bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Effect of a Quaternary Amine (Aliquat 336) on Growth and Photosynthesis of the Green Alga Chlorella emersonii, and the Effect on Photosynthesis in Isolated Spinach Chloroplasts
Authors: EGNÉUS HANS , BLANCK HANS 
Published: April 2006

AbstractA quaternary amine, Aliquat 336, inhibits the growth of the green alga Chlorella emersonii, 14C‐fixation of the alga is also inhibited. The effect and the site of action of the compound was studied by using isolated spinach chloroplasts. The carbon dioxide dependent oxygen evolution of the chloroplasts is inhibited directly upon the addition of the amine and the oxygen evolution is replaced by an oxygen uptake. By investigating some electron transport reactions in the chloroplasts we were able to show that Aliquat 336 affects the electron transport on the level of photophosphorylation. The results from the in vivo and the in vitro experiments thus show that the quaternary amine affects the photosynthetic process.Aliquat 336 is a solvent extractant used in several industrial processes for extraction of metals from aqueous solutions. Aliquat 336 could be considered a presumptive water pollutant as the compound could enter a recipient water body and thus affect photosynthesis.
Inhibiteurs non acides et dormance embryonnaire chez Taxus baccata
Authors: LE PAGE‐DEGIVRY MARIE‐THÉRÈSE 
Published: April 2006

AbstractNon‐acidic inhibitors and embryo dormancy in Taxus baccata L.Embryo dormancy of Taxus baccata is eliminated when the embryos are continuously kept in sterile nutritive liquid medium. After 3 weeks of culture, an important non‐acidic inhibitory complex can be extracted from this liquid medium. At least three substances are involved: two pigments and a compound with some properties that suggest xanthoxin. These substances are neither found in embryos taken directly from the seeds, nor in liquid medium after 8 days of culture, which is the time necessary and sufficient to allow germination after transfer on agar medium. Such behaviour is quite different from that of ABA previously studied and indicates that these non‐acidic inhibitors appear late during the culture and are not directly involved in embryo dormancy.
The Association between Soil and Xylem Water Potential, Leaf Resistance, and Abscisic Acid Content in Droughted Seedlings of Douglas‐fir (Pseudotsuga menziesii)
Authors: BLAKE JOHN , FERRELL WILLIAM K. 
Published: April 2006

AbstractDuring progressive stages of drought and subsequent recovery through rewatering, foliage of 2‐year‐old seedlings of Douglas‐fir was sampled for water potential, stomatal resistance, and abscisic acid content (ABA). Simultaneous measurements of soil matric potential were also made. There was a rapid rise in stomatal resistance in the range of 1500–2000 ng ABA g−1 dry weight of foliage corresponding with a plant water potential of –10 to –12 bars. Soil matric potential seemed more closely associated with ABA increase than did plant water potential. After rewatering, seedlings returned to normal ABA levels within 6 days.
Glycolipid Degradation in Leaves of the Thermophilic Cucumis sativus as Affected by Light and Low‐Temperature Treatment
Authors: DE KOK LUIT J. , KUIPER PIETER J. C. 
Published: April 2006

AbstractTreatment of Cucumis leaf discs with light and low temperature (1°C) resulted in degradation of the total lipids. In addition, a decrease of the linolenic acid content of the glycolipids of leaves and leaf discs took place while at the same time an increase in the content of unidentified degradation products from the glycolipids was observed. The decrease of the linolenic acid content was not due to galactolipase activity, since no monogalactosyl diglyceride acyl hydrolase activity was found. Dark and low temperature did not alter the fatty acid composition. Blue light and low temperature resulted in a decrease of the linolenic acid content, while yellow‐, red‐ and far red light in combination with low temperature were ineffective.
Callus and Plantlet Regeneration from Cell Cultures of Ladino Clover and Soybean
Authors: OSWALD T. H. , SMITH A. E. , PHILLIPS D. V. 
Published: April 2006

AbstractThe auxin to cytokinin ratios are described for promoting growth in the in vitro cultures of soybean (Glycine max (L.) Merr. cv. Bragg) and perennial clover (Trifolium repens L. cv. Regal Ladinc). Callus growth was induced on somatic tissue with 50:1 auxin to cytokinin (w/w) ratio. A 5:1 ratio served for initiation of cell suspensions from callus and for subsequent growth of callus from cells in suspension. A 1:2 ratio served for regeneration of buds and plantlets from the callus grown from cells. Although (2,4‐dichlorophenoxy) acetic acid was the auxin for suspension and regenerative cultures, (2,4,5‐trichlorophenoxy)acetic acid was the more effective auxin for initiation of callus on somatic tissue. All cultures were grown with 6‐furfurylaminopurine as the cytokinin.The phytohormones strongly influenced the rates of culture growth, but determination of culture type was augmented by dl‐alpha tocopherol acetate and iron. Tocopherol and a relatively high complement of iron promoted growth of juvenile cultures, whereas low level of iron and absence of tocopherol favored growth to comparatively more differentiated cultures. Without tocopherol, no callus formed on somatic tissue during the allotted period of incubation. Tocopherol plus a complement of low iron enabled growth of callus on rapidly growing somatic tissue. A high level of iron enabled comparatively more callus growth but suppressed growth of somatic tissue. In suspension cultures tocopherol and a high iron level enhanced dispersion of cells. A low iron complement in the absence of tocopherol induced growth of callus from cells and subsequent regeneration of buds and plantlets from the callus.
Study of the Efficiency of Hydrasyl as an Antitranspirant with an Isotopic Method
Authors: FERRON F. , COSTES C. 
Published: April 2006

AbstractThe antitranspirant efficiency of Hydrasyl varies when it is sprayed over the blade surface of different plant species. The efficiency index of Hydrasyl was obtained by comparing the enrichment of tritium in water of a treated blade with that in a non‐treated blade. The variability of the results depends on the specific regulation of water loss within the plant (physiological parameter) or on the “wettability” qualities of the cuticle (morphological parameter). The study brings to light the limits in the use of an antitranspirant.
Utilization of Exogenous Carbohydrates for Tube Growth and Starch Synthesis in Pine Pollen Suspension Cultures
Authors: NYGAARD PER 
Published: April 2006

AbstractPine pollen (Pinus mugo) grown in suspension cultures readily utilize exogenous carbohydrates for tube growth and starch synthesis: these processes are not influenced by β‐indolylacetic acid, gibberellic acid, kinetin and abscisic acid. It appears that the free sugars of the female gametophyte, namely sucrose, raffinose, and stachyose and their monosaccharide constituents, are the best substrates for growth and polysaccharide synthesis. The oligosaccharides are hydrolysed to their monosaccharide constituents before they are taken up. A preferential uptake of fructose is noted. Non‐metabolizable sugars are not taken up. The data presented establish that tube growth, except for the initial growth phase, can be determined by the availability of exogenous carbohydrates.Measurements of some of the key enzymes in carbohydrate metabolism show that the enzymes were present in the ungerminated pollen grain, and that the enzyme activity increased severalfold during tube growth. The increase in enzyme activity was prevented if inhibitors of protein synthesis were present in the medium.
Nitrate Reduction in Different Grass Species
Authors: DUSKY JOAN A. , GALITZ DONALD S. 
Published: April 2006

AbstractOptimal extraction conditions, assay conditions, and levels of nit rate reductase activity (NRA) were determined for eight forage grass species adaptable to growing conditions in western North Dakota. Optimal pH for extraction of the enzyme nitrate reductase (NADH: nitrate oxidoreductase) for these species ranged from 7.0 to 9.5, whereas assay pH was 7.6 in all eight species. Substrate concentrations ranged from 1.0 to 10.0 mM for maximum NRA with higher concentrations (100 mM) significantly inhibiting NRA. The enzyme was NADH2 (0.1 to 0.2 mM for maximum activity) specific. Enhancement of maximum activity with the addition of cysteine during extraction was species dependent; six species required high cysteine concentrations between 5 mM and 10 mM and one species required only a 2.5 mM concentration. The degree of sulfhydryl protection offered by cysteine also varied. Comparisons were made between in vivo and in vitro assay methods. Ratios of in vitro to in vivo NRA ranged from 2.2. to 10.8. Use of bovine serum albumin as a protein stabilizer during extraction increased the measurable NRA in some species. Applications of nitrate reductase assay techniques to field work will be discussed.
A Cytokinin Complex in the Developing Fruits of Lupinus albus
Authors: DAVEY J. E. , VAN STADEN J. 
Published: April 2006

AbstractThe apices of Lupinus albus L. were analysed for cytokinin activity at three stages of development. Little cytokinin activity could be detected in the apices at the time of flowering. However, a considerable amount of activity was detected as the fruits developed. Separate analyses of seed and pod material indicated that there was a high level of cytokinin in both these parts of the fruit. After fractionation of the peaks of activity obtained from paper chromatograms on Sephadex LH‐20, four peaks of cytokinin activity were recorded. Two of these co‐eluted with zeatin and zeatin riboside. A third peak at an elution volume of 360–440 ml could be hydrolysed with β‐glucosidase to give activity at elution volumes corresponding to those of zeatin and zeatin riboside. This strongly suggested that both glucosylated zeatin and glucosylated zeatin riboside were present in the developing fruits of L. albus. The fourth peak at an elution volume of 160–280 ml did not disappear upon hydrolysis with β‐glucosidase, and it is possible that it represented a nucleotide cytokinin.
Characteristics of Root‐to‐Shoot Transport of Cytokinin 6‐Benzylaminopurine in Intact Seedlings of Citrus aurantium
Authors: MOZES RITA , ALTMAN ARIE 
Published: April 2006

AbstractTransport of the cytokinin 6‐benzylaminopurine‐8‐14C in the root and shoot of intact Citrus aurantium L. seedlings was studied by “replacing” the 0.5 cm root tip with the uptake solution. The cytokinin was transported basipetally in the root and was distributed in an acropetal direction in the stem and into the leaves. Kinetic analysis of the transport for periods of up to 96 h revealed a characteristic advancing front of the label along the axis of the seedling. The estimated velocity of transport of 6‐benzylamino‐purine‐8‐14C in various regions of the intact root was 2.6 to 5.1 mm/h.The transport of 6‐benzylaminopurine was predominantly in the transpiration stream, in stelar tissues of the root. Conditions of high transpiration favored enhanced transport to the shoot and an overall greater accumulation of the label. The total accumulation of 6‐benzylaminopurine in roots of intact seedlings after 48 h of transport was 354% of that in roots of shoot‐less seedlings. Root girdling and treatment of the root with KCN did not reduce the basipetal transport of the label in the root and into the shoot.Radiochromalogram scanning of root extracts and analysis of the ethanol insoluble‐NaOH soluble fraction revealed considerable metabolic changes in the translocated cytokinin. Only 51% of the radioactivity remained in the original 6‐benzylaminopurine peak after 24 h of incubation. Two other, unidentified, metabolites were detected.It is suggested that all the factors that affect the ascent of sap are involved in the long‐distance transport of cytokinins, and that the rate and mode of transport of cytokinins from the root system to the shoot may be a major factor in the expression of their physiological activity.
Comparative Basipetal Transport of 6‐Benzylaminopurine‐8‐14C, Gibberellin A3‐3H, IAA‐2‐14C, and Sucrose‐14C in the Root of Intact Citrus aurantium Seedlings
Authors: ALTMAN ARIE , MOZES RITA 
Published: April 2006

AbstractThe transport and distribution of IAA‐2‐14C, gibberellin A3‐3H, 6‐benzylaminopurine‐8‐14C and sucrose‐14C (U) were studied in whole seedlings of Citrus aurantium L. after “replacing” the root tip with the solution of radiochemicals. All four substances were transported basipetally in the root and were distributed to the stem and leaves. The pattern of distribution of the label from 6‐benzylaminopurine was similar to that of sucrose, while a considerably larger amount of gibberellin A3 was transported to basal regions of the root, away from the tip, and into the shoot. Contrary to these three substances, the basipetal transport of IAA in the root was very low, and the majority of the label was retained in the terminal sections of the root.It is suggested that the different efficiencies at which various hormones move in the transpiration stream in the root may be an important factor in the attainment of a certain balance of hormones in the shoot.
Longitudinal and Transversal Microgradient of Acid Phosphomonoestherase in Growing and Geostimulated Maize Roots
Authors: MAYOR GUY , PILET PAUL‐EMILE 
Published: April 2006

AbstractA relatively simple and reproducible technique to analyse both longitudinal and transversal biochemical microgradients in roots has been presented. Although no statistically significant differences of acid phosphomonoestherase activity were found between upper and lower faces of geostimulated maize roots, an increase of activity was demonstrated in the two first mm of the horizontal roots in comparison with the vertical roots. These results were discussed in conection with the growth variation of these roots.
Some Environmental and Nutritional Factors Affecting Growth and Sporulation of Aspergillus sydowi
Authors: OLUTIOLA P. O. , COLE O. O. 
Published: April 2006

Abstract Aspergillus sydowi (Bain. & Start.) Thom & Church grew and sporulated best at 30°C. The best pH for growth and sporulation was 5.5. Light was stimulatory to sporulation but inhibitory to growth. Among the carbon sources employed, sucrose supported the best growth and sporulation. Nitrate, ammonium and asparagine were good nitrogen sources for growth and sporulation. During utilization of sucrose, the carbohydrates found in the mycelium included dulcitol, inositol, mannitol, arabinose, trehalose and galactose.
Cellulolytic Enzyme System in Culture Filtrates of Aspergillus sydowi
Authors: OLUTIOLA P. O. , COLE O. O. 
Published: April 2006

AbstractDuring growth in liquid culture medium, that contained single soluble or insoluble cellulosic carbon source, Aspergillus sydowi (Bain. & Start.) Thom & Church released cellulolytic enzymes into the medium. The enzymes were separated by gel filtration followed by ion exchange chromatography into three components, all of high molecular weight. One of the components (Ac) has the character of a C1 cellulase enzyme. In the assay for hydrolysis of insoluble cellulose, the combined fractions, especially whenever the fraction under test contained the component Ac, released more glucose than when each component was employed alone.
Lipid Labeling in Normal and Nitrogen‐Deficient Squash (Cucurbita maxima) Leaves
Authors: DALGARN D. , HUBER D. , NEWMAN D. W. 
Published: April 2006

AbstractSquash (Cucurbita maxima Duchesne) plants were grown on normal and on nitrogen‐deficient nutrients. The degrees of label incorporation into chloroplast lipids as well as non‐chloroplast lipids were determined. Nitrogen‐deficient tissues contain less chlorophyll, have a decreased chlorophyll a/b ratio, incorporate more label into phosphatidyl choline and phosphatidyl ethanolamine than into the chloroplast lipids such as mono‐ and digalactosyl diglycerides, have a reduced capacity to incorporate the hexose moieties into the glycolipids but normal capacity to incorporate bases into the phospholipids of non‐chloroplast constituents, and have a normal level of total fatty acids even though the level of linolenate is decreased. All of this would suggest that the most evident changes in membrane lipid constituents during nitrogen‐deficiency occur as changes in the chloroplast lipid constituents as opposed to the non‐chloroplast lipid constituents.
Morphogenetic Effects of Indole‐3‐acetic Acid and Benz(a)anthracene on Tobacco Callus
Authors: KOCHHAR T. S. , SABHARWAL P. S. 
Published: April 2006

AbstractCallus obtained from haploid plants of Nicotiana tabacum was inoculated on media containing indole‐3‐acetic acid (IAA) and benz(a)anthracene (BaA) in various combinations. No cytokinin was included in the medium. Vegetative buds and roots differentiated on this callus. Higher concentrations of BaA favored vegetative bud initiation while higher IAA concentrations promoted root formation. However, these treatments proved ineffective on the callus derived from diploid tobacco plants.
Multiplication cellulaire et production lipidique en culture in vitro chez Taphrina insititiae et Taphrina pruni, parasites de Prunus domestica
Authors: SANCHOLLE MICHEL , SCHNEIDER ALAIN 
Published: April 2006

Abstract Cellular Multiplication and Lipid Synthesis during in vitro Culture of Taphrina insititiae and Taphrina pruni, Parasites of Prunus domestica. Two Taphrina species were grown on “yeast extract/glucose” and harvested at regular intervals. Their growth was estimated by dry mycelial weight and cell nitrogen. Lipids were recovered and measured by weighing. Phospholipids, which form the major portion of polar lipids, were measured by phosphorus assay.Lipidic and nitrogenous products were studied with regard to the evolution of the cultures during the phase of active growth. The cells accumulated fats, but during the phase of autolysis, fat content decreased. Production of nitrogenous components was maximal during the autolytic phase. Phospholipids varied as nitrogenous and inversely to neutral lipids. There was apparently an antagonism between nitrogen assimilation and synthesis of neutral lipids. Different functions of neutral and polar lipids may be involved, so that the former act as a reserve material and the latter represent an essential structural cell constituent.Fatty acids were analysed by gas liquid chromatography at various culture periods. Fatty acids from polar as well as those from neutral lipids exhibited great variations with regard to culture evolution. The ratio insaturated/saturated fatty acids is greater in polar lipids than in neutral lipids. These variations are discussed with regard to their consequences for the function of cell membranes.
A Simplified Medium for the Growth of Maize (Zea mays) Endosperm Tissue in Suspension Culture
Authors: SHANNON J. C. , LIU J.‐W. 
Published: April 2006

Abstract In vitro cultures of maize (Zea mays L.) endosperm derived from the dent inbred A636 have been maintained in liquid culture using Straus' medium for over six years. We have studied the growth of this tissue in four basic media and various modifications of the organic constituents of these media. Auxins and kinetin did not improve growth rate or degree of cell dispersion and thiamine (0.4 mg/l) was the only vitamin required by this tissue. Growth equal to that in the standard Straus medium and improved cell separation was obtained in a medium containing only inorganic salts, sucrose, and thiamine. Although asparagine was not required when high quantities of NH4NO3 and KNO3 were included, more rapid growth was obtained when 2 g/l of asparagine was added. The simplified medium reported in this paper should facilitate the use of maize endosperm tissue in various studies of metabolism, hormone biosynthesis, etc.
Differences in Velocity of Auxin Movement Obtained by Intercept and Peak Arrival Methods
Authors: KRUL WILLIAM R. 
Published: April 2006

AbstractVelocity of IAA movement was determined by noting the time of arrival of an ether‐soluble auxin wave, at a fixed distance, after presentation of an auxin pulse to bean (Phaseolus vulgaris L. cv. Pinto) hypocotyl segments. The effects of IAA adsorption on wave symmetry were reduced by monitoring the arrival of ether‐soluble auxin molecules. Velocity of auxin movement, as estimated by wave arrival, was slower than velocity estimated by the intercept method in controls and in both iodoacetate (IOAA) and 2,3,5‐triiodobenzoic acid (TIBA) treated tissue. Velocity of wave migration was reduced by both treatments but intercept velocity was reduced only by TIBA treatment. Velocity of IAA migration was faster in segments (independent of method of measurement) than from segments into agar by a factor of 4 to 8. The rate limiting step of auxin migration in the traditional agar‐plant sandwich is the partitioning of IAA between the tissue and agar. It was suggested that arrival curves for pulsed auxin migration are analogous to elution profiles of chromatographic columns and that at least two populations of mobile molecules with different velocities exist. It was also suggested that the two velocities represent migration of auxin on two different pathways: the faster velocity representing auxin movement of water films which coast highly crosslinked polymers in the segment and the slower component representing a population which moves primarily within the matrices of crosslinked polymers. Velocity of both populations may be a function of tissue hydration and charge interactions of mobile molecules and matrix polymers.
The effect of Sea Water and Temperature on the Germination Behaviour of Crithmum maritimum
Authors: OKUSANYA O. T. 
Published: April 2006

AbstractThe seeds of Crithmmm maritimum L. were germinated floating on various concentrations of sea water up to 50% at constant temperatures of 5, 10, 15, 20, and 25°C and at alternating temperatures of 5 and 15°C. 5 and 25°C. and 15 and 25°C. Significantly higher germination was obtained at alternating than at constant temperature. When two constant temperatures at which no germination occurred were alternated, good germination was obtained. There was reduced germination and increase in time of first germination as sea water concentration increased, in the absence of sea water, high temperature caused not only severe inhibition of germination but also permanent injury to the seeds. The results help to explain the germination behaviour of the species in nature.
Cadmium Accumulation by the Marine Red Alga Porphyra umbilicalis
Authors: McLEAN MAITLAND W. , WILLIAMSON PRANK B. 
Published: April 2006

AbstractThe characteristics of cadmium accumulation by the marine red alga Porphyra umbilicalis L. in culture are reported. The time course of uptake under various light conditions shows that cadmium is concentrated as the result of an on‐going anabolic process and not as a consequence of a pH gradient as provided by photo‐synthesis. The effect of cycloheximide is in agreement with de novo protein‐synthesis being a prerequisite For cadmium accumulation. Autoradiography suggests a specific intracellular location for bound cadmium—apparently the nucleus.