bluuebunny/crossref_metadata_2025_split huggingface dataset:
“Adaptation” and Chromosome Variability in Excised Roots of Cereals
Authors: Beuzenberg E. J. , Ferguson J. D. , Pearson B. E. 
Published: April 2006

AbstractHeteroploidy, often coinciding with phenotypic or metabolic changes, was found in cereal root cultures. In some cases the changes were apparent after only 4 passages and affected the roots of bread wheat as well as those containing all or some of the wheat and rye genomes. It is unsafe to assume that cultured organised tissues are cytologically stable. The cause of the abnormality is not known but possible mechanisms are discussed.
The Adaptation of Plankton Algae IV. Light Adaptation in Different Algal Species
Authors: Jøsrgensen Erik G. 
Published: April 2006

AbstractTwo types with regard to adaptation to different light intensities are described: tbe Chlorella type and the Cyclotella type. The Chlorella type is mostly found among the green algae, the Cyclotella type among the diatoms. The Chlorella type adapts to a new light intensity mainly by changing the pigment content. Therefore the cells adapted to a high light intensity have a lower chlorophyll a content per cell than cells adapted to a low light intensity. Light saturation is mostly rather low for cells adapted to low light intensities. The light‐saturated rate of photosynthesisist mostly lower for cells adapted to a high light intensity than for cells adapted to a low light intensity. The actual photosynthesis is not much higher at a high light intensity than at a low one. The actual photosynthesis is the photosynthesis at the light intensity where the cells are grown. – The Cyclotella type adapts only by changing the light‐saturated rate. The chlorophyll content is the same in cells grown at low and high light intensities. Light saturation for cells grown at a low light intensity is rather high. The light‐saturated rate is much higher in the case examined at the high light intensity than at the low one. The actual photosynthesis is considerably higher for cells grown at the high light intensities than for cells grown at low light intensities.‐ The two adaptation types are not sharply separated since transition types occur.
α‐Aminoadipic Acid and α,ɛ‐Diaminopimelic Acid in Inoculated Pea Plants (Pisum sativum) and Root Nodule Bacteria (Rhizobium leguminosarum)
Authors: Roponen Ilma E. 
Published: April 2006

AbstractObservations were made on the content of α‐aminoadipic acid and α‐aminophimelic acid (DAP) in pea plants, nodules and Rhizobium leguminosarum, strain HT3. The preparations were purified by ion exchange chromatography, Qualitative analyses were made by paper chromatography, and quantitative analyses by means of an automatic amino acid analysator.In the whole plant and seeds the content of α‐aminoadipic acid soluble in 70% ethanol varied between 10 and 80 μg/g dry weight. The shoot and red nitrogen fixing nodules contained more of this acid than roots and green inactive nodules. In the insoluble fraction of the shoot its concentration was 0.4–0.6 mg/g dry weight. α‐Aminoadipic acid was not found in free living rhizobia, which again contained a considerable amount of α‐aiaminopimelic acid, about 0.5 mg/g dry weight. The synthesis of DAP was intensive also in root nodules. In red nodules, which fixed molecular nitrogen, the content of DAP was 2.1 mg/g dry weight and in green inactive nodules 1.3 mg/g dry weight. It was shown that in the nodules DAP is closely connected with cell wall peptides of bacteroids. DAP could not be found in pea plants outside the nodules.
The Effect of Various Aliphatic Aldehydes and Related Compounds on the Growth of Dipodascus aggregatus
Authors: Nyman Brita 
Published: April 2006

AbstractThe growth of Dipodascus aggregatus in cultures inoculated with cells from the acceleration phase of growth was stimulated by the saturated and unbranched aliphatic C3 C4, and C6 to C11 aldehydes (80 μM]. Nonanal was most active in stimulating growth. The C12 aldehyde inhibited growth. The C5, aldehyde generally inhibited growth. – Nonan did not affect growth. 2‐Nonanone and 5‐nonanone promoted growth insignificantly. – In cultures inoculated with cells from the exponential phase growth was unaffected or even inhibited by all the aldehydes tested. The C4, C5, C10, and C11 aldehydes inhibited growth to a larger extent than nonanal.
The Effect of Age on the Phytochrome‐Mediated Chlorophyll Formation in Dark‐grown Bean Leaves
Authors: Akoyunoglou George 
Published: April 2006

AbstractThe effect of red and far‐red treatment on chlorophyll synthesis in dark‐grown bean leaves was studied at various ages. Although the effect was pronounced in the old leaves, no effect was observed in the young ones (4 days old). In the 5‐day old leaves a measurable effect of red light pretreatment can be observed, whereas the far‐red reversal effect was not observed. — The length of the dark period between the red pretreatment and the continuous illumination is also age dependent. Leaves older than 6 days show a maximum at about six hours, while in the young leaves the red light effect increases with the time of dark incubation up to the 24 hours tested. — The reversal effect of far‐red light on protochlorophyllide regeneration was also examined. The far‐red light has no reversal effect on leaves younger than 6 days old, while on the old leaves it has such an effect.
Auxin Effects on the Aggregation and Heat Coagulability of Cytoplasmic Proteins and Lipoproteins
Authors: Morré D. James 
Published: April 2006

AbstractThe kinetics of induction of heat stability of cytoplasmic proteins and lipoproteins by auxin (2,4,‐D) were determined for basal sections of soybean hypocotyl. Maximum heat stabilization occurred after 4 h of tissue incubation with 10‐5M 2,4‐D. The effect was less pronounced or absent with longer incubations. Membrane fractions sedimenting between 10,000 and 100,000 g and proteins of the 100,000 g supernatant were most affected. The auxin‐induced protein aggregation response varied among experiments. With many tissue lots, the response was small or absent even though the tissue responded to the auxin uniformly by increased growth. The magnitude of response was proportional to the logarithm of auxin concentration but with low 2,4‐D the portion of the homogenate protein coagulated by heat was increased and with supraoptimal concentrations it was decreased relative to the control. The smallest auxin‐induced change in heat coagulability was observed at the auxin concentration nearest the optimum for growth. No direct correlation was found between the auxin‐induced protein and lipo‐protein aggregation phenomenon and total protein, chloroform‐extractable lipid, residual lipid, growth or tissue deformability. Total sulfhydryl equivalent of the homogenates, however, did correlate with auxin effects on aggregation. This result, plus experiments where homogenates were exposed to oxidizing or reducing conditions, suggests that heat stabilization and associated protein aggregation phenomena are related to conversion of protein sulfhydryl to intramolecular disulfide bonds. No significance is attached to heat stabilization of cytoplasmic proteins as a requisite of auxin‐induced growth.
Mineral Uptake in Fusarium oxysporum f. sp. vasinfectum
Authors: Shere S. M. , Jacobson L. 
Published: April 2006

AbstractA method for growing Fusarium oxysporum, a mycelial fungus, and a technique for its use in mineral uptake studies have been described. Some general characteristics of the uptake process were determined. The fungus, grown for 54 hours, was found to take up as much K as 15 to 20 meq/100 g dry weight in 2 to 4 hours from a solution of 5 meq/l KCl. Approximately 3 to 5 meq of this uptake was readily removed by a CaCl2 rinse. The uptake was only slightly sensitive to pH over the range of 4 to 9. Below pH 4 uptake dropped rapidly. The age of the culture appeared to be the dominant factor in determining the rate of uptake. In contrast to other fungi, the presence of glucose during uptake was detrimental to K uptake. Conditions unfavorable for metabolic activity as low temperature, anaerobiosis, or the presence of DNP markedly reduced the uptake rate. Although the fungus took up Na from single salt solutions nearly as well as K, the latter ion was much preferred in mixtures of the two ions. The organism showed no significant metabolic uptake of Ca or Cl. During uptake from KCl solutions, the organic acid content increased. The increase, chiefly in succinic acid and to a lesser extent in acetic and citric acids, amounted to about half the K uptake. The remainder of the K taken up was correlated with a roughly equivalent efflux of cellular Mg.
Properties of Wheat Mitochondria. Study of Substrates, Cofactors and Inhibitors
Authors: Srivastava Hari K. , Sarkissian Igor V. 
Published: April 2006

AbstractIsolated mitochondria of wheat shoots oxidize α‐ ketoglutarate, DL‐malate succinate and NADH with good relative respiration control and ADP: O ratio. They have high affinity for α‐ketoglutarate and NADH as substrates and utilize malate and succinate with a respiration ratio of about one‐half of α‐ketoglutarate. The average ADP : O ratios approach the expected theoretical values, i.e., 3.6 ± 0.2 for α‐ketoglutarate, 1.8 ± 0.2 for succinate, and 2.8 ± 0.2 for malate. The ADP: O ratio with NADH is 1.8 ± 0.2. The maximum coupling of oxidation and phosphorylation is obtained at concentrations of 10 mM, 2 mM, 10 mM and 8 mM for α‐ketoglutarate, NADH, malate and succinate, respectively. — Wheat mitochondria have little or no dependence on added cofactors. Mitochondria prepared by our procedure apparently retain sufficient amounts of endogenous cofactors required for NAD‐linked systems. FAD+ is found to improve succinate oxidation. Cytochrome c does not have any significant effect on respiratory parameters of wheat mitochondria. — Wheat mitochondria are some ‐what resistant to DNP at 1.7 × 10‐5M. Malonate seems to improve coupling of α‐ketoglutarate oxidation. Other Krebs cycle intermediates have been tested on three major substrates of TCA cycle, i.e., α‐ketoglutarate, malate and succinate.
The Localization of Aluminium in the Cortex Cells of Bean and Barley Roots by X‐Ray Microanalysis
Authors: Waisel Y. , Hoffen Avia , Eshel A. 
Published: April 2006

AbstractThe distribution of aluminium, nitrogen, calcium and phosphorus in the cortex cells of bean and barley roots was investigated by means of X‐ray microanalysis. Aluminium was apparently localized inside the cell‐lumens and its distribution over ‐lapped that of nitrogen. More calcium was observed in the cell walls. No correlation between the distribution of aluminium and phosphorus was found.
Root Permeability as Affected by Picloram and Other Chemicals
Authors: Reid C. P. P. , Hurtt W. 
Published: April 2006

AbstractThe effects of picloram (4‐amino 3,5,6‐trichloropicolinic acid) and several other chemicals on root permeability were studied. Initially, effects on cell permeability were investigated by measuring the betacyanin efflux from red beet (Beta vulgaris L.) root sections. Picloram solutions ranging from 10‐3M to 10‐6M had no significant effect on betacyanin efflux when compared to controls. Similar results were found for 10‐4M and 10‐5M 2‐methoxy‐3,6‐dichlorobenzoic acid (dicamba), 10‐4M 2,4‐dichlorophenoxyacetic acid (2,4‐D) and 10 μl/l of ethylene. Compounds that caused significant pigment leakage were 10‐4M and 10‐5M phenylmercuric acetate (PMA), 10‐3M and 10‐4M 2,4‐dinitrophenol (DNP), 10‐3M and 10‐4M 2,4,5–trichlorophenoxyacetic acid (2,4,5‐T) and 10‐3M 2,4‐D.The effects of picloram on root permeability were also studied with bean plants (Phaseolus vulgaris L. cv. Black Valentine) grown in nutrient solution under controlled environmental conditions. Roots treated for 3 hours with 10‐5M picloram showed no significant electrolyte leakage as determined by conductivity measurements of the root‐bathing solution over a period of 52 hours. When bean plants were root‐trated for 3 hours with 10‐5M, and 10‐7M picloram and then decapitated, increased stem exudation by the treated plants as compared to controls was observed. Xylem exudate of the teated plants also showed increased electrolytic conductivity. The increased exudation rate accompanied by increased conductivity indicates that picloram has little effect on root cell membrane integrity, appears not to act as a metabolic inhibitor in the root system, and in some way stimulates salt secretion into the xylem.
Reversal of Ethionine‐Induced Inhibition of Elongation of Avena Coleoptiles by Purines, Adenosine, and Glutamic Acid
Authors: Norris W. E. , Mangum H. E. 
Published: April 2006

AbstractEthionine‐induced inhibition of elongation of Avena coleoptile segments has been measured in water and in indol‐3yl‐acetic acid. In the presence of 10 mM L‐ethionine the inhibition amounts to about 70 %. It has been shown previously that the addition of adenosine triphosphate effectively counteracts this inhibition; optimal ATP concentrations are between 0.25 and 0.5 mM. Adenine, adenine sulfate, adenosine, guanine, S‐adenosylmethionine, and glutamic acid have now been shown to act similarly to ATP in reversing the ethionine‐induced inhibition of elongation.
Occurrence of Indole‐3‐Acetic Acid in Buds of Pinus silvestris
Authors: Aldén Torsten , Eliasson Lennart 
Published: April 2006

AbstractThe major ether‐soluble, growth‐stimulating substance detected by the Avena coleoptile straight‐growth test in extract from sprouting buds of Scots pine (Pinus silvestris L.) was identified as indole‐3‐acetic acid by Rf values in 5 solvent systems and by its elution volume in ethanol on a Sephadex LH‐20 column. When the substance was applied to the growth solution of wheat roots in a special test the growth in length of the roots was at first inhibited, but growth was recovered after about 6 hours in the same manner as when small quantities of IAA were applied. The extracts also contained large amounts of growth inhibitors which interfered with the auxin response if they were not removed.
Growth in Axenic Culture of Isolated Shoot Apices of Eichhornia crassipes
Authors: Raman K. , Narayanaswamy S. 
Published: April 2006

AbstractApical meristem culture of Eichhornia crassipes has shown that for successful regeneration, the excised meristem dome must be associated with at least the youngest leaf primordium as part of the explant and a culture medium containing coconut milk (10 %, v/v), IAA (0.1 mg/l) and kinetin (1 mg/l) as growth supplements with 2 % sucrose as carbon source.
The Effects of Benzylaminopurine on Growth and 14Carbon Translocation in Excised Mustard Cotyledons
Authors: Lovell Peter , Moore Keith 
Published: April 2006

AbstractWhen localized areas of blades of recently excised mustard cotyledons were fed with 14CO2 it was found that the fixation products passed rapidly into the veins and then were translocated to the petiole. Since other cotyledons similarly treated subsequently rooted at the petiole base, this suggested that it acted as a sink for assimilates. Treatment of excised cotyledons with benzylaminopurine (BAP) resulted in the enhancement of blade growth and the suppression of root initiation and development. Quantitative determinations of labelled assimilate in both the cotyledon blade and the terminal 2 mm portion of the petiole were made. It was found that cotyledons treated with BAP at a concentration high enough to suppress completely root initiation had a higher level of radioactivity in the petiole base than the terminal segments in untreated petioles, whether expressed as specific activity or as a percentage of the total radiocarbon fixed. BAP‐treated cotyledons also fixed consistently higher levels of 14CO2, probably due to an increase in photosynthetic area. The results suggest that BAP alters the pattern of differentiation at the base of the petiole rather than the polarity of movement of assimilates to the petiole base.
The Ultrastructure of Spirulina platensis— A New Source of Microbial Protein
Authors: Hedenskog Gudmund , Hofsten Angelica v. 
Published: April 2006

AbstractThe ultrastructure of the blue‐green alga Spirulina platensis has been investigated. The appearance of photosynthetic thylakoids, polyphosphate and cyanophycin granules and nucleoplasm was studied. Cells of Spirulina have also been disintegrated and extracted with different concentrations of sodium hydroxide and the amount of extractable and isoelectrically precipitable nitrogen has been determined. High yields were obtained with about 60 % of the nitrogen precipitable after extraction of disintegrated cells.
Renouvellement des protéines et effet spécifique de la kinétine sur des cultures de cellules de Tabac
Authors: Jouanneau Jeam‐Pierre 
Published: April 2006

Abstract Determination and fractionation of proteins of tobacco cell suspensions requireing kinetin for cell division. — Cell suspensions either in stationary phase without kinetin in the medium or dividing in the presence of this factor have been compared. It was found a) that the specific rates of protein synthesis and protein degradation were not changed by the addition of kinetin during the early period of growth. A quantitative change ocurred only after the first generation period, b) Soluble proteins of these cells were mapped by polyacrylamide gel electrophoresis. The observed protein patterns were very similar as well as the patterns or radioactivity incorporated into the same proteins during the incubation period of the cells. However, a small number of specific discrepancies appeared in the pattern of cells growing in the presence of kinetin matched to the patterns of stationary cells. At least one specific difference in these patterns could be observed before the first cell division occurred.
Pathways of IAA Production from Tryptophan by Plants and by Their Epiphytic Bacteria: A Comparison
Authors: Libbert Eike , Fischer Elfriede , Drawert Anneliese , Schröuder Roswitha 
Published: April 2006

AbstractMetabolites of tryptophan were investigated using 2 systems: a bacterial (Peastem homogenates containing the epiphytic bacteria) and a plant system (pea stem sections under sterile conditions).The plant system produces: indolepyruvic acid (IPyA), indoleacetaldehyde (IAAld) indoleacetic acid (IAA), indoleethanol (tryptophol, IAAol), indolecarboxylie acid (ICA), indolecarboxaldehyde (ICAld). Bacteria produce additionally: indoleactic acid (ILA), tryptamine (TNH2) and the unknown Xb and Yb, but IAAld was not detected.A nonacidic inhibitor extract from pea stems decreases the gain of IAA, IPyA, ILA, Yb. It increases the gain of IAAld, IAAol, TNH2, Xb, and (only in the bacterial system) ICA and ICAld. Three sites of inhibitor action are suggested, namely the steps Try → IPyA, TNH2→ IAAld, IAAld → IAA.
The Influence of Phosphate Uptake on Cation Uptake in Fusarium oxysporum f. sp. vasinfectum
Authors: Shere S. M. , Jacobson L. 
Published: April 2006

Abstract Fusarium oxysporum grown in a low phosphate medium was found to take up several times as much K from KH2PO4 as from KCI solutions. Large amounts of phosphate also were taken up from KH2PO4. Similar large uptakes of Na and phosphate took place from solutions of NaH2PO4. Substantial quanties of phosphate were taken up from solutions of Ca(H2PO4)2 in the absence of any appreciable Ca uptake. When the fungus was grown in a medium containing high phosphate, little or no uptake of phosphate from KH2PO4 solutions occured and the K Uptake was at the same level as from KCI solutions. During large phosphate uptake sizable reductions in the organic acid content of the fungal cells were observed. Much, but not all, of the data could be explained on the basis of maintenance of charge balance within the cells. – The respiratory rate of fungus, grown in a low P medium, was markedly increased in KH2PO4 solution. Fungus, grown in a medium with high phosphate, had a higher respiratory rate which showed only a slight response to KH2PO4 solution. Fungus, grown in a medium with high phosphate, had a higher respiratory rate which showed only a slight response to KH2PO4.
Kinetics of Mitochondrial Complementation
Authors: McDaniel Robert G. , Sarkissian Igor V. 
Published: April 2006

AbstractMitochondrial complementation (enhancement of oxidative activity of mitochondrial occured when mitochondria of some inbrveds of eron were mixed in vitro. It was found that mixtures composed of various proportions of mitochondria of inbreds exhibited complementation. Extracts of mitochondria of one inbred did not promote complementation when they were added to infact mitochondria of inbreds exhihited complententation. Extracts of mitochondria of on einbred did not promote complementation when they were added to infact mitochondria of the second inbred. Serial dillutions of mixtures resulted in a rapid reduction of mitochondrial oxidation (QO2 N) suggesting that intimale association between mitochondria was minimized by the dilution and that this decreased complementation. Similar dilutions of mitochondria from inbreds did not decrease their specific activity. Kinetics of mitochondrial oxidation were measured polarographically and it was found that complementation was measurable immediately (1 min) following the mixing. This suggested that physical contact between mitochondria was necessary for complementation.
Auxin‐induced Growth of Helianthus Tuber Tissue V. Role of DNA synthesis in hormonal control of cell growth
Authors: Kamisaka Seiichiro , Masuda Yoshio 
Published: April 2006

AbstractThe role of DNA synthesis in hormonal control of cell growth was studied, using tissue slices excised from cold‐ stored Helianthus tubers.Metabolic inhibitors of DNA synthesis such as 5‐fluorodeoxyuridine and phenethyl alcohol inhibited the effect of auxin and gibberellie acid on expansion growth, the latter being given during the aging period. The inhibitory effect of 5‐fluorodeoxyuridine on expansion growth was alleviated by the simultaneous addition of thymidine but not by that of uridine.Incorporation of 14C‐thymidine into DNA occurred during the aging period and gibberellic acid stimulated the incorporation of 14C‐thymidine into DNA when given during the aging period. Mitomycin C and 2‐(chloroethyl)‐trimethyl‐ammonium chloride (a growth retardant) inhibited incorporation of labelled thymidine into DNA.
On the Nature of the Heat Resistance of Thermophilic Bacteria
Authors: Ljunger Claes 
Published: April 2006

AbstractThe importance of inorganic ions for the heat stability of thermophilic bacteria was investigated. Cells of Bacillus stearothermophilus, strain 1503, were incubated at elevated temperatures in various media and the number of surviving organisms was determined at suitable intervals. The bacteria rapidly died at temperatures ordinarily employed for their cultivation if the surrounding medium lacked calcium ions. Besides calcium ions, potassium and phosphate ions and glucose, or some other energy source, seemed to be required for the heat stability of the cells. A chemically defined stabilizing medium with these components was developed for the above‐mentioned strain. When any component of this medium was excluded, the heat resistance of this organism was lost. This medium had a stabilizing effect also on the cells of three other strains of B. stearothermophilus. These requirements suggest that the heat stability of thermophilic bacteria is attributable to an active transport of calcium ions from the environment into the cells.