bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of ß-Carotene on Delayed Light Emission from Aggregated Chlorophyll
Authors: Yang Shan-Yuan , Brody S. S.
Published: August 2018

Delayed light emission (DLE) from aggregated chlorophyll is used to probe energy transfer between aggre­ gated chlorophyll and β-carotene. Preilluminated β-carotene when injected into a dark chamber containing aggregated chlorophyll, induces DLE from aggregated chlorophyll. If the dark chamber contains only monomeric chlorophyll, there is no DLE. The intensity of DLE is dependent on the time of illumination of β-carotene. The decay of energy stored by the carotene is not a first order process. The first half life is about 2 min, the next about 10 min
Structure Confirmation for an Unusual Flavanone from Encelia stenophylla
Authors: Iinuma M. , Tanaka T. , Mizuno M. , Wollenweber E.
Published: August 2018

A flavanone with 3′-OH as the sole B-ring substituent has been reported recently as a leaf and stem exudate constituent of Encelia stenophylla. The correctness of this unusual substitution is confirmed by synthesis of this flavanone.
Flavonol Glycosides from Paederia scandens var. mairei
Authors: Ishikura Nariyuki , Yang Zhi-qing , Yoshitama Kunijiro , Kurosawa Kazu
Published: August 2018

Four kaempferol glycosides and five quercetin glycosides have been isolated from a methanolic extract of Paederia scandens var. mairei leaves and stems, in which in addition four un­known glycosides of kaempferol and quercetin are present in a trace. Nine flavonol glycosides including a new glycoside quercetin 3-O-rutinoside-7-O-xylosylglucoside (paederinin) were identified by PC, HPLC, UV spectral and NMR studies.
n-Alkanes -Common Surface Constituents of Pollen from Gymno-and Angiosperms
Authors: Hagenberg Susanne , Wehling Klaus , Wiermann Rolf
Published: August 2018

The surface waxes of several gymnosperm and angiosperm pollen were separated into different lipid classes. n-Alkanes were found to be common constituents of these waxes. They appeared as a homologous series ranging from C20 to C33. The distribution patterns of n-alkanes from gymnosperm pollen displayed little variation whereas those of angiosperm pollen exhib­ited pronounced differences from one another. It is noteworthy that especially for the gymno­sperm species, homologues with even and odd numbers of carbons occurred in similar amounts.
Screening of Basidiomycetes and Ascomycetes for Plant Growth Regulating Substances. Introduction of the Gibberellic Acid Induced de-novo Synthesis of Hydrolytic Enzymes in Embryoless Seeds of Triticum aestivum as Test System
Authors: Hautzel Ralf , Anke Heidrun
Published: August 2018

A new test system for the detection of plant growth regulating activities was successfully employed. In a screening for inhibitors of the gibberellic acid controlled synthesis of hydrolytic enzymes in embryoless wheat seeds (Triticum aestivum) 160 cultures of ascomycetes and basi­diomycetes were tested. In the extracts of two cultures inhibitory activities were detected. From fermentations of a Hypholoma-species (basidiomycetes) 3,5-dichloro-4-methoxybenzyl alcohol was isolated as the active principle.

Galiellalactone and two other new phytotoxins were isolated from cultures of the ascomycete Galiella rufa. At concentrations of 50 μg/ml all four compounds inhibited the de-novo synthesis of α-amylases, proteases, and phosphatases. Further investigations on the mode of action revealed, that all four metabolites interfere with early steps of the biosynthetic path­ ways induced by gibberellic acids. In vivo, the germination of the seeds of several plants was inhibited by these compounds.
Carotenoid Composition of Needles of Picea abies L. Showing Signs of Photodamage
Authors: Young Andrew J. , Britton George , Senser Margot
Published: August 2018

The pigment composition of needles of Picea abies L. taken from sites in the Bavarian forest has been determined. Needles were removed from (a) healthy, control trees, (b) trees which showed visible signs of damage for either 6 months or 3.5 years, and (c) trees which had received supplemental fertilizer application. In general, needles taken from these trees could be placed into three categories; (i) green, (ii) partially chlorotic, and (iii) partially necrotic (brown). Whilst the pigment composition of needles taken from healthy trees was typical of any higher plant, substantial changes in the chlorophyll and carotenoid content of the damaged needles were recorded. Particularly noticeable was an increase in the ratio of total carotenoid/chlorophyll and losses of neoxanthin and violaxanthin. Levels of total carotene (α- and β-carotene) and, especially, of lutein remained high in damaged needles. Levels of zeaxanthin were highest in the brown, partially necrotic, needles.
An Amperometric Study on the Time Constants of Oxygen Release in Thylakoids of Nicotiana tabacum and Oscillatoria chalybea
Authors: Schulder R. , Bader K. P. , Schmid G. H.
Published: August 2018

Measurement of photosynthetic oxygen evolution in tobacco chloroplasts and thylakoids of the filamentous cyanobacterium Oscillatoria chalybea by means of the “Three-Electrode-System”, described by Schmid and Thibault in 1979, yields half-rise times for the directly measured amperometric O2-signal of approximately 2 msec for tobacco chloroplasts and slightly more than 2 msec for thylakoids of Oscillatoria chalybea. An estimate of the possible contribution of the diffusion time required for oxygen to leave the thylakoid membrane (7.5 nm thickness) or the chloroplast (diameter 4 -5 μm) might bring the measured O2-release time below 1 msec in full agreement with measurements by Joliot et al. in 1966.
Protection of Photosystem II by Light in Heat-Stressed Pea Leaves
Authors: Havaux Michel , Strasser Reto J.
Published: August 2018

Modulated 685-nm chlorophyll fluorescence was measured under steady-state conditions in pea leaves adapted to moderate actinic light. When the measurements were performed after a short exposure to heat (42 °C) in darkness, the maximal (Fm) and steady-state (Fs) fluorescence levels were dramatically and irreversibly quenched whereas the basic fluorescence Fo remained unchanged. Concomitantly , photo synthetic O2 evolution was irreversibly inhibited. Analysis of the fluorescence data suggested that the heat treatment affected primarily the PS II reaction center, with the main effect being presumably an increased thermal dissipation of the excita­tion energy transferred to the reaction centers. In contrast, when heat stress was imposed in the presence of light, the loss of variable fluorescence (Fm-Fo) was much less marked and was fully reversible. In addition , no inhibition of in vivo O2 : evolution was observed when the samples heated in the light were recooled at 25 °C. The results indicate that light acted as an efficient protector of PS II against heat injury.
The Effect of Glutathion on the Reaction of cis-and fra/25-Diamminedichloroplatinum(II) with DNA
Authors: Oliński Ryszard
Published: August 2018

Abstract Differential pulse polarography study was used to investigate the influence of glutathion on cis-and trans-DDP induced alterations of DNA structure. Though the applied concentration of glutathion has no effect on the reaction of DNA with cis -DDP , it greatly modifies the reac­tion with trans isomer. This may be an important reason for the ineffectivness of the trans-DDP as an antitumor drug.
Further Isoflavonoids from White Lupin Roots
Authors: Tahara Satoshi , Shibaki Seiji , Ingham John L. , Mizutani Junya
Published: August 2018

Further investigation of the isoflavonoids in white lupin roots has revealed a new coumaronochromone with a 2-hydroxy-3-methyl-3-butenyl side chain (lupinalbin G), three new pyrano-isoflavones (lupinisoflavones K and L, and allolicoisoflavone B) and two new di-hydrofurano-isoflavones each with a 2,3-dihydroxy-3-methylbutyl substituent (lupinisoflavones M and N). The biogenetic pathways for these and other lupin isoflavones are briefly discussed.
Light-Dependent Sucrose Synthesis in Cell-Free (Reconstituted) Lysates of Evacuolated Mesophyll Protoplasts
Authors: Steingraber Manfred , Frohnmeyer Hanns , Hampp Rüdiger
Published: August 2018

Oat mesophyll protoplasts were evacuolated by centrifugation on a Percoll gradient and used as starting material for establishing a functional cell-free system. For this purpose evacuolated protoplasts were osmotically lysed. From the resulting homogenate a cytosolic fraction was obtained by silicon oil filtration. This fraction was used to dilute preparations of lysed evacu­olated protoplasts in order to reduce the number of organelles per volume cytosol. The latter was necessary to increase light-dependent oxygen evolution of the cell-free system. The result­ing kind of “reconstituted” system showed light-dependent sucrose formation (about 100 nmol (mg Chi)-1 · hr-1) with bicarbonate as the only substrate. As this property depends on a functional interaction of chloroplast and cytosolic reactions, this cell-free system appeared to perform essential steps of partitioning of CO2 between starch and sucrose. Addition of about 12 μm fructose 2 ,6 -bisphosphate, an inhibitor of fructose 1,6 -bisphosphatase and an activator of the PPi-dependent fructose 6 -phosphate phosphotransferase, caused sucrose degradation in the light. Thus, this cell-free system allows both the study of cytosolic enzyme activities under quasi in vivo conditions and the manipulation of cellular reaction sequences by plasma mem­brane-impermeable compounds.
Degradation of the D -l Protein Subunit of Photosystem II in Isolated Thylakoids by UV Light
Authors: Trebst Achim , Depka Brigitte
Published: August 2018

Thylakoid membranes from spinach were irradiated with UV light of 254 nm. Photosynthetic electron flow driven by photosystem II, but not by photosystem I is fully inactivated in about 2-5 min. Inactivation of electron flow is prevented by inhibitors of the QB site of both the DCMU and of the phenol type. UV light inactivates electron How both under anaerobic and aerobic conditions. This is in contrast to white light where fast inactivation occurs only under anaerobic conditions and where only inhibitors of the DCMU-type protect. Inactivation of electron flow by UV light is followed on a slower time scale by a specific degradation of thylakoid membrane proteins. As shown by immunoblotting the D-1 protein and to a smaller extent also the D-2 protein subunit - that together form the reaction center of photosystem II - are de- graded during UV light irradiation. The disappearance of these proteins occurs only under aerobic conditions. Both types of QB site inhibitors prevent the degradation of the two plasto-quinone-binding proteins. A degradation product of the D-l protein is observed at about 8 kDa size. The results are discussed in their relevance to rapid turnover and photoinhibition in vivo and to the topology of the quinone-binding site in the D-1 and D-2 protein.
Arsenic Depuration via the Tridacna Gill Membrane
Authors: Benson Andrew A.
Published: August 2018

Arsenate absorbed by zooxanthcllac in Tridacna species is converted to water-solubie arsen- ical products which accumulate in the kidney with concentrations up to 2%. Kinetic uptake experiments with radioarsenatc revealed rapid labeling in the algae and in the membrane lipids of the gills. Since the arsenic content of the gills is low. it is concluded that turnover is rapid and that the gills are the site of arsenic depuration in these clams. The amphipathic lipid nature of the gill arsenicals suggests membrane lipid mediation of the process.
Rhythmic Leaf Movements under Physical Loading of the Leaves
Authors: Pedersen M. , Johnsson A. , Herbjørnsen R.
Published: August 2018

The effect of physical loading on period and amplitude of the ultradian oscillating leaflets of Codariocalyx motorius (= Desmodium gyrans) and the circadian oscillating leaves of Oxalis regnellii was investigated. In Codariocalyx the leaflets were loaded with pieces of copper thread which were clamped to the leaflet. Weights of the loads varied from 3 to 12 mg, and a typical leaflet is 1.5 mg. In about 80% of the cases we recorded an increase of the period length due to the loading in the order of 10% (the period length is typically 3-4 min). The amplitude was lowered in all the cases, the magnitude depending on the size of the weight used. In most of the cases, when not too heavily loaded, both amplitude and period returned to (or close to) the previous value when the leaflets were unloaded. In Oxalis the leaves were loaded with metal clips fixed to the leaflets at the midrib position. All three leaflets on a stalk were loaded. The clips used weighed 390 ± 0.4. 640 ± 6 and 810 ± 4 mg respectively, and a typical leaflet is 91 ± 4 mg. For the heaviest weights at least, this resulted in a lowering of the amplitude, but the oscillations continued, and we could not observe any effect on the period of the rhythmic movements.
Electron Microscopic Study of the Polymyxin Treated Vibrio cholerae Cells
Authors: Mandal T. K.
Published: August 2018

Polymyxin B produces dose dependent changes in the surface topography of pathogenic Vibrio cholerae cells. The susceptibilities of various vibrio strains to PB are also studied through analytical techniques. Statistical analysis shows significant differences among the four vibrios with regard to their sensitivities to PB, the classical strains being the most sensitive. Treating the classical strain with subinhibitory concentration of PB. we observed with both SEM and TEM that the normal smooth surface of the cell envelope develops some protruded structures (blebs and crenations). Further the TEM study of the ultrathin sections reveal that the rod like projections are formed by protrusions of the outer-membrane of the cell wall.
Flavonoids from Vicia faba Seed Exudates
Authors: Tomás-Lorente Francisco , Garcia-Grau Manuela M. , Tomás-Barberán Francisco A.
Published: August 2018

From the seed exudates of Vicia faba L. (cv. Muchamiel) the flavonoid aglycones 7,3′,4′-trihydroxyflavone, 7,4′-dihydroxyflavone, quercetin and kaempferol, and the flavonoid glycosides quercetin 7-glucoside and kaempferol 7-glucoside were identified. This is the first time that the flavonoids present in Vicia seed exudates are described. The study of the flavonoids present in legume seed and root exudates is especially important since these substances may act as chemical signals activating or inhibiting Rhizobium nodulation genes. In fact, the activating effect on Rhizobium nod genes of 7,3′,4′-trihydroxyflavone and 7,3′-dihydroxyflavone has previously been reported. It is remarkable, that these compounds increase dramatically in mature pods, and these tissues might have an additional ecological role in the signal function on Rhizobium to establish the symbiosis
Lack of Light Regulation of NADPH: Protochlorophyllide Oxido-Reductase mRNA in Cress Seedlings (Lepidium sativum L.)
Authors: Kittsteiner Ursula , Paulsen Harald , Schendel Rudolf , Rüdiger Wolfhart
Published: August 2018

A cDNA clone for NADPH: protochlorophyllide oxi­doreductase from barley was subcloned for production of antisense-mRNA. This enabled heterologous hybridi­ zation with RNA from cress seedlings (Lepidium sativum L.). The m RNA level for NADPH: protochlorophyllide oxidoreductase did not decrease in cress seedlings during irradiation with continuous far-red or white light up to 12 h. The amount of NADPH: protochlorophyllide oxi­ doreductase protein, identified by Western blot de­ creased 5-fold after continuous irradiation with white light for 12 h. Species differences for light regulation of RNA are discussed.
UDP-D-Xylose: Flavonol 3-O-Xylosyltransferase from Young Leaves of Euonymus alatus f. ciliato-dentatus
Authors: Ishikura Nariyuki , Yang Zhi-qing
Published: August 2018

From the young leaves of Euonymus alatus f. ciliato-dentatus, a novel enzyme, UDP-D-xylose: flavonol 3-O-xylosyltransferase (F3XT), catalyzing the transfer of D-xylose from UDP-D-xylose to the 3 position of 3,5,7,4′-tetrahydroxyflavone (kaempferol), was detected and purified about 16-fold by precipitation with ammonium sulfate and DEAE-cellulose CC, by which F3XT was separated from two coexisting flavonol O-glucosyltransferases (FGT). Thus, F3XT was isolated as a soluble enzyme with a pH optimum of 7.0 in Tris-HCl buffer. The molecular weight of F3XT , which had an isoelectric point at pH 6.1, was estimated by elution from a column of Sephadex G-100 to be about 48 kDa. The activity of F3XT was stimulated by 14 mM 2-ME and strongly inhibited by 1 m

Abstractм Cu2+, 1 mм Zn2+, and various re­ agents that react with sulfhydryl groups. Among the substrates tested for F3XT , kaempferol was the best. The Km values for kaempferol and UDP-xylose were determined to be 0.83 jim and 25 μM, respectively. F3XT mediated the transfer of xylose exclusively to the 3-hydroxyl group of kaempferol. Isorhamnetin, quercetin and fisetin also can function as xylosyl acceptor though less efficiently, but neither the 7-O-glucosides nor the 3-O-glucosides of kaempferol and quercetin were able to accept D-xylose. Dihydroflavonols were not xylosylated.
Is the in vivo Photosystem I Function Resistant to Photoinhibition? An Answer from Photoacoustic and Far-Red Absorbance Measurements in Intact Leaves
Authors: Havaux Michel , Eyletters Murielle
Published: August 2018

Preillumination of intact pea leaves with a strong blue-green light of 400 W m-2 markedly inhibited both photoacoustically monitored O2-evolution activity and PS II photochemistry as estimated from chlorophyll fluorescence measurements. The aim of the present work was to examine, with the help of the photoacoustic technique, whether this high-light treatment deteriorated the in vivo PS I function too. High-frequency photoacoustic measurements indicated that photochemical conversion of far-red light energy in PS I was preserved (and even transiently stimulated) whereas photochemical energy storage monitored in light exciting both PS I and PS II was markedly diminished. Low-frequency photoacoustic measurements of the Emerson enhancement showed a spectacular change in the PS II/PS I activity balance in favor of PS I. It was also observed that the linear portion of the saturation curve of the far-red light effect in the Emerson enhancement was not changed by the light treatment. Those results lead to the conclusion that, in contrast to PS II, the in vivo PS I photofunctioning was resistant to strong light stress, thus confirming previous suggestions derived from in vitro studies. Estimation of the redox state of the PS I reaction center by leaf absorbance measurements at ca. 820 nm suggested that, under steady illumination, a considerably larger fraction of PS I centers were in the closed state in high-light pretreated leaves as compared to control leaves, presumably allowing passive adjustment of the macroscopic quantum yield of PS I photochemis­ try to the strongly reduced photochemical efficiency of photoinhibited PS II.
Teratogene und metamorphosehemmende Wirkung von Retinsäure in Ciona intestinalis / Teratogenic and Metamorphosis-Inhibiting Activity of Retinoic Acid in Ciona intestinalis
Authors: Denucé J. Manuel
Published: August 2018

Exposure of embryos of the sea squirt, Ciona intestinalis, to all-trans-retinoic acid (between 10-5 and 10-7 m) causes specific malformations of the larvae and suppression of settlement and metamorphosis. Whether the vitamin A derivative was administered at the 2-cell stage, or at the early gastrula stage did not affect the nature or the extent of the ensuing anomalies. Malformations include a dorsal bulge of the body, an irregular disposition of ocellar pigment, and a twisted tail. Treated larvae have no statocyst pigment. There is also a reduction in size of the body, compared to control larvae. Retinoic acid retarded hatching, or even blocked it (at 10-5m). Obviously retinoic acid interferes with the induction of metamorphosis, possibly through neutralizing one or more factor|s responsible for settlement and metamorphosis. The possible role of thyroxin in these processes is being critically evaluated.
Marine Biosurfactants, II. Production and Characterization of an Anionic Trehalose Tetraester from the Marine Bacterium Arthrobacter sp. EK 1
Authors: Passeri A. , Lang S. , Wagner F. , Wray Victor
Published: August 2018

Within a screening for biosurfactants we could isolate various n-alkanes utilizing marine bacteria which were capable of synthesizing glycolipids. One strain was identified as Arthrobacter sp. EK 1 which produced trehalose lipids. After purification by column and thick layer chromatography the main fraction, an anionic 2,3,4,2′-trehalose tetraester, was obtained. The chain lengths of fatty acids ranged from 8 up to 14, furthermore succinate could be detected. Since the place of substitution of succinate has so far not been cited in literature, a definitive structural elucidation was carried out chemically by hydroboration and by 1H, 2 D1H, 13C and 13C - 1H correlation NMR measurements. All investigations confirmed the exact position of succinate at C2 atom of trehalose. After improvement of growth conditions the production of the trehalose tetraester increased up to 4.8 g/1 during a fermentation in a 20 1 bioreactor under nitrogen limitation.
Marine Biosurfactants, III. Toxicity Testing with Marine Microorganisms and Comparison with Synthetic Surfactants
Authors: Poremba Knut , Gunkel Wilfried , Lang Siegmund , Wagner Fritz
Published: August 2018

Eight synthetic and nine biogenetic surfactants were tested on their toxicity. Because of their possible application as oil dispersants against oil slicks on sea. the test organisms used were marine microorganisms (mixed and pure cultures of bacteria, microalgae, and protozoa). Bacterial growth was hardly effected or stimulated, whilst that of algae and flagellates was reduced. All substances tested were biodegradaded in sea water. The bioluminescence of Photobacter

phosphoreum (Microtox test) was the most sensitive test system used. A ranking shows that most biogenetic surfactants were less toxic than synthetic surfactants. No toxicity could be detected with the glucose-lipid GL. produced by the marine bacterium Alcaligenes sp. MM 1.
Significance of the Non-Oxidative Pentose Phosphate Pathway in Aspergillus oryzae Grown on Different Carbon Sources
Authors: Peleato Maria Luisa , Muiño-Blanco Teresa , Cebrian Pérez José Alvaro , López-Pérez Manuel José
Published: August 2018

Specific enzyme activities of the non-oxidative pentose phosphate pathway in Aspergillus oryzae mycelia grown on different carbon sources were determined. Mycelia grown on glucose, mannitol and ribose show the highest specific activities, ribose 5-phosphate isomerase being specially very enhanced. Moreover, transketolase, transaldolase, ribose 5-phosphate isomerase and ribulose 5-phosphate 3-epimerase were determined in different developmental stages of mycelia grown on glucose, mannitol and ribose. The non-oxidative pentose phosphate pathway is more active during conidiogenesis, except for ribulose 5-phosphate 3-epimerase, suggesting a fundamental role of this pathway during that stage to supply pentoses for nucleic acids biosynthesis. A general decrease of the enzyme activities was found in sporulated mycelia. Arabinose 5-phosphate was tested as metabolite of the pentose pathway. This pentose phosphate was not converted into hexose phosphates or triose phosphates and inhibits significantly the ribose 5-phosphate utilization, being therefore unappropriate to support the Aspergillus oryzae growth.
Pheromone Blends of Predaceous Bugs (Heteroptera: Pentatomidae: Podisus spp.)
Authors: Aldrich J. R. , Kochansky J. P. , Lusby W. R. , Borges M.
Published: August 2018

Male predaceous stink bugs (Pentatom idae: Asopinae) in the genus Podisus release longrange attractant pheromones from a pair of hypertrophied glands opening underneath the wings. Pherom one com positions are reported for four additional Podisus spp.: two Neotropical species (P. connexivus and an undetermined Podisussp.), and two Nearctic species (P. placidus and P. mucronatus). Males of each species release (E)-2-hexenal, plus species-specific major components that include α-terpineol, linalool, 9-hydroxy-2-nonanone, and (E)-2-hexenyl tiglate. The pheromonal chemistry of the Neotropical species closely resembles that for the previously studied Nearctic species, P. macuiiventris and P. fretus.
Cataract Induction by 1,2-Naphthoquinone II. Mechanism of Hydrogenperoxide Formation and Inhibition by Iodide
Authors: Kroner R. , Kleber E. , Elstner E. F.
Published: August 2018

Naphthalene cataract is probably due to peroxide production through naphthoquinone (NQ) redox cycling and/or glutathione conjugation. Both mechanisms yield losses of essential SH-groups in cristallins and are thus probably involved in protein modification finally visible as lens opacity. 1,2-N aphthoquinone produces H2O2 in the presence of either ascorbate, glutathione, NADH or - to a lesser extend - by homogenates of lens protein preparations. In the presence of 1,2-naphthoquinone and the above reductive additions, both, oxygen uptake and H2O2 formation can be observed. Reductive oxygen activation in these systems are diminuated by iodide in a concentration-dependent manner. Since maleimide-treated proteins are less capable to activate oxygen by 1,2-naphthoquinone, a direct oxygen activation by the interactions of 1,2-naphthoquinone with protein-SH is indicated. Catalysis of “diaphorase”-type (dia) enzymes via NADH - dia - 1,2-NQ - O2 seems not to operate in hydrogenperoxide production during 1,2-naphthoquinone lens toxicity.
Flavonoid Aglycones From The Bud Exudates Of Three Betulaceae
Authors: Wollenweber Eckhard , Mann Karin , Roitman James N.
Published: August 2018

Bud Exudates of three Betulaceae were analyzed for minor flavonoid aglycones. Three flavonoids not previously reported were found in Alnus koehnei, four in Betula nigra. A novel flavonol, morin-3,2′,4′-trimethyl ether, is described for Ostrya carpinifolia
Ferribactins -the Biogenetic Precursors of Pyoverdins
Authors: Taraz K. , Tappe R. , Schröder H. , Hohlneicher U. , Gwose I. , Budzikiewicz H. , Mohn G. , Lefèvre J. F.
Published: August 2018

From ferribactins which accompany pyoverdins in iron deficient cultures of fluorescent pseudomonads a subunit has been obtained formed by condensation of D-tyrosin with L-2,4-diaminobutyric acid to give 2-(1-R-amino-2-p-hydroxyphenylethyl)-1,4,5,6-tetrahydropyrimidine-4-S′-carboxylic acid (1). Evidence is presented that 1 is the precur or of the typical pyoverdin chromophore 7 a.
Plant ADP-Glucose Pyrophosphorylase -Recent Advances and Biotechnological Perspectives (A Review)
Authors: Kleczkowski Leszek A. , Villand Per , Lönneborg Anders , Olsen Odd-Arne , Lüthi Ernst
Published: August 2018

Recent advances in studies on plant ADP -glucose pyrophosphorylase (AGP), the key enzyme of starch biosynthesis, are presented. AGP constitutesthe First committed and highly regulated step of starch synthesis in all plan ttissues. The importance of AGP in carbohydrate metabolism and several of its features, such as potent regulation by cellular effectors (3-phosphoglycerate and Pi), an unusual two subunit-types structure, tissue-specific and developmentally-regulated expression, and presence of the AGP -deficient mutants, make it an attractive, but complex, target forbiotechnological manipulations. Some strategies for future research on AGP are discussed.
UV-VIS Absorption Spectra at High Pressure of C-Phycocyanin and Allophycocyanin from Mastigocladus laminosus
Authors: Schneider S. , Wokusch Th. , Tiltscher H. , Fischer R. , Scheer H.
Published: August 2018

The behaviour of monomers and trimers of C-phycocyanin and allophycocyanin under high pressure is studied by UV-VIS absorption spectroscopy. It is found that fast variations of pressure (Δp ≥ 500 bar) and/or temperature are accompanied by significant changes in the absorption spectra (intensity and/or spectral shift). The induced differences disappear, however, in part, when the samples are left for several minutes at the final pressure (relaxation effect). The observed spectral variations are different from those connected with a change in state of aggregation and could therefore be due to small modifications of the chromophore-protein arrangement.
Effects of Phenylamide Pesticides on the GSH-Conjugation System of Phytophthora spp. Fungi
Authors: Oros Gyula , Kőmíves Tamás
Published: August 2018

Phytophthora cactorum, Ph. cambivora, Ph. cinnamomi, Ph. citricola, Ph. cryptogea, Ph. drechsleri, Ph. infestans, Ph. megasperma, Ph. parasitica, and Ph. syringae contain GSH-conjugation systems as indicated by the presence of active GST enzyme in addition to GSH. Basal levels of both GSH and GST in the thalli of Phytophthora strains studied did not correlate with either fungal sensitivity to phenylamides (acetochlor, butachlor, metolachlor, dimethachlor, propachlor, ofurace, CGA-29212, metalaxyl, RE-26745, benalaxyl, furalaxyl, LAB-149202) or their acquired resistance to metalaxyl. Thalli of Phytophthora strains from axenic cultures ex­ posed to sublethal concentrations of the above pesticides contained significantly higher levels of both GSH and GST than the untreated controls. This response was independent of the sen­sitivity and tolerance of the strains to phenylamides.

When the responses of Phytophthora strains to phenylamide chemicals were compared by means of principal component analysis, four independent components were detected account­ ing for 88% of the total variation. Biological properties (basal and induced levels of GST and GSH, growth intensity, degree of acquired resistance to metalaxyl, sensitivity to propiconazole and to cis-and trans-tridemorph) of the strains contributed differently to this variation. It was concluded that, in contrast to plants, sensitivity or tolerance of Phytophthora species to phenylamide pesticides is not regulated by the efficiency of the GSH-conjugation system. In addition, our data clearly indicate that the acetanilide pesticides have multiple sites of action in the Phytophthora genus.
Mode of Safener Action of Dimepiperate, a Thiolcarbamate Herbicide, on Bensulfuron Methyl Activity
Authors: Yuyama Takeshi , Shirakura Shinichi , Ishizuka Kozo
Published: August 2018

Bensulfuron methyl is a sulfonylurea herbicide controlling a broad spectrum of broadleaf and sedge weeds in paddy rice. Safening effects with certain thiolcarbamate herbicides for grass control have been discovered in the process of combination products development. The results of mode of safening studies revealed that the enhancement of metabolic inactivation rate of bensulfuron methyl in plants was the basis of safening.

Among these thiolcarbamates, dimepiperate was unique in exhibiting safening action even in direct water-seeded rice. Further studies on dimepiperate effects on root-applied bensulfu­ron methyl indicated that rice root elongation, enhanced metabolism in roots and in shoots, were the key to the safening effects. The translocation rate of bensulfuron methyl, from roots to shoots, on the other hand, was not significantly affected by dimepiperate.
Effects of EPTC and Dichlormid on Membrane Lipid Composition of Maize Leaves and Roots
Authors: Barta István Cs.
Published: August 2018

The changes in fatty acid composition of maize leaf lipids caused by EPTC were generally similar to known effects of this herbicide in other plants: decreasing of linolenic acid content and increasing of its precursors, palmitic, stearic, oleic and linoleic acids. However, novel effects were detected in roots where the proportion of minor fatty acid palmitoleic acid was increased from 2.1 to 7.6 and 16.6% by EPTC and EPTC + dichlormid treatments, respective­ly. Simultaneously, the phospholipid content of root lipids was increased by both EPTC as well as EPTC + dichlormid treatments. The possible effects of EPTC and dichlormid on lipid biosynthesis of maize are discussed.
The Inhibition of Glutathione Reductase by Quinones
Authors: Bironaitė Daiva A. , Čėnas Narimantas K. , Kulys Juozas J. , Medentsev Alexander G. , Akimenko Vasiliy K.
Published: August 2018

Fully substituted quinones including some naturally occurring oxyquinones acted as inhibitors of yeast gluta­thione reductase (EC 1.6.4.2). They were competitive, mixed or uncompetitive inhibitors for NADPH , possess­ing Ki in the range of 1 -200 μᴍ and uncompetitive in­ hibitors for glutathione. Rhein (4,5-dioxy-9,10-anthraquinone-2-carbonic acid) and 9,10-phenanthrenequinone were the most effective inhibitors. It is concluded that certain quinones can bind to the NADP(H)-binding site and to the heteroaromatics binding site at the inter­ face domain (P. A. Karplus, E. F. Pai, and G. E. Schulz, Eur. J. Biochem. 178, 693 -703 (1989)) of the enzyme.
Sesquiterpene Hydrocarbons in Glandular Trichome Exudate of Rosa rugosa Leaves
Authors: Hashidoko Yasuyuki , Tahara Satoshi , Mizutani Junya
Published: August 2018

From glandular trichome of Rosa rugosa, three major sesquiterpene hydrocarbons [acora- 3(4),7(15)-diene, carota-4(5),ll(12)-diene (isodaucene) and carota-l,4-diene], and two minor [daucene and acora-3(4),7(8)-diene] were identified. The presence of these carotadienes, which are possibly precursors of the corresponding C-14-oxygenated carotanoids, suggested that the formation of the carotane skeleton followed by the regio-specific oxygenation at C-14 occur in the biosynthesis of R. rugosa carotanoids.
Binding of Lipids onto Polypeptides of the Thylakoid Membrane I. Galactolipids and Sulpholipid as Prosthetic Groups of Core Peptides of the Photosystem II Complex
Authors: Voß R. , Radunz A. , Schmid G. H.
Published: August 2018

Photosystem II complexes were prepared from chloroplasts of wild type tobacco Nicotiana tabacum var. John William’s Broadleaf and from two chlorophyll mutants derived from it, namely N. tabacum Su/su and N. tabacum Su/su var. Aurea. The hydrophobic peptides of these complexes were analyzed for bound lipid molecules by means of monospecific lipid antisera. A comparison of the peptide composition of the complexes of the three chloroplast types by means of polyacrylamide gel electrophoresis showed that the peptide composition was qualitatively identical. A major quantitative difference referred to a 66 kDa peptide which appeared to be much stronger in gels of photosystem II peptides originating from the yellowgreen and the yellow tobacco variety. Furthermore, we were able to show that different SDS polyacrylamide gel electrophoresis runs of the same PS II preparation yielded differences in the band strength of this peptide. Comparative densitometric measurements showed that an increase in this 66 kDa peptide was always correlated with a decrease in the D1 and D2 peptides. Obviously, the 66 kDa peptide is the heterodimer of D1 and D2. Differences in the peptide composition of photosystem II preparations from the 3 tobacco species refer above all to peptides of the light-harvesting complex with molecular masses of 28 and 26 kDa.

After the transfer of the peptides from the polyacrylamide gel to nitrocellulose membranes, they were incubated with monospecific antisera to monogalactolipid, digalactolipid or sulfolipid. These experiments showed that the 66 kDa peptide reacted with antibodies to digalactolipid and with those to sulfolipid. The 66 kDa peptide reacts in the Western blot procedure also with an antiserum to a 66 kDa peptide prepared and characterized earlier and which was shown to inhibit electron transport reactions in the region of the reaction center of photosystem II. The monospecific antiserum to monogalactolipid reacts with the D1 and D2 peptide as well as with the chlorophyll-binding polypeptides of the masses 42 and 48 kDa, and also with the 26 and 28 kDa peptides of the light-harvesting complex as well as with the extrinsic peptides exhibiting the molecular masses, 33 ,21 -23 and 18 kDa. Whereas lipase treatment apparently destroys the lipids as antigenic determinants of the peptides on the nitrocellulose membrane, periodate treatment or treatment of the photosystem II preparations with organic solvents do not prevent the reaction of the 66 kDa peptide with the sulfolipid antiserum. These experiments show as the 66 kDa peptide appears to be the heterodimer of D1 and D2, that the galactolipids mono- and digalactosyldiglyceride as well as the sulfolipid are bound, much like prosthetic groups, onto the core peptides.
Modulation by Monovalent Anions of Calcium and Caffeine Induced Calcium Release from Heavy Sarcoplasmic Reticulum Vesicles
Authors: Hasselbach Wilhelm , Migala Andrea
Published: August 2018

Both calcium and caffeine induced calcium release from actively loaded heavy sarcoplasmic reticulum vesicles were studied to analyze the dependence of both activities on the composition of the release medium with respect to monovalent anions. Calcium is unable to induce net calcium release while caffeine remains effective as releasing agent when the experimental media contain neither chloride nor nitrate ions. Caffeine induced calcium release is not suppressed by chelating residual medium calcium (approximately 0 .5 -1 μᴍ) with 2 mᴍ EGTA added 15 s prior to 10 mᴍ caffeine. Calcium release from vesicles loaded in media containing 0.2 ᴍ gluconate as monovalent anion is induced when the medium is supplemented with chloride or nitrate. The release amplitude increases linearly when K-gluconate is replaced by KCl. At constant ionic strength the release amplitude becomes maximal at a chloride concentration of 0.2 ᴍ. The chloride effect completely disappears when 2 mᴍ EGTA are added simultaneously. When chloride is replaced by nitrate, as releasing agent, maximal release is achieved already by addition of 0.1 ᴍ K-nitrate. The releasing effect of nitrate can only partially be suppressed by EGTA. The different effectiveness of gluconate, chloride and nitrate as calcium release supporting ions corresponds to their activating effect on the binding of ryanodine to the calcium release channel in the vesicular membranes.
Notes: Fluorescence of Chromatin DNA by an Oxazolium Scintillator
Authors: Stockert Juan C.
Published: August 2018

Aqueous solutions of a yellow and highly fluorescent derivative from dimethyl-POPOP, obtained by treating a chloroform solution of this oxazole scintillator with dimethylsulfate, induce a strong blue-green or yellowgreen fluorescence in chromatin DNA under ultraviolet (365 nm) or violet-blue (436 nm) excitation, respectively. It is suggested that this new and selective fluorescence reaction could originate from binding of the oxazolium derivative into the minor groove of DNA.
Photoreduction of NADP+ in Photosystem II of Higher Plants: Requirement for Manganese
Authors: Allakhverdiev Suleyman I. , Klimov Vyacheslav V.
Published: August 2018

The effects of reversible manganese extraction on NADP+ photoreduction were studied with higher plant subchloroplast preparations of photosystem II (PS II). Under anaerobic conditions, when the reaction centers (RCs) of PS II are “closed” (i.e. in the state [P680 Pheo] QA), and in the presence of ferredoxin-ferredoxin-NADP+ reductase, NADP+ reduction is observed at a rate of 0.8 -1.1 nmol/mg × chlorophyll × h. After complete removal of manganese from PS II, the rate of NADP+ reduction is reduced 40 - 50-fold. Upon the addition of Mn at a concentration of approx. 4 Mn atoms per reaction center, the NADP+ reduction is restored up to 85 -90% of the initial value. When half of this amount of Mn is combined with about 40 times of the equivalent concentration of other divalent ions (Ca2+, Sr2+, Mg2+ etc.) the reaction is also reactivated. Dinoseb (10-6 m) an inhibitor of electron transfer in PS II prevents NADP+ photoreduction. It is concluded that under conditions when the first quinone acceptor, QA, is in its reduced state (QA
-) electrons are transferred from reduced pheophytin (Pheo·̅) to NADP+, indicating that PS II can reduce NADP+ without the participation of PS I. On the basis of these and literature data, an alternate pathway for electron phototransfer in PS II reaction centers of higher plants is suggested. Some problems concerning the Z-scheme are discussed.
Photoinactivation of Photosynthetic Electron Transport under Anaerobic and Aerobic Conditions in Isolated Thylakoids of Spinach
Authors: Chaturvedi Rekha , Singh M. , Sane P. V.
Published: August 2018

The effect of exposure to strong white light on photosynthetic electron transport reactions of PS I and PS II were investigated in spinach thylakoids in the absence or presence of oxygen. Irrespective of the conditions used for photoinactivation, the damage to PS II was always much more than to PS I. Photoinactivation was severe under anaerobic conditions compared to that in air for the same duration. This shows that the presence of oxygen is required for prevention of photoinactivation of thylakoids. The susceptibility of water-splitting complex in photoinactivation is indicated by our data from experiments with chloride-deficient chloroplast membranes wherein it was observed that the whole chain electron transport from DPC to MV was much less photoinhibited than that from water. The data from the photoinactivation experiments with the Tris-treated thylakoids indicate another photodam age site at or near reaction centre of PS II. DCMU-protected PS II and oxygen-evolving complex from photoinactivation. DCMU protection can also be interpreted in terms of the stability of the PS II complex when it is in S2 state.
Differential Wound Activation of Members of the Phenylalanine Ammonia-Lyase and 4-Coumarate: CoA Ligase Gene Families in Various Organs of Parsley Plants
Authors: Lois Rodrigo , Hahlbrock Klaus
Published: August 2018

We analyzed the developmental regulation and the activation by wounding of several stressrelated genes in various parsley organs. The genes encode phenylalanine ammonia-lyase (PAL) and 4-coumarate: CoA ligase (4 CL), two enzymes of general phenylpropanoid metabolism; a flavonoid specific enzyme, chalcone synthase (CHS); a furanocoumarin specific enzyme, bergaptol O-methyltransferase (BMT); and a pathogenesis-related protein (PR 1). All genes or gene families exhibited high levels of expression in roots and during certain stages of leaf development. PAL, 4 CL and CHS were preferentially expressed in young leaves, BMT and PR 1 in old leaves. An appreciable increase in CHS mRNA levels was observed in wounded leaves. By contrast, root wounding led to a decrease in the existing CHS m RNA levels. A biphasic response (a decrease followed by an increase) to wounding was seen for BMT and PR 1 m RNA s in roots and for BMT mRNA in attached leaves. Using gene-specific oligonucleotide probes to measure the expression rates of three of the four PAL genes and of the two 4 CL genes separately we observed a differential behavior of the individual family members under many of the conditions tested. While PAL-3 was preferentially activated in wounded leaves and 4CL-1 in wounded roots, PAL-2 and 4C L-2 were primarily responsible for the high constitutive expression levels in roots and flowering stems respectively. Despite the differential expression of their individual members, the PAL and 4 CL gene families displayed very similar changes in the overall patterns of expression, reflecting their closely related functions in phenylpropanoid metabolism.
Isoflavone And Pterocarpan Malonylglucosides And ß - L,3 - Glucan - And Chitin-Hydrolases Are Vacuolar Constituents In Chickpea (Cicer Arietinum L.)
Authors: Mackenbrock Ulrike , Vogelsang Ralph , Barz Wolfgang
Published: August 2018

Cell suspension cultures of chickpea (Cicer arietinum L.) were used to prepare protoplasts and vacuoles. The vacuolar preparation revealed only slight contaminations of cytoplasmic marker enzymes. HPLC analysis of the vacuolar extract showed that the malonylglucosides of isoflavones, isoflavanones and pterocarpans are exclusively located in the vacuole. Experiments designed to determine the subcellular localization of the isoflavone malonylglucoside: malonylesterase suggest an association of this enzyme with the vacuolar membrane. Finally, a β-l,3-glucanase and a chitinase with basic isoelectric points were also found to be localized in the chickpea vacuoles
Isolation Of A Photosystem Ii Associated 36 Kda Polypeptide And An Iron-Stress 34 Kda Polypeptide From Thylakoid Membranes Of The Cyanobacterium Synechococcus Pcc 6301 Grown Under Mild Iron Deficiency
Authors: Michel Klaus-Peter , Pistorius Elfriede K.
Published: August 2018

A 36 kDa polypeptide which previously was shown to be present in purified photosystem II complexes from Synechococcus PCC 6301 and which crossreacts with the antiserum raised against the soluble L-amino acid oxidase of 50 kDa from Synechococcus PCC 6301 (A. E. Gau, G. Wälzlein, S. Gärtner, M. Kuhlmann, and E. K. Pistorius, Z. Naturforsch. 44c, 971, 1989), was isolated from thylakoid membranes of the same cyanobacterium grown under mild iron deficiency. This peptide is present in about equal amounts in thylakoid membranes of Synechococcus PCC 6301 grown under regular or iron deficient conditions. The antiserum raised against this thylakoid membrane bound 36 kDa peptide crossreacts with the soluble L-amino acid oxidase of 50 kDa. These results further support our conclusion that the thylakoid membrane bound 36 kDa polypeptide is a modified form of the soluble 50 kDa L-amino acid oxidase. In addition, a 34 kD a polypeptide was isolated from iron stressed thylakoid membranes, and an antiserum was also raised against this protein. Immunoblot experiments with this antiserum show that the 34 kDa peptide is present in elevated amounts in thylakoid membranes from Synechococcus cells grown under iron deficiency and that it is alm ost absent in thylakoid membranes from cells grown under regular conditions
Cantharidin-Secretion by Elytral Notches of Male Anthicid Species (Coleoptera: Anthicidae)
Authors: Schütz Claudia , Dettner Konrad
Published: August 2018

Within the beetle family Anthicidae or ant-like flower beetles the canthariphilous species Notoxus monoceros shows a pair of notch-like structures on the apices of male elytra. A reservoir- like swelling at the apex of each elytron contains a bilobed gland. Its glandular tubules run into the sclerotized notch. Gaschromatographic investigations of elytral notches and the testes of cantharidin-fed and unfed male Notoxus monoceros revealed huge quantities of cantharidin stored in these organs in fed specimens. Other body parts, such as legs, elytral parts or flight muscles, had low cantharidin-titres, both in cantharidin-fed and unfed beetles. The cantharidin- titres of unfed individuals were very low compared with cantharidin-fed specimens, although cantharidin was present, mostly in notches. During sexual display the females bite several times into these notches and easily copulate, if the males had access to offered cantharidin crystals. Thus, the elytral notches of male Notoxus monoceros seem to function as „testorgans” for females which are able to select males with high cantharidin loads prior to copulation. Even small quantities of cantharidin stored in notches of field caught specimens seem of advantage for males in competing for a female partner.
Chemical Constituents of Urospermum picroides
Authors: Giner Rosa María , Cuellar María Jesús , Recio María Carmen , Máñez Salvador , Ríos José Luis
Published: August 2018

Seven phenolic compounds were isolated from the aerial parts of U. picroides. They were identified by UV spectra, TLC and HPLC-DAD as luteolin, luteolin-7-glucoside, quercetin, quercetin-3-galactoside, kaempferol-3-galactoside, chlorogenic and isochlorogenic acids. Other phenolics were characterized by HPLC-DAD analysis: gallic, protocatechuic, caffeic, ferulic and isoferulic acids, quercetin-3-glucoside and luteolin-4′-glucoside.