In vivo bicarbonate requirement for water oxidation by Photosystem II in the hypercarbonate-requiring cyanobacterium Arthrospira maxima

2007 ◽  
Vol 101 (11-12) ◽  
pp. 1865-1874 ◽  
Author(s):  
Damian Carrieri ◽  
Gennady Ananyev ◽  
Tyler Brown ◽  
G. Charles Dismukes
Keyword(s):  
Photosystem Ii ◽  
Water Oxidation ◽  
Arthrospira Maxima

Inactivation of Photosynthetic O2 Evolution in the Cyanobacterium Anacystis nidulans PCC 6301: Influence of Nitrogen Metabolites and Divalent Cation Concentration

1991 ◽  
Vol 46 (11-12) ◽  
pp. 1024-1032 ◽  
Author(s):  
Gudrun Wälzlein ◽  
Elfriede K. Pistorius
Keyword(s):  
Photosystem Ii ◽  
Nitrogen Source ◽  
Divalent Cation ◽  
Water Oxidation ◽  
Divalent Cations ◽  
Nitrogen Deficiency ◽  
Anacystis Nidulans ◽  
O2 Evolution ◽  
Cation Deficiency

Abstract An investigation about the in vivo inactivation of photosynthetic water oxidation has been carried out in the cyanobacterium Anacystis nidulans (Synechococcus PCC 6301). Photosystem II and photosystem I activity as well as the relative amount of the D1 and manganese stabilizing peptide of photosystem II were determined after growing the cells in nutrient media with variations in the nitrogen source and the concentration of the major divalent cations (Mg2+ and Ca2+). The results show a rapid inactivation of water oxidation in A. nidulans in response to nitrogen deficiency and in response to reduced Mg2+ and Ca2+ concentrations. The inactivation of water oxidation observed under divalent cation deficiency could be greatly accelerated when L-amino acids instead of ammonia or nitrate were used as nitrogen source. Under these conditions inactivation of water oxidation correlated with a rapid loss of D1 and with a slower loss of the manganese stabilizing peptide from photosystem II. A possible regulation of the photosystem II activity in A. nidulans by nitrogen metabolites is suggested.

Effect of Magnesium and Calcium Ions on the Photoelectron Transport Activity of Low-Salt Suspended Hydrilla verticillata Thylakoids: Possible Sites of Cation Interaction

1998 ◽  
Vol 53 (9-10) ◽  
pp. 849-856
Author(s):  
Sujata R. Mishra ◽  
Surendra Chandra Sabat
Keyword(s):  
Electron Transport ◽  
Photosystem Ii ◽  
Electron Donor ◽  
Water Oxidation ◽  
Electron Flow ◽  
Hydrilla Verticillata ◽  
Transport Activity ◽  
Low Salt ◽  
Electron Transport Activity ◽  
Stimulation Of

Stimulatory effect of divalent cations like calcium (Ca2+) and magnesium (Mg2+) was investigated on electron transport activity of divalent cation deficient low-salt suspended (LS) thylakoid preparation from a submerged aquatic angiosperm, Hydrilla verticillata. Both the cations stimulated electron transport activity of LS-suspended thylakoids having an intact water oxidation complex. But in hydroxylamine (NH2OH) - or alkaline Tris - washed thylakoid preparations (with the water oxidation enzyme impaired), only Ca2+ dependent stimulation of electron transport activity was found. The apparent Km of Ca2+ dependent stimulation of electron flow from H2O (endogenous) or from artificial electron donor (exogenous) to dichlorophenol indophenol (acceptor) was found to be identical. Calcium supported stimulation of electron transport activity in NH2OH - or Tris - washed thylakoids was electron donor selective, i.e., Ca2+ ion was only effective in electron flow with diphenylcarbazide but not with NH2OH as electron donor to photosystem II. A magnesium effect was observed in thylakoids having an intact water oxidation complex and the ion became unacceptable in NH2OH - or Tris - washed thylakoids. Indirect experimental evidences have been presented to suggest that Mg2+ interacts with the water oxidation complex, while the Ca2+ interaction is localized betw een Yz and reaction center of photosystem II.

scholarly journals Soil Application of Effective Microorganisms (EM) Maintains Leaf Photosynthetic Efficiency, Increases Seed Yield and Quality Traits of Bean (Phaseolus vulgaris L.) Plants Grown on Different Substrates

2019 ◽  
Vol 20 (9) ◽  
pp. 2327 ◽  
Author(s):  
Marcello Iriti ◽  
Alessio Scarafoni ◽  
Simon Pierce ◽  
Giulia Castorina ◽  
Sara Vitalini
Keyword(s):  
Phaseolus Vulgaris ◽  
Photosystem Ii ◽  
Sandy Soil ◽  
Photosynthetic Efficiency ◽  
Quality Traits ◽  
Phaseolus Vulgaris L ◽  
Effective Microorganisms ◽  
Yield And Quality ◽  
Bean Plants

EM (effective microorganisms) is a biofertilizer consisting of a mixed culture of potentially beneficial microorganisms. In this study, we investigated the effects of EM treatment on leaf in vivo chlorophyll a fluorescence of photosystem II (PSII), yield, and macronutrient content of bean plants grown on different substrates (nutrient rich substrate vs. nutrient poor sandy soil) in controlled environmental conditions (pot experiment in greenhouse). EM-treated plants maintained optimum leaf photosynthetic efficiency two weeks longer than the control plants, and increased yield independent of substrate. The levels of seed nutritionally-relevant molecules (proteins, lipids, and starch) were only slightly modified, apart from the protein content, which increased in plants grown in sandy soil. Although EM can be considered a promising and environmentally friendly technology for sustainable agriculture, more studies are needed to elucidate the mechanism(s) of action of EM, as well as its efficacy under open field conditions.

The S2 to S3 transition for water oxidation in PSII (photosystem II), revisited

2018 ◽  
Vol 20 (35) ◽  
pp. 22926-22931 ◽  
Author(s):  
Per E. M. Siegbahn
Keyword(s):  
Photosystem Ii ◽  
Water Oxidation ◽  
Light Flash

The formation of O2 from water requires four transitions, each one after the absorption of one light flash.

scholarly journals Electronic Structure of Tyrosyl D Radical of Photosystem II, as Revealed by 2D-Hyperfine Sublevel Correlation Spectroscopy

2021 ◽  
Vol 7 (9) ◽  
pp. 131
Author(s):  
Maria Chrysina ◽  
Georgia Zahariou ◽  
Nikolaos Ioannidis ◽  
Yiannis Sanakis ◽  
George Mitrikas
Keyword(s):  
Electronic Structure ◽  
Photosystem Ii ◽  
Water Oxidation ◽  
Spinacia Oleracea ◽  
Higher Plants ◽  
Correlation Spectroscopy ◽  
Oxygen Evolving Complex ◽  
Higher Plant ◽  
Proton Coupled Electron Transfer ◽  
S Oxidation

The biological water oxidation takes place in Photosystem II (PSII), a multi-subunit protein located in thylakoid membranes of higher plant chloroplasts and cyanobacteria. The catalytic site of PSII is a Mn4Ca cluster and is known as the oxygen evolving complex (OEC) of PSII. Two tyrosine residues D1-Tyr161 (YZ) and D2-Tyr160 (YD) are symmetrically placed in the two core subunits D1 and D2 and participate in proton coupled electron transfer reactions. YZ of PSII is near the OEC and mediates electron coupled proton transfer from Mn4Ca to the photooxidizable chlorophyll species P680+. YD does not directly interact with OEC, but is crucial for modulating the various S oxidation states of the OEC. In PSII from higher plants the environment of YD• radical has been extensively characterized only in spinach (Spinacia oleracea) Mn- depleted non functional PSII membranes. Here, we present a 2D-HYSCORE investigation in functional PSII of spinach to determine the electronic structure of YD• radical. The hyperfine couplings of the protons that interact with the YD• radical are determined and the relevant assignment is provided. A discussion on the similarities and differences between the present results and the results from studies performed in non functional PSII membranes from higher plants and PSII preparations from other organisms is given.

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