Variations in Photosynthetic Electron-Transport Pathways in Chlorella vulgaris

1978 ◽  
Vol 6 (5) ◽  
pp. 904-906
Author(s):  
JOHN SINCLAIR ◽  
AKINORI SARAI
Keyword(s):  
Electron Transport ◽  
Chlorella Vulgaris ◽  
Photosynthetic Electron Transport ◽  
Transport Pathways

scholarly journals Reactions of substituted furo[3,2-b]pyrrole-5-carboxhydrazides and their biological activity

2005 ◽  
Vol 3 (4) ◽  
pp. 622-646 ◽  
Author(s):  
Renata Ga<parová ◽  
Daniel Zbojek ◽  
Margita Lácová ◽  
Katarína Král'ová ◽  
Anton Gatial ◽  
...  
Keyword(s):  
Biological Activity ◽  
Reaction Time ◽  
Electron Transport ◽  
Microwave Irradiation ◽  
Chlorophyll Content ◽  
Chlorella Vulgaris ◽  
Photosynthetic Electron Transport ◽  
Imidazole Derivatives ◽  
Spinach Chloroplasts

AbstractThe reactions of substituted furo[3,2-b]pyrrole-5-carboxhydrazides 1 with 5-arylfuran-2-carboxaldehydes 2, 4,5-disubstituted furan-2-carboxaldehydes 3 and thiophene-2-carboxaldehyde 4 has been studied. The advantage of microwave irradiation on some of these reactions was reflected in the reduced reaction time and increased yields. Reactions of 1 with 4-substituted 1,3-oxazol-5(4H)-ones 11 led to diacylhydrazines 13 or to imidazole derivatives 14 depending on the temperature. 1,2,4-Triazole-3-thione 17 was synthesized by two-step reaction of 1 with phenylisothiocyanate and subsequent base-catalyzed cyclization of thiosemicarbazide 16. The effects of hydrazones 5–10 on inhibition of photosynthetic electron transport in spinach chloroplasts and chlorophyll content in the antialgal suspensions of Chlorella vulgaris were investigated.

Exposure of high-light-grown cultures of Chlorella vulgaris to darkness inhibits the relaxation of excitation pressure: uncoupling of the redox state of the photosynthetic electron transport chain and phenotypic plasticity

Botany ◽  
2017 ◽  
Vol 95 (12) ◽  
pp. 1125-1140 ◽  
Author(s):  
Lauren Hollis ◽  
Norman P.A. Hüner
Keyword(s):  
Electron Transport ◽  
Chlorella Vulgaris ◽  
Electron Transport Chain ◽  
Redox State ◽  
Light Harvesting ◽  
Photosynthetic Electron Transport ◽  
High Light ◽  
Photon Flux ◽  
Photosynthetic Electron Transport Chain ◽  
Transport Chain

Chlorella vulgaris acclimated to high light (HL) conditions exhibited a pale-green phenotype characterized by reduced chlorophyll and light harvesting polypeptide abundance compared with the dark green phenotype of the control, low-light-grown (LL) cultures. We hypothesized that if chloroplast redox status was the sole regulator of phenotype, exposure to darkness should cause reversion of the HL to LL phenotype. Surprisingly, HL cells transferred to darkness or dim light failed to green. Thus, phenotypic reversion is light-dependent with an optimal photon flux density (PFD) of 110 μmol photons·m−2·s−1. HL cells shifted to this PFD exhibited increased chlorophyll and light harvesting polypeptide abundance, which were inhibited by 2,5-dibromo-3-methyl-6-isopropyl-benzoquinone but not by 3-(3′,4′-dichlorophenyl)-1,1-dimethylurea. We conclude that photoacclimation of HL-grown cells to LL is governed by the redox state of the intersystem photosynthetic electron transport chain (PETC) at this PFD. At lower light levels, cells maintained the HL phenotype, despite an oxidized status of the PETC. Because 110 μmol photons·m−2·s−1 was the optimal PFD for protochlorophyllide oxidoreductase accumulation, we suggest that stabilization of light-harvesting polypeptides by chlorophyll binding may also govern photoacclimation in C. vulgaris. The possible role of the metabolic balance between respiration and photosynthesis is also discussed.

scholarly journals Regulation of photosynthetic electron flow on dark to light transition by ferredoxin:NADP(H) oxidoreductase interactions

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Manuela Kramer ◽  
Melvin Rodriguez-Heredia ◽  
Francesco Saccon ◽  
Laura Mosebach ◽  
Manuel Twachtmann ◽  
...  
Keyword(s):  
Electron Transport ◽  
Electron Flow ◽  
Carbon Assimilation ◽  
Photosynthetic Electron Transport ◽  
Immunogold Labelling ◽  
Free Radical Damage ◽  
Transport Pathways ◽  
Photosynthetic Electron Flow ◽  
Radical Damage

During photosynthesis, electron transport is necessary for carbon assimilation and must be regulated to minimize free radical damage. There is a longstanding controversy over the role of a critical enzyme in this process (ferredoxin:NADP(H) oxidoreductase, or FNR), and in particular its location within chloroplasts. Here we use immunogold labelling to prove that FNR previously assigned as soluble is in fact membrane associated. We combined this technique with a genetic approach in the model plant Arabidopsis to show that the distribution of this enzyme between different membrane regions depends on its interaction with specific tether proteins. We further demonstrate a correlation between the interaction of FNR with different proteins and the activity of alternative photosynthetic electron transport pathways. This supports a role for FNR location in regulating photosynthetic electron flow during the transition from dark to light.

scholarly journals Heterocyst Thylakoid Bioenergetics

Life ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 13 ◽  
Author(s):  
Ann Magnuson
Keyword(s):  
Nitrogen Fixation ◽  
Electron Transport ◽  
Water Oxidation ◽  
Production Systems ◽  
Photosynthetic Electron Transport ◽  
Transport Pathways ◽  
Cell Factories ◽  
Diazotrophic Growth ◽  
Photosynthetic Water Oxidation

Heterocysts are specialized cells that differentiate in the filaments of heterocystous cyanobacteria. Their role is to maintain a microoxic environment for the nitrogenase enzyme during diazotrophic growth. The lack of photosynthetic water oxidation in the heterocyst puts special constraints on the energetics for nitrogen fixation, and the electron transport pathways of heterocyst thylakoids are slightly different from those in vegetative cells. During recent years, there has been a growing interest in utilizing heterocysts as cell factories for the production of fuels and other chemical commodities. Optimization of these production systems requires some consideration of the bioenergetics behind nitrogen fixation. In this overview, we emphasize the role of photosynthetic electron transport in providing ATP and reductants to the nitrogenase enzyme, and provide some examples where heterocysts have been used as production facilities.

scholarly journals Photosynthetic electron transport transients in Chlorella vulgaris under fluctuating light

2019 ◽  
Vol 44 ◽  
pp. 101713 ◽  
Author(s):  
Marlene Bonnanfant ◽  
Bruno Jesus ◽  
Jeremy Pruvost ◽  
Jean-Luc Mouget ◽  
Douglas A. Campbell
Keyword(s):  
Electron Transport ◽  
Chlorella Vulgaris ◽  
Photosynthetic Electron Transport ◽  
Fluctuating Light

Influence of Buthidazole, Diuron, and Atrazine on Some Light Reactions of Photosynthesis

Weed Science ◽  
1983 ◽  
Vol 31 (6) ◽  
pp. 879-883 ◽  
Author(s):  
Robert M. Devlin ◽  
Antoni J. Murkowski ◽  
Irena I. Zbieć ◽  
Stanislaw J. Karczmarczyk ◽  
Elzbieta M. Skórska
Keyword(s):  
Electron Transport ◽  
Plant Species ◽  
Exposure Time ◽  
Chlorella Vulgaris ◽  
Fluorescence Emission ◽  
Photosynthetic Electron Transport ◽  
Luminescence Decay ◽  
Enhanced Fluorescence ◽  
Algal Cultures

The influence of buthidazole {3-[5-(1,1-dimethylethyl)-1,3,4-thiadiazol-2-yl]-4-hydroxy-1-methyl-2-imidazolidinone}, diuron [3-(3,4-dichlorophenyl)-1,1-dimethylurea], and atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine] on fluorescence emission and post-luminescence decay in chlorella (Chlorella vulgarisBeyer) was studied. All three herbicides blocked photosynthetic electron transport and thus enhanced fluorescence. Buthidazole was the most active, a 79% increase in fluorescence being observed when algal cultures were exposed to 1 × 10-6M herbicide for 5 min, and a 206% increase with an exposure time of 60 min. Postluminescence in chlorella exposed to 1 × 10-6M buthidazole for 5, 10, 20, and 60 min was inhibited 15, 34, 58, and 69%, respectively. Diuron and atrazine inhibition of postluminescence was much less than that of buthidazole. The ratio of relative fluorescence to relative postluminescence can be sued to give a numerical value (C) for the phytotoxicity of this type of herbicide to a given plant species.

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