bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chemical differences between wildtype and gibberellin mutants of tomato determined by pyrolysis‐mass spectrometry
Authors: NIEMANN G. J. , EIJKEL G. B. , KONINGS H. , PUREVEEN J. B. M. , BOON J. J. 
Published: April 2006

ABSTRACTLeaf, stem and root material of wild‐type and gibberellin (GA)‐deficient mutants of tomato (Lycopersicum esculentum L.) were analysed by pyrolysis‐mass spectrometry for possible differentiation in chemical allocation pattern among cell wall and cytoplasm. GA‐deficiency is accompanied by changes in the relative growth rate (RGR). RGR‐correlated changes were found in leaves in the comparative amounts of cellulose‐ and protein‐derived fragments. The low‐RGR genotypes contained more protein and nucleic acid, the high‐RGR ones more cellulose. In root material, a higher contribution of cellulose, hemicellulose and G‐ and S‐lignin was found for the lower‐RGR plants and comparatively high protein in the high‐RGR genotypes. For stems, less clear results were obtained, possibly because of variation in the ratio of syringyl‐ and guaiacyl‐lignin. Part of the results might be explained by a GA‐dependent change in cell size.
Enhanced ethylene production by primary roots of Zea mays L. in response to sub‐ambient partial pressures of oxygen
Authors: BRAILSFORD R. W. , VOESENEK L. A. C. J. , BLOM C. W. P. M. , SMITH A. R. , HALL M. A. , JACKSON M. B. 
Published: April 2006

ABSTRACTEthylene production by primary roots of 72–h‐old intact seedlings of Zea mays L. cv. LG11 was studied under ambient and sub‐ambient oxygen partial pressures (pO2) using a gas flow‐through system linked to a photoacoustic laser detector. Despite precautions to minimize physical perturbation to seedlings while setting‐up, ethylene production in air was faster during the first 6h than later, in association with a small temporary swelling of the roots. When roots were switched from air (20–8kPa O2) to 3 or 5kPa O2 after 6h, ethylene production increased within 2—3 h. When, the roots were returned to air 16 h later, ethylene production decreased within 2—3 h. The presence of 10kPa CO2 did not interfere with the effect of 3kPa O2. Transferring roots from air to 12–5kPa did not change ethylene production, while a reduction to 1 kPa O2 induced a small increase. The extra ethylene formed in 3 and 5 kPa O2 was associated with plagiotropism, swelling, root hair production, and after 72 h, increased amounts of intercellular space (aerenchyma) in the root cortex. Root extension was also slowed down, but the pattern of response to oxygen shortage did not always match that of ethylene production. On return to air, subsequent growth patterns became normal within a few hours. In the complete absence of oxygen, no ethylene production was detected, even when anaerobic roots were returned to air after 16 h.
Response of small birch plants (Betula pendula Roth.) to elevated CO2 and nitrogen supply
Authors: PETTERSSON R. , McDONALD A. J. S. , STADENBERG I. 
Published: April 2006

ABSTRACTSmall birch plants were grown for up to 80 d in a climate chamber at varied relative addition rates of nitrogen in culture solution, and at ambient (350 μmol mol‐1) or elevated (700 μmol mol‐1) concentrations of CO2. The relative addition rate of nitrogen controlled relative growth rate accurately and independently of CO2 concentration at sub‐optimum levels. During free access to nutrients, relative growth rate was higher at elevated CO2. Higher values of relative growth rate and net assimilation rate were associated with higher values of plant N‐concentration. At all N‐supply rates, elevated CO2 resulted in higher values of net assimilation rate, whereas leaf weight ratio was independent of CO2. Specific leaf area (and leaf area ratio) was less at higher CO2 and at lower rates of N‐supply. Lower values of specific leaf area were partly because of starch accumulation. Nitrogen productivity (growth rate per unit plant nitrogen) was higher at elevated CO2. At sub‐optimal N‐supply, the higher net assimilation rate at elevated CO2 was offset by a lower leaf area ratio. Carbon dioxide did not affect root/shoot ratio, but a higher fraction of plant dry weight was found in roots at lower N‐supply. In the treatment with lowest N‐supply, five times as much root length was produced per amount of plant nitrogen in comparison with optimum plants. The specific fine root length at all N‐supplies was greater at elevated CO2. These responses of the root system to lower N‐supply and elevated CO2 may have a considerable bearing on the acquisition of nutrients in depleted soils at elevated CO2. The advantage of maintaining steady‐state nutrition in small plants while investigating the effects of elevated CO2 on growth is emphasized.
A branch bag and CO2 control system for long‐term CO2 enrichment of mature Sitka spruce [Picea sitchensis (Bong.) Carr.]
Authors: BARTON C. V. M. , LEE H. S. J. , JARVIS P. G. 
Published: April 2006

ABSTRACTThis paper describes the construction and performance of branch bags and a CO2 control system used to fumigate branches of mature Sitka spruce trees with air enriched in CO2 (700 μmolmol‐1). It contains some examples of results obtained using the system over the course of the first two growing seasons. The branch bags have run continuously for 2 years with very few problems. CO2 concentrations were within 20 μmol mol‐1 of the target concentration for more than 90% of the time. Temperatures within the bags were slightly higher than ambient (1–2 °C) and this had some effect on phenology. Attenuation of quantum flux density (photosynthetically active radiation) was 10–15%. The branch bag system has enabled investigation into the effects of elevated CO2 on mature tissue without the problems and expense of fumigating whole trees. Growth in elevated CO2 resulted in an increase in starch and a decrease in soluble protein content of needles. Stomatal conductance was higher in elevated CO2 grown needles, and there was some evidence of an increase in photosynthetic capacity.
Cell Physiological Studies on the Avena Coleoptile Treated with Ribonuclease
Authors: Masuda Yoshio 
Published: April 2006

It was revealed with excised Avena coleoptile that the growth promoting effect of indole‐3‐acetic acid was inhibited by pretreatment with ribonuclease (Masuda 1959a, b). This effect of ribonuclease was presumed to involve its digestive action on the ribonucleic acid at the protoplasmic surface (Masuda 1959b). Ribonuclease treatment decreases the cation binding capacity of the ribonucleic acid at the protoplasmic surface (Masuda 1959a).On the other hand, it has been confirmed that indole‐3‐acetic acid bas a remarkable effect on the physico‐chemical properties of protoplasmic surface such as permeability (Masuda 1955) and adhesiveness of protoplasm to the cell wall (Masuda 1957, Masuda and Takada 1957).The purpose of the present study is to see the effect of ribonuclease on some protoplasmic properties of cells of Avena coleoptile and substantiate the authors view on the participation of ribonucleic acid in the cell elongation.
Permeability of the Plasmalemma as Compared with that of the Tonoplast
Authors: Haapala Eva 
Published: April 2006

In recent years there has been an increasing tendency to regard the tonoplast as the decisive diffusion barrier of the protoplast. The plasmalemma has been assumed to be more or less freely permeable, especially to ions (Brooks 4, Arisz 1, Epstein 8, Briggs and Robertson 3, Sutcliffe 12). This view is, however, based on observations which are far from unequivocal.In the following we shall try to elucidate the question of the relative permeability and susceptibility of the two plasma membranes towards sodium hydroxide and sodium carbonate. The tests were made on internodal cells of Nitellopsis obtusa, staminal hairs of Tradescantia virginiana and T. zcbrina and epidermal cells of Allium cepa var. sanguinetim. These cells show protoplasmic streaming and either contain anthocyanins or were stained with neutral red.In these experiments the plasmalemma, or some other layer outside the streaming part of the protoplasm, is assumed to be more or less impermeable towards sodium hydroxide as long as protoplasmic streaming is going on in the cells lying in the strongly alkaline solution. On the other hand, by the time the colour of the cell sap changes a considerable amount of NaOH must have passed through the whole protoplast, including both plasmalemma and tonoplast. The principal object of the experiments was, therefore, to compare (a) the time necessary to stop the protoplasmic streaming, irreversibly, with (b) the time required for the colour of the vacuole to change either to yellow (neutral red) or to blue (anthocyanin).
Protochlorophyll/Chlorophyll Conversion by Single Flash Illumination
Authors: Madsen Axel 
Published: April 2006

Previous studies (Smith and Benitez 1954) have shown the rate of the photochemical conversion of protochlorophyll to chlorophyil‐a in etiolated leaves to be proportional to the product of the light intensity used and the duration of the illumination.This relation, however, is considered to be valid only in the case of moderate light intensities and relatively short periods of illumination. Thus Koski (1950) found a reduction of the total content of pigments in etiolated corn leaves following 180 sec illumination of 150 fc (approximately 1600 lux); she considered this to be a destructive effect of the light. Virgin (1955) found a considerable destruction of chlorophyll to take place in etiolated barley leaves during illumination with 600 fc (about 6500 lux).In the present paper it is shown that by using very high light intensities and very short periods of illumination it is possible to transform approximately 40 percent of the protochlorophyll of etiolated wheat leaves to chlorophyll‐a without effecting any light induced loss of the total content of pigments.
p‐Hydroxybenzoic Acid, a Growth Regulator, Isolated from Woody Cuttings of Ribes rubrum
Authors: Vieitez E. , Seoame E. , Gesto D. V. , Mato C. , Vazquez A. , Carnicer A. 
Published: April 2006

AbstractWoody cuttings of Ribes rubrum, an easy plant to root, were extracted with methanol. One fraction of this extract was both water and ether soluble; a part of it was only water soluble. From the water and ether soluble fraction a crystalline compound was isolated which was fully identified with p‐hydroxybenzoic acid (PHB) by m.p., mixed m.p., infrared spectrum, ultraviolet absorption in neutral and alkaline methanol and chemical analyses.For Avena coleoptiles straight growth test, p‐hydroxyhenzoic acid was found to have a significant growth promoting activity in the range 20–100 μg/ml. and it showed strong growth inhibition at concentrations higher than 200 μg/ml.From the same extract fraction a phenolic ester was isolated by paper chromatography which showed a weak growth inhibiting activity. This compound was identified as an ester of p‐hydroxybenzoic acid by micro‐scale reactions.From the extract soluble only in water further amounts of crystalline p‐hydroxybenzoic acid were obtained by alkaline hydrolysis. This PHB may have arisen from the breakdown of pelargonidin glucosides.
Stomatal Opening as a Practical Indicator of Moisture Stress in Cotton
Authors: Alvim Paulo de T. 
Published: April 2006

AbstractThe response of stomata to varying soil moisture content was studied in cotton by means of a new type of porometer suitable for field work. The results showed that maximum stomatal aperture was only attained when soil moisture was near the upper limit of the so called “available range”. These results indicate the possibility of making practical use of the new type of porometer for the purpose of determining soil moisture deficiency under field conditions, thus aiding in irrigation practices.
The in vitro Germination of Pollen of Setaria sphacelata 2. Relationships between Boron and Certain Cations
Authors: De Bruyn J. A. 
Published: April 2006

AbstractThe effects of different calcium levels upon germination and tube growth of the pollen of Setaria sphacelata (Schum.) Stapf and Hubbard were studied at low, optimal and high levels of boron. Calcium (10 and 100 mg/1) stimulated germination at all levels of boron and enhanced tube growth to an even greater degree. The inhibitory effects of high boron levels (50 mg/1) were largely overcome by addition of 10 to 100 mg/1 calcium. Magnesium (1 and 10 mg/1) stimulated germination and tube growth at optimal and high boron levels, but 100 mg/1 magnesium were highly inhibitory. Potassium and sodium had little effect upon pollen germination or tube growth at any level of boron supply. It was concluded that calcium, together with sucrose and borate, might be required for optimal germination and growth of the pollen tubes. Nevertheless, the tubes obtained were much shorter than required for fertilisation in vivo, indicating either that some essential factor was still missing or that the pollen is inherently incapable of producing tubes of adequate length.I wish to thank dr. Donald T. Krizek for critically reading the manuscript.
Enhancement of Enzymatic Synthesis of Citrate in vitro by Indole‐3‐Acetic Acid
Authors: Sarkissian Igor V. 
Published: April 2006

AbstractIndoleacetic acid in physiological concentrations was shown to enhance the synthesis of citiate by purified citrate condensing enzyme from castor beans and pig heart. Michaelis constants reveal that with indoleacetic acid in the reaction mixture a higher concentration of acetyl‐CoA was necessary to give maximal velocity. V values with indoleacetic acid in the reaction (physiological concentrations) exceeded V without indoleacetic acid in reaction. Citric acid synthesized from 14C acetyl CoA was highly radioactive when indoleacetie acid was present in the reaction, indicating that indoleacetic acid did in fact enhance the synthesis. The data were discussed from the point of view that these studies may provide the basis for studies directed at ultimate understanding of the mechanism of action of indoleacetic acid.
The Deciduous Behavior of a Tropical Plant, Plumeria acuminata
Authors: Murashige Toshio 
Published: April 2006

AbstractThe deciduous behavior of the tropical perennial Plumeria acuminata Ait., cultivar Sherman White, was investigated. The temperature during the period of experiment varied only 3°C, the mean maxima and minima, respectively, being; 28.5° and 23.5°C for summer months and 25.5° and 20.6°C for winter months. The length of the day‐light period ranged from 14¼ hours on the longest day in June to 11¾ hours on the shortest day in December.Under naturally prevailing conditions of temperature and day‐lengths, cessation of leaf formation and shedding of foliage occurred during the longer‐night, autumn‐winter months. The shedding was manifested in two stages: from mid‐October to mid‐January there was a slow but steady decrease in the number of leaves per plant, and in late January there occurred an abrupt abscission of all remaining leaves. Light interruptions during the middle of each night prevented a net loss in foliage as well as the en masse shedding in late January.Stem elongation was retarded during the autumn‐winter months, but its rate was fully restored when the long nights were interrupted with artificial light. Flowering was unaffected by day‐length.On the basis of these observations it is concluded that the deciduous behavior of Plumeria and perhaps other tropicals, alike temperate climate species, is governed by photoperiod. Cessation of leaf formation and en masse shedding of foliage are induced by long nights. However, in contrast to temperate zone plants, in which deciduousness is an adaptation against the winter cold and freeze, deciduousness provides tropical plants a survival advantage, perhaps, against seasonally recurring droughts.
The Effect of Nouaual on Dipodascus aggregatus
Authors: Nyman Brita 
Published: April 2006

AbstractThe growth of a strain of Dipodascus aggrrgatus Francke‐Grosmann was strongly promoted by the aliphatic aldehyde nonanal. The highest effect was found with 80–160 μmol of nonanal per 1.The growth‐promoting activity of nonanal is principally the result of an ability to shorten the lag phase. Neither the maximum value for growth nor the growth rate seem to be increased.The growth‐promoting activity of nonanal could be observed only if the cells used for inoculation were taken from a culture in the phase of accelerated growth.The highest growth‐promoting activity was observed when the nonanal was added before inoculation, a large effect was still observed when it was added 24 hours after inoculation, but there was no effect when it was added 33 hours after inoculation.The growth‐promoting activity of nonanal remained unchanged when a mixture of 15 vitamins and growth factors was given to the medium.Nonanol and nonanoic acid stimulated growth, although to a lower degree than nonanal.There was a gradual increase in the growth‐promoting effect of nonanal as the pH of the medium was increased between 3.0 and 8.0, showing that this effect is most pronounced at the higher pH values.
The Effect of Nutritional Factors and Certain Growth Substances on the Growth of Disks Cut from Young Leaves of Phaseolus
Authors: Dale J. E. 
Published: April 2006

AbstractThe roles of some chemical factors influencing leaf expansion were investigated using disks cut from the primary leaves of young plants of Phaseolus grown in subdued light. Mineral nutrients, cobalt, sucrose, GA and IAA or NAA at suitable concentrations all caused increases in fresh and dry weights of such disks. When all these substances were applied together the increases in diameter and in fresh and dry weight and cell number were very large and comparable with the rates found in intact leaf tissue. The response of disks to sucrose was found to be light dependent, and a number of other significant interactions were noted. Disks cut from older leaves, in which cell division had ceased, did not show large increases in fresh weight in response to treatment with sucrose, and in this such disks differ from those cut from leaves in which cell divisions are continuing. The possible significance of this is discussed and the roles of light and the other chemical factors investigated are assessed in terms of influence on cell division and expansion in disk tissue.
The Interaction of (2‐Chloroethyl) trimethylammonium Chloride and Gibberellic Acid in Strawberry
Authors: Guttridge G. G. 
Published: April 2006

AbstractApplications of (2‐chloroethyl) trimethylammonium chloride (CCC), by foliar spray or to the soil, shortened petioles and decreased top and root growth of strawberry plants. Application of gibberellic acid increased petiole length and fresh weights of tops but not of roots. Applied together gibberellic acid overcame the depression of growth in weight of tops induced by CCC and countered the depression in petiole lengths. Gibberellic acid induced elongation of internodes of the vegetative stem and the elongation was increased substantially by concurrent application of CCC.This synergism in stem growth indicates a lack of antagonism between CCC and exogenous gibberellic acid in strawberry. The implications are discussed.
Effect of Temperature on Germination of Spores from Some Bacillus and Clostridium Species
Authors: Lundgren Lillian 
Published: April 2006

AbstractThe effect of temperature on germination of spores of Bacillus subyilis, B. megaterium. B. cereus, Clostridium sporogenes, Cl. butyricum and Cl. bifermentans was studied.At lower temperatures (+5°C to +10°C) the three Glostridium species germinated to a less extent than the three Bacillus. species.The optimum temperature for germination of the six species varied between +35°C and +45°C.The Clostridium species were more tolerant to heat than the Bacillus species.
The Effect of Simulated Caterpillar Damage on CO2 Fixation and Translocation in Banana Leaves
Authors: Johnson Barbara E. , Brun W. A. 
Published: April 2006

AbstractA study was undertaken to see how a small hole in a leaf such as caused by a feeding caterpillar will influence photosynthesis and translocation in the remaining leaf tissue. Banana leaves were exposed to C14O2 at various intervals before and after holes were made in the leaves with a cork borer. Radioautographs were taken to study the extent of CO2 fixation and translocation.Results show that photosynthesis is impaired for only 24 hours. Downward translocation is affected for 48 hours. Caterpillar damage of small areas does not seem to affect normal leaf functions beyond these time limits.
Non‐Enzymatic Reduction of Nitrite by Means of Ascorbic Acid in Citrus and Other Higher Plant Tissues
Authors: Bar‐Akiva A. , Sternbaum J. 
Published: April 2006

AbstractIt has been proved that the nitrite reduction in the leaves and other plant tissues of citrus and other green plants is partly or mainly a non‐enzymatic chemical process, and a heat‐stable factor present in these tissues is responsible for this reduction.It is suggested that ascorbic acid plays a major role in this chemical reaction since the reduction is inhibited by ascorbic acid oxidase. A significant association was also found between the ascorbic acid content and the nitrite reduction capacity of citrus leaves.Evidence has been presented that this non‐enzymatic chemical reduction of nitrite occurs also in vivo as undetached citrus leaves on branches placed in NaNO2 solution have shown diminution of their ascorbic acid content along with the absorption of nitrite. Stronger accumulation of nitrite in these leaf tissues was observed under dark conditions, apparently due to the inhibition of the biosynthesis of the ascorbic acid.
The Effect of Temperature and Light on the Germination of Lettuce Seeds
Authors: Berrie Alex. M. M. 
Published: April 2006

Abstract‘Grand Rapids’ lettuce. seed will not germinate in darkness at 30°. An exposure in temperatures between 5°C and 25°C for a short period after the initiation of germination can effectively overcome the high temperature imposed dormancy. If the exposure to low temperature is from the beginning of germination it is less effective.The low temperature induced germination is not reversed by far red light of 725 nm and seed not responding to the low temperature do respond in a classical fashion to red and far red irradiations.It is considered that the results justify acceptance of the hypothesis that an inhibitor of germination is produced during the initial stages of germination and that this formation is strongly temperature dependent so that there is much accumulation. At low temperatures an alternative metabolic pathway predominates leading to the production of an essential metabolite. At high temperatures this metabolite is produced from the inhibitor (or inert compound) by a mechanism under the control of the phytochrome system.