bluuebunny/crossref_metadata_2025_split huggingface dataset:
Flavonoids from Vicia faba Seed Exudates
Authors: Tomás-Lorente Francisco , Garcia-Grau Manuela M. , Tomás-Barberán Francisco A. 
Published: August 2018

Abstract
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

Abstract
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

Abstract
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.
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.
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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.
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.
Photoreduction of NADP+ in Photosystem II of Higher Plants: Requirement for Manganese
Authors: Allakhverdiev Suleyman I. , Klimov Vyacheslav V. 
Published: August 2018

Abstract
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

Abstract
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

Abstract
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.
Cantharidin-Secretion by Elytral Notches of Male Anthicid Species (Coleoptera: Anthicidae)
Authors: Schütz Claudia , Dettner Konrad 
Published: August 2018

Abstract
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 Composition and Surface Structures of Epicuticular Leaf Waxes from Castanea sativa and Aesculus hippocastanum
Authors: Gülz P.-G. , Müller E. , Herrmann T. 
Published: August 2018

Epicuticular leaf waxes of Castanea sativa and Aesculus hippocastanum contain the same lipids in form of homologous series of hydrocarbons, wax esters, aldehydes, primary alcohols and fatty acids in similar concentrations without any main component dominating. In Ae. hippocastanum wax acetates are present, additionally. Both waxes are found to contain triterpenols and triterpenol esters in remarkable amounts. β-Amyrin, α-amyrin and lupeol are present in both plant waxes, in Ae. hippocastanum wax friedelanol and friedelanone, additionally.
The epidermis of both plants are covered with a thin continuous wax layer without crystalloids. But the adaxial leaf surface of C. sativa shows granular wax sculptures and therefore a different micromorphological ultrastructure for both leaf sides.
3′,3‴ -Binaringenin, a New Biflavonoid from Pilotrichella cuspidata (Meteoriaceae, Musci)
Authors: Seeger Tassilo , Geiger Hans , Zinsmeister Hans Dietmar , Frahm Jan-Peter , Witte Ludger 
Published: August 2018

.
From Pilotrichella cuspidata the new biflavonoid 3′,3‴ -binaringenin was isolated. Its structure was elucidated spectroscopically.