bluuebunny/crossref_metadata_2025_split huggingface dataset:
Milestones in the Development of Herbicide Safeners
Authors: Stephenson Gerald R. , Yaacoby Tuvia 
Published: August 2018

Abstract
The concept of using chemical safeners to improve herbicide selectivity became widely known in 1969 with the introduction of naphthalic anhydride (NA) to improve the tolerance of maize to thiocarbamate herbicides. Soon thereafter dichlormid was also developed as a safener for thiocarbamates in maize. At present there are at least eight different chemical safeners that have been developed commercially. Many of these safeners have been most effec­tive for chloroacetamide or thiocarbamate herbicides in monocotyledonous crops such as maize or sorghum. Some are like dichlormid and have been developed as physiologically selec­tive safeners that can be combined in the formulation with the herbicides. Others, like NA , are either less selective or less active in the soil and must be used as dressings on the crop seed. Most of the presently used safeners are for soil active herbicides. The challenge for the future will be to develop safeners that are effective for the newer postemergence herbicides in dicoty­ledonous as well as monocotyledonous crops.
Chemistry and Structure-Activity Relationships of Herbicide Safeners
Authors: Kőmíves Tamás , Hatzios Kriton K. 
Published: August 2018

Abstract
The discovery and commercial success of safeners against thiolcarbamate herbicide injury to corn has stimulated a rapid progress and opened new possibilities for further research and development in the last decade. Compounds with new chemistry, increased efficacy, and a broader selectivity spectrum were synthesized and developed for agricultural use. Structure-activity relationship studies helped to optimize their chemical properties and to understand their biological modes of action. Several examples indicate close similarity between chemical structures possessing herbicidal and safener properties. In some cases this differentiation may be marginal, as shown in crops pretreated with low herbicide doses leading to safening effects. In other examples, however, structural optima for safening and herbicidal efficacy can be clearly differentiated.
Oxabetrinil Reversal of Metolachlor and Acid Soil Stress
Authors: Wilkinson R. E. , Duncan R. R. 
Published: August 2018

Abstract
Metolachlor and excess Mn2+ (acid soil stress) induce alterations in gibberellin precursor biosynthesis that can explain the morphological responses to these physiological stresses. Oxa­betrinil protects sorghum [Sorghum bicolor (L.) Moench] from the influence of metolachlor and excess Mn2+. Sorghum cultivar variations in response to excess Mn2+ are explicable as dif­ferential rates of ent-kaurene biosynthesis between acid soil sensitive and tolerant cultivars. Concentrations of Mn2+ present in vegetative leaves and reproductive stem tissues were not different. Therefore, cultivar differences in ent-kaurene biosynthesis explain the acid soil toler­ance differences rather than differential Mn2+ absorption, translocation, and/or compartmentation. Metolachlor and safener responses are found in cellular compartments and tissues that do not match a decreased herbicide concentration through absorption, transport, or degrada­tion as a sole mode of action for safeners.
Lipophilic Phenolic Constituents from Helichrysum Species Endemic to Madagascar
Authors: Randriaminahy Michel , Proksch Peter , Witte Ludger , Wray Victor 
Published: August 2018

Abstract
Eight species of the genus Helichrysum, all of them endemic to Madagascar, were analyzed for lipophilic phenolic constituents deposited on the surfaces of leaves and stems. A total of 35 compounds was isolated and identified by spectroscopic means. Chalcones (10) comprised the largest group of compounds encountered, followed by flavonols (8), flavanones (7), flavones (4), benzophenones (3) and phloroglucinol derivatives (3). Many of the flavonoids were characterized by unsubstituted B-rings and/or C- or O-bound prenyl or neryl substituents. The Helichrysum species analyzed in this study are very similar to African species of this genus with regard to their lipophilic phenolic constituents. The phenolic com pounds studied thus appear to be conservative chemical characters of Helichrysum that were retained more or less unchanged during the origin of endemic taxa in Madagascar.
Occurrence of Secondary Carotenoids in PS I Complexes Isolated from Eremosphaera viridis De Bary (Chlorophyceae)
Authors: Vechtel Burkhard , Pistorius Elfriede K. , Ruppel Hans Georg 
Published: August 2018

Abstract
Photosystem I complexes of Eremosphaera viridis De Bary (Chlorophyceae, Chlorococcales) were isolated and partially characterized. In the isolated PS I complexes, peptides of 64-60, 26, 23, 20, 15, 11 and 8.5 kDa could be detected. When Eremosphaera was grown under regular conditions the pigment composition of the isolated PS I complexes was similar to that found in PS I complexes from other green algae. However, when Eremosphaera was grown under nitrogen deficient conditions, PS I complexes contained the secondary carotenoids canthaxanthin and traces of astaxanthin and echinenone in addition to β-carotene, violaxanthin and lutein. The results presented indicate that the secondary carotenoids are associated with the LHC I of PS I. To our knowledge this represents the first report about the association of secondary carotenoids with light harvesting pigment protein complexes of green algae.
Reactions of Cloned Poplars to Air Pollution: Premature Leaf Loss and Investigations of the Nitrogen Metabolism
Authors: Ballach Hans-Joachim , Oppenheimer Simone , Mooi Jan 
Published: August 2018

Abstract
Young poplar cuttings (Populus nigra L. cv. Loenen and P. maximowiczii Henry x P. nigra L. cv. Rochester) were exposed for six weeks in open-top chambers to realistic concentrations of pollutant mixtures: 1) control; 2) SO2/NOx; 3)O3/ NOx and 4)SO2/O3/NOx. In this sequence of fumigation variants, the degree of influence of the various parameters of the nitrogen metabolism and of premature leaf drop increased very frequently compared to the control plants, P. nigra L. proving to be the more sensitive species.
The elevated Kjeldahl nitrogen content of the fumigated leaves was accompanied by either an increase in free amino acids or in total protein or, in the case of particularly large rises (SO2/O3/NOx variants), by increases in both substance groups. Proteolytic processes as a cause of the elevated content of free amino acids could be excluded to a large extent. A diminished de novo synthesis of proteins obviously led to a shift in the amino acid/protein relationship. In the younger fumigated leaves, the total concentration of free amino acids exceeded the values of the older leaves. The elevated amino acid content of the fumigated leaves was produced to a high degree by the glycolate pathway and the Krebs cycle. The increased turnover of the carbon skeletons was connected with a drastic starch degradation, especially in the older leaves.
The interaction of the amino acid and carbohydrate metabolisms is probably an important regulator in the promotion of rapid growth of young leaves in order to compensate premature leaf loss.
Differences in Membrane Order between C 3 H 10 T1/2 Cells and Their Transformed Counterparts as Measured by EPR
Authors: Grossi G. F. , Durante M. , Napolitano M. , Lanzone A. , Riccardi P. , Santini M. T. 
Published: August 2018

Abstract
Membrane order of mouse embryo fibroblasts and their ionizing radiation and chemically transformed counterparts was investigated using EPR spectroscopy after labeling the membrane of the cells with the fatty acid spin label, 5-nitroxy stearic acid. The EPR spectra were recorded at temperatures ranging from 18 to 38 °C for both control and transformed cells. The distance between the outer hyperfine splitting (2 T′||), which is used as an indicator of membrane order, varies in these two cell types. Below 28 °C, 2T′II is higher in transformed fibroblasts than in normal cells, whereas above this temperature membrane order is the same. Lipid analysis as carried out by the measurement of the cholesterol/membrane proteins and sphingomyelin/lecithin ratios, showed no difference in the amounts of the main membrane rigidifiers. These findings suggest that cell transformation of mouse fibroblasts induced by radiation or chemicals may produce alterations in the cell membrane, as evidenced by variations in its order at low temperature. These measured differences are presumably not attributable to its fatty acids composition but to its glycoproteins content, since changes in membrane regidifiers were not observed between normal and transformed cells.
Soluble Carbohydrates in Mycorrhized and Non-Mycorrhized Fine Roots of Spruce Seedlings
Authors: Rieger Andreas , Guttenberger Martin , Hampp Rüdiger 
Published: August 2018

Abstract
We present results on the compartmentation of carbohydrates such as sucrose, glucose, fructose, and mannose in different parts of an ectomycorrhiza established between Picea abies and Amanita muscaria and compare it with non-mycorrhized fine roots. Lyophilized mycorrhizas and fine roots (< 2 mm length) were dissected into about 0.5 mm thick slices which represent 4 zones of different physiological functions. The total amount of the analyzed carbohydrates was about 30% higher in non-mycorrhized (n-myc) compared to mycorrhized (myc) fine roots, with sucrose being the dominating sugar in both root types. A longitudinal distinction of sucrose pools showed lowest levels in the middle parts of a mycorrhiza, which represent areas of most intense symbiotic interaction. Fine roots without fungal infection did not show longitudinal variations in sugar content.
The Vacuolar Localization of Grapevine Peroxidase Isoenzymes Capable of Oxidizing 4-Hydroxystilbenes
Authors: Calderón Antonio A. , García-Florenciano E. , Pedreño María A. , Muñoz Romualdo , Barceló A. Ros 
Published: August 2018

Keywords
A study of the subcellular localization of peroxidase isoenzymes capable of oxidizing 4-hydroxystilbenes to viniferin-type compounds has been carried out in cultured cells derived from Vitis vinifera cv. Gamay berries. The study revealed that these isoenzymes are apparently located, in soluble form, in the vacuolar sap and are strongly inhibited by vacuolar anthocyani( di)ns in the concentration range found in planta. These results suggest that the inhibition of the 4-HS peroxidase system in vacuoles, as a consequence of anthocyani(di)n accumulation, could be responsible for the loss of viniferin production potential which accompanies grape berry veraison.
Analysis of Phenolics of Bud Exudates of Populus cathayana and Populus szechuanica by GC-MS
Authors: Greenaway W. , English S. , May J. , Whatley F. R. 
Published: August 2018

Abstract
Analysis of GC-MS data revealed 58 com ponents of bud exudate from P. cathayana (Section Tacamahaca) and 40 components of bud exudate from P. szechuanica (Section Tacamahaca) of which 47 and 35 respectively were phenolics. The bud exudates were very similar in composition, containing flavanones and chalcones (61% and 51% respectively), flavones (15% and 12%) and pentenyl caffeates (11% and 6%). The major single component of the exudate of both poplars was pinobanksin- 3-acetate (26% and 33%). The bud exudates of P. cathayana and P. szechuanica are similar to those of European and American Section Aigeiros poplars and unlike those of North American Section Tacamahaca poplars.
In vitro Demonstration of a Biosynthetic Sequence for the Cruciferae Phytoalexins
Authors: Devys Michel , Barbier Michel 
Published: August 2018

Abstract
Periodate-induced degradation of cyclobrassinin monosulphoxide gives brassilexin in 40% yield. The sequence: cyclobrassinin to brassilexin through cyclobrassinin sulphoxide is now demonstrated for the group of phytoalexins found in the Cruciferae.
Studies of Components of the Thylakoid Membrane of Undamaged and Damaged Spruce Trees at Different Mountain Sites
Authors: Wild Aloysius , Strobel Petra , Flammersfeld Ute 
Published: August 2018

During a five-year period, components of the thylakoid membrane in needles of the second generation of undamaged and damaged trees of Norway spruce were studied at three different mountain sites in West Germany. Visible signs of damage at these sites are a yellowing of the light-exposed sides of the needles as well as the loss of needles. The goal of this study was to determine damage-induced alterations in composition and physiological reactions of the thylakoid membranes in spruce needles. In order to meet this purpose, contents of chlorophyll a and b, electron transport rate of photosystem II, contents of the D 1 protein, cytochrome f, as well as P-700 were measured.
The chlorophyll content in the needles of the damaged spruce trees was significantly lower than in the needles of the undamaged trees. In addition to this, the typical annual course of chlorophyll content was exclusively observed in the needles of the undamaged spruce trees. If related to dry weight, a drastic reduction of the electron transport rate and of the redox components of the thylakoid membrane was observed due to damage, indicating a degeneration of the photosynthetic membranes. The contents of D1 protein and the photosynthetic electron transport rates were also markedly reduced in the needles of the damaged trees, when related to chlorophyll content of thylakoids, suggesting an early and particular impairment of photosystem II. The comparison of spruce trees showing different signs of damage demonstrates that certain biochemical parameters concerning the photosynthetic membranes (chlorophyll, cytochrome f, ratio photosystem II/I) reflect the extent of damage and are suitable for an early indication of a beginning, but still invisible damage of spruce trees.
Halogenation Enhances the Photosystem II Inhibitory Activity of 4-Hydroxypyridines: Structure-Activity Relationships and Their Mode of Action
Authors: Asami Tadao , Baba Masatoshi , Koike Hiroyuki , Inoue Yorinao , Yoshida Shigeo 
Published: August 2018

Abstract
A range of 4-hydroxypyridines were synthesized and their activity as PET inhibitors were investigated with regard to their structural resemblance to plastoquinone in photosynthetic electron transport (PET). The activity of these compounds was markedly enhanced upon modifying their structures: introduction of halogens into both the 3-and 5-positions of the pyridine ring and additional substitution at the α-position of the side chain at 6-position were effective among others in enhancing the activity. Insertion of a phenyl ring into the side chain at 6-position of the pyridine ring also increased the activity. Substituents on the phenyl ring greatly affected the activity: when substituted with an appropriate functional group, the compounds became 10-to 100-fold more active. The mode of action of both halogenated and non-halogenated 4-hydroxypyridines were investigated by means of thermoluminescence measurements and cross resistance examination against atrazine-resistant thylakoids having mutation in D 1 protein. It was inferred that upon halogenation, 4-hydroxypyridines changed their mode of action from plastoquinone-pool inhibitors to phenol-type inhibitors.
Photosystem II Inhibition by Pyran-enamine Derivatives
Authors: Yoneyama Koichi , Nakajima Yoshihiro , Ogasawara Masaru , Kuramochi Hitoshi , Konnai Makoto , Iwamura Hajime , Sato Fumihiko , Ichinose Katsunori , Asami Tadao , Takahashi Nobutaka , Yoshida Shigeo 
Published: August 2018

Abstract
Through the studies on structure-activity relationships of 5-acyl-3-(1-aminoalkylidene)-4-hydroxy-2 H-pyran-2,6(3 H)-dione derivatives in photosystem II (PS II) inhibition, overall lipophilicity of the molecule was found to be a major determinant for the activity. In the substituted N -benzyl derivatives, not only the lipophilicity but also the electronic and steric characters of the substituents greatly affected the activity. Their mode of PS II inhibition seemed to be similar to that of DCMU , whereas pyran-enamine derivatives needed to be highly lipophilic to block the electron transport in thylakoid membranes, which in turn diminished the permeability through biomembranes.
Inhibition of Photosynthesis by 4-Nitro-6-alkylphenols: Structure-Activity Studies in Wild Type and Five Mutants of Chlamydomonas reinhardtii Thylakoids
Authors: Draber W. , Hilp U. , Likusa H. , Schindler M. , Trebst A. 
Published: August 2018

Abstract
Photosynthesis inhibition data were determined with thylakoids of the green alga Chlamydomonas reinhardtii on twenty-two 2-bromo-4-nitro-6-alkyl -and 2,4-dinitro-6-alkyl-phenols. Wild type and five different mutants of the algae were employed with defined changes in the psbA gene and a single amino acid substitution in the herbicide binding protein D 1 of photo­ system II. Their response to the various inhibitors was quite different from that of the wild type. Tolerance as well as enhanced inhibitory activity was found in the mutants, with tolerance in all phenols in the val219 ile and of some in the phe255 tyr mutant and supersensitivity of most phenols in the ala251 val, ser264 ala and leu275 phe mutant. This implies that the phenols are bound specifically to the D 1 protein. Structure-activity studies revealed parabolic relationships with all descriptors increasing with the alkyl chain length for wild type and most mutant inhibition values. Molecular modelling chains in different phenols in the QB binding niche same direction.
Significance of Photosystem II Core Phosphorylation Heterogeneity for the Herbicide-Binding Domain
Authors: Giardi Maria Teresa 
Published: August 2018

Abstract
In recent papers the heterogeneous nature of photosystem (PS) II core phosphorylation has been revealed (Giardi et al., BBRC 176, 1298 -1305 (1991); Plant Physiol. 100, 1948 -1954 (1992)). In this paper the action of endogenous and exogenous phosphatases both on the distribution of phosphorylated PS II core populations and on herbicide-binding activity in photosystem II preparations from Spinacia oleracea L. has been investigated. The results indicate that these phosphatases modify the photosystem II core phosphorylation heterogeneity at a different level. Dark incubation causes a partial dephosphorylation of D1 and D2 proteins by endogenous phosphatase(s) and changes the relative distribution of phosphorylated photosystem II core populations, while the action of the alkaline phosphatase leads to extensive dephosphorylation and to the detachment of PsbH protein from the photosystem II core. Dephosphorylation by the two alternative methods results in a differential modification of herbicide-binding activity. It is suggested that photosystem II heterogeneity with respect to the herbicide action, observed in vivo, could be a consequence of PS II core phosphorylation heterogeneity.
Differential Effect of Hg(II) on [d(A)n · d(T)n] and [d(A-T)n · d(A-T)n] Sequences: Circular Dichroism (CD) Measurements and Endonuclease Digestion Studies Using Poly[d(A) · d(T)] and Poly[d(A-T) · d(A-T)] as Substrates
Authors: Ok Seung Ryong , Gruenwedel Dieter W. 
Published: August 2018

Abstract
The long-wavelength positive CD bands of poly[d(A) · d(T)] and poly[d(A-T) · d(A-T)] become inverted upon the addition of Hg(ClO4)2. Poly[d(A) · d(T)] requires higher levels of mercury to undergo inversion than poly[d(A-T) · d(A-T)]. Mercurated poly[d(A) d(T)] is digested more rapidly than the control by DNase I or staphylococcal nuclease at low levels of Hg(ClO4)2. Let r = [Hg(ClO4)2]added/[DNA-P]. A 4- to 5-fold rate increase occurs with DNase I at r = 0.25; a 2-fold increase with staphylococcal nuclease at r = 0.2. By contrast, digestion of poly[d(A-T )· d(A-T)] decreases immediately with increasing r. The noted rate increases appear to be due to a modification of poly[d(A)-d(T)] helix structure prior to the chiroptical conversion. The modification is interpreted as a widening of the minor groove, permitting, thus, a better binding of DNase I to its substrate. The overall changes in CD as well as enzymatic digestion rates are taken to signal mercury-induced alterations in helix screwness from rightto- left. They are totally reversible subsequent to the removal of mercury.
Azadirachtin Inhibits Proliferation of Sf 9 Cells in Monolayer Culture
Authors: Rembold H. , Annadurai R.S. 
Published: August 2018

Abstract
Azadirachtin A in ppm quantity inhibits proliferation and monolayer formation of Spodoptera frugiperda (Sf 9) insect cells in monolayer culture. The incubated cells demonstrate reduced rates of protein synthesis which finally leads to cell death. This growth inhibiting activity is compared with other botanicals such as ohchinin, salannin and volkensin. The high and specific activity of azadirachtin A on insect cells is discussed in comparison with its effect on a mammalian cell line, based on 2D PAGE analysis of the total protein contents.
Inter-and Intraspecific Variation of the Nucleotide Sequence of the Cytochrome b Gene in Cory's (Calonectris diomedea), Manx Shearwater (Puffinus puffinus) and the Fulmar (Fulmavus glacialis)
Authors: Wink M. , Heidrich P. , Kahl U. , Swatschek I. , Witt H .-H , Ristow D. 
Published: August 2018

Abstract
Cytochrome b, DNA Sequence, Polymerase Chain Reaction (PCR), Molecular Evolution, Procellariidae The cytochrome b gene of three European taxa of the family of Procellariidae was amplified from total DNA and sequenced. The sequence comparison shows that the Fulmar (Fulmarus glacialis) is significantly distinct from shearwaters, whereas Cory’s (Calonectris diomedea) and Manx Shearwater (Puffinus puffinus) are closely related. Although the populations of C. dio­medea can be distinguished morphologically, the sequences of cyt b differ only slightly between the Atlantic and Mediterranean subspecies (i.e. C. d. borealis versus C. d. diomedea) and do not reveal other population differences within subspecies.
Pheromone 92 [1]. Duftstoffe aus den abdominalen Haarbüscheln des männlichen Totenkopfschwarmers Acherontia atropos L. (Lepidoptera: Sphingidae) / Pherom ones 92 [1], Odorous Substances from the Abdominal Hair Brushes of the Male Sphingid Moth Acherontia atropos L. (L epidoptera: Sphingidae)
Authors: Bestmann Hans Jürgen , Erler Joachim , Vostrowsky Otto , Wasserthal Lutz Th. 
Published: August 2018

Abstract
Duftstoffe aus den abdominalen Haarbüscheln des männlichen Totenkopfschwarmers Acherontia atropos L. (Lepidoptera: Sphingidae) Pherom ones 92 [1], Odorous Substances from the Abdom inal Hair Brushes of the Male Sphingid Moth Acherontia atropos L. (L epidoptera: Sphingidae) Hans Jürgen Bestm ann, Joachim Erler, Otto Vostrowsky From abdominal hair brushes of male hawk moths Acherontia atropos (Lepidoptera: Sphingidae) 24 volatiles have been detected and identified by GC-MS analysis, caryophyllene (17), humulene (18), linalool (6), linalyl propionate (12) and geranic acid methylester (9) comprising the main constituents. Analyzing the terpenoid composition of volatiles from insects reared on different host plants as well as that of the essential oils from these plants it could be demon­ strated, that most components of the odour blend are not derived from the food plants but can be de novo synthesized by the insects.