bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cyclic Variations in Plant Properties under Constant Environmental Conditions
Authors: Barrs H. D. , Klepper Betty 
Published: April 2006

AbstractCyclic fluctuations in stomatal aperture, transpiration rate and leaf water potential under constant environmental conditions have been investigated in intact plants of cotton, pepper, and sunflower. Stomatal aperture and transpiration rate were least when leaf water potential was high and were greatest when leaf water potential was low.Lowest leaf water potential values lagged behind the occurrence of highest transpiration rates, and high overall resistance to water flow occurred in cycling plants. Both of these are considered essential for the occurrence of persistent cyclic behaviour. Hydropassive opening of stomates as the leaves wilted facilitated cycling in cotton and pepper, but not in sunflower, where hydropassive opening did not occur.The roots were identified as the site of the major resistance to water flow in the plant and further experiments directly showed the importance of this root resistance in initiating cycling by causing water stress in the leaves as the stomates opened.Root resistance varied diurnally, becoming increasingly important at night. Root resistance naturally rose to high levels in cotton. High levels were induced in pepper or sunflower by having the roots in deionized water for several days or by anoxia.Quantitative measurements of overall plant resistance were made from leaf water potential and transpiration rate data.The results are discussed and it suggested that plant resistance may indirectly be of importance in the movement of water from the plant to the air.
Evidence for a Tumor‐associated Factor Active in the Promotion of Crown‐gall Tumor Growth on Primary Pinto Bean Leaves
Authors: Lippincott James A. , Lippincott Barbara B. , El Khalifa M. D. 
Published: April 2006

AbstractThe growth of crown‐gall tumors on primary pinto bean leaves (Phaseolus vulgaris L. cv. “Pinto”) between day 3 and day 6 after inoculation was found to be proportional to the number of tumors on the leaves. Similar differences observed in the growth of tumors induced by adenine, methionine and asparagine requiring mutants of Agrobacterium tumefaciens (Smith and Town.) Conn appear to be due to the same phenomenon. Tumors induced by these auxotrophs thus show no obvious growth differences from those induced by the prototrophic strain despite the lower specific infectivity and the existence of a mutational lesion in these bacteria. A diffusible growth factor(s) produced by the tumor tissue is proposed to account for the relation between tumor number and early tumor growth.
Extraction of Auxin and of Other Growth Regulators from Citrus Steins by Centrifugal Force
Authors: Goldschmidt E. E. , Monselise S. P. 
Published: April 2006

AbstractA method is described whereby diffusible native growth substances are forcibly extracted by centrifugation. Centrifugates are relatively pure, highly active when tested for auxins and gibberellins, and contain far less inhibitors than solvent extracts.
The Effect of Some Promoters and Inhibitors on the Light Controlled Germination of Strawberry Seeds; Fragaria vesca semperflorens Ehr.
Authors: Thompson P. A. 
Published: April 2006

AbstractSeed of Fragaria vesca semperflorens Ehr. fails to germinate if kept in continuous darkness after sowing, but responds to short periods of exposure (5 to 10 min) of low intensity red light. Sensitivity increases with increasing time between sowing and light treatment. The promotive effect of light was inhibited by coumarin, but the inhibitory effects of low levels of coumarin could be removed by increasing the quantity of red light given. Thio‐urea induced a percentage of seeds to germinate in the dark, but the effect could not be correlated with the light effect. Seven gibberellins were tested at concentrations between 1 and 50 nig/1. A 4 showed very high activity fully replacing the light requirement at 10 mg/l, but none of the others did so.
The Relationship between Growth and Proline Incorporation after Auxin Treatment of Mung Bean Hypocotyls
Authors: Kuraishi Susumu , Kasamo Kunihiro , Yamaki Toshio 
Published: April 2006

AbstractIndoleacetic acid (IAA) stimulates the incorporation of 14C‐proline into both the cyloplasmic and the cell wall fractions of the hypocotyl of mung bean (Phaseolus aureus Roxb. cv. Black). It neither stimulates the transfer of 14C‐proline from the cyloplasmic fraction into the cell wall fraction, nor the retention of 14C‐proline in the wall or cytoplasmic fractions. Moreover, the stimulation of growth caused by IAA parallels the stimulation of the incorporation of proline into the cytoplasmic fraction, but does not parallel the stimulation into the cell wall fractions.The stimulation of the incorporation into the cyloplasmic fraction seems to appear within 30 minutes after auxin treatment, at about the same time the increase in the growth is observed in response to IAA, suggesting a connection between these effects. On the other hand, the stimulation of the proline incorporation into the cell wall fraction seems to require more than 90 minutes after auxin treatment, suggesting no close connection between growth and proline incorporation into the cell wall fraction.
Nitrogen Metabolism of Vicia faba
Authors: Olsson R. , Boulter D. 
Published: April 2006

Abstract Vicia faba plants were grown for four and six weeks without externally supplied nitrogen. Some nitrogen was transported to the plant axis from the cotyledons throughout this period, but the amount available was insufficient to support maximum shoot growth. During this period the protein content of the shoot declined whilst the free amino acids, especially aspartic acid, glutamic acid, histamine and the combined pool for threonine, serine, asparagine and glutamine and ammonia, increased in amount. In contrast to the shoot the protein content of the root increased as did their free amino acid content, but the increase in the latter was less than in the shoot and only the combined value for threonine, serine, asparagines and glutamine increased significantly. During tbe last two weeks growth, some soluble non‐amino acid compound appeared to donate nitrogen to the pool of free amino acids in the root and shoot.
Action de solvants basiques sur le spectre d'absorptiou des complexes pigmentes extraits de la bactérie pourpre Rhodospirillum rubrum
Authors: Aghion Jacques , Crevier Louise 
Published: April 2006

Abstract Absorption spectrum of Rhodospirillum rubout pigment complexes in basic solvents. — The adsorption and aggregation of bacteriochlorophyll are studied in various polar solvents, at different concentrations. It is shown that 3 absorption bands exist in these conditions, duplicating 3 of the absorption bands found in vivo: the 772 nin, the 830 nm and the 890 nm‐bands. The 800 nm‐band cannot be formed in vitro. The relations between the respective concentrations of the 3 states of bacteriochlorophyll found In vitro are calculated and discussed.
Effects of Photodynamic Action on the Cell Membrane of Euglena
Authors: Bellin Judith S. , Ronayne M. E. 
Published: April 2006

AbstractThe effects of photodynamic action on the cell membrane of Euglena gracilis were investigated by means of studies on dye binding and electrophoretic mobility. Molecular species of alkaline or acid dyes can penetrate the membrane to about the same extent. Once the cell has been injured by pbotodynamic action, ils ahility to exclude large ions is partially lost; it becomes greatly more permeable to dye anions. Binding of rose bengal induces an increased negative charge on Euglena cells which is reversed by subsequent photosensitized damage to the cells.
Metabolism of Indole‐3‐acetaldehyde
Authors: Rajagopal R. 
Published: April 2006

AbstractInfiltration of indolcacelaldehyde (IAAId) into living tissues of sonic lower and higher plants gives rise simultaneously to both indoleacetic acid (IAA) and Iryptophol (T‐ol). But on a molar basis, there is no correlation between the products indicating a disimitation. Expressed juice of Avena coleoptiles by itself, exhibits only IAA forming activity. Approximately two moles of IAAld are consumed for each mole of IAA formed at pH 4.5, but only if necessary corrections are made for losses of substrate and products. Addition of reduced NAD or NADP readily induces tryptophol formation. But even at pH 4.5, adding reduced NADP causes greater tryptophol formation, leading to a marked divergence in the acid‐alcohol ratio. Varying the pH in the presence of reduced coenzymes also alters the ratio, with alcohol formation predominating. NAD and NADP have no influence on the formation of IAA from IAAld by the whole cytoplasm of Avena coleoptiles. Whole cytoplasm of Asparagus shoots forms both IAA and tryptophol from IAAld, but in widely varying amounts, devoid of any suggestive stoichiometry between the products.With the acetone powder of Avena coleoptiles including the first leaf, data indicating an apparent disimitation of IAAld are obtainable only at pH 4.5. On altering the pH however, unequal amounts of the two products, namely IAA and tryptophol, are formed and hence a different ratio results. Acetone powders of wheat coleoptiles and Asparagus shoots do not yield data supporting disimitation either at pH 4.5 or 7.2.IAA formation in Avena is aerobic while tryptophol formation is seemingly independent of oxygen supply. The former activity is selectively abolished by 10−3M dithionite while the latter activity suffers a similar suppression in the presence of 10−3M manganese sulphate. Varying the IAAld concentration results in unequal amounts of the two products, revealing the dissimilar affinity of the two activities for the common substrateSaturation to a level of 30 percent with ammonium sulphate throws out most of the acid‐forming activity whereas the alcohol‐forming system appears mostly in the protein fraction precipitated between 30 and 40 percent saturation. The enzyme system of Avena coleoptiles oxidizing IAAld to IAA can also be easily separated by Sephadex gel filtration and its independent activity demonstrated in the total absence of tryptophol formation.Based on the heterogeneous properties of the two activities, metabolism of IAAld in Avena coleoptiles is believed to be mediated by two independent enzyme systems without the intervention of a mutase or a dismutation mechanism.
Wirkung von Wuchs– und Hemmstoffen auf die Kambiumtätigkeit und Reaktionsholzbildung
Authors: Casperson Gerhard 
Published: April 2006

Abstract Effects of Growth Promoters and Inhibitors on Cambium Activity and Formation of Reaction Wood. — The cambium activity of horizontal bent apicotyls of Aesculus hippocastanum can be stimulated by auxins (2,4‐D) or kinetin applied artificially. The effect of kinetin was equal on the upper and lower side of the stem. Applied in high concentration to the upper side 2,4‐D acted as inhibitor of cell division on this side but as promoter on the lower side. TIBA was active at the spot of application only. The formation of reaction wood was influenced remarkably by auxins but only slightly by TIBA or kinetin. The results are discussed in term of the theory of growth substances of Went and Cholodny.
The Amount of γ‐Amino Butyric Acid and the Activity of Glutamic Decarboxylase in Aging Leaves
Authors: Lähdesmäki P. 
Published: April 2006

AbstractThe amount of γ‐amino butyric acid as measured by thin‐layer chromatography, and the specific activity of glutamic decarboxylase as measured both by Warburgapparatus (CO2) and by thin‐layer chromatography (γ‐ABA) were determined in leaves of different ages. Datura suaveolens, Medicago sativa and Salvinia natans were used as experimental plants.The amount of γ‐ABA increases in the leaves of Salvinia natans, Medicago sativa and Datura suaveolens in proportion to the age of the leaves. In the case of Salvinia natans, the amount of γ‐ABA in old leaves is about twice as much as in young ones: in the case of Medicago sativa and Datura suaveolens the increase is slightly less. In Salvinia natans the amount of γ‐ABA reaches its greatest value in the third to fifth leaf, in Medicago sativa and Datura suaveolens later. This increase in the amount of γ‐ABA with respect to the age variation of the leaves, is reflected in the growth of leaves. In Salvinia natans the third or fourth leaf is full‐grown, in Medicago sativa and Datura suaveolens this stage is reached in the seventh or eighth leaf.The activity of glutamic decarboxylase parallels the γ‐ABA accumulation in that it increases when the leaves grow. The increase of glutnmic decarboxylase activity takes place more rapidly in the aging leaves of Medicago sativa than in those of Datura suaveolens. The activities observed are somewhat higher when the amounts of γ‐ABA are analysed than when the CO2 evolved is measured.KM‐values for glutamic decarboxylase were calculated using various substrate concentrations to test the enzyme activity. The KM‐values obtained were 7.0 · 10−3M in the case of Medicago sativa, and 7.9 · 10−3M in the case of Datura suaveolens.
The Time Effect of Auxin and Calcium on Growth and Elastic Modulus in Hypocotyls
Authors: Uhrström Inger 
Published: April 2006

AbstractThe relationship between Young's modulus and longitudinal growth has been studied on growing segments of etiolated sunflower hypocotyls. The modulus was determined by means of the resonance frequency method. IAA in a concentration of 2.8 10−5 M produces a decrease in the modulus with a time lag of 4 minutes, while an increase in growth is observable only after 6 minutes. Addition of IAA results in a stronger decrease in the modulus if the segments are placed in a solution of 0.1 M mannitol rattier Hum in water. Through plasmometric measurements it has been found that the elastic extensibility is insignificant compared with the growth. After the addition of IAA, there occurs a marked elongation both in 0.1 M mannitol and in water, and at the same time a decrease in the elastic extensibility of the segments is observed. In the growing segments an increased modulus causes an in creased elastic extensibility, a matter which is directly contrary to the relationship found in a physical system with an applied external force. An explanation of this discrepancy has been given. With an excess of calcium the modulus increases, while the elongation decreases. Calcium deficiency implies both a decreased modulus and a decreased growth. With the addition of 10−3 M Ca(NO3)2 to segments raised without calcium the modulus increases after only 10 minutes, while an increase in longitudinal elongation is observable after 30 minutes. With the addition of IAA to the calcium deficient segments the modulus decreases to the same extent as in an optimal supply o f calcium. The results are discussed with reference to other investigations about elasticity and growth. It has been concluded that plastic extensibility cannot he of great importance in longitudinal growth. Time studies of the auxin effect and I he interaction between auxin and calcium have confirmed the hypothesis that one of the primary actions of auxin consists in a loosening of the cell wall matrix. Calcium always increases Youngs modulus and gives the cell wall a more rigid structure. Furthermore, calcium in a certain concentration is necessary for longitudinal growth.
Gibberellin Induced Changes in Diffusible Auxins from Savoy Cabbage
Authors: Andersen A. Skytt , Muir Robert M. 
Published: April 2006

AbstractDiffusates from apices of young plants of savoy cabbage treated with gibberellie acid (GA) and apices of control plants have been examined with respect to their content of Indole auxins. Three indole Compounds were detected and identified on the basis of their chromatographic characteristics in several systems. These compounds were: glucoubrassicin, indole‐3‐acetic acid (IAA) and indole‐3‐acetonitrile (IAN).An effect of GA on the total auxin activity of the diffusate was noted 90 hours after treatment, while an increase in stem height occurred 48 hours later. This increase in auxin effect of the entire diffusates was shown bv chromogenic development and bioassay of chromatograms of diffusates to be a result of an increase in level of the IAA content. A concomitant decrease in I the glucobrassicin content was indicated.Since GA was found to have no effect on the enzymatic conversion of tryptophan or tryptamine to IAA, it is proposed that the effect of GA is on the conversion of glucobrassicin to IAA.
Physiological and Biochemical Studies of Chilling Injury in Bananas
Authors: Murata Takao 
Published: April 2006

AbstractThe physiological changes in green bananas (cv. Sin‐zun), which are very sensitive to chilling injury, were studied during and after exposure to low temperatures (4±1°C, 6±0.5°C) for various periods. While the fruits injured by chilling did not fail to produce CO2 and ethylene, the pattern of both CO2‐ and ethylene production in these chilled fruits (9 and 15 days at 6°C) after transfer to 20°C was not normal. The contents of acetaldehyde and ethanol in chilled fruits, both in peels and pulps, increased with the advance of chilling, injury. There was an accumulation of α‐keto acids in the peels of chilled fruits. Only half the conversion of 14C (fed as succinic acid‐1, 4‐14C) to citric acid and isocitric acid was observed in chilled tissues as compared with healthy ones; the activity of citrate synthase in banana peels appears therefore to be inhibited by chilling injury. A histological study of the tissues showed that the browning substances (polyphenols) present in chilled fruits accumulate around the vascular tissues.
Effect of Green and White Flashes on the Activity of the Enzyme Ribulose‐diphonphate Carboxylase in Darkgrown Barley Plants
Authors: Dasstou C. , Akoyunoglou G. 
Published: April 2006

AbstractThe effect of short impulses of white and green light on the activity of ribulosediphosphate carboxylase in dark‐grown barley leaves has been studied Intermittent white light induces an increase in the activity of the enzyme. After 90 flashes a 30% increase in the activity is observed. Intermittent green light has no effect on the activity of the enzyme.A correlation between the increase in the activity of the enzyme and the accumulation of chlorophyll under the effect of intermittent white light has been observed.
Biochemical Aspects of Parasitism by the Angiosperm Parasites: Host‐parasite Interrelationship in Phosphatase Activity
Authors: Mattoo R. L. , Viswanathan P. N. , Krishnan P. S. 
Published: April 2006

AbstractInfection by Cuscuta and Orobanche causes significant losses in dry solids and protein content in host plant or plant part. Changes occur in phosphatase activity towards fructose‐1,6‐diphosphate at alkaline pH and β‐glycerophosphate at acid pH, expressed per mg protein or g fresh tissue. The leaves of all hosts infected by Orobanche show an increase in the alkaline fructosediphosphatase activity, whereas as far as the infection by Cuscuta is concerned the general response is a decrease in the enzyme in the shoots. The alterations in the phosphatase activity towards β‐glycerophosphate at acid pH in the shoots are not consistent. However, there is a marked increase in the acid phosphatase activity against β‐glycerophosphatase in the roots of the infected hosts. The significance of these findings has been discussed in the light of host‐parasite interrelationship.
The Effect of Nonanal on Dipodascus aggregatus II. Influence of the Prehistory of the Inoculum and of the Presence of Ethanol
Authors: Nyman Brita 
Published: April 2006

Abstract Nonanal, added in ethannlic solution, in concentrations lower than 40 to 80 μM did not affect the growth of Dipodascus aggregatus, provided the inoculum had been harvested from the exponential phase of growth. Growth could even be inhibited by 80 μM.If the inoculum had been grown to the exponential phase and then for another period, to the acceleration phase, in fresh liquid medium, growth was strongly promoted by 80 μM nonanal. If cells from the exponential phase were grown for another period in the supernatant fluid of centrifuged cultures from the exponential phase, 80 μM affected growth in the following way: in five different experiments growth was not stimulated, in one experiment undoubtedly promoted, and weakly stimulated in another one.The growth of cultures inoculated with cells grown only on malt agar was not affected by 80 μM nonanal.Pretreatment of cells, harvested from the acceleration phase, with nonanal (80 μM) in the presence of ethanol did not diminish the growth‐promoting action of nonanal on the cultures inoculated with these cells. Nonanal, in the absence of ethanol, in a concentration of 10 μM did not affect the growth of cells, harvested from the acceleration phase, whereas 100 μM nonanal strongly inhibited growth.An attempt is made to explain the results starting from the endogenous metabolism.
Some Physical‐kinetic Considerations in Penetration of Naphthaleneacetic Acid through Isolated Pear Leaf Cuticle
Authors: Norris Robert F. , Bukovac Martin J. 
Published: April 2006

AbstractThe penetration of naphthaleneacetic acid (NAA) through enzymatically isolated pear leaf cuticle (Pyrus communis L. cv. Bartlett) is reported herein. Penetration of NAA increased with increasing lime and attained a steady state in approximately 20 minutes. The quantity of NAA penetrating was directly related to the concentration of the donor solution. NAA that penetrated the cuticle was shown to he unaltered. The Penetration of NAA from inside to outside is similar to that from outside to inside. Isolated stomatous lower cuticle permitted approximately 10‐foId greater penetration of NAA than the astomatous upper cuticle. The penetration of NAA through isolated pear leaf cuticle is highly temperature dependent, exhibiting a temperature coefficient (Q10) of about 5.6 between 15° and 25 C. The low quantities of chemicals penetrating through the isolated cuticle reported herein and elsewhere are considered to he a characteristic of the technique and not an absolute limitation of the cuticle. Cuticular penetration could account for physiological quantities of NAA entering the plant.
The Ultrastructure of a Cyanophage Attack on Anabaena variabilis
Authors: Granhall Ulf , Hofsten Angelica V. 
Published: April 2006

AbstractCyanophages multiplying on the nitrogen fixing blue‐green alga Anabaena variabilis Kütz. were revealed by electron microscopy.Severe ultrastructural changes have been observed in the vegetative cells, whereas the heterocysts appeared resistant to the cyanophage. A lytic cycle was observed from adsorption to lysis.
Factors Affecting Spore Germination of Volvariella volvacea
Authors: Chang Shu‐Ting , Chu Sze‐Shuen 
Published: April 2006

AbstractEnvironmental factors affecting basidiospore germination were studied with Volvariella volvacea, the edible straw mushroom which is common in South East Asia. A relatively mild heal shock is necessary for spore germination. The spores give best germination at 40°C although early hyphal growth is better at 35°C the germination of spores is affected by temperature. pH. a presoaking treatment and spore density. Higher pH supports more germination but seems unfavourable for early mycelial growth. Presoaking treatment in phosphate buffer solution or distilled water also stimulates germination markedly.