bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chemical Examination of Viable and Non‐Viable Rice Seeds
Authors: CHATTERJEE A. , SAHA P. K. , GUPTA PADMA DAS , GANGULY S. N. , SIRCAR S. M. 
Published: April 2006

AbstractA chemical examination has revealed four phenolic compounds in nonviable rice seeds (Oryza sativa L.). Their inhibitory bioactivity in the wheat coleoptile extension bioassay and the absence of these components in viable seeds have confirmed the relation of the phenolics with nonviability of the seeds. The compounds isolated from nonviable rice seeds were Kaempferol‐4′‐methyl ether, Kaempferol, quercetin and caffeic acid as identified on the basis of physical and chemical evidences.
Absorption and Re‐distribution of Nitrogen during Growth and Development of Field Bean, Vicia faba
Authors: COOPER D. R. , HILL‐COTTINGHAM D. G. , LLOYD‐JONES C. P. 
Published: April 2006

AbstractThe absorption of nitrate by field bean plants at different times of development was investigated to determine the distribution and subsequent utilization of N up to the maturity of the beans.Nodulated plants were grown in sand culture and pulse‐labelled with 15NO3 for 4 short periods during development. Whole plants were sampled at intervals until maturity and analysed for total nitrogen and 15N.There was a rapid increase in the bean dry weight and total N after fruit set and, at maturity, the beans contained about three times as much N as had ever been in the rest of the plant. Nitrate absorption continued steadily throughout plant development but nodule N fixation made a progressively greater contribution to the total N in the plant. Over a quarter of the total 15N absorbed was found in the roots immediately after each treatment and little of this was subsequently translocated upwards in spite of the large increase in shoot N taking place. Above ground the most powerful “sink” for recently absorbed and redistributed N was initially the youngest vegetative tissue. However after fruit set competition developed between the growing tip and the developing beans until at the later stages the beans became the more powerful. Quantitatively redistribution made only a small contribution to bean N.
The Action of Fusicoccin Alone and with Some Plant Growth Substances on Tobacco Tissue Cultures
Authors: SPARAPANO LORENZO 
Published: April 2006

AbstractThe interaction of fusicoccin, a terpenoid glucoside produced by Fusicoccum amygdali Del., and some plant growth regulating substances, i.e., indole‐3‐acetic acid, kinetin, 2,4‐dichlorophenoxy‐acetic acid and abscisic acid, was investigated on pith and sub‐cultured callus cultures of Nicotiana tabacum L. Addition of fusicoccin alone to the basal medium, either in the light or in the dark, caused a fairly good development of tobacco callus. When fusicoccin and kinetin were simultaneously added to the culture medium, the callus growth increased. However, fusicoccin in combination with indole‐3‐acetic acid caused limited callus development: the tissue appeared brown and reduced in volume. Addition of fusicoccin with 2,4‐dichlorophenoxyacetic acid stimulated growth of callus and chlorophyll was formed under light. Finally, abscisic acid did not interfere with the effect of fusicoccin on the callus growth.
The Photostability of Different Chlorophyll Forms in Dark Grown Leaves of Wheat
Authors: AXELSSON LENNART 
Published: April 2006

AbstractThe stability against high intensity irradiation (red light, 700 W m−2) was investigated for the chlorophyll(ide) pigments formed after the primary photoreduction of the protochlorophyll(ide) in dark grown leaves of wheat. After photoreduction, most of the chlorophyll(ide) exists in a form with an absorption maximum at 684 nm. This form is gradually transformed into a form with an absorption maximum at 673 nm (the Shibata shift). It was possible to ascribe a specific photostability to each of the pigment forms. This photostability was higher for the 673‐form than for the 684‐form. A red‐shift in the absorption maximum following upon the Shibata shift, reflects the successive transformation of the 673‐form into other pigment forms, which were quite photostable at the intensity used.
The Photostability of Different Chlorophyll Forms in Dark Grown Leaves of Wheat
Authors: AXELSSON LENNART 
Published: April 2006

AbstractThe stability against high intensity irradiation (red light, 700 W m −2) was investigated for the chlorophyll(ide) pigments formed after photoreduction of the protochlorophyllide of dark grown leaves of wheat.The reaction kinetics for the photodecomposition of the 673‐form was the same as for photooxidation of chlorophyll in vitro, which is a second order reaction with respect to the chlorophyll concentration. The 684‐form was photodecomposed in a first order reaction. This deviation from the in vitro kinetics may be explained by a gradual ‘decrease’ in the photostability of the pigment during the irradiation, possibly dependent on a gradual increase in the internal concentration (‘aggregation’) of the pigment. The photo‐stability was found to be 4–5 times higher for the 673‐form than for the 684‐form (the half‐lives were 10.5 and 2.3 min respectively). Connections between the presence of photosynthetic activity and the reaction kinetics for the photodecomposition of the chlorophyll(ide) are discussed.
Combined Effects of Abscisic Acid and Sucrose on Growth and Senescence of Rose Flowers
Authors: BOROCHOV AMIHUD , MAYAK SHIMON , HALEVY ABRAHAM H. 
Published: April 2006

AbstractThe effects of sucrose and abscisic acid (ABA) and their interaction on development and senescence of petals were studied with leafless roses cultivar Super Star. Sucrose and ABA had opposing effects on the cut flowers. Sucrose retarded and ABA promoted processes associated with senescence: wilting, increase in pH, “blueing” and decrease in protein content of petals. These opposing effects are mutually antagonized when both chemicals are applied. ABA applied to flowers cut at the bud stage, promoted the rate of petal growth (but not their final size), increased respiration and caused a decrease in sucrose and an increase in level of reducing sugars.It is suggested that one way by which ABA accelerates senescence of cut roses is by promoting petal growth and respiration, thus decreasing the carbohydrate level in the petals and triggering the chain of metabolic processes leading to aging.
Occurrence of a Cytokinin Glucoside in the Leaves and in Honeydew of Salix babylonica
Authors: VAN STADEN J. 
Published: April 2006

AbstractHoneydew and leaf extracts from Salix babylonica indicate that large quantities of cytokinin are present in the leaves and are transported through the phloem of this plant during late autumn. The active compound in the extracts could be hydrolysed with β‐glucosidase, whereafter it showed the same chromatographic behaviour as zeatin. It is proposed that cytokinins in the leaves are converted to the glucoside and then redistributed to the rest of the plant organs where it is stored.
Rapid, Blue‐Light‐Induced Transpiration Response Restricted to Plants with Grass‐like Stomata
Authors: JOHNSSON MARIANNE , ISSAIAS SUSANNA , BROGARDH T. , JOHNSSON A. 
Published: April 2006

AbstractIt is shown that the response of transpiration to light is different in species from Gramineae and Cyperaceae compared to species from other families. Blue light (380–500 nm) causes both a rapid response (rise time 2 min) and a slow response (rise time 5 to 10 min) in species from these two families but induces only a slow response in other families. Red light results only in a slow response in all plants investigated.It is hypothesized that the rapid response to blue light is due to the special anatomy and/or function of the so‐called grass‐like (graminaceous) stomata of plants belonging to Gramineae or Cyperaceae.
Kinetics of Potassium and Magnesium Uptake by Intact Soybean Roots
Authors: JOSEPH R. ANTONI , VAN HAI TANG 
Published: April 2006

AbstractThe kinetics of uptake of K+ and Mg2+ were studied by using intact soybean [Glycine max (L.) Merr. cv. Amsoy] roots. Uptake of K+ in the concentration range 1.29 × 10−5 to 1.82 × 10−3 M can be represented by two phases of a single, multiphasic mechanism. Similarly, uptake of Mg2+ in the concentration range 4.10 × 10−6 to 2.49 × 10−4M was biphasic.
Characterization of the Aminoacylation of Cytoplasmic Transfer Ribonucleic Acids from Germinating Soybeans
Authors: TESTER C. F. 
Published: April 2006

AbstractExtracts from germinating soybean [Glycine max (L.) Merr.] cotyledons were assayed for aminoacyl‐tRNA formation. This esterification reaction depends on several factors, which must be determined and controlled for each system investigated. The reaction was maximum when the Mg: ATP ratio was 12.5 and concentrations were 9 and 0.72 mM, respectively. The optimum temperature for the in vitro reaction was 25°C. In addition, the reaction was inhibited by inorganic pyrophosphate and magnesium could be replaced by spermidine.
Activities of Various Peptidases in Cotyledons of Germinating Peanut (Arachis hypogaea)
Authors: MIKOLA JUHANI 
Published: April 2006

AbstractThe activities of several carboxy‐ and aminopeptidases were assayed in extracts prepared from the cotyledons of resting and germinating peanut seeds as well as from growing and fully differentiated peanut leaves.Carboxypeptidases acting on two carbobenzoxydipeptides Z‐Phe‐Ala and Z‐Ala‐Phe at pH 5.2 showed minimal activities in “resting” cotyledons, and only slight increases occurred during 7‐day germination at 28°C. In peanut leaves the corresponding activities were quite high, about 20‐ and 6‐fold compared to “germinating” cotyledons.Peptidases acting on Leu‐Tyr at pH 8.6 and on Ala‐Gly at pH 7.8 were highly active in resting cotyledons, and the activities remained essentially constant during germination; corresponding activities in leaves were much smaller (about 15–25% of those in cotyledons).“Naphthylamidases” hydrolyzing the β‐naphthylamides of Phe, Leu, and Arg at pH 7.2, were also highly active in resting cotyledons; during germination the first activity stayed at a constant level while the other two decreased progressively. Leaves showed relatively high activities on Phe‐bT‐NA and Leu‐β‐NA but only minimal activity on Arg‐β‐NA.It is tentatively concluded that the peptidases acting on Leu‐Tyr and on Ala‐Gly as well as the naphthylamidases function in the mobilization of the reserve proteins of peanut cotyledons during germination. The carboxypeptidases, in contrast, do not seem to play a major role in this process.
Two Sites of Hormonal Action during Germination of Chenopodium album Seeds
Authors: KARSSEN C. M. 
Published: April 2006

AbstractDuring the overall germination process in the light‐requiring seeds of Chenopodium album L. two sites of hormonal action can be distinguished.The start of visible growth is induced in darkness by the gibberellins 4 and 7 (GA4+7) or by ethylene. Added cytokinins are inactive although 8‐14C‐kinetin shows rapid penetration into the seed and rapid turnover. The induction of growth by GA4+7 and the uptake of 8‐methylene‐14C‐GA3 are enhanced at lower pH values. Prolonged incubation in darkness results in a decreased responsiveness of the seeds towards GA4+7 and ethylene.A second site of hormonal action is located during the progress of growth inside the covering structures. ABA inhibits radicle growth, while GA4+7, GA3, kinetin, zeatin and ethylene reduce the inhibition.
Chemical Factors Affecting Palmelloid‐Forming Activity of Chloroplatinic Acid on Chlamydomonas eugametos
Authors: NAKAMURA KAZUO , SAKON MARGARET , HATANAKA MUREEN K. 
Published: April 2006

AbstractIn order to elucidate the physiological mechanism of palmelloid formation of the unicellular green alga Chlamydomonas eugametos by chloroplatinic acid, the factors causing inhibition of the palmelloid formation were studied in various media. Chloroplatinic acid lost its palmelloid‐forming effect in the presence of nitrite ion and amines having a second functional group. Nitrate, potassium, and sodium ions and monofunctional amines were without influence on the effect of chloroplatinic acid. These results indicate that the active form of platinum (IV) may undergo ligand substitution, the resulting complex being unable to cause palmelloid formation.
Nitrogen Constituents in Manganese‐Deficient Lemon Leaves
Authors: LERER MICHAEL , BAR‐AKIVA AVIGDOR 
Published: April 2006

AbstractTotal (Kjeldahl) nitrogen content of manganese‐deficient lemon leaves was found to be about 40% higher (on a dry weight basis) than in the analog control leaves. The nitrate‐N content rose in the deficient leaves from 18.2 mg/100 g to 95.6 mg/100 g dry weight. Among the N constituents studied, the free amino acids increased by about 42%, the protein amino acids by about 22%, and the total protein by more than 22%, all on a fresh weight basis. Acrylamide gel electrophoresis and ammonium sulfate fractionation showed qualitative differences in the various proteins. The increase of the protein fraction in the ‐Mn leaves may be attributed in part to the decrease of dry matter in these leaves (25.8% as compared to 30.7% in the control leaves) and in part to accumulation of apparent proteinous material in manganese‐deficient tissues.
Variation of Alkaloid Production in Nicotiana rustica Callus Cultures
Authors: TABATA MAMORU , HIRAOKA NOBORU 
Published: April 2006

AbstractCallus cultures have been established from the seed, root and leaf of Nicotiana rustica L. var. brasilia in a synthetic medium containing 1 μM 2,4‐D and μM kinetin. These callus tissues behaved similarly not only in growth and organogenesis but also in nicotine production. The nicotine contents of callus cultures, which were in the order of 0.25–0.58% of dry weight during a few passages subsequent to callus induction, rapidly decreased to trace amounts in succeeding subcultures in association with the decline of the root‐regenerating activity. On the other hand, free cells prepared from a callus tissue in the third passage developed into individual clones showing wide differences in growth and nicotine production. One of these clones gave rise to a relatively stable strain which is capable of producing nicotine at a high rate (0.29% of dry weight) in the absence of organization. The significance of these findings is discussed in connection with some results which have been reported for other callus cultures of Nicotiana species.
Comparison of N6‐benzyladenine and N‐4‐pyridyl‐N′‐phenylurea Effects on Lateral Bud Growth, Flowering and Seed Production of Brussels Sprouts (Brassica oleracea var. gemmifera)
Authors: THOMAS T. H. 
Published: April 2006

AbstractN‐4‐pyridyl‐N′‐phenyl urea (NC5392) showed similar activity to N6‐benzyladenine (BA) in stimulating lateral bud development on Brussels sprout (Brassica oleracea var. gemmifera) seedlings particularly on de‐rooted plants, but increased average bud weight far more than did BA. Both compounds increased flowering of young plants given an insufficient cold stimulus and seeds from treated plants showed a higher germination percentage than those from untreated plants.
Effect of Gibberellic Acid and Some Phenols on Flowering of Impatiens balsamina, a Qualitative Short‐day Plant
Authors: NANDA K. K. , KUMAR SURINDER , SOOD VINI 
Published: April 2006

AbstractGA3 as well as SA (salicylic acid) and β‐N (β‐naphthol) induce floral buds in Impatiens balsamina under strictly non‐inductive photoperiods. The floral bud initiation is accelerated when 1 mg/1 SA is used in combination with 100 mg/1 GA3. 100 mg/1 GA3+ 1 mg/1 SA and 100 mg/1 GA3+ 100 mg/1 β‐N increase the number of floral buds as compared with 100 mg/1 GA3 alone.
The Water Relations of Pinus sylvestris III. Diurnal and Seasonal Patterns of Water Potential
Authors: HELLKVIST JERK , PARSBY JAN 
Published: April 2006

AbstractThe water potential (ψ) in twigs from four clones of Scots pine (Pinus sylvestris L.) growing in close proximity to each other was measured in a pressure chamber during five selected periods between May 1972 and March 1973. Diurnal and seasonal patterns of ψ are presented in relation to irradiance, air temperature and vapour pressure deficit (VPD) for one cloudy and one clear day in each experimental period. Significant differences in ψ were found amongst most of the clones. Larger amplitudes and earlier day‐time minima in ψ were found during the summer than during the winter. Noon values of ψ of less than −12 bars were regularly found during the summer months.Plots of ψ against irradiance or VPD during a day, showed marked hysteresis as the result of the simultaneous influence on ψ of several environmental factors. Close linear relations resulted when ψ was plotted against potential evaporation rate (calculated from the Penman‐Monteith formula). The slopes of these regression lines, essentially the flow resistance, showed marked seasonal variations. At both high and low evaporation rates, the clone that grew the fastest had the lowest values of ψ, and the clone that grew the slowest had the highest values of ψ, while the other two clones had intermediate values. Differences in solute potential or in stomatal, plant or soil resistance are discussed as possible explanations of the more or less constant differences between the clones during the year of observations.
Localization and Activity of Naphthylamidases in Germinating Seeds of Scots Pine, Pinus sylvestris
Authors: SALMIA M. AULIKKI , MIKOLA JUHANI J. 
Published: April 2006

AbstractExtracts prepared from endosperms of germinating seeds of Scots pine, Pinus sylvestris L., rapidly hydrolysed the β‐naphthylamides of L‐phenylalanine and L‐leucine optimally at pH 6.5 and that of L‐arginine at pH 7.7. Disc electrophoresis followed by activity staining showed that the activities were due to two naphthylamidases (aminopeptidases) with different substrate specificities.Seeds were allowed to germinate at 20°C on agar gel in the dark and the activities on the three substrates were assayed from separated endosperms and seedlings at various stages of germination. The activities in the endosperm of resting seeds were relatively high and they remained unchanged throughout the period of reserve protein mobilization (seedling length up to 50 mm), after which they began to decrease. The activities of the naphthylamidases are rather small compared with those of the two alkaline peptidases of pine, contributing about 17% of the total amino‐peptidase activity in the endosperm of germinating seeds. The total aminopeptidase activity is sufficient to account for the rate of storage protein mobilization during germination.In the seedlings the naphthylamidase activities (per seedling) increased continuously during germination, and activities per g dry weight were higher than those in the endosperm.
Amelioration of Chilling Injuries in Cucumber Seedlings by Abscisic Acid
Authors: RIKIN ARNON , RICHMOND AMOS E. 
Published: April 2006

AbstractExposure of cucumber seedlings (Cucumis sativus L.) to chilling temperature resulted in injuries such as increased leakage of cellular materials, loss of water and wilting. In addition, the development of the seedlings after the exposure to chilling was impaired. Abscisic acid applied to the seedlings prior to chilling significantly ameliorated these injuries.
The Effect of Leaf Water Potential, Leaf Temperature and Light Intensity on Leaf Diffusion Resistance and the Transpiration of Leaves of Malus sylvestris
Authors: WEST D. W. , GAFF D. F. 
Published: April 2006

AbstractThe relationship between leaf resistance to water vapour diffusion and each of the factors leaf water potential, light intensity and leaf temperature was determined for leaves on seedling apple trees (Malus sylvestris Mill. cv. Granny Smith) in the laboratory. Leaf cuticular resistance was also determined and transpiration was measured on attached leaves for a range of conditions.Leaf resistance was shown to be independent of water potential until potential fell below — 19 bars after which leaf resistance increased rapidly. Exposure of leaves to CO2‐free air extended the range for which resistance was independent of water potential to — 30 bars.The light requirement for minimum leaf resistance was 10 to 20 W m−2 and at light intensities exceeding these, leaf resistance was unaffected by light intensity.Optimum leaf temperature for minimum diffusion resistance was 23 ± 2°C. The rate of change measured in leaf resistance in leaves given a sudden change in leaf temperature increased as the magnitude of the temperature change increased. For a sudden change of 1°C in leaf temperature, diffusion resistance changed at a rate of 0.01 s cm−1 min−1 whilst for a 9°C leaf temperature change, diffusion resistance changed at a rate of 0.1 s cm−1 min−1.Cuticular resistance of these leaves was 125 s cm−1 which is very high compared with resistances for open stomata of 1.5 to 4 s cm−1 and 30 to 35 s cm−1 for stomata closed in the dark.Transpiration was measured in attached apple leaves enclosed in a leaf chamber and exposed to a range of conditions of leaf temperature and ambient water vapour density. Peak transpiration of approximately 5 × 10−6 g cm−2 s−1 occurred at a vapour density gradient from the leaf to the air of 12 to 14 g m−3 after which transpiration declined due presumably to increased stomatal resistance. Leaves in CO2‐free air attained a peak transpiration of 11 × 10−6 g cm−2 s−1 due to lower values of leaf resistance in CO2 free air. Transpiration then declined in these leaves due to development of an internal leaf resistance (of up to 2 s cm−1). The internal resistance was masked in leaves at normal CO2 concentrations by the increase in stomatal resistance.
Elongation, Solute Loss, Osmotic Potential Changes, and Respiration Rate Changes during the Treatment of Avena Coleoptile Segments with Superoptimal Auxin Concentrations
Authors: RUESINK ALBERT W. , FEEMAN TERESA 
Published: April 2006

AbstractWhen treated with 100 μg/ml (0.57 mM) indole‐3‐acetic acid at pH 4.5, Avena sativa coleoptile segments elongate rapidly at first but begin to shrink after a few hours and eventually approach their initial length. Sufficient quantities of potassium and reducing sugars leak into the medium to reflect a significant change in osmotic potential of the tissues due to solute loss. Plasmometric measurements of subepidermal cell osmotic potentials reveal no alterations in that cell layer due to superoptimal auxin treatments: therefore other cells, presumably those of the epidermis, must be responsible for both the obvious loss of segment turgor and most of the solute loss. The relationship of the change in length to change in volume is the same for segments growing in no auxin, optimal auxin, and superoptimal auxin, indicating that cell swelling in other dimensions is not related to the differences in elongation. The respiration rate in superoptimal auxin falls several hours before the growth slows and stops. This result and the observation that auxin must be accumulated by segments to exert a growth inhibition suggest a site of inhibitory auxin action at or inside of the plasma membrane and not just upon the cell wall.
Water Relations of the Hemiparasite Rhinanthus serotinus before and after Attachment
Authors: KLAREN CHRISTINE H. , VAN DE DIJK SIEBREN J. 
Published: April 2006

AbstractGrowth of the hemiparasite Rhinanthus serotinus (Schönh.) Oborny was greatly stimulated after attachment of the parasite to the roots of the host plant, Hordeum vulgare L. Before attachment the hydrostatic pressure in the xylem, determined by the pressure bomb technique, was found to be lower in Rhinanthus than in the host. It increased after the formation of haustoria between host and parasite. Apparently, the water transport to Rhinanthus was facilitated. The hydrostatic pressure remained lower than that of the host, accounting for the flow of water and solutes in the direction of the parasite and indicating that there exists a resistance to water transport in the haustoria. Water and solutes were absorbed by the cells, which increased in size. The turgor pressure of the parasite rose steeply, but the osmotic potential was hardly affected.