bluuebunny/crossref_metadata_2025 huggingface dataset:
Intracellular Conversion of Malate and Localization of Enzymes Involved in the Metabolism of Malate in Photoautotrophic Cell Cultures of Chenopodium rubrum
Authors: Amino Shin-ichi
Published: August 2018

Cells from photoautotrophic cultures of Chenopodium rubrum were fractionated for the isolation of purified chloroplasts and mitochondria. The subcellular localization of the enzymatic activities involved in the metabolism of malic acid was investigated. Highly purified chloroplasts were obtained from the protoplasts, whereas peroxisomes were still present in the mitochondrial fraction. NAD - and NADP-dependent malate dehydrogenase and malic enzyme activities were found in the mitochondrial and chloroplast fractions, respectively. Exogenously supplied [14C]labelled malate was metabolized by the photoautotrophic cell suspension, obviously to the greater part in mitochondria.
Flavonol Synthase Activity and the Regulation of Flavonol and Anthocyanin Biosynthesis during Flower Development in Dianthus caryophyllus L. (Carnation)
Authors: Stich K. , Eidenberger T. , Wurst F. , Forkmann G.
Published: August 2018

Flavonol synthase (FLS) was demonstrated in crude extracts from flower buds of Dianthus caryophyllus (carnation). The enzyme catalyzed the conversion of dihydrokaempferol and ihydroquercetin to kaempferol and quercetin, respectively. The reaction required 2-oxoglutarate, ferrous ion and ascorbate as co-factors and had a pH optimum at about 7.4. The demonstration of FLS activity allowed comparative studies on flavonol and anthocyanin biosynthesis during bud and flower development. Besides FLS the flavonoid enzymes chalcone synthase (CHS), flavanone 3-hydroxylase (FH T) and dihydroflavonol 4-reductase (DFR) were measured. DFR is specifically involved in anthocyanin synthesis, while CHS and FHT provide dihydroflavonol, the common substrate for both FLS and DFR . Maximum expression of CHS, FHT and FLS activity was already observed in small buds, whereas DFR activity started to increase much later and reached its highest level in opened flowers. A substantial correlation was observed between the time courses of FLS and DFR activity and the accumulation of flavonols and anthocyanins, respectively. The competition of FLS and DFR for dihydroflavonols was found to be largely circumvented by different substrate specificities and by the sequential expression of the two enzymes. Both flavonols and anthocyanins are obviously not, or only to some extent, subject to degradation.
Synthesis of Long-Chain Triazine Aldehydes - Substrates of Bacterial Luciferase and Photosynthetic Inhibitors
Authors: Jockers R. , Schmid R. D.
Published: August 2018

S-triazines are photosynthetic inhibitors. They have been substituted with ω-aminoundecanoic acid. The coupling products have been transformed into triazine aldehydes. These compounds displace radioactive terbutryn and have inhibitory effects on photosynthesis in plants and bacteria. Triazine aldehydes were shown to be effective substrates for bacterial luciferase. A competitive assay between photosystem-II-herbicides and aldehyde-labeled triazines is discussed.
A Sex Attractant for Male Orthosia gothica L. (Lepidoptera: Noctuidae)
Authors: Tòth M. , Szöcs G. , Bengtsson M.
Published: August 2018

In field trapping tests male Orthosia gothica (Lepidoptera: Noctuidae) were captured in traps baited with blends of (Z)-9-tetradecenyl acetate, (Z)-9-tetradecenol, (Z)-5-tetradecenyl acetate and (Z)-l 1-tetradecenyl acetate. The highest catches were recorded in traps baited with a 20:20:1:1 blend. The above quaternary blend is a potent sex attractant of this species, and it can be recommended in dosages of 10-100 μg per dispenser for monitoring purposes.
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

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From Pilotrichella cuspidata the new biflavonoid 3′,3‴ -binaringenin was isolated. Its structure was elucidated spectroscopically.
Growth Responses to Flooding and Recovery of Deciduous Trees
Authors: Frye Jonathan , Grosse Wolfgang
Published: August 2018

Tree seedling flooding tolerance for 22 species was assessed under controlled field conditions. Initial heights under control (freely draining soil, n = 20 per species) and flooded (standing water, depth = 10 cm, n = 20 per species) conditions were measured in March 1990. Survival, height and diameter growth were determined after 120 days. Recovery from flooding effects was assessed in the following growing season from March to August, 1991. Taxodium distichum (L.) L. C. Rich, exhibited enhanced growth when flooded. Acer saccharinum L., Fraxinus excelsior L., and Quercus robur L. increased diameter but not height growth. The following species exhibited reduced growth and/or survival: Acer campestre L., Acer pseudoplatanus L., Acer rubrum L., Betula nigra L., Betula papyrifera Marsh, Betula pubescens Ehrh., Betula pendula Roth, Crataegus monogyna Jacq., Fagus grandifolia Ehrh., Prunus padus L., Prunus serotina Ehrh., Quercus palustris M uenchh., Quercus petraea (Mattuschka) Liebl., Rhamnus cathartica L., Salix purpurea L., Sorbus aucuparia L., Tilia cordata Mill., and Ulmus glabra Huds. emend. Moss. Recovery from flooding in the second growing season was well established with A. saccharinum, C. monogyna, Qu. palustris, Qu. petraea, S. purpurea, U. glabra, while height growth relative to the flooding period was retarded in A. rubrum, F. grandifolia, F. excelsior, Qu. robur, Rh. cathartica, and S. aucuparia. Mortality increased with B. p a pyrifera and F. grandifolia. Flooded trees of B. nigra, B. pendula, and Rh. cathartica appeared to be strongly handicapped by losing their natural resistance against frost even in the following growing season. By decreasing shoot height growth and biomass production, long-term flooding is suggested to reduce the competitive ability of most tree species in the succession of natural forests in habitats which will be inundated more frequently in future when precipitation is increased by the predicted climatic change.
Saline Growth Conditions Favour Supercooling and Increase the Freezing Tolerance of Leaves of Barley and Wheat
Authors: Bender Michael , Heber Ulrich , Dietz Karl-Josef
Published: August 2018

When young plants of barley and wheat grown in hydroponic culture were subjected to salt stress, their freezing tolerance increased with increasing severity of salt stress. Detached leaves from salt-stressed plants also exhibited an increased ability to supercool. Avoidance of ice formation permitted leaf survival at subzero temperatures which were no longer tolerated when ice nucleation resulted in extracellular freezing. The increased freezing tolerance under salt stress is attributed to osmotic adjustment of the plants. Increased cellular solute concentrations decrease the extent of cellular dehydration at freezing temperatures, thereby decreasing mechanical and chemical stresses on biomembranes during freezing and thawing.
Inhibition by Cytokinin of the Accumulation of Betacyanin in Suspension Cultures of Phytolacca americana
Authors: Hirano Hiroshi , Sakuta Masaaki , Komamine Atsushi
Published: August 2018

The accumulation of betacyanin was reduced by the addition of various cytokinins to suspension cultures of Phytolacca americana. The decrease in the accumulation of betacyanin was overcome by exogenously supplied tyrosine which is a precursor of betacyanin. Benzylaminopurine (BAP) decreased the level of free tyrosine in the cells. Feeding experiments using labeled tyrosine revealed that BAP reduced the incorporation of labeled tyrosine into betacyanins (to about 50% of the control rate). These results suggest that both the availability of tyrosine and the biosynthetic activity of the pathway from tyrosine to the betacyanins are involved in the inhibition of the accumulation of betacyanins by cytokinins in Phytolacca americana cells.
An Auxin Binding Protein is Localized in the Symbiosome Membrane of Soybean Nodules
Authors: Jacobi Andreas , Zettl Rolf , Palme Klaus , Werner Dietrich
Published: August 2018

Binding of tritiated indole-3-acetic acid ([3H]IAA) to symbiosome membranes of soybean nodules occurred in a protein-dependent manner and was competitively inhibited by unlabeled indole-3-acetic acid (IAA), 1-naphthaleneacetic acid (1-NAA) and dithiothreitol (DTT), but not by tryptophan and benzoic acid. The symbiosome membranes bound IAA with a KD of 1 × 10-6 m. Photoaffinity labeling identified an auxin-binding protein (ABP) in the symbiosome membrane with an apparent molecular mass of 23 kDa. This 23 kDa protein was labeled either with 5-azido-[7-3H]indole-3-acetic acid ([3H]N3IAA) or with 5′-azido-[3,6-3H2]-1-naphthylphthalamic acid ([3H2]N3NPA). Labeling of the 23 kDa protein with [3H]N3IAA was competitively inhibited by unlabeled IAA and 1-NAA. NPA and quercetin, inhibitors of polar auxin transport, as well as rutin, a glycosylated derivative of quercetin, competed with IAA for binding. Conversely, [3H2]N3NPA labeling was inhibited by unlabeled IAA and NPA. The 23 kDa symbiosome membrane protein was partially solubilized with Triton X-100 and nearly completely using Triton X-114. The observation that auxin transport inhibitors compete with IAA for binding suggests that the symbiosome membrane ABP could be part of an auxin efflux carrier system required to control the auxin concentration in infected soybean nodule cells.
Microbial Reduction of Aromatic Carboxylic Acids
Authors: Arfmann Hans-Adolf , Abraham Wolf-Rainer
Published: August 2018

Several benzoic, cinnamic and phenylacetic acid derivatives were screened with 20 microorganisms, mainly fungi, for the reduction of their carboxylic function. For all organisms several compounds were reduced in fairly good yields up to 80% to the corresponding alcohol. No general rule could be established, concerning the substitution pattern, as to which compounds were transformed to the alcohol. Generally the reactions were accomplished within 48-70h. Only minor, if any, side products were detected. Dicarboxylic acids, such as phthalic or phenylglutaric acids and similar compounds could not be reduced by the microorganisms tested.
Biochemical Model Reactions on the Prooxidative Activity of Homocysteine
Authors: Preibisch Gudrun , Kiiffner Christina , Elstner Erich F.
Published: August 2018

The sulfur amino acid homocysteine has recently been addressed as marker for vessel damaging and atherosclerotic dispositions. The atherogenic index has been correlated with the one of cholesterol and is significantly higher in cholesterinemic as compared to normal lipidemic persons. In the present communication biochemical model reactions are presented indicating the prooxidative activity of homocysteine where a cooperative effect with the transition-metals copper and iron is indicated.
Neue Untersuchungen über Flavonoide in Viscum album L. ssp. abietis, album und austriacum / New Investigations on Flavonoids from Viscum album L. ssp. abietis, album and austriacum
Authors: Lorch Elmar
Published: August 2018

Hydrolyzed alcoholic extracts of Viscum album L. were analyzed by HPLC for their flavonoid content. Besides the known flavonoid aglyca 4′,5,7-trihydroxy-3′- methoxyflavanone (homoeriodictyol), 5,7-dimethoxy-4′- hydroxyflavanone, 3′-methylquercetin (isorhamnetin) and 3′,7-dimethylquercetin (rhamnazin) another flavanone derivate, 4′,5-dihydroxy-7-methoxyflavanone (sakuranetin) was detected in mistletoe extracts for the first time. With the described method it is possible to distinguish the three mistletoe subspecies abietis, album and austriacum.
Biochemical Activities of Propolis Extracts. I. Standardization and Antioxidative Properties of Ethanolic and Aqueous Derivatives
Authors: Volpert Regina , Elstner Erich F
Published: August 2018

Ethanolic extracts of Propolis are used as antiinflammatory and wound healing drugs since ancient times. In order to facilitate a comparison of different extracts, the standardization on the basis of quantitative determination of prominent components of these extracts has been substituted for simple biochemical “activity” tests. One of these activity tests bases on the in­ hibition of peroxidase-catalyzed oxidation of indole acetic acid indicating the presence of a defined mixture of monophenolic and diphenolic compounds. Other tests (diaphorase-catalyzed reductions and xanthine oxidase-catalyzed oxidations) demonstrate significant radical scavenging properties. Water-soluble extracts of propolis exhibit higher antioxidative and inhibitory activities as compared to the ethanolic extract.
Hydrogen Bonding of Cyanoacrylates with the D 1 Peptide
Authors: Phillips John N. , Banham Wendy K.
Published: August 2018

Representatives of two structural types of cyanoacrylate PS II inhibitors have been studied in respect to their pI50 values and qualitative rate of binding with wild type and S 264 G mutant thylakoids isolated from Brassica napus. Both are potent inhibitors of photosynthetic electron transport and both show a large discrimination between wild type and mutant thylakoids under equilibrium conditions. However one, an N-methylanilino cyanoacrylate, has an initial rapid reaction with both wild type and mutant thylakoids, but continues to react slowly with the wild type species until equilibrium is reached, while the other, a benzylamino cyanoacry­ late, equilibrates rapidly with both species as does the classical PS II inhibitor, atrazine. These differences in kinetic behaviour have been interpreted in terms of different H-bond interactions with the serine-264 hydroxyl group. It is suggested that the slow binding reaction is due to the N -methylanilino compound interacting as an H-bond acceptor with the serine-264 hydroxyl hydrogen thus disrupting an intramolecular ser-264-his-252 H-bond within the D 1 peptide. Rapid equilibration on the other hand, has been attributed to the benzylamino derivative acting as an H-bond donor to the serine-264 hydroxyl oxygen and strengthening the 264 -252 H -bond by conjugation. It is proposed that atrazine and other classical PS II inhibitors act in this way and that this may explain their ability to inhibit trypsin degradation of the D 1 peptide, if the 264-252 intramolecular H-bond plays an important role in stabilizing the peptide conform ation. It is also speculated that photodegradation may be related to the ability of QB
- to act as an H-bond acceptor and disrupt the 264-252 H-bond.
Binding of Triazines and Triazinones in the QB-Binding Niche of Photosystem II
Authors: Tietjen Klaus G. , Draber Wilfried , Goossens John , Jansen Johannes R. , Kluth Joachim F. , Schindler Michael , Wroblowsky Heinz-Jürgen , Hilp Ursula , Trebst Achim
Published: August 2018

A series of 20 triazines (derivatives of 2-alkylamino-4-benzylam ino-6-chloro-1,3,5-triazines) and 37 triazinones (derivatives of 3-alkyl-4-amino-6-phenyl-1,2,4-triazin-5-ones) is tested for inhibitory potency in photosynthetic electron flow through photosystem II of wild type Chlamydomonas reinhardtii and of five mutants with aminoacid substitutions in the D 1 protein at valine 219, alanine 251, phenylalanine 255, serine 264, and leucine 275. The data are used for computer modelling of the possible location of the compounds within a three dimensional model of the QB-binding niche of the D 1 protein.
The Role of D 1* in Light-Induced D 1 Protein Turnover in Leaves
Authors: Syme Anna J. , Bolhàr-N ordenkampf Harald R . , Critchley Christa
Published: August 2018

Light-induced degradation of the D 1 protein of photosystem II (PS II) was determined by radioactive pulse-chase labelling experiments in intact leaves of Schefflera polybotrya. PS II photochemical efficiency was monitored by measuring chlorophyll fluorescence. A significant and consistent decline in the Fv/ Fm ratio was taken to indicate photoinhibition. The formation and degradation of a modified form of the D 1 protein, D 1*, was different under photoinhibi-tory or non-photoinhibitory light conditions. At photoinhibitory irradiance greater amounts of D 1 * were formed relative to D 1, and the degradation of D 1* was slower when compared with non-photoinhibitory irradiance. The formation and degradation of D 1* were therefore shown to be at least partly light intensity dependent. Higher light intensities appeared to slow D 1* degradation, which suggests a modification in PS II turnover properties.
Kinetics of Electron Transfer between QA and QB in Wild Type and Herbicide-Resistant Mutants of Chlamydomonas reinhardtii
Authors: Crofts Antony R . , Baroli Irene , Kramer David , Taoka Shinichi
Published: August 2018

We have investigated the electron transfer kinetics for reduction of plastoquinone by photo­ system II in six mutant strains of Chlamydomonas reinhardtii by following the decay of the high fluorescence state after flash activation, and compared the separate reactions of the two-electron gate with those of a wild type strain. By analysis of the electron transfer kinetics, and separate measurement of the equilibrium constant for stabilization of the bound semiquinone after one flash, we have been able to deconvolute the contributions of rate constants and equilibrium constants for plastoquinone binding and electron transfer to the overall process. Two mutations, S 264 A and A 251 V, led to a marked slowing of kinetics for reduction of plastoquinone to the bound semiquinone. In S 264 A , the second electron transfer was also slower, but was normal in A 251 V. In mutant G 256 D , the electron transfer kinetics were normal after the first flash, but slowed after the second. In mutants L 257 F , V 219 I, and F 255 Y , the electron transfer kinetics after both flashes were similar to those in wild type. We discuss the results in terms of a model which provides a description of the mechanism of the two-electron gate in terms of measured kinetic and equilibrium constants, and we give values for these parameters in all strains tested.
Comparison of Photosynthetic Activities in Triazine-Resistant and Susceptible Biotypes of Chenopodium album
Authors: Curwiel Victor B. , Schansker Gert , de Vos Oscar J. , Rensen Jack J. S.
Published: August 2018

Triazine-resistant and susceptible Chenopodium album plants were grown at low and at high light irradiances. At the lower light irradiance the dry matter production of the resistant and the susceptible plants were almost similar. At the higher irradiance the resistant biotype had a significantly lower production. Fluorescence studies showed that the photochemical yield and the photosystem II electron transport rate were lower in the resistant biotype. It could be demonstrated in intact leaves that the lower productivity of the resistant biotype is caused by a higher sensitivity to photoinhibition. However, when studying effects of photoinhibition on electron flow and photophosphorylation in isolated thylakoids of the two biotypes, no significant differences between resistant and susceptible plant materials were observed. It is suggest­ ed that the difference between resistant and susceptible biotypes connected with processes protective against photoinhibition in intact leaves, are lost during the isolation of thylakoids.
Pleiotropy in Triazine-Resistant Brassica napus: Leaf and Environmental Influences on Photosynthetic Regulation
Authors: Dekker Jack
Published: August 2018

Since the first discovery of s-triazine-resistance (R ) in higher plants, the altered D -1 protein product of the psbA gene has been regarded as less photosynthetically efficient in those R biotypes of a species. Decreases in electron transport function in the chloroplast have been believed to be the cause of decreased carbon assimilation rates and plant productivity in many reports. W hat is less clear in the literature is whether this change in D -1 structure and electron transport function directly modifies whole-leaf photosynthesis and plant productivity or only indirectly influences these functions. The dynamic nature of these responses have led several to conclude that the primary effect of R is complex, involves more than one aspect of photosynthesis, and can be mitigated by other processes in the system. Electron transport limitations are only one possible regulatory point in the photosynthetic pathway leading from light-harvesting and the photolysis of water, through ribulose bisphosphate carboxylase/oxygenase, to sucrose biosynthesis and utilization. Herein we discuss this complex issue, arguing that D -1 function can’t be evaluated in isolation from the leaf, the organism, and possibly from the community response. Carbon assimilation in R and the susceptible wild type (S) is a function of several interacting factors. These include the pleiotropic effects resulting from the psbA mutation (the dynamic reorganization of the R chloroplast) interacting with other regulatory components of photosynthesis, microenvironmental conditions, and time (including ontogeny and time of day). Previous work in our laboratory indicated a consistant, differential, pattern of Chi a fluorescence, carbon assimilation, leaf temperature, and stomatal function between S and R Brassica napus over the course of a diurnal light period and with ontogeny, i.e. R is a chronomutant. Dekker and Sharkey have shown that the primary limitation to photosynthesis changes with changes in leaf temperature, and that electron transport limitations in R may be significant only at higher temperatures. The recognized R plants interact with the environment in a different way than does S. Under environmental conditions highly favorable to plant growth, S often has an advantage over R. Under certain less favorable conditions to plant growth, stressful conditions, R can be at an advantage over S. These conditions may have been cool (or hot), low light conditions interacting with other biochemical and diurnal plant factors early and late in the photoperiod, as well as more complex physiological conditions late in the plant’s development. It can be envisioned that there were environmental conditions in the absence of s-triazine-herbicides in which R had an adaptive advantage over the more numerous S individuals in a population of a species. Under certain conditions R might have exploited a photosynthetic niche under-utilized by S.
Synthesis and Bleaching Activity of 1-Ethyl-and 1 -Propy 1-5-Substituted Imidazoles
Authors: Yamada Naotaka , Kuwano Eiichi , Eto
Published: August 2018

Twenty-eight 1-ethyl-and 1-propyl-5 -substituted imidazoles were synthesized an d their bleaching activity was evaluated by using the lettuce seedling test. 5-Phenyl-1-propylim idazole (1) caused distinct chlorosis, while none of the c ompounds with various alkenyl groups at the 5-position o the imidazole ring show ed this bleaching activity. Introduction of a bromo, chloro, fluoro, methyl or trifluoromethyl groupa t the 4-position on the benzene ring of com­pound 1 increased the activity in comparison with that of compound 1. 5-[4-(3-Chlorobenzyl-oxy)phenyl]-l-ethylimidazole (15) an d l-ethyl-5-[4-(3-methylbenzyloxy)phenyl]imidazole (21), analogs with a large substituent at the 4 -position on the benzene ring, also caused pronounced chlorosis in the lettuce seedlings. Both compounds 1 and 15 a t 30 ppm decreased total c arot­enoid content in the lettuce seedlings to less than 40% of that in the control, and the reduction of total carotenoid content correlated well with treatment dose.
A Quantum Chemical Study of "Light-Dependent Herbicides"
Authors: Akagi T. , Sakashita N.
Published: August 2018

Common structural features were investigated for “light-dependent herbicides” (LDH s, also called peroxidizing or photobleaching herbicides). Quantum chemical calculations of 143 herbicidal compounds revealed that LUMO levels of LDH s were similar and strikingly low. Using the LUMO position as an anchor, presumably known structure-activity relationships could be explained. Overall molecular similarity between oxyfluorfen and chlorophthalim was examined by molecular field fitting. The result supported LUMO position correspondence.
Paraquat (Methylviologen): Its Interference with Primary Photochemical Reactions
Authors: Hiyama Tetsuo , Ohinata Akira , Kobayashi Shin-ichi
Published: August 2018

Paraquat(methylviologen), a widely used nonspecific herbicide, is ptoreduced in the primary photochemical reaction of photosystemI. Using two types of the photosystem I reaction center preparations, i.e. one with FeSA/FeSB and the other without, the immediate electron donor to methylviologen was determined to be FeSx (P430) rather than FeSA/FeSB.
On the Occurrence of Caffeoyltartronic Acid and Other Phenolics in Chondrilla juncea
Authors: Terencio M. C. , Giner R. M. , Sanz M. J. , Máñez S. , Ríos J. L.
Published: August 2018

Caffeoyltartronic acid and other eleven phenolic com pounds were identified in the MeOH extract of Chondrilla juncea: the flavonoids luteolin, luteolin-7-glucoside, luteolin-7-galactosylglucuronide and quercetin-3-galactoside; the phenolic acids protocatechuic, caffeic, chlorogenic, isochlorogenic and isoferulic and the coumarins cichoriin and aesculetin. The taxonomic im plications of these com pounds have been discussed.
The Biflavonoid Pattern of Anacolia webbii
Authors: Seeger Tassilo , Geiger Hans , Mues Rüdiger , Zinsmeister Hans Dietmar
Published: August 2018

From Anacolia webbii the following five biflavonoids could be isolated: 2,3-dihydrophilonotisflavone, philonotisflavone, dicranolomin, 5′,3‴-dihydroxyamentoflavone and 5′,3‴-dihydroxyrobustaflavone. The compounds were identified spectroscopically.
Phellodonic Acid, a New Biologically Active Hirsutane Derivative from Phellodon melaleucus (Thelephoraceae, Basidiomycetes) [1]
Authors: Stadler Marc , Anke Timm , Dasenbrock Johannes , Steglich Wolfgang
Published: August 2018

A new hirsutane derivative, phellodonic acid (1), has been isolated from fermentations of Phellodon melaleucus strain 87113. Its structure was elucidated by spectroscopic methods. The compound exhibits antibiotic activities towards bacteria and fungi. 1 is the first bioactive metabolite from cultures of a species belonging to the family Thelephoraceae.
Two Forms of Phosphoenolpyruvate Carboxylase in Chlorella kessleri
Authors: Grotjohann N. , Hippe C.
Published: August 2018

FPLC of crude cell extracts of Chlorella kessleri reveals two protein fractions with phosphoenolpyruvate carboxylase activity. Their mole masses, 955 kDa and 543 kDa , suggest that they are dimer and monomer of the same enzyme. Further data, how ever, indicate that they are more likely two different iso-forms of phosphoenolpyruvate carboxylase: Attempts to interconvert both proteins in vitro, such as through treatment with NaCl, metabolites and thiolor histidine-group effecting reagents, were unsuccessful. The substrate affinity of the large protein was slightly higher than that of the small protein (Km = 1.13 and 0.76 mᴍ, respectively); and the sensitivity to enhanced temperature was more pronounced in the large than in the smaller protein (half lifes = 23 min and 55 - 60 m in, respectively). Some properties of both fractions, however, proved identical: 1. pH optima at pH 8.5 - 9,2. Hill coefficients approx. 1,3. no significant regulatory effect of glutamine, glutamate, aspartate and malate, 4. increase in Km and in Hill coefficient by citrate, and 5. identical behaviour in ion exchange chromatography. Functions and localization of the assumed two iso-forms of phosphoenolpyruvate carboxylase remain to be clarified.
Survey of the Taxonomic and Tissue Distribution of Microsomal Binding Sites for the Non-Host Selective Fungal Phytotoxin, Fusicoccin
Authors: Meyer Christiane , Waldkötter Kerstin , Sprenger Annegret , Schlösset Uwe G. , Luther Markus , Weiler Elmar W.
Published: August 2018

The recent identification of the fusicoccin-binding protein (FCBP) in plasma membranes from monocotyledonous and dicotyledonous angiosperms has opened the basis for an elucidation of the toxin’s mechanism(s) of action and indicated a widespread occurrence of the FCBP in plants. Results of a detailed taxonomic survey of fusicoccin-binding sites are reported. Binding sites were not found in prokaryotes, animal tissues, fungi and algae including the most direct extant ancestors of the land plants (Coleochaete). From the Psilotales (Psilophytatae) to the monocotyledonous angiosperms, all taxa analyzed possessed high-affinity microsomal fusicoccin-binding sites. A heterogeneous picture emerged for the Bryophvta. Anthoceros crispulus (Anthocerotae), the only hornwort available to study, lacked fusicoccin binding. Within the Hepaticae as well as the Musci, species lacking and species exhibiting toxin binding were found. The binding site thus seems to have emerged very early in the evolution of the land plants. The tissue distribution of fusicoccin-binding sites was studied in Vicia faba L. shoots. All tissues analyzed showed fusicoccin binding, although not to the same extent. On a per-cell basis, guard cells were found to contain, compared to mesophyll cells, a nine-fold higher number of binding sites. Based on cell surface area, the site density is by a factor of 32 higher in guard cells than in mesophyll cells. Tissue specific expression of the binding sites is suggested by these findings.
Genetic Engineering of Disease and Pest Resistance in Plants: Present State of the Art
Authors: Strittmatter Günter , Wegener Dorothee
Published: August 2018

Rapid progress in gene technology has allowed, on the one hand, insight to be gained into the complex molecular mechanisms of plant/pathogen recognition and the natural defence strategies of host plants. On the other hand, this technology can also be used for the controlled and efficient generation of genetic variability and for the identification of desirable genotypes, far beyond the possibilities of classical breeding. The first successful attempts have been made to improve resistance against pathogenic viruses, bacteria, fungi and insects by engineering transgenic plants. The majority of these strategies were based on constitutively expressing single proteins that are either toxic to the pathogen/pest, or interfere with its reproductive cycle. More refined strategies, which are at the stage of testing, try to mimic and modify naturally-evolved defence reactions of plants and, thereby, will potentially confer a more durable resistance to a broad range of pathogens
Comparative FTIR and 13C CP/MAS NMR Spectroscopic Investigations on Sporopollenin of Different Systematic Origins
Authors: Wilmesmeier Sabine , Steuernagel Stefan , Wiermann Rolf
Published: August 2018

Comparative phytochemical investigations were carried out on sporopollenins of the follow­ ing plant species: Bryophyta -Reboulia hemisphaerica and Polytrichum strictum; Pteridophyta -Equisetum arvense, Selaginella selaginoides micro-and megaspores; Gymnospermae -Cycas circinalis; Angiospermae -Typha angustifolia and Tulipa cv. “Apeldoorn”. Although the range of the analyses included species from the Bryophyta to the Angiospermae, fundamen tal correspondences could be detected in the 13C NMR and FTIR spectra concerning the occur­rence of aliphatics, aromatics, ether and carbonyl/carboxylic functions in varying degrees. While the amount of aliphatics strongly dominated in the molecular structure of all other sporopollenins investigated here, it was found in sporopollenin of Equisetum arvense in a much lower extent. Despite the different morphology of Selaginella selaginoides micro-and mega­ spores, their sporopollenin spectra were nearly identical
Naturally Occurring Antidotes against Benzimidazole Fungicides
Authors: Tahara Satoshi , Matsukura Yumiko , Katsuta Hiroyuki , Mizutani Junya
Published: August 2018

TLC bioautography using precoated glass thin-layer plates impregnated with benomyl or carbendazim (MBC), and Cladosporium herbarum as a test fungus was evaluated as a facil way to detect plant secondary metabolites antidoting against benzimidazole fungicides. In addition to emodin and a-tocopherol from Polygonum sachalinense, three phenolics, 3,5-dihydroxy- 4-methylstilbene and 5-methoxy-6,7-methylenedioxyflavone from P. lapathifolium, and 2,6-dim ethoxybenzoquinone from P. thunbergii were isolated and characterized as new benzimidazole antidotes. Emodin exhibited the antidoting activity not only against benomyl but also against carbendazim (M BC), thiabendazole (TBZ), thiophanate-methyl and nocodazole. Furthermore, emodin showed antidoting activity against MBC in the wild-type Neurospora crassa and against diethofencarb in the mutant of N. crassa resistant to benzimidazole fungicides but highly susceptible to diethofencarb
Kinobeon A, A Novel Red Pigment Produced in Safflower Tissue Culture Systems
Authors: Wakayama Sachio , Kusaka Kazuhito , Kanehira Tsutomu , Yamada Yasuyuki , Kawazu Kazuyoshi , Kobayashi Akio
Published: August 2018

The production of safflower pigments by tissue culture techniques was carried out using the calh induced from various parts of the plant. After massive cell selection efforts, a culture cell line (KB 7) was found to produce a considerable amount of a red pigment. Addition of cellulose powder and D-phenylalanine into the medium dramatically improved the pigment production. After purification, red crystals were obtained. Its UV/VIS spectrum as well as the HPLC behavior was clearly different from that of carthamin found in the mother plant and those of another typical plant pigments, suggesting that it was a novel compound. Therefore, this pigment was named kinobeon A.
Serratiochelin, a New Catecholate Siderophore from Serratia marcescens
Authors: Ehlert G. , Taraz K. , Budzikiewicz H.
Published: August 2018

The catecholate siderophore serratiochelin isolated from an iron deficient culture medium of Serratia marcescens TW was characterized by mass spectrometry and NMR and by GC/MS analysis of the hydrolysis products as 1-(2,3-dihydroxybenzamido)-3-[4 S,5R-2-(2,3-dihydroxyphenyl)- 5-methyl-2-oxazoline-4-carboxamido]propane. The structure of serratiochelin was confirmed by synthesis. The bacterial strain also produces chrysobactin.
Uncoupling by Trehalose of Ca2+ Transport and ATP Hydrolysis by the Plasma Membrane (Ca2++Mg2+) ATPase of Kidney Tubules
Authors: Sola-Penna Mauro , Vieyra Adalberto , Meyer-Fernandes José Roberto
Published: August 2018

Trehalose, the disaccharide of glucose, inhibits both initial rate and maximal capacity of ATP-dependent Ca2+ transport in inside-out vesicles of basolateral membrane from kidney proximal tubules. This inhibition (I0.5 = 60 mᴍ) cannot be attributed to an increase in Ca2+ permeability, since the rate of EGTA-stimulated Ca2+ efflux from preloaded vesicles is not modified by trehalose. In the presence of 600 mᴍ trehalose, Ca2+ uptake was almost completely inhibited, but the Ca2+-stimulated ATPase activity was unaffected; thus trehalose uncouples the Ca2+ transport from the ATPase activity. The Ca2+ transport inhibition by trehalose is reversible, since the inhibition disappeared when the vesicles were pre-incubated with 600 mᴍ trehalose and then diluted in reaction medium to measure Ca2+ accumulation. Other mono- and disaccharides such as glucose, fructose, galactose, sucrose, maltose and lactose were tested but were not so effective as trehalose. The uncoupling of Ca2+ transport from hydrolysis can be explained by an interaction of trehalose with the phospholipid environment of the enzyme that induces conformational changes in specific domains of the enzyme so as to impair the coupling process.
Uptake, Translocation, and Metabolism of 3,4-Dichloroaniline in Soybean and Wheat Plants
Authors: Bockers Margret , Rivero Christiane , Thiede Brigitte , Jankowski Thomas , Schmidt Burkhard
Published: August 2018

The roots of 13-day-old soybean ( Glycine max L.) and 7-day-old wheat ( Triticum aestivum L.) hydroponic plants were exposed to [14C]-3,4-dichloroaniline (1.0 and 0.4 mg/1 (6.2 and 2.5 μᴍ) , respectively) and harvested after 48/120 h (soybean) and 72 h (wheat). Both species metabolized the xenobiotic almost quantitatively to N-(β-D-glucopyranosyl)-3,4-dichloroaniline, N-malonyl-3,4-dichloroaniline, 6′-O-malonyl-N-(β-D-glucopyranosyl)-3,4-dichloroaniline and non-extractable residues. In the soybean experiments 58.8 (48 h) and 54.6% (120 h) of the applied radioactivity were found in the nutrient; this fraction consisted primarily of N-malonyl-3,4-dichloroaniline. 37.3/24.1% (48/120 h) were detected in the plants. In the soybeans, 36.2 and 52.7% (48/120 h) of the absorbed 14C were translocated, mainly into hypocotyls, primary and secondary leaves. After 120 h, the main metabolite was N-malonyl- 3,4-dichloroaniline (38.5% ); considerable levels of this metabolite accumulated in the primary and secondary leaves (10.4 and 10.4%). The glucosides were mainly found in the roots of the soybean plants. Totals of 23.5 and 35.1% (48/120 h) were transformed to non-extractable residues. In wheat, 78.3% of the applied 3,4-dichloroaniline was absorbed after 72 h. This fraction was partially translocated to the leaves, but most of the residues remained in the roots (90.3% of absorbed 14C). In wheat, a total of 45.6% was transformed to nonextractable residues. The soluble radioactivity in the roots consisted of nearly equal amounts of the glucosides and the N-malonyl conjugate. The processes observed in soybean and wheat roots resembled those of the respective cell suspension cultures published previously.
Changes in Levels of a-Tocopherol and Ascorbate in Spruce Needles at Three Low Mountain Sites Exposed to Mg2+-Deficiency and Ozone
Authors: Schmieden U. , Wild A.
Published: August 2018

The main objective of this study was the com parison of changes in levels of α-tocopherol and ascorbate in needles of spruce trees with various degrees of damage at three low mountain sites. The ascorbate content in needles of spruce trees with various degrees of dam age differs in the course of seasons as well as in the absolute level. The antioxidant status was affected mainly during summer. The content of ascorbate in needles of dam aged trees was significantly increased compared to that of undamaged trees. Despite seasonal and daily fluctuations, the level of ascorbate seems to be a good indicator for the degree of dam age in the case of symptoms described as montane yellowing. Together with an increasing content of α-tocopherol per chlorophyll, a rise of ascorbate content indicates enhanced oxidative stress in the needles of damaged trees, particularly in summer. Asc/αToc ratios were increased in needles of damaged trees. At the studied sites enhanced oxidative stress could be caused by the com bined action of Mg2+-deficiency, high ozone concentrations and high-light intensity, all inducing an increased production of radicals in combination with a reduced photosynthetic capacity
Photoautotrophic Chenopodium rubrum Cell Suspension Cultures Resistant against Photosynthesis-Inhibiting Herbicides I. Selection and Characterization
Authors: Thiemann Jutta , Barz Wolfgang
Published: August 2018

Abstract For establishing metribuzin-resistant, photoautotrophic Chenopodium rubrum cell cul­tures plated cells, callus cultures or suspension cultures were subjected to selection proce­ dures. The most effective procedure was the stepwise increase in the concentration of the herbicide from 0.01 μᴍ to 10 μᴍ in suspension cultures, which resulted in the isolation of eight different metribuzin-resistant photoautotrophic cell lines. Conjugation metabolism or a decrease in the uptake and translocation of the selective agent were not responsible for resist­ ance, which was stable in the absence of the inhibitor over numerous growth cycles. Meas­ urements of the photosynthetic electron transport, analyses of fluorescence induction kinetics and determination of the binding properties of 14C-labelled metribuzin to isolated thylakoids indicated that resistance of the cell lines is based on an alteration in the photosystem II her­ bicide-binding protein (D 1 protein). RFLP analysis of the psbA gene of the eight resistant cell lines demonstrated that none of them possess an amino acid exchange in position 264 of the D1 protein leading to altered herbicide-binding properties.
Molecular Mobility of the Water Molecules in Aqueous Sucrose Solutions, Studied by 2H-NMR Relaxation
Authors: Girlich D. , Lüdemann H.-D.
Published: August 2018

Deuteron spin lattice relaxation times T1 of sucrose/D2O solutions are given as function of temperature, pressure, frequency and concentration. From the temperature dependence of the 2H -T1 the rotational dynamics of the hydrated sucrose complex and the water molecules are determined. For high pressure and high concentrations the temperature dependence of the water molecules is described by a Vogel-Tammann-Fulcher equation. The ideal glass transition temperatures TO
H2O derived for the water molecules are at higher concentrations almost constant and smaller than the TO
suc of the sugar molecules
Biflavonoids of Selaginella denticulata Growing in Spain
Authors: López-Sáez José Antonio , Pérez- Alonso María José , Negueruela Arturo Velasco
Published: August 2018

From Selaginella denticulata the following seven biflavones were isolated: amentoflavone, 7,4′,7″,4‴-tetra- O-methylamentoflavone, cryptomerin B, hinokiflavone, isocryptomerin, sotetsuflavone (7-O-methylamentoflavone) and robustaflavone
Anthocleistol, A New Secoiridoid From Anthocleista Nobilis
Authors: Madubunyi Ifeanyi I. , Adam Klaus Peter , Becker Hans
Published: August 2018

The root bark of Anthocleista nobilis is used in Nigeria against liver diseases, malaria and gastrointestinal worms. The secoiridoid pattern of the root bark was investigated. Sweroside and Anthocleistol a new secoiridoid have been isolated from the methanol extract. The structures were elucidated from spectroscopic data
Phytoalexine mit Indolstruktur aus Kohlrabi {Brassica oleracea var. gongylodes)+ / Indole Phytoalexins from the Kohlrabi (Brassica oleracea var. gongylodes)+
Authors: Gross Dieter , Porzel Andrea , Schmidt Jürgen
Published: August 2018

UV-irradiation of sliced stem tubers of kohlrabi (Brassica oleracea var. gongylodes) followed by incubation for 4 days, resulted in the production of two new sulphur-containing indole phytoalexins, cyclobrassinone and 1 -methoxyspirobrassinin, whose structures were elucidated on the basis of spectroscopic data. Three known indole phytoalexins, spirobrassinin, methoxybrassitin and methoxybrassinin, and several m inor phytoalexin-like compounds not yet identified were also isolated. The accumulation of these indole phytoalexins was also induced by abiotic elicitation with CuCl2.

Feeding both of L-[β-14C]tryptophan and L-[14CH3]methionine to UV-irradiated stem tuber tissue of kohlrabi indicated that the S-containing indole phytoalexins were biosynthesized from these amino acids.
Immunological Evidence for the Binding of β-Carotene and Xanthophylls onto Peptides of Photosystem I from Nicotiana tabacum
Authors: Makewicz A. , Radunz A. , Schmid G. H.
Published: August 2018

Photosystem I preparations were obtained from wild type tobacco Nicotiana tabacum var. John William’s Broadleaf (JWB) and from the two chlorophyll-deficient mutants N. tabacum Su/su and N. tabacum Su/su var. Aurea. The preparations were characterized with respect to the chlorophyll a/b ratio, their photosynthetic activity and their absorption spectroscopic properties. Peptides from these preparations were analyzed by SDS polyacrylamide gel electrophoresis and transferred for the detection of bound carotenoids according to the Western blot procedure to nitrocellulose or Immobilon membranes. The PS I preparation from the wild type JWB consisted of the core and the LHCP complex. The core complex contains the two core peptides with the same apparent MW of 66 kDa and several peptides with the lesser molecular masses of 22, 20, 19, 17, 16, 10 and 9 kDa. The light-harvesting protein complex consists of 4 subunits with the molecular masses 28, 26, 25 and 24 kDa. The PS I preparations of the yellow-green mutant Su/su and of the Aurea mutant Su/su var. Aurea contain as impurity traces of the D1 and D2 core peptides of photosystem II and also traces of the chlorophyll-binding photosystem II peptides with the molecular masses 42 and 47 kDa.

The peptides of the photosystem I preparation were characterized by specific photosystem I antisera: An antiserum to the photosystem I complex reacts in the Western blot only with the homologous peptides of photosystem I. In comparative analyses with photosystem II preparations this antiserum (directed to photosystem I) reacts, as expected, only with the peptides of the light-harvesting complex. An antiserum to the CP 1 core peptides reacts only with the 66 kDa peptides of photosystem I and gives no cross reaction with heterodimer forms of the D1/D2 core peptides of photosystem II.

In the Western blot procedure by means of polyclonal monospecific antisera to carotenoids it was demonstrated that β-carotene is bound in high concentration onto the core peptides CP 1 and to a lesser extent onto the two larger subunits of the LHCP complex, exhibiting the molecular masses of 28 and 26 kDa. Neoxanthin is bound onto the same peptides. In contrast to this, lutein was only identified on the core peptides CP 1 and violaxanthin only on the larger subunits of the LHCP complex. As the carotenoids are labelled with antibodies, even after SDS treatment in the electrophoresis, it is assumed, that the carotenoids are covalently bound via the ionon ring to the respective peptide
Binuclear Manganese(III) Complexes as Electron Donors in D1/D2/Cytochrome b 559 Preparations Isolated from Spinach Photosystem II Membrane Fragments
Authors: Allakhverdiev S. I. , Karacan M. S. , Somer G. , Karacan N. , Khan E. M. , Rane S. Y. , Padhye S. , Klimov V. V. , Renger G.
Published: August 2018

The capability of different manganese complexes to act as PS II electron donors in D1/D2/ cytochrome b 559 complexes has been analyzed by measuring actinic light-induced absorption changes at 680 nm (650 nm) and 340 nm, reflecting the photoaccumulation of Pheophytin- (Pheo-) and the reduction of NADP+ respectively. The data obtained reveal: a) the donor capacity of synthetic binuclear Mn(III)2 complexes containing aromatic ligands significantly exceeds that for MnCl2 in both cases, i.e. Pheo- photoaccumulation and NADP+ reduction; b) manganese complexes can serve as suitable electron donors for light-induced NADP+ reduction catalyzed by D1/D2/cytochrome b559 complexes and ferredoxin plus ferredoxin- NADP+ reductase under anaerobic conditions and c) the specific turnover rate of the system leading to NADP+ reduction is extremely small.

The implications of these findings are briefly discussed.