bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Effect of Chilling of the Physiological and Simulated Apex of 2‐ and 3‐leaf Plants of Pisum sativum L. cv. Alaska on Lateral Shoot Growth, C‐14 IAA Movement and P‐32 Accumulation
Authors: Husain Syed Mushtaq , Linck Albert J. 
Published: April 2006

AbstractThe apex of a 3‐leaf pea plant was chilled in cold chambers maintained at 5–7°C. The lateral shoots 1 through 5 grew, and shoot 5 eventually dominated other lateral shoots. The apex when returned to the ambient temperature did not reimpose apical dominance. The growing lateral shoots competed with the stem apex.The apices of 2‐ and 3‐leaf plants were chilled and P‐32 distribution in these plants was studied in the entire plant, at various intervals of time. Phosphorus‐32 accumulation followed the growth pattern of the plant. The lateral shoots accumulated P‐32 activity and very little activity was accumulated by the apex. The dominating shoots 2 and 5 accumulated the maximum amount of activity in 2‐ and 3‐leaf plants, respectively.Labeled‐IAA moved basipetally through the stem when applied to the cut stump simulating the apex. By cold treatment the translocation of IAA was influenced more than its absorption. The plant seems to metabolize this compound in the later periods of application. The plant now becomes “insensitive” to auxin and the lateral shoots grow.
Endogenous Diurnal Rhythm in the Osmotic Surplus of the Guard Cells
Authors: Stålfelt M. G. 
Published: April 2006

AbstractThe osmotic surplus of the guard cells —i.e., the difference between the guard cells’and epidermal cells’omotic value at incipient plasmolysis (Vicia Faba) —exhibits an endogenous diurnal‐periodic variation that is synchronous with the endogenous diurnal periodicity in the movements of the guard cells. The osmotic surplus of the guard cells is found to arise and drop by changes not only in these cells, but also in the epidermal cells.
Effect of Leaf Aging on Water Deficit—Water Potential Relationships of Dogwood Leaves Growing in Two Environments
Authors: Knipling Edward B. 
Published: April 2006

AbstractWater deficit‐water potential relationships were determined at approximately monthly intervals from May to August on leaves collected from dogwood trees growing in two environments. The relationships were not the same for leaves of different ages or for leaves of the same age, but growing in the different environments. With aging of the leaves, the relationships shifted to progressively lower water potentials for a given water deficit. Increased leaf dry weight, decreased cell wall elasticity, and decreased osmotic potentials accompanied leaf aging. These changes and the shifts in the relationships were greatest for leaves growing under high light intensity and dry environmental conditions. The lack of constancy in the relationships reduces the usefulness of water deficit or relative turgidity as an estimator of water potential. For the purposes of some workers, however, the relationships may be sufficiently constant for mature leaves of a given species growing in a relatively constant environment.
Sulfhydryl and Disulfide Patterns Associated with Vernalization of Wheat
Authors: Ellis R. W. , Trione E. J. 
Published: April 2006

AbstractAnalyses of plumules from seedlings of a winter wheat variety (Elgin) and a spring wheat variety (Red Bobs) indicated that SH and SS contents based on protein levels were similar in the whiter and spring wheat tissues grown at 20 C. Boll) varieties, when grown nt 3 C, contained greater concentrations of SH and SS groups, based on protein levels, than those present in the tissues grown at 20 C. The spring wheat tissues at 3 C maintained relatively constant levels of SH and SS during the growth period.Sulfhydryl (SH) and SS groups based on fresh weights were present in greater quantities in the tissues of the spring wheat grown at 20 C than in the winter wheat tissues grown at 20 C. The high SH and SS concentrations present in the warm‐grown spring wheat tissues were due to a high concentration of protein extracted from that tissue. The SH and SS contents per unit fresh weight were quite similar in the cold‐grown tissues of both varieties during the growth period. Both varieties at both temperatures showed a similar decrease in SH and SS contents, based on fresh weights, as maturation progressed.The spring wheats grown at 3 C and 20 C and the winter wheat grown at 3 C all showed similar characteristics and differed considerably from the winter wheat grown at 20 C. These data were positively correlated with the flowering potential of the wheat varieties.
The Effect of Toxic Doses of Copper upon Respiration, Photosynthesis and Growth of Chlorella vulgaris
Authors: McBrien David C. H. , Hassall Kenneth A. 
Published: April 2006

AbstractWhen cells of Chlorella vulgaris absorb copper under anaerobic conditions, subsequent respiration, photosynthesis and growth of the cells are all severely inhibited. This does not occur when the metal is absorbed under aerobic conditions. When, after aerobic absorption of copper, the cells are exposed to a period of anaerobiosis, respiratory inhibition is as profound as when the uptake is anaerobic. In this case, however, respiration must eventually recover, for growth is not affected so severely as it is when copper is taken up under anaerobic conditions. It is concluded that the extra copper absorbed under anaerobic conditions is directly or indirectly responsible for the greatly increased toxicity to growth, and that this copper is bound to sites not normally available under aerobic conditions. Some aspects of the apparently unique toxic effect of copper suggest that these extra sites are sulphydryl groups.
Permeability and Respiratory Properties of Germinating Pollen
Authors: Dickinson David B. 
Published: April 2006

AbstractA study of permeability and respiration of germinating lily pollen (Lilium longi‐florum, variety Ace) was conducted. Calcium was needed in the culture medium to maintain the integrity of the cell membranes. Carbohydrates leaked from pollen when calcium was absent, but little or no leakage occurred when calcium was present. A culture medium containing penlaerythritol was developed for this study. Pentaerythritol allowed normal germination and did not interfere with measurement of carbohydrates. Intact pollen grains possessed a β‐fructofuranosidase external to the cell membrane which hydrolyzed sucrose in the culture medium. External α‐ or β‐glucosidases were absent, although soluble α‐glucosidase was present within the pollen.Oligomycin, an inhibitor of oxidative phosphorylation, eliminated the 3‐phase patters of respiration associated with normal germination. O2 uptake was inhibited by oligomycin while CO2 output was stimulated. 2,4‐Dinitrophenol, an uncoupler of oxidative phosphorylation, reversed the inhibition of O2 uptake caused by oligomycin.
Action Spectra for Light‐induced Elongation in Fern Protonemata
Authors: Miller John H. , Miller Pauline M. 
Published: April 2006

AbstractThe action spectrum for promotion of elongation of protonemata of Onoclea sensibilis has peaks at 400–420, 580–600 and 640–660 nm. The largest growth increments at saturating light doses are produced by yellow and far‐red light. Elongation induced by yellow and far‐red irradiation persists in old as well as young filaments, while red‐light promotion is found only in young filaments. The growth promotion caused by yellow light is partially reversed by red light down to the level of growth produced by red irradiation alone. Elongation of rhizoids is under reversible red, far‐red control, while yellow light is inactive. A model is proposed and discussed in which the light‐sensitive elongation of filaments is accounted for by the presence of three distinct photoreceptors: phytochrome; a pigment absorbing yellow light. P580; and a pigment absorbing blue light, P420.
The Uptake and Metabolism of Sulphate in Scenedesmus as Influenced by Citrate, Carbon Dioxide, and Metabolic Inhibitors
Authors: Kylin Anders 
Published: April 2006

AbstractThe incorporation of sulphur from external sulphate into different fractions was studied in cells with a P content of 0.6 to 1 mg/g fresh weight as against 3 to 5 mg/g fresh weight in normal cells. — There is a flat and broad optimum for the action of pH in the region between 5.7 and 7. — In most cases, citrate inhibits the uptake of sulphur. — Five per cent CO2 in the air enhances the incorporation of S. It is suggested that the effects of CO2 may well be exerted by way of the carboxylation and decarboxylation mechanisms in the cells. — Selenate inhibits the formation of DNA‐S and protein S more than that of lipid S, but the main effect in both cases seems to be in an early step of the assimilation of sulphate. In the absence of external phosphate, the inhibition is counteracted by CO2, especially in darkness. Phosphate enhances the action of selenate on the organic S fractions, and in its presence CO2 and darkness make the inhibition more pronounced. — Without P in the medium, the effects of selenate on uptake into the inorganic sulphate fraction are smaller than when the organic fractions are concerned. In the presence of CO2 even stimulations due to selenate have been observed. External phosphate brings the inhibition of uptake into cellular SO42‐ to the same level as found in the case of organic S. More than one pathway for the uptake as SO42‐seem possible. — Anaerobiosis and menadione affect the organic S fractions more than the sulphate; 2,4‐dinitrophenol has a more uniform action all over the field.
The Effect of the Plant Growth Retardants Amo 1618 and CCC on Gibberellin Production in Fusarium monili‐forme: Light Stimulated Biosynthesis of Gibberellins
Authors: Mertz D. , Henson W. 
Published: April 2006

AbstractThrough the use of a single gene dwarf mutant of Zea mays L., dwarf‐1, the interaction of growth retardants with gibberellin biosynthesis was studied in Fusarium monitiforme. It was demonstrated that the growth retardants 2‐isopropyl‐4‐dimcthylamine‐5‐methyphenyl‐1‐piperidine‐cai'boxylate methyl chloride (Amo 1618) and (2‐chloroethyl) trimethylammonium chloride (CCC) are more effective inhibitors of gibberellin biosynthesis in cultures maintained under continuous illumination.Light grown cultures produced significantly more biologically active gibberellin‐like materials than dark grown cultures. Stock cultures exposed to light also promoted the subsequent biosynthesis of gibberellins in the dark. Chromatographical analysis of the soluble gibberellins extracted from the culture medium revealed that large amounts of chromatographically detectable A3 and A7 were produced in light cultures with only A7 produced in the dark. Light also induced a greater incorporation of acelate‐2‐14C into the gibberellins A7, A3 and an unidentified gibberellin.Growth returdants occasionally caused a complete disappearance of chromatographically detectable gibberellins in the dark; however, in the light at no concentration tested was it possible to detect the complete disappearance of gibberellin‐like material. A3 was always detectable.Like higher plants, different strains of F. moniliforme exhibit variation which makes them more or less sensitive to the growth retardants. This variation is interpreted to mean that there may be more than one pathway leading to the synthesis of the gibberellins.
Extracellular Organic Carbon from Some Green Algae
Authors: Forsberg Curt , Taube ÖRn 
Published: April 2006

AbstractA preliminary study of the extracellular organic carbon in cultures of Ankistro desmus falcatus, Scenedesmus quadricauda, Chlorella pyrenotdosa and Crucigenia tetrapedia have been performed. Carbon analyses, parallel to the increase in cell numbers, were made with an infrared analyzer after oxidation of the organic carbon to CO2. During the phase of declining relative growth rate and the stationary phase of growth the species excreted organic carbon. For Scenedesmus and Ankistrodesmus an uptake period took place before the excretion period. Approximately 500 · 106 cells/1 were required until excretion started for the former species. The highest figures for the organic carbon liberated by the four species ranged between 3 and 9 mg/l (approx. 8–23 mg organic matter/I). When distributed per cell the extracellular carbon corresponded to 1–3 μg · 10−6 with a mean for the average excretion for the species tested of 6 · 10−8μg/cell · day. For Scenedesmus the extracellular carbon was calculated to be 2–5 per cent of the cell‐bound carbon.
Cytokinin‐like Activities of 4‐Benzylaminobenzimidazole
Authors: Kuraishi Susumu , Yamaki Tosmo 
Published: April 2006

AbstractA new compound, 4‐benzylaminobenzimidazole was synthesized. The only difference between benzylaminobenzimidazole and benzylaminopurine is the presence in the former of carbon atoms instead of the nitrogen at positions 1 and 3 of the purine ring. Although the new compound has no purine ring in the molecule, it has several cytokinin activities such as stimulation of leaf growth in Raphanus and retention of chlorophyll in Brassica leaves. Benzylaminobenzimidazole has no effect on germination of tobacco seeds kept in the dark.
Studies of the Cultural Physiology of the Lichen Alga Trebouxia
Authors: Fox Cecil H. 
Published: April 2006

AbstractThe pholosynthetic growth of three species of Trebouxia was so slow as to preclude the usual inorganic methods of algal cultivation. Heterotrophic growth was much stronger — as many as 0.4 doublings per day were obtained in Bold's solution with glucose and amino acid hydrolysates. Ammonium salts of inorganic acids could not be used in the culture medium because they caused excessive reductions in pH. Although the organisms showed variations in their growth response to amino acids, no specific requirement was found. T. erici produced significantly lower quantities of photosynthetic pigments in the dark. Of the nineteen carbohydrates tested, only glucose, mannitol, and galactosc stimulated growth of the algae. Preliminary studies showed that Trebouxia incorporated 14CO2 more slowly than Chlorella pyrenoidosa. However, the carbon fixed by Trebouxia remained soluble in 80% ethanol longer than Chlorella. The carbon incorporated as CO2 in short term experiments was greater than would be expected from the growth rates of the organisms studied.
Nucleic Acid Metabolism Involved in Auxin‐induced Elongation of Yeast Cells
Authors: Shimoda Chikashi , Masuda Yoshio , Yanagishima Naohiko 
Published: April 2006

AbstractThe following results were obtained using a variant yeast strain, N55, which can respond to the cell‐elongating action of auxin.Base analogs of nucleic acids (2‐thiouracil, 8‐azaguanine, and 5‐fluorouracil) inhibited the auxin‐induced elongation of yeast cells only when they were added to the preculture prior to auxin treatment. The inhibitory effect of 2‐thiouracil and 5‐fluorouracil was reversed by uracil and that of 8‐azaguanine by guanine. Actino‐mycin D inhibited the auxin‐induced elongation when given to the culture containing auxin, but not when given to the preculture. The similarity in these respects between yeast and tissues of higher plants is discussed.
Carotenoid Synthesis in Leaves of Etiolated Wheat Seedlings after Varying Light and Dark Treatments
Authors: Virgin Hemming I. 
Published: April 2006

AbstractA short impulse of red light has a varying effect on carotenoid synthesis in dark‐grown wheat seedlings. Except for β‐carotene, which remains unchanged in the dark (it increases in continuous light), the carotenoid synthesis shows the same tendency as during constant irradiation. Thus, lutein and neoxanthin slowly increases, while violaxanthin decreases. During a period of constant light following various periods of darkness after the short impulse of light, the pigment changes correspond to those occurring in the dark, but are much more pronounced. The changes are discussed on the basis of phytochrome action.
The Changes of The Level of Triterpenoids in Calendula officinalis during Vegetation
Authors: Kasprzyk Zofia , Fonberg‐Broczek Monika 
Published: April 2006

AbstractUsing thin‐layer chromatography for separation and colorimetric test with CoClj for determination, qualitative and quantitative composition of triterpenoids was estimated in Calendula officinalis dining vegetation. It was found that sterols and oleanolic acid as well as trace amounts of triterpenic monols occur in all organs of the plant during the whole vegetative period. Triterpenic diols and greater quantities of triterpenic monols appear in flowers. The biosynthesis rate of triterpcnoids is highest in young organs of the plant that is in seedlings, young leaves and flower buds. During flowering the content of sterols and oleanolic acid increases in all plant organs except of old leaves. A high level of oleanolic acid in the root during the flowering period implies that oleanolic acid glycosides can be transported from older leaves to underground parts of the plant. Biosynthesis of triterpenic monols, Ψ‐taraxasterol and taraxasterol, precedes the formation of the diols faradiol and arnidiol. It can be inferred from the course of accumulation of these compounds that monols are the precursors of diols and that hydroxylation occurs in flowers.
Scopoletin and Polyphenol‐Induced Lag in Peroxidase Catalyzed Oxidation of Indole‐3‐acetic Acid
Authors: Schaeffer G. W. , Buta J. G. , Sharpe F. 
Published: April 2006

AbstractThe rate of initial indole‐3‐acetic acid (IAA) oxidation with horseradish peroxidase is modified with scopoletin, scopolin and other phenolic derivatives. In the presence of phenolics there is an initial lag phase in the oxidation. The early lag is dissipated enzymatically after which the rale of IAA oxidation again returns to normal. Chlorogenic and sinapic acids produce the longest lag periods of the compounds reported here, whereas the glucoside, scopolin, produced the least inhibition. Scopoletin is more than 10× as inhibitory as scopolin.
Metabolism of DL‐Tryptophan‐3‐14C by the Fruitlets of Citrus aurantifolia
Authors: Khalifah Rashad A. 
Published: April 2006

AbstractDeveloping lime fruit [Citrus aurantifolia (Christm.) Swingle] was supplied with dl‐tryptophan‐3‐14C in a special medium. An incubation period of six hours was sufficient for the radioactivity to reach an equilibrium between the fruit tissue and the incubation medium. Analyses of the fruit tissue and the medium for acidic and neutral metabolites of tryptophan indicated the existence of indolic products. The auxin indole‐3‐acetic acid (IAA) was identified among the products by dry column chromatography and biological assay. Other acidic metabolites included indolepyruvic acid and an unidentified material. Neutral metabolites included indolealdehyde, indoleacetaldehyde, and two unidentified compounds. Biological activity in the Avena curvature test was obtained from extracted compounds which corresponded to IAA and indolepyruvic acid in the acidic fraction and indoleacetaldehyde in the neutral fraction. Radioactive tryptophan was also found in both the acidic and the neutral fractions due to its amphoteric nature. The experiment demonstrated the conversion of tryptophan to its indolic metabolites, including indole‐3‐acetic acid, in this Citrus tissue.
The Distribution of Acidic and Neutral Peptidases in Barley and Wheat Kernels
Authors: Prentice Neville , Burger W. C. , Kastenschmidt Jeannine , Huddle John David 
Published: April 2006

AbstractThe activity of barley and wheat peptidases which hydrolyze alpha‐N‐benzoyl‐dl‐arginine‐p‐nitronnilide (BAPA) and alpha‐N‐benzoyl‐l‐arginine ethyl ester (BAEE) has been measured in proximal and distal portions of ungerminated grain and in these tissues during 6 and 7 day incubations.The proximal portion of ungerminated barleys contained the major part of both the acidic (BAPA‐ase and acidic BAEE‐ase) and neutral (neutral BAEE‐ase) peptidases. In ungcrminated wheat these acidic and neutral peptidases were nearly evenly distributed between the proximal and dislal portions. Commercial wheat embryo was very high in acidic peptidase but contained no neutral peptidase.During the germination of both wheat and barleys, acidic and neutral peptidase activity in the seedlings increased with time. No such consistent increase was observed for aleurone and starchy endosperm tissue for any of these grains.Aleurone and starchy endosperm tissue incubated in the absence of the proximal portion of the kernel showed reduced peptidase activities.
Membrane Functions and Tolerance to Aromatic Hydrocarbon Fungitoxicants in Conidia of Fusarium solani
Authors: Georgopoulos S. G. , Zafiratos Catherine , Georgiadis Eugenia 
Published: April 2006

AbstractWith the use of 32P‐labeled phosphate and 42K2CO3 the effect of diphenyl on permeability and uptake properties of the cytoplasmic membrane in wild type and diphenyl‐tolerant mutant conidia of Fusarium solani f. cucurbitae was studied. No general damage to the membrane with unspecific leakage of cell constituents was demonstrated under conditions in which diphenyl prevents germination of wild type conidia.The fresh conidia do not require exogenous supply of energy for the uptake of phosphate or of potassium. In the wild type the entry of 32P is inhibited but that of 42K strikingly stimulated by diphenyl. Independently of the tolerant mutant gene present, the mutant conidia are significantly less sensitive to the phosphate uptake inhibition and not affected at all by diphenyl with respect to the uptake of potassium. The latter difference from the wild type seems to indicate genetic control of some property of the potassium transport system in this fungus.
14C‐Studies on Apple Trees. I. The Effect of the Fruit on the Translocation and Distribution of Photosynthates
Authors: Hansen Poul 
Published: April 2006

AbstractThe presence of fruits affects the translocation and distribution of photosynthates from apple leaves to other organs of the tree. An attempt has been made to study the relationship in greater detail by following the distribution of 14C introduced in the form of 14CO2 on shoots with and without fruits, respectively. Determinations of the 14C‐content were made on different parts of the shoot sampled at varying intervals after the introduction of the tracer. The l4C‐labelling and the content of sorbitol and sugar in the leaves were determined by means of paper chromatography.A total of nearly 90 per cent of the 14C taken up by the leaves can be transferred to a fruit close by, the majority during the first 4 to 5 days following the addition of the 14C. The content of 14C in the leaves is reduced more rapidly in shoots with fruits than in those without. Young leaves retain more of the added 14C than do fully developed ones.The greatest changes with time are found in the methanol‐soluble 14C‐compounds. Immediately following application, the leaves contain 58 to 80 per cent of the 14C added in sorbitol, 7 to 9 per cent in sucrose, and 1 to 4 per cent in the form of glucose. Within 5 days after the introduction of 14C the amount of 14C‐sorbitol is reduced very considerably, while in certain cases the amount of 14C‐glucose increases. The 14C‐sorbitol content was higher in leaves from shoots without fruits than in those from fruit‐bearing shoots, and this applied also to the total contents of sorbitol and of glucose.
Effect of Variation of Sporulation Time and Temperature on Thermostability of Bacillus cereus Spores
Authors: Lundgren Lillian 
Published: April 2006

AbstractThe optimum temperature for sporulation of a strain of Bacillus cereus was estimated at 30°–35°C, where the maximum yield of spores was obtained between 18 and 24 hours’ incubation. Sporulation was more rapid, but less extensive at 40°C and did not occur at all at 45°C.The heat resistance of the spores increased with the sporulation temperature from 20° to 40°C. The spores appear to be more susceptible to heat destruction in the early stage of spore production than after further incubation.