bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mineral Nutrition and Morphine Production in Papaver somniferum
Authors: COSTES C. , MILHET Y. , CANDILLON C. , MAGNIER G. 
Published: April 2006

AbstractMineral nutrition of poppy (Paparer somniferum L.) was studied in its effects on morphine production. Hydroponic cultures were carried out with nutritive solutions percolating over sand.The anion NO3‐ is the most efficient form of nitrogen for the production of fresh matter, dry matter or total morphine; in the latter respect, it rates higher than the NH4NO3 form which, on the other hand, gives higher alkaloid contents, while both cation NH4+ and urea have depressive effects.Phosphates have apparently little effect on the growth of the poppy, but solutions enriched with assimilable phosphate do stimulate flower proliferation and fruit development, without increasing markedly the total morphine output.Mg2+ and Ca2+ are important factors; Mg deficiencies will bring about a marked elongation of stems and early flowering, without any notable decrease in morphine outputs; conversely, Ca deficiencies will cause a drop in alkaloid production, while more calcium in the solution will give stronger elongation, a larger number of capsules and a marked increase in the weight of dry matter and morphine outputs, without any marked change in content.Sodium will favour poppy development (flowers and capsules) and will increase both the content and output of morphine. Na+ should therefore be introduced whenever possible in the fertilizing of poppy crops.
Chemical Forms of Manganese and Zinc in Phloem Exudates
Authors: VAN GOOR B. J. , WIERSMA D. 
Published: April 2006

AbstractInvestigations were performed to study the chemical form in which manganese and zinc are transported in sieve tubes. As a test plant Ricinus communis was used. From this plant phloem sap can be obtained in a rather pure state. The plants received labelled manganese or zinc. In the experiments on manganese translocation a radioactive phosphorus isotope was added to the nutrient solution to test if complex compounds of the cation contain also phosphorus. Components of the phloem exudate were determined by means of physicochemical separation methods.Almost all zinc but only a part of the manganese were bound to organic compounds. The major part of the manganese was in ionic form. The molecular weight of the complexing com‐pound(s) of manganese was estimated to be between 1000 and 5000 and of zinc between 1000 and 1500. The complexes probably contain some phosphorus. The charge of the zinc complex is negative.
Adaptation to Water Stress in Wheat
Authors: SIMMELSGAARD S. E. 
Published: April 2006

AbstractThree experiments were designed to investigate to what extent adaptation to water stress take place. Wheat (Triticum aestivum L. cv. Kolibri) was grown in water culture at constant temperature, air humidity, and light intensity. When the plants were 16 days old, the potential of the root medium (ψr) was lowered by 1 bar every second day by means of polyethyleneglycol 1500 down to −4 or −7 bar and then remained at these levels. As a control one experiment was grown at −0.7 bar. By regression it was found that when ψr was lowered by I bar, osmotic potential in leaf (ψπ) decreased 1.46 bar, and leaf water potential (ψt) 0.68 bar, which mean an increase of turgor of 0.78 bar. At the same time the leaf water content did fall 0.30 g per g dry matter. Specific transpiration rate increased significantly after ψr was kept constant, but the increase in area of fresh leaves was strongly reduced due to wilting of old leaves.After an “adaptation” period during which ψr remained at −0.7, −4, and −7 bar, respectively, for at least 1 week. ψr was altered so as to cover the range from 0 to −14 bar and ψπ, ψr, transpiration and diffusion resistance in stomata (rs) were measured. The levels of ψπ and ψ1 were lower (more negative) and turgor potential higher in plants grown at low ψr. The transpiration in pre‐stressed plants showed less sensitivity to the alteration of ψr than in the non‐stressed plants. The values of ψr at which rs increased greatly, were found to be about −13, −15, and −18 bar for plants grown at −0.7, −4, and −7 bar, respectively.
Mechanism of Action of the Herbicide 2‐Chloro‐3(4‐chlorophenyl) Propionate and its Methyl Ester: Interaction with Cell Responses Mediated by Auxin
Authors: ANDREEV G. K. , AMRHEIN N. 
Published: April 2006

AbstractChlorfenprop‐methyl (the herbicidal component of BIDISIN®), and to a lesser extent the free acid, chlorfenprop, inhibit auxin mediated cell responses in coleoptiles of Avena sativa L. and Zea mays L., such as cell elongation, auxin‐uptake, ‐transport and ‐metabolism, acidification of growth media, and binding of naphthyl‐I‐acetic acid to auxin‐specific binding sites in homo‐genates of corn coleoptiles. Within a very narrow concentration range (1 to 2μM) chlorfenprop‐methyl arrests growth from 0 to 100% in sensitive cultivars. The compound displays neither auxin‐nor anti‐auxin‐activity, and only the l(—)‐enantiomer is active. The interaction of the herbicide with auxin at the level of membranes is proposed.
The State of Protochlorophyll and Chlorophyll in Corn Roots
Authors: BJÖRN L. O. 
Published: April 2006

AbstractThe protochlorophyll(ide) present in primary roots of dark‐grown corn (Zea mays) seedlings has an in vivo absorption maximum at 634 nm. Red light converts the pigment to chlorophyll(ide) a with an absorption maximum at 675 nm.
Photosynthesis of Conifers in Relation to Annual Growth Cycles and Dry Matter Production
Authors: FRY D. J. , PHILLIPS I. D. J. 
Published: April 2006

AbstractObservations that deciduous larch species can show annual growth increments equal to or greater than evergreen conifers, and that the saturating light intensity for photosynthesis in needles of Larix leptolepis was almost twice those for several evergreen conifers, led to a study of the photosynthetic mechanism in L. leptolepis. Several features of photosynthesis in L. leptolepis placed this species in an intermediate position between classical C3 and C4 plants. Incorporation of 14C from 14CO2 by enzyme preparations of larch needles was eight times greater with PEP as substrate than with ribulose bis phosphate; a chlorophyll a/b ratio of 3.5 was obtained; needles possessed a green starch‐containing endodermis but with little orientation of mesophyll cells to this “bundle sheath”; no clear ultrastructural dimorphism was observed between chloroplasts of mesophyll and endodermal cells; a CO2‐compensation point of 20 μl‐l−1 was recorded; and the first measurable product of photosynthesis appeared to be malate rather than phospho‐glyceric acid. These results are discussed in relation to the deciduous habit of L. leptolepis and its high productivity in comparison with other conifers.
A Role for Auxin and Auxin Transport Inhibitors on the Ca Content of Artificially Induced Parthenocarpic Fruits
Authors: BANGERTH FRITZ 
Published: April 2006

AbstractArtificially induced parthenocarpic fruits of apples, pears and tomatoes, as well as seeded fruits treated with 2,3,5‐triiodobenzoic acid, frequently show symptoms of Ca deficiency and a low Ca content. It was concluded that auxins, probably produced by the seeds, play a significant role in Ca translocation into fruits. Exogenous indoleacetic acid but not 4‐chlorophenoxyacetic acid applications could replace the effect of seeds in this respect. Auxin transport, rather than auxin accumulation, seems to be necessary for Ca transport, as can be concluded from the effect of auxin transport inhibitors.
The Effect of Root Formation on the Levels of Protein, Chlorophyll, RNA, DNA and Carbohydrates in Excised Cotyledons of Cucurbita pepo
Authors: MOHAMMAD A. M. S. , AL‐MASHHADANI Y. 
Published: April 2006

AbstractIn attached cotyledons of Cucurbita pepo L. protein, chlorophyll, RNA, DNA and carbohydrates were found to increase to a maximum level 14 days after commencement of germination, followed by a sharp decline thereafter. Cotyledons excised and planted in a nutrient solution 14 days after sowing showed maximum levels of protein, chlorophyll, RNA, DNA and soluble and insoluble sugars 52 days after planting. The increase in these compounds coincides with the full development of the root system. Excision earlier or later than 14 days resulted in lower levels of protein and other compounds. The decrease in the level after 52 days was parallel to the senescing phase of the cotyledons.
The Critical Oxygen Pressures for Respiration in Intact Plants
Authors: ARMSTRONG W. , GAYNARD T. J. 
Published: April 2006

AbstractTwo methods for determining critical respiratory oxygen pressure in whole plants are described.By a polarographic method involving the use of cylindrical platinum electrodes the following critical oxygen pressures for root respiration were found: Rice (cv. Norin 36). 0.024 atm: Rice (cv. Norm 37). 0.026 atm: Eriophorum angustifolium. 0.02 atm. These values contrast markedly with those obtained in vitro, and support earlier criticisms of in vitro measurements: they call into question the use of such data in the modelling of root aeration. When the results were assessed by an electrical analogue system, it was concluded that the respiratory activity in the intact root does not follow the normally accepted hyperbolic relationship with oxygen partial pressure. The experimental data were simulated most closely by assuming the critical oxygen pressure to be a function of respiratory responses in the low porosity (high diffusional impedance) tissues of the root meristem and stele, and respiratory activity in the moderately porous root cortex to be unaffected at values greater than 0.001 atm.A critical oxygen pressure of 0.025–0.04 atm for E. angustifolium was found from analyses of the gas phase oxygen in the leaves of whole plants after submergence in the dark. It was concluded that the higher value found by this method was most likely a function of respiratory responses in root tissue remote from the leaf and should not be regarded as the critical oxygen pressure for leaf respiration. The form of the oxygen concentration vs. time plot again suggested a very much lower critical oxygen pressure for certain of the plant tissues.
Simultaneous Measurement of the Bioelectric Potential of the Cell Wall and the Vacuoles during the Oscillatory Response to the Nitella Cell
Authors: RADENOVIĆ Č. , VUČINIĆ Ž. 
Published: April 2006

AbstractSimultaneous measurements of bioelectric potentials of the vacuole and cell wall in cells of Nitella mucronata were made by inserting glass microelectrodes into the vacuole and cell wall respeclively. During the oscillation of the bioelectric potential of the vacuole. induced by sudden changes of the external bathing solution or by the impalement of the cell with a microelectrode. the cell wall potential also exhibited fluctuations of variable intensities in phase and concomitant with spikes of the vacuolar potential oscillation. However, the polarity of the pulses of the cell wall potential was reverse to that of the spikes of the vacuolar potential. These results suggest that the same event is registered at both sides of the plasmalemma membrane across which these phenomena are occurring. The results also support the voltage clamp and tracer flux measurements on these cells which indicate that during the generation of single action potentials, induced by current, the plasma lemma transiently increases its permeability to Cl− and K+ ions expelling them from the cell. The variable intensity of the transient hyperpolarizations of the cell wall potential is explained by the distance of the microelectrode in the cell wall from the plasmalemma.
Carbon Dioxide as an Essential Requirement for Cultured Sycamore Cells
Authors: GATHERCOLE R. W. E. , MANSFIELD K. J. , STREET H. E. 
Published: April 2006

AbstractCarbon dioxide (optimum concentration c. 1.0%) is essential to the initiation of the growth in suspension culture or on agar plates of cultured sycamore cells. By effective flushing of the cultures with CO2‐free air it is possible to demonstrate this requirement with initial cell densities up to 50 × 103 cells ml−1. This growth‐promoting activity of carbon dioxide is not related to any effect it may have on the pH of the culture medium. The cells fix applied carbon dioxide into organic and amino acids but attempts to replace the carbon dioxide requirement by non‐toxic levels of organic or amino acids have not been successful.
Growth and Sucrose Metabolism of Carrot Callus Strains with Normal and Low Acid Invertase Activity
Authors: PARR D. R. , EDELMAN J. , HAWKER J. S. 
Published: April 2006

AbstractThe properties of two strains of carrot (Daucus carota) callus are presented. One has a very low acid invertase activity which is accompanied by differences in morphology and metabolic rate, but not in growth rate. We conclude that one of the main functions of plant acid invertases is in controlling the levels of sugars which, by interaction with hormones, affect differentiation, both morphological and biochemical. The effect of tris on sucrose metabolizing enzymes, and the cause of the “sucrose effect” are considered.
Isolation and Analysis of Protein Bodies from Cotyledons of Lablab purpureus and Phaseolus vulgaris (Leguminoseae)
Authors: MIÈGE MARIE‐NOËLLE , MASCHERPA JEAN‐MICHEL 
Published: April 2006

AbstractProtein bodies, isolated by differential and isopycnic centrifugation, have been observed in transmission and scanning electron microscope and biochemically analysed. The powders of the axes and of the cotyledons contain numerous protein bodies, which in the scanning microscope appear to be surrounded by a more or less torn membrane. The proportion of intact, isolated protein bodies is influenced by the grinding methods, but even in the best conditions soaking disaggregates the majority of them. After isopycnic centrifugation, their debris gather in different density zones. Analyses of each zone have revealed that the caseinases are associated with particles of higher density than are peptidases and trypsin inhibitors. A minority population of small‐size protein bodies resists the homogenization and fractioning modalities. A double origin of the protein bodies is considered.
Environmentally Induced Changes in the Cell Walls of Tomato Leaves in Relation to Cell and Protoplast Release
Authors: CASSELLS ALAN C. , BARLASS MARTIN 
Published: April 2006

AbstractFactors involved in the isolation of protoplasts from the leaves of tomato plants grown over a wide range of environmental conditions have been studied. Increases in calcium pectate in summer grown (“hard”) plants are suggested as a barrier to cell wall degradation. A one‐step method involving the addition of sodium citrate to pectinase plus cellulase gives high yield of protoplasts from hard plants.Attempts to convert isolated palisade cells to protoplasts have failed.The plant culture conditions are described such that protoplasts may be isolated throughout the year using low enzyme concentrations.
Photosynthetic Electron Transport in Plants of Sitka Spruce Subjected to Differing Light Environments during Growth
Authors: LEWANDOWSKA M. , HART J. W. , JARVIS P. G. 
Published: April 2006

AbstractSeedlings of Picea sitchensis (Bong.) Carr. (Sitka spruce) have been grown in four different light regimes in growth chambers. Chloroplast fragments have been isolated from the needles and Photosystem I and Photosystem II activities measured. Measurements were made at eight photon flux densities giving light response curves for photosystem activity in needles grown in the four different light regimes. Chlorophyll concentration was higher in needles from the low cultivation light environments than in those from the high light environments. Photosystem activity was higher in needles from the high cultivation light environments. Evidence that Photosystem I was limiting photosynthesis in needles grown in the high light environments was obtained.
The Geotropic Curvature in Roots of Norway Spruce (Picea abies) Containing Anthocyanins
Authors: IVERSEN TOR‐HENNING , SIEGEL KNUT 
Published: April 2006

AbstractSeedlings of Norway spruce (Picea abies L.) have been found to synthesize anthocyanins in the root tips as well as in the hypocotyls upon irradiation with white light when kept at 4°C for 6–8 days. In addition, it has also been found that the elongation and the geotropic curvature of spruce roots are dependent on the light conditions.The course of the geotropic curvature in spruce roots containing anthocyanins has been followed during a period of 5 h, in which the seedlings were geotropically stimulated continuously in the horizontal position. When the stimulation was performed in white light and in darkness at 21°C, significantly larger curvatures were observed in the roots pretreated at 4°C in darkness than in the roots containing anthocyanins. The specific curvature (curvature in degrees per mm elongation), however, was approximately the same in both types of roots stimulated in white light. This was due to a retarded elongation of the roots pretreated with light at 4°C and containing anthocyanins. A smaller difference in elongation rate between roots with and without anthocyanins was observed in the dark than in the light, but even in the dark the anthocyanin‐containing roots grew more slowly than roots without anthocyanins.In order to find out if it is the anthocyanin content or the illumination which affects the elongation and geotropic curvature in the roots, a series of similar experiments was performed using cress seedlings grown at 4°C in light or darkness. Roots of cress seedlings cultivated under conditions which would induce anthocyanin formation in spruce roots exhibited the highest geotropic responses both in light and darkness as compared to cress seedlings grown at 4°C in darkness.As in the case of spruce roots an increase in elongation was observed in cress roots illuminated during the geotropic stimulation. These similarities in the behaviour made it relevant to compare the development of the geotropic curvature in cress and spruce roots.
Flower Bud Atrophy in Baccara Roses. V. The Effect of Different Growth Substances on Flowering
Authors: ZIESLIN N. , HALEVY A. H. 
Published: April 2006

AbstractThe effect of various growth regulators on the atrophy of terminal flower buds was tested on Baccara roses. Treatments with gibberellic acid (GA) and 2‐chloroethyl trimethyl ammonium chloride (CCC) reduced the atrophy of the flowers. The application of 2‐chloroethyl phosphonic acid (CEPA) to the buds enhanced abortion, and the effect was more marked on the lower than on the upper shoot. The stage most sensitive to CEPA was when the shoots were 8–35 cm long. Treatment with abscisic acid (ABA) had no effect of the degree of “blindness”, nor did kinetin applied to the apex affect flowering. Spraying with benzyl adenine increased both the rate of sprouting of the lateral buds and the extent of “blindness” of the sprouting shoots, but did not reduce the number of flowers per branch.
Importance of Photosynthetic Cotyledons for Early Growth of Woody Angiosperms
Authors: MARSHALL P. E. , KOZLOWSKI T. T. 
Published: April 2006

AbstractAt various times after seed germination, epigeous cotyledons were excised or treated with DCMU (3‐(3,4‐dichlorophenyl)‐1,1‐dimethylurea) to inhibit cotyledon photosynthesis of seedlings of Acer negundo L., Ailanthus altissima (Mill.) Swingle, Eucalyptus globulus Labill., Fraxinus pennsylvanica Marsh., Robinia pseudacacia L., and Ulmus americana L. In all species, DCMU inhibited expansion of cotyledons, elongation of roots, initiation of lateral roots, and expansion of foliage leaves. During the first 10 days after radicle emergence decotylization also variously inhibited growth of plant parts. Photosynthetic rates per cotyledon varied among species in the following order: Robinia pseudacacia > Ailanthus altissima≥Fraxinus pennsylvanica > Ulmus americana. The length of time that cotyledon photosynthesis contributed to growth of axial parts varied widely among species.
Uptake of Gibberellic Acid in Intact and Scarified Seeds of Barbarea vulgaris
Authors: TAYLORSON R. B. 
Published: April 2006

AbstractUptake of gibberellic acid as a function of duration of exposure, external concentration, and seed lot was measured in seeds of yellow rocket (Barbarea vulgaris R. Br.) by means of lettuce hypocotyl bioassays of the acidic, basic, or neutral fractions of seed extracts and by uptake of 14C‐GA3. In intact seeds, where mM levels of GA3 promoted only 25% germination, uptake was completed within 24 h of exposure. The maximum uptake was about 0.2% of external amount. Although germination promotion by GA3 differed among seedlots of yellow rocket, relative uptake (percentage of the external GA3) was nearly the same.The relative rate of uptake of GA3 was similar for scarified and intact seeds, but germination was promoted in scarified seeds by much lower levels of GA3 than in intact seeds. Total uptake in scarified seeds was much higher, however (about 10% of the external amount). In seeds imbibed in H2O, practically no endogenous GA‐like activity was detected in either the acidic, basic, or neutral fractions.It was also apparent that intact seeds could take up quantities of GA3 that failed to promote germination, but were comparable to quantities that promoted germination in scarified seeds.
Extraction and Recovery of Cytokinin Glucosides by Means of a Cation Exchange Resin
Authors: VAN STADEN J. 
Published: April 2006

AbstractCytokinin glucosides can be extracted rapidly and efficiently from plant material by means of the acid cation exchange resin Dowex 50W X8 (Baker's Analysed Reagent). In the present investigation no evidence could be found that these cytokinins are hydrolysed or retained by the Dowex resin.
Adenosine Triphosphatases Bound to Plasmalemma, Mitochondria, and Microsomes or Present in the Cytoplasmic Phase from Potato Tubers
Authors: JOLLIOT ALAIN , DEMANDRE CHANTAL , MAZLIAK PAUL 
Published: April 2006

AbstractBetween pH 4–10, basal ATPase activity, measured in the absence of mineral ions, was 10 to 100 times higher in the final cytoplasmic supernatant from potato tuber homogenates than in the membraneous fractions (purified plasmalemma, purified mitochondria and microsomes). The soluble ATPase was slightly inhibited, whereas the membrane‐bound ATPases were all stimulated by Mg2+ ions. A further stimulation by Na+ or K+ ions was only observed in purified plasmalemma or mitochondria, at alkaline pH (7.5–9.5). At a fixed (Na++ K+) concentrations (80 mM), this last stimulation was much greater in purified mitochondria (350%) than in plasmalemma (33%); it also increased with (Na++ K+) concentrations up to 200 mM in mitochondria whereas, in plasmalemma, it was roughly constant for monovalent ion concentrations between 20 and 200 mM.General properties of the plasma membrane‐bound ATPase have been determined, i.e. substrate specificity, activity variations with quantity of substrate, temperature, pH, etc. Divalent cations stimulated strongly the ATPase in the following order: Mn2+ > Mg2+ > Ca2+. The maximum ATP hydrolysis velocity for that part of ATPase activity which is strictly dependent on Mg2+ ions was 3.85 μmol × mg−1 protein × h−1. This plasma membrane ATPase was not sensitive to ouabaïn or to oligomycin.
Effect of Vanadium Pentoxide on the Incorporation of (2‐14C)‐Acetate into Fungal Lipids
Authors: ANEKWE GREGORY E. 
Published: April 2006

AbstractMycelia of Glomerella cingulata grown in the presence of vanadium pentoxide (V2O5), incorporated many times less (2‐14C)‐acetate into their lipids than mycelia of the same organism grown in the absence of V2O5. All neutral and polar lipid fractions investigated were affected. These data suggested that V2O5 depressed lipid biosynthesis in G. cingulata.