loop model of eukaryotic clocks in that the cyanobacterial clock system regulates gene expression patterns globally, and specific clock gene promoters are not essential in mediating the circadian feedback loop. A novel model, the oscilloid model, proposes that the KaiABC oscillator ultimately mediates rhythmic changes in the status of the cyanobacterial chromosome, and these topological changes underlie the global rhythms of transcription. The authors suggest that this model represents one of several possible modes of regulating gene expression by circadian clocks, even those of eukaryotes. Keywords circadian; biological clock; kai; prokaryote; global gene expression; supercoiling Animals, plants, fungi, and cyanobacteria all display daily or circadian rhythms in their biochemistry, physiology, and/or behavior that are controlled by biological clocks (Dunlap et al., 2004). A variety of biological processes in various organisms are controlled by biological clocks such as gene expression, photosynthesis, sleeping/waking, and development, and this regulation is thought to help organisms adapt to the daily changes in light, temperature, and other factors in their environment. Circadian regulation of gene expression (i.e., the levels of specific proteins in cells) can be accomplished by clock control of transcription, mRNA stability, translation, and protein degradation. A particularly fascinating example of translational control by a circadian clock is that in the dinoflagellate alga, Gonyaulax (Rossini et al., 2003). However, we focus our discussion specifically on clock control of cyanobacterial gene expression at the level of transcription.In general, studies of circadian gene expression in eukaryotes have often used microarray analyses to show that a relatively small proportion of genes (~5%-15%) in eukaryotic genomes display rhythms in mRNA abundance. While microarray technology is well advanced, it should be noted that microarrays are not very sensitive to small changes of mRNA abundance, and moreover, they are not a good measure of rhythmic transcriptional activity for mRNAs that are either very unstable or very stable. Therefore, microarray results might not be reflective of transcriptional control in detail.

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“…For example, the first report of circadian rhythms in S. elongatus showed that the gene encoding the key photosynthesis protein D1 ( psbAI ) exhibited persistent rhythms of the transcript (28), implying a circadian rhythm of photosynthetic capacity. However, a later study that measured photosynthetic oxygen evolution did not find a circadian rhythm of photosynthetic capacity in LL in the same species (103)! Therefore, we should be cautious about extrapolating from gene expression to activity of metabolic pathways.…”

Section: Clock Control Of Metabolism In Prokaryotic Cyanobacteria?mentioning

confidence: 93%

“…RF1, and Cyanothece sp. ATCC 51142) but not in other species (e.g., S. elongatus PCC 7942) (103, 104). …”

Section: Clock Control Of Metabolism In Prokaryotic Cyanobacteria?mentioning

confidence: 94%

Metabolic Compensation and Circadian Resilience in Prokaryotic Cyanobacteria

Johnson

Egli

2014

Annu. Rev. Biochem.

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For a biological oscillator to function as a circadian pacemaker that confers a fitness advantage, its timing functions must be stable in response to environmental and metabolic fluctuations. One such stability enhancer, temperature compensation, has long been a defining characteristic of these timekeepers. However, an accurate biological timekeeper must also resist changes in metabolism, and this review suggests that temperature compensation is actually a subset of a larger phenomenon, namely metabolic compensation, which maintains the frequency of circadian oscillators in response to a host of factors that impinge on metabolism and would otherwise destabilize these clocks. The circadian system of prokaryotic cyanobacteria is an illustrative model because it is composed of transcriptional and nontranscriptional oscillators that are coupled to promote resilience. Moreover, the cyanobacterial circadian program regulates gene activity and metabolic pathways, and it can be manipulated to improve the expression of bioproducts that have practical value.

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Observation of the circadian photosynthetic rhythm in cyanobacteria with a dissolved-oxygen meter

Cited by 28 publications

References 8 publications

Carbon dioxide fluxes from biologically-crusted Kalahari Sands after simulated wetting

Carbon dioxide fluxes from biologically-crusted Kalahari Sands after simulated wetting

No Promoter Left Behind: Global Circadian Gene Expression in Cyanobacteria

Metabolic Compensation and Circadian Resilience in Prokaryotic Cyanobacteria

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