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1989 (172)
1Author    H. Eidrun, A. Nke, E. Lisabeth, H. Illen, -. M. Aske, W. Olfgang SteglichRequires cookie*
 Title    9 ß-Hydroxymarasmic Acid and Other Sesquiterpenoids from Submerged Cultures of a Basidiomycete [1]  
 Abstract    9 ß-Hydroxymarasmic acid, a new sesquiterpenoid, marasmic acid and isovelleral were isolated from cultures of a basidiomycete. Comparison of the antimicrobial activity of the three natural compounds together with two n-butyl ether derivatives of marasmic acid revealed MICs against bacteria in the range of 0 .2 —20 ng/ml. The antifungal, cytotoxic and phytotoxic activities of isovelleral were similar to those exhibited by marasmic acid, whereas the marasmic acid deriva­ tives were considerably less active than the parent compound. Isovelleral was the only compound to show hemolytic activity. 
  Reference    Z. Naturforsch. 44c, 1 (1989); received August 31 1988 
  Published    1989 
  Keywords    Marasmic Acid, 9 ß-Hydroxymarasmic Acid, Isovelleral, Sesquiterpenoids, Antibiotics, Basidiomycetes 
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 TEI-XML for    default:Reihe_C/44/ZNC-1989-44c-0001.pdf 
 Identifier    ZNC-1989-44c-0001 
 Volume    44 
2Author    U. T. H Ro, R. M. Artin, J. ReichlingRequires cookie*
 Title    Rare Eugenol-and Z-Coniferyl Alcohol Derivatives in Roots of Three Coreopsis Species  
 Abstract    Roots of Coreopsis tinctoria. Coreopsis lanceolata. Coreopsis grandiflora, Compositae, Phenyl-propanoids Roots of three species of the genus Coreopsis (Compositae), C. tinctoria, C. lanceolata and C. grandiflora were investigated for the occurrence of phenylpropanoids. In addition to phenyl-propanoids already known from other Coreopsis species some new derivatives of eugenol-and Z-coniferyl alcohol were found. In this report we present their structures together with their 'H NMR. I3C NMR and MS data. Two aromatic acetylenes — one of them not previously described for Coreopsis species — were identified as well. 
  Reference    Z. Naturforsch. 44c, 7 (1989); received June 20/August 2 1988 
  Published    1989 
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 TEI-XML for    default:Reihe_C/44/ZNC-1989-44c-0007.pdf 
 Identifier    ZNC-1989-44c-0007 
 Volume    44 
3Author    R. Udolf Schendel, W. Olfhart, R. ÜdigerRequires cookie*
 Title    Electrophoresis and Electrofocusing of Phytochrome from Etiolated Avena sativa L  
 Abstract    Phytochrome from etiolated oat seedlings (Avena sativa L.) was investigated by "native" gel electrophoresis and by isoelectric focusing. At pH 8 . 8 the Pfr form migrated faster than the Pr form in electrophoresis. We assume a difference in the surface charge rather than a difference in shape for the phytochrome forms. This assumption was confirmed by isoelectric focusing which clearly showed relatively more negative charge in the Pfr form than in the Pr form. The role of the peptide region from residue 323 to 360 is discussed in this connection. It carries 9 negatively charged residues, it is exposed only in the Pfr form and it has already been described as a signal region for rapid protein degradation (PEST sequence, see Rogers et al., Science 234, 364—368, 1986). The experiments on electrofocusing revealed a microheterogeneity of phytochrome which was present in the native state as well as in the completely unfolded state. The most probable reason could be either posttranslational modification or genetic polymorphism of phytochrome in oat. 
  Reference    Z. Naturforsch. 44c, 12 (1989); received November 25 1988 
  Published    1989 
  Keywords    Microheterogeneity, Pest Sequence, Phytochrome Denaturation, Protein Conformation 
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 TEI-XML for    default:Reihe_C/44/ZNC-1989-44c-0012.pdf 
 Identifier    ZNC-1989-44c-0012 
 Volume    44 
4Author    Z. Schweiz, NaturforschRequires cookie*
 Title    Biosynthesis of Cytochalasans. XI. New Results on the Incorporation of Phenylalanine into Cytochalasin D by Zygosporium masonii [1]  
 Abstract    Incorporation of L-[2-:H]phenyl-[2-:H]alanine and L-phenyl-[2-l3C, l:,N]alanine into cytochala­ sin D by Zygosporium masonii involved the complete loss of both the a -;H-and the a-'^N-atom. Incorporation of a mixture of L-phenyl-[l;>N]alanine and L-[U-l4C]phenylalanine into cytochalasin D and protein amino acids (phenylalanine, leucine, isoleucine) was accompanied by a substantial loss of 15N with respect to 14C. These effects are attributed to rapid exchange reactions taking place while L-phenylalanine is part of the intracellular pool of amino acids. In addition, the medium-and concentration-dependent incorporation of the carbon skeleton of exogeneous D-phenylalanine into cytochalasin D is reported. In a peptone-based complex medium, D-phenyl-alanine is poorly incorporated. Throughout the whole concentration range (0 —250 mg/1), the incorporation rates are less than 10% of those of L-phenylalanine. In a minimal medium contain­ ing NH 4 NO3 as nitrogen source however, D-phenylalanine is preferred over the natural enantiomer by a factor of 1.28 up to 6.78, depending on the concentrations of exogeneous d -and L-phenylalanine. These effects are attributed to the medium-dependent activities of different amino acid transport systems responsible for the uptake of d -and L-phenylalanine in Z. masonii. 
  Reference    Z. Naturforsch. 44c, 19 (1989); received September 7 1988 
  Published    1989 
  Keywords    Cytochalasans, Cytochalasin D, Biosynthesis, Phenylalanine, Zygosporium masonii 
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 TEI-XML for    default:Reihe_C/44/ZNC-1989-44c-0019.pdf 
 Identifier    ZNC-1989-44c-0019 
 Volume    44 
5Author    W. Olfram, R. UllrichRequires cookie*
 Title    Effects of Glufosinate on Anion Uptake in Lemna gibba G  
 Abstract    The duckweed Lem na gibba G 1 was used as a model to study inhibitory sites with the herbicide and glutamate analogue glufosinate (PPT). Growth and chlorophyll formation were partly inhib­ ited by 25 n-M, completely suppressed by 250 (im PPT. Photosynthesis showed partial inhibition within few hours, dark respiration (0 2 consumption) increased already within one hour. In the presence of 1 mM PPT in the light, the ammonium pool of Lem na increased to 600% within few hours, later to 1000%. The overall amino acid pool exhibited a slower increase to 300%, the nitrate pool only a slight increase, while total phosphate remained almost unchanged. In the dark all these effects were less pronounced than in the light. Nitrate, nitrite and phosphate uptake were partially inhibited by PPT, especially after 19 h PPT pretreatment. Nitrate reductase activity in vitro, after PPT treatment in vivo, showed an inhibition similar to that of nitrate uptake. Ammo­ nium was not taken up but released under the same conditions. The data are explained by a combined effect of PPT, by inhibition of glutamine synthetase leading to accumulation of ammonium from photorespiration and proteolysis, by membrane depolarization and inhibition of anion/proton cotransport, by secondary uncoupling of phosphory­ lation, and by secondary inhibition of nitrate reductase activity. 
  Reference    Z. Naturforsch. 44c, 33 (1989); received July 13/November 11 1988 
  Published    1989 
  Keywords    Ammonium Accumulation, Nitrate Reductase Activity, Nitrate Uptake, Phosphate Uptake, Phosphinothricin Photosynthesis, Respiration 
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 TEI-XML for    default:Reihe_C/44/ZNC-1989-44c-0033.pdf 
 Identifier    ZNC-1989-44c-0033 
 Volume    44 
6Author    Iren, K. Ruk, K. Rzysztof, L. Ichszteld, T. Eresa, M. IchalskaRequires cookie*
 Title    Evidence for the Generation of Singlet Molecular Oxygen during Dopa and Dopamine Peroxidation  
 Abstract    Participation of singlet molecular oxygen (' 0 2) in peroxidation of dopa and dopamine was studied by measurements of chemiluminescence spectra, the influence of solvents with various lifetime of 0 : ('Ag) and 0 2 ('A g)-quenchers on quantum yield of chemiluminescence. A decrease of absorption and fluorescence intensities of 1,3-diphenylizobenzofuran (DPBF) was also studied in the presence of dopa and dopamine oxidized with alkaline H:0 2 as a criterion for the involvement of '0 2. 
  Reference    Z. Naturforsch. 44c, 39 (1989); received July 18/October 10 1988 
  Published    1989 
  Keywords    Dopa, Dopamine, Singlet Molecular Oxygen, Chemiluminescence 
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 TEI-XML for    default:Reihe_C/44/ZNC-1989-44c-0039.pdf 
 Identifier    ZNC-1989-44c-0039 
 Volume    44 
7Author    B. K. Jeldstad, A. Johnsson, K.M F Uruheim, A. Schie, B. Ergan, J. K. RaneRequires cookie*
 Title    Hyperthermia Induced Polyphosphate Changes in Propionibacterium acnes as Studied by 31P NMR  
 Abstract    The polyphosphate component in MP NMR spectra of the Gram-positive Propionibacterium acnes increased after hyperthermia treatment. The cells were exposed to temperatures in the interval from 15 °C to 45 °C. The amount of polyphosphate increased with increasing tempera­ ture. There were no temperature induced changes in the other phosphorous components seen in the spectra with exception of a decrease in ATP for higher temperatures. The increase in poly­ phosphates was less than that obtained from cells irradiated by near ultra-violet light. 
  Reference    Z. Naturforsch. 44c, 45 (1989); received October 10. 1988 
  Published    1989 
  Keywords    Polyphosphates, Hyperthermia, 31P NM R, Propionibacterium acnes, Oxidative Stress 
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 TEI-XML for    default:Reihe_C/44/ZNC-1989-44c-0045.pdf 
 Identifier    ZNC-1989-44c-0045 
 Volume    44 
8Author    Requires cookie*
 Title    Inhibitors Influencing Plant Enzymes of the Polyamine Biosynthetic Pathway  
 Abstract    Several enzymes involved in polyamine biosynthesis namely ornithine, arginine and S-adenosyl-methionine decarboxylase as well as spermidine synthase, were analyzed in partially purified wheat extracts. For all enzymes effective inhibitors were found. Among them the most interesting was l-aminooxy-3-aminopropane, which inhibited all three decarboxylases. Classical polyamine biosynthesis inhibitors like difluoromethylornithine, difluoromethylarginine. methyl glyoxal bis-(guanylhydrazone) and cyclohexylamine were also inhibitory on plant enzymes. A remarkable difference in the amount of arginine and ornithine decarboxylase existed in wheat. Arginine decarboxylase seems to be more important at least during the early stage of development. Influence of polyamine synthesis inhibitors on polyamine levels is more likely to come from arginine decarboxylase inhibitors. As inhibitors of all essential enzymes involved in plant polyamine biosynthesis were found, the study of the importance of polyamines in plant physiology will be considerably facilitated. 
  Reference    Z. Naturforsch. 44c, 49 (1989); received September 1 1988 
  Published    1989 
  Keywords    Triticum vulgare, S-Adenosylmethionine Decarboxylase, Arginine Decarboxylase, Ornithine Decarboxylase, Spermidine Synthase 
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 TEI-XML for    default:Reihe_C/44/ZNC-1989-44c-0049.pdf 
 Identifier    ZNC-1989-44c-0049 
 Volume    44 
9Author    H. Ansru Ed, F. Elix, Jost HarrRequires cookie*
 Title    Influence of Inhibitors of Polyamine Biosynthesis on Polyamine Levels and Growth of Plants  
 Abstract    Abutilon theophrasti, Lycopersicon esculentum, S-Adenosylmethionine Decarboxylase, Arginine Decarboxylase. Ornithine Decarboxylase, Spermidine Synthase Inhibitors of enzymes involved in polyamine biosynthesis which stop the growth of bacteria, fungi and animal cell systems were analyzed for their potential to interfere with plant cell systems. Several compounds were found to be potent inhibitors of plant enzymes, namely the decarboxyl­ ases of ornithine, arginine and S-adenosylmethionine as well as the aminopropyltransferase. Application of enzyme inhibitors (a-difluoromethylornithine. l-aminooxy-3-aminopropane, a-difluoromethylarginine, methylglyoxal bis(guanyl-hydrazone), cyclohexylamine) or combina­ tions of these on whole plant systems resulted neither in a large decrease in polyamine content nor in a significant growth reduction. The lack of response cannot be explained by hindered inhibitor uptake into plants. Inhibition of single enzymes may induce alternative biosynthetic pathways. 
  Reference    Z. Naturforsch. 44c, 55 (1989); received August 1 1988 
  Published    1989 
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 TEI-XML for    default:Reihe_C/44/ZNC-1989-44c-0055.pdf 
 Identifier    ZNC-1989-44c-0055 
 Volume    44 
10Author    M. Arbeth, Christ, JostH. Arr, Hansruedi FelixRequires cookie*
 Title    Transport of Polyamines in Sugar Beet Seedlings  
 Abstract    The high levels of polyamines generally found in cotyledons of seedlings might be exported to hypocotyls and radicles. l4C-Labelled putrescine applied to a sugar beet seedling through a cotyledon was found in small amounts as putrescine in the hypocotyl or radicle within a few minutes. Significant amounts of the labelled putrescine, however, were metabolized rapidly to compounds which could not be extracted into the organic phase on dansylation. 
  Reference    Z. Naturforsch. 44c, 59 (1989); received August 1. 1988 
  Published    1989 
  Keywords    Beta vulgaris, Cotyledon Hypocotyl, Metabolism Putrescine Radicle 
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 TEI-XML for    default:Reihe_C/44/ZNC-1989-44c-0059.pdf 
 Identifier    ZNC-1989-44c-0059 
 Volume    44 
11Author    AkikazuH. Atanaka, Kajiwara Tadahiko, Matsui Kenji, Masanori YamaguchiRequires cookie*
 Title    Product Specificity in an Entire Series of ((o-6Z,(i)-9Z)-C13~C2o-Dienoic Acids and -Dienols for Soybean Lipoxygenase  
 Abstract    Hydrophobic Interaction. (6Z,9Z)-Pentadecadienol. Soybean Lipoxygenase, Substrate Specificity Substrate specificity of soybean lipoxygenase-1 (EC 1.13.11.12) was studied using as synthetic substrate analogs an entire series of (co-6 Z,co-9 Z)-C l3~ C 2(rdienoic acids and (co-6Z,co-9Z)-C l2~ C 2(i-dienols. The relative activity of lipoxygenase-1 against linoleic acid (C|S2COOH) was the highest among the dienoic acids and that of (6Z.9Z)-pentadecadienol (C | 5 2OH) was the highest among the dienols. Soybean lipoxygenase-1 oxygenated almost at to-6 position of the dienoic acids independently of the chain length. With the dienols as substrate, the position of oxygenation was much influenced by the chain length. Above all, C 15:2OH was selectively oxygenated at co-10 rather than at co-6 . Kinetic analyses revealed that longer and more hydrophobic dienols had higher affinity but lower velocity of oxygenation reaction. But higher velocity was obtained when smaller K m value was observed for the dienoic acids. To elucidate stereospecificity of the oxygenation to C |5:2OH, optically active authentic samples were prepared via biological asymmetric reduction with baker's yeast. The oj-6 oxygenation to Ci5:2OH was found to be (S)-specific (R/S = 26/74) as is that to C,82COOH. whereas the co-10 oxygenation showed low enantioselectivity (R/S — 60/40). 
  Reference    Z. Naturforsch. 44c, 64 (1989); received June 27/October 5 1988 
  Published    1989 
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 TEI-XML for    default:Reihe_C/44/ZNC-1989-44c-0064.pdf 
 Identifier    ZNC-1989-44c-0064 
 Volume    44 
12Author    Ulrich FischerRequires cookie*
 Title    Characterization of Two Soluble Basic Cytochromes Isolated from the Anoxygenic Phototrophic Sulfur Bacterium Chlorobium phaeobacteroides  
 Abstract    Chlorobium phaeobacteroides, Green Sulfur Bacteria, Flavocytochrome c-552, Cytochrome c-555 Chlorobium phaeobacteroides contains two soluble basic c-type cytochromes, a flavocyto­ chrome c-552 and a small cytochrome c-555. Both electron transfer proteins were highly purified by ion exchange chromatography and gel filtration. The flavocytochrome c-552 exhibits maxima at 552 nm, 523 nm and 416 nm in the reduced state and at 409.5 nm with two shoulders at 440 nm and 480 nm in the oxidized form. The best purity index { A ^ A ^ obtained was 0.65. The molecular properties of this flavocytochrome are as follows: isoelectric point, pH 9.5 — 10; redox potential, +63 mV; molecular weight, 56,000. Cytochrome c-555 is a small basic hemoprotein with an isoelectric point of pH 9.5 — 10, a molecular weight of 9,500 and a midpoint redox potential of +105 mV. The best purity index {AlfJ A 418) obtained was 0.176. The oxidized form of this cytochrome has a maximum at 411.5 nm, while the reduced state shows three maxima (a-band at 554.5 nm; ß-band at 523 nm, and y-band at 418 nm). The a-band is asymmetrical with a typical shoulder at 551 nm. 
  Reference    Z. Naturforsch. 44c, 71 (1989); received October 6 1988 
  Published    1989 
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 TEI-XML for    default:Reihe_C/44/ZNC-1989-44c-0071.pdf 
 Identifier    ZNC-1989-44c-0071 
 Volume    44 
13Author    Monika Kern, Jobst-H Einrich KlemmeRequires cookie*
 Title    Inhibition of Bacteriochlorophyll Biosynthesis by Gabaculin (3-Amino, 2,3-dihydrobenzoic Acid) and Presence of an Enzyme of the C5-Pathway of 5-Aminolevulinate Synthesis in Chloroflexus aurantiacus  
 Abstract    Chloroflexus aurantiacus, ö-Aminolevulinate, Bacteriochlorophyll. Gabaculin. Glutamate-Q-pathway Biosynthesis of bacteriochlorophyll c and a in the thermophilic phototrophic prokaryote. Chloroflexus aurantiacus 0k-70-fl, was strongly inhibited by the antibiotic gabaculin (3-amino 2,3-dihydrobenzoic acid), an inhibitor of the glutamate-C5-pathway of ö-aminolevulinate (A LA) synthesis. The key enzyme of the Shemin-pathway of ALA formation, ALA synthase (EC 2.3.1.37), was not detected in cell extracts of Chi. aurantiacus. However, the extracts catalyzed ALA formation from glutamate 1-semialdehyde, a reaction being highly sensitive to gabaculin. 
  Reference    Z. Naturforsch. 44c, 77 (1989); received September 23. 1988 
  Published    1989 
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 TEI-XML for    default:Reihe_C/44/ZNC-1989-44c-0077.pdf 
 Identifier    ZNC-1989-44c-0077 
 Volume    44 
14Author    A. A. Juknat, D. D. Örnem Ann, H. SengerRequires cookie*
 Title    Different Porphobilinogenases in Cytoplasm and Isolated Chloroplasts from Light-Grown Euglena gracilis Z  
 Abstract    Porphyrinogens. Euglena gracilis Z ., Porphyrin Biosynthesis. Porphobilinogenase. Euglena Chloroplasts Lysed cells as well as different fractions of isolated, disrupted chloroplasts from light grown Euglena gracilis were tested for their capability of porphyrin biosynthesis. It is shown that the formation of the soluble porphobilinogenase (PBG-ase) fraction is inhibited by cycloheximide indicating its biosyntheses on 80S ribosomes, whereas the formation of the membrane bound chloroplast PBG-ase is chloramphenicol sensitive. Different pH-optima are demonstrated for the two enzymes. From the presented results it is deduced from those isolated from dark grown cells. 
  Reference    Z. Naturforsch. 44c, 81 (1989); received September 26. 1988 
  Published    1989 
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 TEI-XML for    default:Reihe_C/44/ZNC-1989-44c-0081.pdf 
 Identifier    ZNC-1989-44c-0081 
 Volume    44 
15Author    B. Ert+, W. E. Ck, H. Ard T+, K. Jäkel, P. Moser, D. Sozzi+, C. VogelRequires cookie*
 Title    Quantitative Structure Activity Relationships of Fungicidally Active Triazoles: Analogs and Stereoisomers of Propiconazole and Etaconazole  
 Abstract    The preparation of the four stereoisomers of propiconazole (TILT®) is described. Their inhibi­ tion of the 14a-C-demethylation of the sterol nucleus is examined and compared with the inhibi­ tion by the four stereoisomers of etaconazole (SONAX®). The quantitative structure-activity relationships (Q SAR) of substituted l,3-dioxolane-2-yl-methyltriazoles and l,3-dioxane-2-yl-methyltriazoles on in vivo fungicidal activity are investigated. 
  Reference    Z. Naturforsch. 44c, 85 (1989); received September 8. 1988 
  Published    1989 
  Keywords    Propiconazole, Etaconazole, Triazoles, Fungicides, OSAR 
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 TEI-XML for    default:Reihe_C/44/ZNC-1989-44c-0085.pdf 
 Identifier    ZNC-1989-44c-0085 
 Volume    44 
16Author    Aloysius Wild, Christine ZieglerRequires cookie*
 Title    The Effect of Bialaphos on Ammonium-Assimilation and Photosynthesis I. Effect on the Enzymes of Ammonium-Assimilation  
 Abstract    In this investigation, the effect of bialaphos (phosphinothricyl-alanyl-alanine) on the enzymes involved in NH4+-assimilation — glutamine synthetase, glutamine-2-oxoglutarate aminotrans­ ferase, glutamate dehydrogenase — is examined and compared to the effect of phosphinothricin (glufosinate) on the same enzymes. Bialaphos was given to whole plants (in vivo) and to leaf homogenate (in vitro). The investigation showed that bialaphos has an inhibiting effect on glutamine synthetase in vivo, but not in vitro. In contrast to this, phosphinothricin inhibits glutamine synthetase in vitro as well as in vivo. It was found that bialaphos, similar to phosphinothricin, does not inhibit glutamine-2-oxoglutarate aminotransferase and glutamate dehydrogenase in vivo or in vitro. Only at bialaphos concentrations exceeding 10 mM, there is an inhibition of glutamate dehydrogenase in vitro. Using radioactive ['Hjbialaphos (phosphinothricyl-'H-alanyl-alanine) it could be demonstrated that in the plant, bialaphos is split into phosphinothricin and alanine. The phosphinothricin released is probably the active herbicide component. Consequently, the herbicidal effects of phosphinothricin and bialaphos are the same. In troduction 
  Reference    Z. Naturforsch. 44c, 97 (1989); received September 23 1988 
  Published    1989 
  Keywords    Ammonium-Assimilation, Bialaphos, Glutamine Synthetase Herbicide Phosphinothricin 
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 TEI-XML for    default:Reihe_C/44/ZNC-1989-44c-0097.pdf 
 Identifier    ZNC-1989-44c-0097 
 Volume    44 
17Author    Christine Ziegler, Aloysius WildRequires cookie*
 Title    The Effect of Bialaphos on Ammonium-Assimilation and Photosynthesis II. Effect on Photosynthesis and Photorespiration  
 Abstract    The application of bialaphos (phosphinothricyl-alanyl-alanine) effects a quick photosynthesis inhibition under atmospheric conditions (400 ppm C 0 2, 21% 0 2). However, under conditions (1000 ppm C 0 2, 2% 0 2) under which photorespiration cannot occur there is no photosynthesis inhibition. In the previous investigation it could be shown that bialaphos splits in plants into phosphinothricin and alanine. The inhibition of glutamine synthetase through freed phosphino­ thricin results in an NH4+-accumulation and a decrease in glutamine. With the addition of glutamine, photosynthesis inhibition by bialaphos can be reduced. An NH4+-accumulation takes place under atmospheric conditions as well as under non-photorespiratory conditions; though in the latter case, in less amounts. After adding glutamine and other amino acids the NH4+-accumu-lation increases especially. This indicates that NH4+-accumulation cannot be the primary cause for photosynthesis inhibition by bialaphos. The investigations indicate that for the effectiveness of either bialaphos or phosphinothricin, a process in connexion with photorespiration plays a consid­ erable role. The glyoxylate transamination in photorespiration could be inhibited, which results probably on a glyoxylate accumulation. Corresponding investigations showed inhibition of photo­ synthesis as well as a direct inhibition of RubP-carboxylase with glyoxylate. 
  Reference    Z. Naturforsch. 44c, 103 (1989); received September 23 1988 
  Published    1989 
  Keywords    Ammonium-Accumulation Bialaphos, Phosphinothricin, Photorespiration, Photosynthesis 
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 TEI-XML for    default:Reihe_C/44/ZNC-1989-44c-0103.pdf 
 Identifier    ZNC-1989-44c-0103 
 Volume    44 
18Author    Anastasios Melis, C. Onrad, W. M. Ullineaux, JohnF. AllenRequires cookie*
 Title    Acclimation of the Photosynthetic Apparatus to Photosystem I or Photosystem II Light: Evidence from Quantum Yield Measurements and Fluorescence Spectroscopy of Cyanobacterial Cells  
 Abstract    Cells of the cyanobacterium Synechococcus 6301 were grown under illumination whose spectral composition favoured absorption either by the phycobilisome (PBS) light-harvesting antenna of photosystem II (PS II) or by the chlorophyll (Chi) a light-harvesting antenna of photosystem I (PS I). Cells grown under PS I-light developed relatively high PS II/PS I and PBS/Chl ratios. Cells grown under PS II-light developed relatively low PS II/PS I and PBS/Chl ratios. Thus, the primary difference between cells in the two acclimation states appeared to be the relative concentration of PBS-PS II and PS I complexes in the thylakoid membrane. Measurements of the quantum yield of oxygen evolution suggested a higher efficiency of cellular photosynthesis upon the adjustment of photosystem stoichiometry to a specific light condition. The quantum yield of oxygen evolution was nevertheless lower under PBS than Chi excitation, suggesting quenching of excitation energy in the photochemical apparatus of PS II in Synechococcus 6301. This phenomenon was more pronounced in the PS II-light than in the PS I-light grown cells. Room temperature and 77 K fluorescence emission spectroscopy indicated that excess excitation energy in the PBS was not transferred to PS I, suggesting the operation of a non-radiative and non-photochemical decay of excitation energy at the PBS-PS II complex. This non-photochemical quenching was specific to conditions where excitation of PS II occurred in excess of its capacity for useful photochemistry. 
  Reference    Z. Naturforsch. 44c, 109 (1989); received October 1 1988 
  Published    1989 
  Keywords    Photosystem Stoichiometry, Thylakoid Membrane, Light-Harvesting, Excitation Energy Dis­ tribution, Oxygen Evolution 
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 TEI-XML for    default:Reihe_C/44/ZNC-1989-44c-0109.pdf 
 Identifier    ZNC-1989-44c-0109 
 Volume    44 
19Author    P. Solymosi, E. LehoczkiRequires cookie*
 Title    Co-Resistance of Atrazine-Resistant Chenopodium and Amaranthus Biotypes to other Photosystem II Inhibiting Herbicides  
 Abstract    Biotypes of Amaranthus retroflexus L., A. hybridus L., A. bouchonii Thell. and Chenopodium album L. insensitive to atrazine were collected from maize monoculture where atrazine had been applied extensively. Atrazine-resistant biotypes of A. retroflexus and A. hybridus showed phen­ medipham and lenacil co-resistance and atrazine-resistant biotype of C. album showed fenuron co-resistance. An atrazin-resistant biotype of A. bouchonii with co-resistance to diuron was not resistant to fenuron, lenacil and phenmedipham. 
  Reference    Z. Naturforsch. 44c, 119 (1989); received August 22 1988 
  Published    1989 
  Keywords    Atrazine-Resistance, Atrazine and Diuron, Fenuron, Lenacil, Phenmedipham Co-Resistance, Amaranthus bouchonii, A hybridus, A retroflexus, Chenopodium album 
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 TEI-XML for    default:Reihe_C/44/ZNC-1989-44c-0119.pdf 
 Identifier    ZNC-1989-44c-0119 
 Volume    44 
20Author    Hartmut Gimmler, Lothar Schneider, Rosemarie KaadenRequires cookie*
 Title    The Plasma Membrane ATPase of Dunaliella parva  
 Abstract    ATPase. Anion Transport, Calcium. Dunaliella, Magnesium Plasma membrane Mg2+, Ca2+ ATPases were isolated from Dunaliella parva by differential centrifugation and subsequent sucrose gradient centrifugation and analyzed for their properties with special emphasis on ecophysiological requirements of this extremely salt-tolerant alga. Most properties (Vmax-and AfM-values, substrate specificity, vanadate and DES sensitivity, resistance against ouabain) indicate that the ATPases of the plasma membrane of D. parva are basically of the same type as that found in the plasma membrane of other algae or higher plants. However, some interesting deviations from the normal characteristics of plasma membrane ATPases of plants were observed for the Dunaliella ATPases. These modifications partially may reflect adaptations of the ATPase and/or the microenvironment of the ATPase to the highly saline environment of this alga; 1) The plasma membrane ATPase of D. parva requires unusually high concentrations of divalent cations (up to 100 mM Mg2+ or Ca:+) for maximal activity. Both cations can substitute for each other. 2) The plasma membrane ATPase of D. parva is extremely resistant against salt. It was stimulated by NaCl or KC1 at concentrations up to 800 m M , whereas at higher salt concentrations the enzyme was inhibited. However, about 2.5 m NaCl was required for half-maximal inhibition of ATPase activity. 3) The ATPase was inhibited by inhibitors of anion transport such as SITS and D ID S . which suggests direct or indirect involvement of ATPase in anion transport. The possible functions of the plasma membrane ATPases are discussed with special emphasis on problems related to the hypersaline environment of this alga. 
  Reference    Z. Naturforsch. 44c, 128—138 (1989); received August 12/October 10. 1988 
  Published    1989 
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 Identifier    ZNC-1989-44c-0128 
 Volume    44 
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