bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cytokinins and Transfer Ribonucleic Acids. I. Presence of Cytokinins in Various Amino‐acid Specific Transfer Ribonucleic Acids of Baker's Yeast
Authors: Klämbt D. , Kovoor A. 
Published: April 2006

AbstractSoluble ribonucleic acid of baker's yeast was fractionated by countercurrent distribution and assayed for both cytokinin activity, using tobacco pith callus tissue, and for certain specific amino‐acid acceptor activities.Two groups of fractions showed cytokinin activity, one of which corresponds to serine and tyrosine transfer ribonucleic acids which are known to contain isopentenyl adenine, while the other corresponds lo undetermined species of ribonucleic acids.
Auxin‐Synergists in the Rooting of Cuttings
Authors: Gorter Christine J. 
Published: April 2006

AbstractIndole, α‐ and β‐naphtol are synergistic with auxins in enhancing root production of cuttings of Phaseolus vulgaris.To find an explanation for this synergism the activity was compared with that of phenolic compounds which are known to be:a. inhibitors of the IAA oxidase system,b. cofactors of the conversion of tryptophane to IAA.Both processes appeared to occur in the bean cuttings (as estimated by root production), but none of the phenols bad an activity equally strong as the “synergists”.It is suggested that indole as well as α‐ and β‐naphtol act as other injurious substances in “just sublethal” dose (Soekarjo 1966).
Interrelationships of Cotyledonary Shoots in Pisum sativum
Authors: Lovell Peter H. 
Published: April 2006

AbstractUnequal two shoot systems of tall and dwarf varieties of Pisum sativum L. ev, Improved Pilot and Meteor, respectively, were used in experiments where manipulative treatments involving the removal of one or other or both of the shoot apices were carried out. These were combined with GA treatments. Twenty four hours after treatment, 14CO2 was applied to the lowest expanded leaf on the larger shoot, and the distribution of radioactivity was determined after a further 24 hours. Removal ot the apex of the larger shoot reduced the level of translocation from the treated leaf, the effect being enhanced by the additional removal of the other apex. This (Heel was more marked in the tall than in the dwarf variety.In untreated control plants of both varieties there was very little transfer ot labelled material from the larger (dominant) shoot to the smaller (weaker) shoot. This pattern was not affected by the removal of the apex from the weaker shoot. In Improved Pilot, removal of the apex from the stronger shoot led to considerable transfer of radioactive material to the weaker shoot, GA treatment having little effect. However, in Meteor, transfer of radioactivity from the stronger to the weaker shoot. after removal of the apex from the stronger shoot, only occurred after the application of GA. Removal of both shoot apices again resulted in low levels of transfer of labelled material to the weaker shoot in both varieties.These results are consistent with the hypothesis that there is competition between the two shoots for photosynthates produced by the leaves and that treatments reducing the competitive ability of one shoot, reduce the level of nutrients received by that shoot and can result in transfer of materials from it to the other shoot. Continuation of such a situation will result in increased inequality and perhaps ultimately in the death of the weaker shoot.
Endogenous Diurnal and Nocturnal Activity of Guard Cells as Indicated by Stomatal Aperture and Protoplasmic Streaming
Authors: Pallas J. E. 
Published: April 2006

AbstractThe hourly stomatal apertures on epidermal strips of Antirrhinum majus, Rheum rhaponticum, Vicia faba, and Zebrina pendula fixed by Lloyd's technique were compared with the number of stomata found to contain streaming at the same time.With all four species there was an indication of an endogenously controlled rhythm in stomatal opening with both increases and decreases in aperture and streaming during daytime hours in either the light or dark. A similar endogenously activated rhythm was also found at night in Rheum and Vicia.Some relationships exist between changes in stomatal aperture and streaming. Streaming in guard cells may only be a byproduct of metabolism, but as such, it serves the useful purpose as a mixer of chemical activity.
The Relationship between myo‐Inositol, ATP and Rotational Streaming
Authors: Soran Viorel , Lazăr Georgeta 
Published: April 2006

AbstractThe rotational streaming of cytoplasm in barley root hairs has been stimulated about 1.3–1.8 times through continuous treatment with various solutions of myo‐inositol. The stimulation attained the same level as after ATP administration and was dependent on the external myo‐inositol supply with the employed concentrations. The stimulation was cut off by simultaneous treatment with myo‐inositol and uranyl salts. By using uranyl acetate the rate of streaming was maintained about the value of the control. The uranyl chloride caused an inhibition in the rotational streaming and later made it to cease altogether. The simultaneous treatment with myo‐inositol and 2.4‐DNP (dinitrophenol) induced a quick inhibition in 60% of the root hairs. consecutively stopping rotational streaming.It is assumed that the stimulation of rotational streaming is not due to the direct effect of myo‐inositol but to ATP formed in the reaction: inositol hexaphosphate ++ ADP ↔ ATP + inositol. According to the results obtained by testing with uranyl salts, the phosphorylation of inositol probably takes place at the cell surface. The effect of 2,4‐nNP points to the presence of two competitive metabolic processes involved in ATP consumption: the upkeep of rotational streaming and the uptake of substances by the plant cell.
Germination of Species of Labiatae in Response to Gibberellins
Authors: Thompson P. A. 
Published: April 2006

Gibberellic acid at between 1 and 1000 mg/1 was used to treat fruits of different Labiatae species kept at an unfavourable temperature for normal germination (25°C). Germination requirements were diverse, but all germinated in response to gibberellic acid. Minimum effective concentrations varied widely from 1 mg/1 with Salvia glutinosa up to 1000 mg/1 with Lycopus europaeus and Scutetlaria galericulata.When species were tested under conditions in which a proportion of the fruits germinated naturally the results suggested that, even under marginal conditions, relatively high concentrations of gibberellic acid were required to promote germination, although hypocotyl extension in each of the species responded to much lower levels (0.1 mg/1).Treatments applied to fruits of Lycopus europaeus and two Galeopsis species showed that modifications to the physical conditions of the test, such as light and temperature, produced only small changes in response to gibberellic acid. This effect was found even when situations in which a proportion of seeds germinated without gibberellin treatment were compared with conditions extremely unfavourable for germination.Comparisons of the effects of gibberellic acid (A3) and gibberellin A4 suggested that the latter promoted germination at approximately one hundred times the dilution of the former when tested on Lycopus europaeus and Galeopsis pyrenaica.
Relation Between the Chlorophyll Content and Paleness of Gibberellic Acid‐Treated Leaves
Authors: Szalai I. 
Published: April 2006

AbstractThe rate of chlorophyll synthesis as a function of lime was examined in plants of Hordeum vitlgare L. cultivated in Knop solution containing 1 mg/1 GA3. The action of concentration on the relations of chlorophyll components was investigated in GA3 solutions of five different concentrations.The relations of total chlorophyll contents, including those of the a and b components, were determined from ethanol and aqueous acetone extract at various periods of treatment, at the same moment but with different concentrations of GA3.A significant difference is noted between the chlorophyll contents of the GA3 treated plants and those of the control. The chlorophyll contents of treated plants are decreasing. The difference increases with raising GA3 concentration.The components were separated on thin layer with the partition method, and the spots were eluted. The density was measured with a spectrophotometer.Among the yellow components in the treated plants, the carotenes (α and β carotenes) increase as compared with the control plants. The total quantity of xanthophylls (lutein, zeaxanthine, lutein‐5, 6‐epoxide, violaxanthine and neoxanthine) almost equals the xanthophyll amount in the control plants; there is no significant difference.The paleness of leaves treated with GA3 is provoked by the quantitative change of pigment components; the chlorophylls o and b decrease, the xanthophylls remain unchanged and the carotenes increase.
Differenciation cellulaire et composés sulfhydrylés acido‐solubles de la racine de Lens culinaris Med.
Authors: Zryd Jean‐Pierre 
Published: April 2006

Abstract Cell differentiation and acid‐soluble sulfhydryl compounds in the root of Lens culinaris. Med. — The content of acid‐soluble sulfhydryl compounds (SH + S‐S) is determined amperometrically in tissues of the Lens root. Two distinct zones are analysed: first the meristematic one (0 to 1.6 mm from the tip) and secondly the elongating one (1.6 to 3.7 mm). Measurements concerned the first 80 hours of the root growth. SH/S‐S ratio is minimum in the meristematic ZONE. Connections seem to exist between the growth rate and the amount of SH compounds in the elongating zone. These facts suggest that the increase of cytoplasmic SH is associated with the reduction of protein‐disulfur‐bridges, which account for t he intermicrofibrilar bindings in the cell wall. The effects of auxins (indoleacetic acid and naphtylacetic acid) treatments are also studied. They are strictly localized in the apical zone and their intensity depends upon the auxin concentration. SH‐level is rising: this is due partially to a reduction of acid‐soluble S‐S.
Mannitol Biosynthesis in Pyrenochaeta terrestris I. D‐Maunitol‐1‐Phosphate: NAD Oxidoreductase
Authors: Aitken W. Brent , Wright James R. , Tourneau Duane Le 
Published: April 2006

AbstractCell‐free extracts of mycelial mats of Pgrenochaeta terrestris grown in stationary culture on synthetic glucose or sucrose ‐ salts liquid media contained D‐mannitol‐1‐Phosphate:NAD oxidoreductase (EC 1.1.1.17) activity. Greatest activity occurred early in the growth period. The optimum pH for the reduction of NAD+ in the presence of Fru‐6‐P was 7.4–7.5 while the optimum pH for the oxidation of NADH in the presence of Mtl‐1‐P was 8.1–8.2. The enzyme was stabilized to some extent in Tris‐maleate buffer, pH 7.5, and by the addition of 10% (NH4)2SO4, to this buffer. A 10‐ to 16‐fold purification was attained by a combination of (NH4)2SO4 fractionation and gel filtration on Sephadex G‐100. The enzyme was relatively specific in its substrate and coenzyme requirements. The Km values were determined as: Fru‐6‐P ‐ 3 × 10−4 M, Mtl‐1‐P ‐ 1 × 10−4 M, and NAD+ and NADH ‐ 3 × 10−5 M.
Gas Chromatographic Determination of Phytol in Plant Material
Authors: Liljenberg Conny , Odham Göran 
Published: April 2006

AbstractPhytol can be gas chromatographed without decomposition on an all‐glass column with 2% Hyprose SP‐80 on Chromosorb W; is stationary phase. Utilizing this a technique has been developed by which phytol of plant origin can be quantitatively determined. The practical limit of sensitivity is about 0.02 μg of phytol.
Mannitol Biosynthesis in Pyrenochaeta terrestris II. D‐Mannitol‐l‐phosphatase
Authors: Aitken W. Brent , Wright James R. , Letourneau Duane 
Published: April 2006

AbstractCell‐free extracts of mycelial mats of Pyrenochaeta terrestris contained an enzyme which hydrolyzed mannitol‐l‐phosphate to mannitol and inorganic phosphate. Greatest mannitol‐1‐phosphatase activity occurred early in the growth period when the mannitol content of the mats was at a maximum. The enzyme was active over a broad pH range with optimum activity between pH 6.5–7.0 in 0.05 M Tris‐maleate buffer. Maiinitnl‐1‐phosphatase was inhibited by reagents known to inhibit enzymes containing ‐SH groups. A 10‐fold purification was attained by a combination of (NII4)2 SO4 fractionation and gel filtration on Sephadex G‐100. The partially purified enzyme required Mg−2 for activity and did not hydrolyze a number of sugar phosphates. Km values for mannitol‐l‐phosphate and Mg−2 with the partially purified extract were 3 × 10−3 M and 1 × 10−4 M respectively.
Biochemical Aspects of Parasitism by the Angiosperm Parasites: Changes in Nucleic Acid Content of Infected Hosts
Authors: Setty Pravina N. , Beg M. U. , Singh Madhav , Krishnan P. S. 
Published: April 2006

AbstractThe acid‐insoluble phosphate in the tissues of three species of Cuscuta and of Orobanche cernua and in the infected hosts has been fractionated into phospholipids, RNA, DNA and phosphoprotein. Infection by parasites was attended, in general, by a decrease in RNA and an increase in DNA.
The Changes in Soluble Protein of Excised Barley Leaves during Senescence and Kinetin Treatment
Authors: Atkin Roger K. , Srivastava B. I. Sahai 
Published: April 2006

AbstractSterile detached barley leaves were floated on water or kinetin (10 mg/1)and supernatant extracts (30,000 x g for 30 min) were prepared from these leaves over an 8 day incubation period. Changes in selected total enzyme levels and in individual soluble protein components wore compared.Ribonuclease, deoxyribonuclease and peptidase activities rose in senescing leaves, even as total protein levels fell. Kinetin to some extent depressed these activities. Evidence of considerable loss of ribonuclease and to a lesser extent of deoxyribonuclease into the surrounding medium was obtained.Soluble supernatant ant extracts were resolved on DEAE‐Sephadex (A‐50) columns into about 15 components. While most components were degraded during senescence they did so at different rates. Kinetin lowered the rate of degradation of all components. Since no conclusive evidence of a new protein(s) was obtained in water and kinetin treated leaves, it was considered that any protein changes may have been of a quantitative rather than qualitative nature.
The Inhibition of Seedling Growth by Streptomycin Sulfate
Authors: Druhy Robert E. , Khan Anwar A. 
Published: April 2006

AbstractThe action of streptomycin sulfate (SS) on the growth of germinating seeds was investigated. It inhibited root growth more than shoot growth. Chemical analysis of roots indicated that nucleic acids decreased but their elution pattern from a column of methylated albumin kieselghur showed no qualitative differences. SS decreased the number of cells undergoing mitosis per root tip. This number was correlated with root length. One nM N5‐benzyladenine reversed the effect of SS on both root length and mitosis. Thus the effect of SS appears specific to cell division. SS failed to affect oxidative phosphorylation in isolated mitochondria so its effect on cell division would not be secondary to the inhibition of energy conservation. It s possible inhibition of enzyme activity is selective since it also failed to affect RNase activity in vitro.
Movement of Water and Solutes in Sieve Tubes of Willow in Response to Puncture by Aphid Stylets. Evidence against a mass flow of solution
Authors: Peel A. J. , Field R. J. , Coulson C. L. , Gardner D. C. J. 
Published: April 2006

AbstractExperiments are described in which bark strips of willow were sealed to polythene tubes having two compartments. This allowed investigations to be made of the transport along the sieve tubes of tritiated water, 14C‐labelled sugars, and 32P‐phosphates from one compartment, towards a stylet situated in the bark over the other compartment.Although activity from both 14C and 32p was detected in the stylet exudate usually within 1 hour from isotope application, tritium activity was never detected even after a period of 8 hours in most experiments, though in certain cases, very low activities were detected after 4 hours. Subsequent experiments in which stylets were sited over both compartments showed that tritium activity moved laterally into the punctured sieve element more rapidly than either 14C or 32P. Experiments using both live and dead bark in which stylets were not employed, showed that within 4 hours tritium activity had moved by diffusion along the whole length of a bark strip, therefore after this time tritium activity could have moved into the stylet exudate by a diffusional process.The lack of rapid longitudinal movement of tritiated water along the sieve tubes, indicates that the transport process is unlikely to be a mass flow of solution.
Untersuchungen über Beziehungen zwischen Zellteilung und Morphogenese bei Gewebekulturen vou Daucus carota III. Der Eiufluss des Kinetins auf die Ultrastruktur der Zellen
Authors: Neumann K. H. , Cireli E. , Cireli B. 
Published: April 2006

Abstract Relationship between cell division and morphogenesis of tissue culture of Daucus carota. III. The influence of kinetin on the ultrastructure of cells.— A previous paper reported a close correlation between cell division as influenced by kinetin and respiration, i.e. a high kinetin induced cell division rate corresponds with low oxygen consumption of the explants. This earlier observation was now confirmed. No significant differences between the ultrastructure of mitochondria of explants cultured with kinetin and those of explants cultured without kinetin could be observed, although the number of mitochondria per cell seems to be increased in explants cultured without kinetin. However, also the number of ribosomes in cells of explants cultured without kinetin seems to be increased as compared with those treated with kinetin. Kinetin apparently has no significant influence on the ultrastructure of cell organells under the conditions employed.
The Effect of Nonanal on Dipodascus aggregatus
Authors: Nyman Brita 
Published: April 2006

AbstractBiotin can not replace nonanal for Dipodascus aggregatus. The growth‐promoting effect of nonanal (80 μW) remained unchanged when the concentration of biotin was increased from 2 μm per 1 to 200 μm per I. Oleic acid stimulated the growth of D. aggregates. However, unlike nonanal, oleic acid promoted growth even if cells from the exponential phase of growth were used as inoculum. The concentrations of oleic acid required to produce growth–stimulation were considerably higher than the concentrations of nonanal required to promote growth. The growth‐stimulating effect f nonanal seems to be different from t he effect of oleic acid. The incorporation of 1C‐ghtCOM by D. aggregates was stimulated by the addition of nonanal (80μm) to the growth medium. The uptake of glucosamine was not affected by nonanal (80 or 160 μM in the presence of ethanol, 0.8 to 100μ in the absence of ethanol). Hexokinase activity in cell‐free homogenates was not affected by the addition of nonanal over a concentration range from 0.0059 to 1250μM.
Arginine in Growing Cells of Sugarcane. Nutritional Effects, Uptake and Incorporation into Proteins
Authors: Maretzki A. , Nickell L. G. , Thom M. 
Published: April 2006

AbstractThe growth of sugarcane cell cultures derived from parenchyma tissues of three different varieties of sugarcane showed a marked dependence on the presence of arginine when the cells were cultured in a synthetic liquid medium containing a mixture of amino acids. The cells appeared lo have access to n normal biosynthetic pathway of arginine biosynthesis but took up exogenously supplied arginine rapidly and efficiently. Arginine was not limiting for protein formation, nor were proteins with AN unusually high number of arginine residues evident. The low level of arginine effective in bringing about the growth response is suggestive of a regulatory function for this amino acid in sugarcane cells.
Diurnal Periodicity and Plaut Growth
Authors: Ketellapper H. J. 
Published: April 2006

AbstractThe experiments were carried out to investigate whether other plant species, in addition to tomato plants, show injury symptoms when grown for 2 to 4 weeks in an aperiodic environment and to obtain information about physiological mechanisms involved in the response to the absence of environmental periodicity. The growth of seedlings of pea, peanut, and soybean, exposed to different daylengths at constant temperature, increased with Increasing length of the light period up to 16 to 20 hours, defending on the species. Further lengthening of the photoperiod did not result in significant increases in dry matter accumulated. The absence of environmental periodicity did not cause injury in these three species. Tomato plants responded in an entirety different manner. The optimal photoperiod for dry matter production by tomato plants was 18 hours and photoperiods longer than 20 hours caused interveinal chlorosis. Thus, tomato plants have an absolute requirement for a daily periodicity, white the other species do not in short‐term experiments. Under conditions of constant temperature development of chlorosis by tomato plants may be prevented by a daily dark period of 4 hours or longer or by a daily period of drastically lowered tight intensity. Complete darkness is not essential, however. This suggests that development of chlorosis is not mediated through a photoperiodic response system. Involvement of a circadian oscillation may also be excluded. Aperiodic environmental conditions appear to affect the physiology of the tomato plant in a direct manner, possibly by influencing chlorophyll synthesis or degradation.
Marine Brown Algae Requiring Vitamin B12
Authors: Pedersén Marianne 
Published: April 2006

AbstractThe brown algae Lithosiphon pusillus, Ectocarpus fasciculatus and Pylaiella litoralis were cultivated in bacteria‐free cultures in artificial sea water, ASP 6F. The growth was tested with different additions of vitamins and other metabolites. Lithosiphon pusillus and Ectocarpus fasciculatus were found to require vitamin B12 for optimal growth.The zoospores of Pylaiella litoralis, when cultured in medium Asp 6F with kinetin added, had an absolute requirement for vitamin B12.
Growth Regulators and Wood Formation in Pinus silvestris
Authors: Hejnowicz A. , Tomaszewski M. 
Published: April 2006

AbstractThe formation of new xylem in the spring is preceded by bud development. In decapitated pine stem the formation of xylem is arrested until the outgrowth of interfascicular buds takes place. When indole‐3yl‐acetic acid (IAA) is applied to the cut surfaces of decapitated stems it induces the formation of a xylem ring on the whole length of 5‐ycar old trees. Naphthaleneacetic acid (NAA) causes the formation of xylem; however, the width of the growth ring is several times broader at the point of application than at the base of the leader. Cis‐ and trans‐cinnamic acids, coumarin, L‐tryptophan, kinetin (Kin), benzylaminopurine (BAP) and gibberellic acid (GA) alone do not induce cambial divisions; however, GA and the cytokinins given jointly with IAA or NAA accelerated the basipetal stimulus which has been induced by the auxins, resulting in normal xylem formation. 2,3,5‐Triiodobonzoic acid (TIBA) given jointly with IAA‐induced formation of compression wood in the apical part of the stem and narrow diameter tracheids at the base. When carboxyl labelled IAA or NAA are applied to pine segments it is found that the basipetal movement of IAA is much quicker than that of NAA. GA and the cytokinins increase the rate of transport of both auxins, whereas TIBA arrests the bulk of auxin in the apical part of the stem.