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1Author    Fabrice Franck, GeorgH. SchmidRequires cookie*
 Title    Flash Pattern of Oxygen Evolution in Greening Etioplasts of Oat  
 Abstract    Etioplasts isolated from oat leaves that have received two 5 m in illum ination periods, spaced apart by a 90 min dark interval, are able to evolve oxygen. If this oxygen evolution is measured as consequence o f short saturating light flashes a pattern is obtained w hich in agreem ent with the Kok-Joliot model shows a dam ped oscillation w ith a periodicity o f four. As usual for most other systems the maximum flash yield is observed under the third flash. In continuous light such slightly greened etioplasts show a small oxygen gush. From our studies it appears that the second 5 min illumination period is obligatory for oxygen evolution. O m ission o f this period leads to a condition in which under flashes strictly no oxygen is evolved. In continuous light under these conditions no oxygen gush but rather an uptake is observed after onset o f illum ination. It appears that in greening etioplasts the flash pattern shows som e peculiarities when compared to the normal green conditions. Thus, a flash sequence o f a greening etioplast always shows a substantial positive amperometric signal under the first flash. The h alf tim e o f the state which would belong to this signal is 3 to 4 min in a greening etioplast, isolated from leaves that have received 2 h light. In the course o f greening this h alf tim e decreases continuously and reaches a normal and constant value o f approx. 1 0 s in chloroplasts from green oat or etiochloroplasts that are prepared from leaves that have received 15 h o f light. The result is discussed in terms o f metastable S3 which seems to be a property o f the developing oxygen evolving system in greening oat leaves. In the greening system as we use it is shown for the first tim e that the photoenzym e protochlorophyllide chlorophyllide reductase is D C M U sensitive. 
  Reference    Z. Naturforsch. 39c, 1091 (1984); received August 17 1984 
  Published    1984 
  Keywords    Flash Yield, Oxygen, S-States, Etioplasts 
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 TEI-XML for    default:Reihe_C/39/ZNC-1984-39c-1091.pdf 
 Identifier    ZNC-1984-39c-1091 
 Volume    39 
2Author    P. He, R. Schulder, K. P. Bader, G. H. SchmidRequires cookie*
 Title    Effect of Cyanide on the S2-and S3-State in the Filamentous Cyanobacterium Oscillatoria chalybea  
 Abstract    Filam Low concentrations o f cyanide affect the flash-induced oxygen evolution pattern in thyla-koid preparations o f the filamentous cyanobacterium Oscillatoria chalybea. At a cyanide con­ centration o f 2 x 10~6 m the effect lies exclusively on the S2-and S3-state whereas the sub­ sequent flash yields and the steady state are barely affected, showing that the reaction center is not touched by the reagent. The influence o f the chemical is characterized by the fact that at basic pH (7 .5 -8 .5) the deactivation mode o f S2 and S3 is changed, showing that the cyanide-ion is the reactant. Whereas in the control the deactivation o f S, yields as usual S, and S_,, the deactivation pattern in the presence o f cyanide shows that S2 deactivates -without giving S, -, to a more reduced state, probably S0. In the flash pattern the two signal amplitudes o f the first two flashes are lowered to zero in the presence o f 2 x 10~6 m cyanide and becom e uptake signals at higher cyanide concentrations. It is seen that in the presence o f cyanide S2 and to a lesser extent S3 in the Oscillatoria system apparently react with oxygen. In tobacco thylakoids no effect o f cyanide on the flash pattern itself is observed, even at higher concentrations (e.g. 1 0 " 4 m), although the signal amplitudes o f the entire pattern are affected at such concentra­ tions. Photosystem II o f cyanobacteria is characterized by the absence o f the two extrinsic 16 kD a and 23 kD a peptides. As shown by mass spectrometry inside-out vesicles from tobacco thylakoids, in which these two extrinsic peptides have been removed by NaCl-washing, exhibit sim ultaneously flash-induced 0 2-evolution and an 0 2-uptake which both require the presence o f CL and C a2+ ions. Both the evolution signal and the uptake signal are D C M U sensitive and are inhibited by KCN. An amperometrically measured flash pattern o f inside-out tobacco ves­ icles shows, if the assay is supplemented with CL ions, the usual flash pattern known from the literature. The experiments seem to indicate that even in the washed inside-out condition the S-state system o f higher plants is much less sensitive to ambient oxygen than in the phylo-genetically older system o f the filamentous cyanobacterium Oscillatoria chalybea. 
  Reference    Z. Naturforsch. 47c, 69—7 (1992); received September 30 1991 
  Published    1992 
  Keywords    entous Cyanobacterium, Water-Splitting, S-States 
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 TEI-XML for    default:Reihe_C/47/ZNC-1992-47c-0069.pdf 
 Identifier    ZNC-1992-47c-0069 
 Volume    47 
3Author    P. He, K. P. Bader, G. H. Schm, G. Renger, K. P. Bader, G. H. SchmidRequires cookie*
 Title    Mass Spectrometric Analysis of N 2-Formation Induced by the Oxidation of Hydrazine and Hydroxylamine in Flash Illuminated Thylakoid Preparations of the Filamentous Cyanobacterium Oscillatoria chalybea  
 Abstract    Analogue In tobacco chloroplasts hydrazine-dependent dinitrogen form ation measured by mass spec­ trometry as the consequence o f short saturating light flashes is always linked to a substantial oxygen uptake (1990). However, in thylakoids o f the filamentous cyanobacterium Oscillatoria chalybea this dinitrogen formation is not linked to an apparent 0 2-uptake, even at the high concentration o f 1 mM hydrazine. Whereas in tobacco chloroplasts Tris-treatment does not affect hydrazine de­ pendent dinitrogen formation up to a concentration o f 3 mM hydrazine, Tris-treatment o f thy­ lakoids o f O. chalybea affects strongly both oxygen evolution and dinitrogen evolution under a single turnover flash as well as under ten flashes. In contrast to tobacco chloroplasts, the pres­ ence o f hydrazine up to concentrations o f 3 mM does not substantially affect photosynthetic 0-,-evolution. The observed dinitrogen evolution is affected by D C M U regardless whether in­ duced by a single turnover flash or by ten flashes, whereas in tobacco dinitrogen evolution and the 0-,-uptake linked to it (which is not observed in the cyanobacterium) were clearly not af­ fected by D C M U in the single turnover flash. In Oscillatoria the earlier described Photosystem II-mediated H-,0-, formation and decom position is influenced by hydrazine. In the presence o f 300 hm hydrazine the usually present 0 2-uptake leading to H:0 : formation appears dimin­ ished. 
  Reference    Z. Naturforsch. 46c, 629 (1991); received March 21 1991 
  Published    1991 
  Keywords    Filamentous Cyanobacterium, Photosystem II, Water Splitting, S-States, Hydrogen-Peroxide 
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 TEI-XML for    default:Reihe_C/46/ZNC-1991-46c-0629.pdf 
 Identifier    ZNC-1991-46c-0629 
 Volume    46 
4Author    Yoshihiro Shiraiwa, GeorgH. SchmidRequires cookie*
 Title    Effect of the C 0 2-Concentration during Growth on the Oxygen Evolution Pattern under Flash Light in Chlorella  
 Abstract    Photosynthetic 0 2-evolution patterns were determined in cells of Chlorella vulgaris 211 — 11 h, grown under air enriched with 2% C 0 2 (High C 0 2-cells) and under ordinary air (Low C 0 2-cells). Oxygen evolution in these algae was measured as consequence of short saturating light flashes with the three electrode system according to Schmid and Thibault, Z. Naturforsch. 34c, 414 
  Reference    Z. Naturforsch. 41c, 269 (1986); received November 25 1985 
  Published    1986 
  Keywords    Oxygen Evolution, Flash Sequence, S-States, Carbonic Anhydrase, C 0 2-Effect, Chlorella 
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 TEI-XML for    default:Reihe_C/41/ZNC-1986-41c-0269.pdf 
 Identifier    ZNC-1986-41c-0269 
 Volume    41