bluuebunny/crossref_metadata_2025_split huggingface dataset:
Use of Fluorescent Brighteners to Visualise the Sites of Cellulose Synthesis in the Root Hairs of Species of Peperomia
Authors: TAMPION J. , McKENDRICK M. E. , HOLT G. 
Published: April 2006

AbstractBranched and unbranched root hairs of Peperomia fraseri and P. blanda were examined by bright field transmission and fluorescence microscopy in the presence of the optical brightener Photine HV. Many highly fluorescent bands and spots were detected along the length of the root hairs, in addition to those in the expected site of tip growth at the apex of the hairs.
Growth, Sex Expression and Yield of Squash Melon (Citrullus vulgarisvar. fistulosus) as Influenced by 2(chloroethyl)phosphonic acid, 2,3,5‐tri‐iodobenzoic acid and (2‐chloroethyl) trimethyl‐ammonium chloride
Authors: SAIMBHI M. S. , THAKUR M. R. 
Published: April 2006

AbstractSingle aqueous sprays of 2(chloroethyl)phosphonic acid (CEPA) 250, 500 and 1000 mg/1; 2,3,5‐triiodobenzoic acid (TIBA) 25, 50 and 100 mg/1; and (2‐chloroethyl) trimethyl‐ammonium chloride (CCC) 250, 500 and 1000 mg/1 were applied to squash melon (Citrullus vulgaris Schrad. var. fistu‐losus Stocks.) at the 2–3 leaf stage. Though the final length of the main axis and number of lateral branches were not affected by any treatment, CEPA retarded growth of young plants by reducing the internodal length. It did not change the flowering pattern but delayed flowering and reduced the production of both pistillate and staminate flowers. However, it increased the per cent femaleness as a result of comparatively more suppression of staminate flowers. The TIBA 25 and 50 mg/1 and CCC 500 mg/1 did not affect the staminate flower production but increased the pistillate flowers, which increased the per cent femaleness. The CEPA decreased while both TIBA 25 and 50 mg/1, and CCC 500 mg/1 increased the number of fruits per plant and the yield. The mode of action of the chemicals has been discussed.
Cytokinins in Populus×robusta: Changes during Chilling and Bud Burst
Authors: HEWETT E. W. , WAREING P. F. 
Published: April 2006

AbstractCytokinin levels in sap and vegetative buds of Populus×robusta Schneid have been determined during chilling and bud burst. From non‐detectable levels in December and January, parallel increases in cytokinin levels occur in sap and buds during February and March, both in material from the field and that held at 2°C in the dark. The maximum in the sap occurs two weeks prior to natural bud burst, and 3 weeks, prior to the maximum attained in the buds. Excised twigs, forced to bud burst, show a similar pattern. The role of roots as a possible source of cytokinins is discussed.Partition chromatography on Sephadex LH‐20 indicates that at least 5 cytokinins are present in buds, two of which have similar elution volumes to zeatin and zeatin riboside‐The main activity in the sap is confined to a zeatin riboside‐like component.
Ozone Induced Carbon Dioxide Evolution in Tobacco Callus Cultures
Authors: ANDERSON WILBUR C. , TAYLOR O. C. 
Published: April 2006

AbstractCallus derived from Bel–W3 and Bel–B tobacco plants when exposed to ozone turned brown as a consequence of surface cell destruction. Ozone fumigations above a threshold concentration of 0.10 μl/1 for two hoars caused an increase in the rate of tissue carbon dioxide (CO2) evolution. The maximum increase in CO2 evolution was about 65 percent for both the ozone sensitive Bel–W3 and resistant Bel–B callus. However, the ozone dosage required to attain maximum increase in CO2 evolution was approximately two times greater for the resistant variety. Callus cultures that grew roots were observed to be more resistant to ozone. The addition of the antioxidant N,N'dipnenyl–p–phenylenediamine (DPPD) m the nutrient medium retarded ozone induced CO2 evolution.
Endogenous Levels of Growth Regulators and Their Relationship to the Rooting of Dahlia Cuttings
Authors: BIKAN I. , HALEVY A. H. 
Published: April 2006

AbstractThe relationship between the level of endogenous growth regulators and the rooting ability of dahlia cuttings was investigated. Easy‐to‐root vegetative cuttings were compared with difficult‐to‐root, flower bud bearing cuttings and the easy‐to‐root cv. Choot Hashani was compared with the difficnlt‐to‐root cv. Orpheo. No differences in the level of extracted or diffusable auxin, nor in the level of rooting cofactors, were found between easy‐to‐root and difficult‐to‐root cuttings. No activity could be found at the Rf zone corresponding to Cofactor 4 which is considered the main rooting cofactor in other plants. Higher inhibitor activity levels (assayed by the wheat coleoptile test and the mung bean rooting test) were found in difficult‐to‐root than in easily rooted cuttings. Furthermore, the inhibitor activity level in exadates from decapitated plants, was higher in esodates from plants which bore difficult‐to‐root cuttings than from plants bearing easy‐to‐root ones. Grafting of an easy‐to‐root plant onto a difficult‐to‐root stock caused inhibition of rooting in the cuttings taken from the scion. Results suggest that inhibitors formed in the root system, move upwards and accumulate in the plant, there causing the inhibition of rooting. Evidence from chromatographic comparisons and exogenous treatments with ABA indicate that the main inhibitor involved in the inhibition of rooting in dahlia cuttings is not ABA.
The Intra‐cellular Localization of the Herbicide Diphenamid in Corn Root .Tip
Authors: YAKLICH R. W. , SCOTT E. G. 
Published: April 2006

AbstractThe intra‐cellalar localization of the herbicide N,N‐dimethyl–2,2‐diphenylacetamide (diphenamid) was examined in 10 mm root tips of corn seedlings (Zea mays L. cv. Shawnee). Experiments are described which culminate in the observation that a significant, measurable effect on root growth occurs within 12 hours after treatment with diphenamid. Corn seedlings were then treated with 14‐C‐diphenamid for 12 hours and the 10 mm root tips excised and homogenized. By use of differential centrifugation and gel filtration, the root homogenate was separated into fractions; as follows; cell wall, mitochondria, microsomal, protein and eluate. The highest concentration of the herbicide was found in the root tips. Furthermore, most of the radioactivity was found in the eluate. Results are discussed as to localization of diphenamid in the microsomal and protein fraction and possible mode of action.
Hormonal Control of Differentiation of Shoots, Roots and Embryos in Leaf and Stem Cultures of Petunia inflata and Petunia hybrida
Authors: RAO P. S. , HANDRO W. , HARADA H. 
Published: April 2006

AbstractFactors influencing adventitious bud and root development, callus induction and embryogenesis were investigated in stem and leaf cultures of Petunia inflata R. E. Fries and Petunia hybrida cv. Cascade and cv. Rose du ciel grown on a synthetic nutrient medium. Indoleacetic acid caused limited callus development and root formation whereas naphthaleneacetic acid Induced abundant roots. 2,4‐Dichlorophenoxyacetic acid promoted callus growth and differentiation of embryos which eventually developed into plantlets. Cytokinins such as benzyladenine, zeatin and kinetin induced bud development. A combination of auxins and cytokinins caused an interaction which was manifested in altered morphogenetic response. Thus 2,4‐dichlorophenoxyacetic acid in conjunction with benzyladenine caused suppression of bud development and retarded differentiation of embryos. Likewise, when benzyladenine was used with indoleacetic acid root development was totally inhibited and abundant buds were produced.
The Relationship between Chlorophyllide Accumulation, the Amount of Protochlorophyllide636 and Protochlorophyllide650 in Dark Grown Wheat Leaves Treated with δ‐Aminolevulinic Acid
Authors: SUNDQVIST CHRISTER 
Published: April 2006

AbstractThe influence of different amounts of protochlorophyl‐lide636 and protochlorophyllide350 on light Induced chloro‐phyllide formation was. studied in wheat leaves treated with δ‐aminolevulinic acid. The phototransformation of proto‐chlorophyllide was performed with weak red light. This transformation is unaffected by the δ‐aminolevulinic acid treatment, whilst the accumulation of chlorophyllide, both the rate and the amount, is greatly stimulated by moderate amounts of protochlorophyllide636. The presence of large amounts of protochlorophyllide636 decreases the rate of chlorophyllide formation, but increases the final amount of chloro‐phyllide formed. A decreased level of protochlorophyllide650, obtained by treatment with NaN3, results in a decreased transformation rate. Inhibitors; of protein synthesis do not seem to influence the transformation of protochlorophyllide636 to chlorophyllide, suggesting that no new synthesis of protein is required. The experimental results indicate that the final steps in chlorophyll biosynthesis are protochlorpnyllide636→ protochlorophyllide650→ chlorophyllide → chlorophyll.
Rapid Changes in Abscisic Acid‐like Inhibitors Following Alterations in Vine Leaf Water Potential
Authors: LOVEYS B. R. , CSIRO P. E. KRIEDEMANNI 
Published: April 2006

AbstractEndogenous levels of abscisic acid‐like inhibitors doubled within 15 minutes of leaf excision in Vitis vinifera under laboratory conditions. At that stage water potential Ψ had fallen to ‐15 bars and stomatal closure was occurring. After prolonged stress (6 days and final Ψ ‐13 bars) inhibitor levels in intact vine leaves increased by a factor of 44 but showed a rapid decline following rewatering. Photosynthetic activity was not immediately restored, and its gradual recovery was not directly related to inhibitor level.
Diffusible and Extractable Gibberellins in Bean Cotyledons in Relation to Dwarfisni
Authors: GOTO N. , ESASHI Y. 
Published: April 2006

AbstractDwarfism in bean plants (Phaseolus vulgaris L.) is investigated in relation to the diffusible and extractable gibberel‐lins in cotyledonary tissues. These gibberellins were partitioned into four parts prior to thin layer chromatograplty: non‐acidic and acidic ethyl acetate fractions, and non‐acidic and acidic butanol fractions.Cotyledonary segments from a tall plant (cv. Kentucky Wonder) seem to diffuse, preferentially acropetally, more gibberellins in each fraction than those from a dwarf plant (cv. Masterpiece). The diffusion increases with the length of the segments and decreases with period after sowing. From experiments on extraetable gibberellins, however, it is concluded that these phenomena actually result from differences in the gibbereliin contents of the tall and the dwarf plants, from differences in the gibberellin contents of the distal and proximal parts of cotyledons, and from the gibberellin contents before and after imbibition.Ten kinds of gibberellin‐Iike substances are detectable in the diffusates, exudates and extracts from the cotyledons of both the plants; two in the non‐acidic ethyl acetate, three in the acidic ethyl acetate (GA1, GA6 and another), two in the non‐acidic butanol, and three in the acidic butanol frac—tion. They are almost identical in quality in the dwarf and tall plants, but in the latter they are more abundant in the cotyledons, particularly in their distal part.With respect to the change in content during the period after sowing, the gibberellin‐Iike substances are classified in three groups; unchanging, decreasing (GA1, GA6, others) and increasing (butanol soluble glucosyl esters and glucosides of gibberellins)‐. The increase of glucose‐bound gibberellins and the decrease of free gibberellins during the sowing period suggest the occurrence of conversion. This is obvious only in the tall plants. The gibberellin content in cotyledons is higher in the tall plant than in the dwarf plant. Thus, the marked hypocotyl growth in the tall plants may be dependent on the higher content of gibberellins in their cotyledons and on the higner rate of conversion from free to bound forms.
Short‐ and Long‐term Effects of High Temperatures (47–49 °C) on Tobacco Leaves, in. Efflux and 32P Incorporation into Phospholipids
Authors: BENZIONI ALIZA , ITAI CHANAN 
Published: April 2006

AbstractThe efflux of 36C and 14C metabolites from heat‐treated tissue was studied. A two‐minute heat treatment at 47.5°C increased the leakiness of the membranes. The heat effect may be reversed either by treatment with kinetin or may occur spontaneously with time. The spontaneous reversal is tem—perature dependent and resembles the recovery of CO2 fixa—tion after heat treatment. The loss of membrane integrity is reflected in the rate of incorporation of 32P into phospho—lipids.
Changes in Endogenous Growth Kegulators in Loblolly Pine Seeds During the Process of Stratification and Germination
Authors: PAUL K. B. , PATEL C. S. , BISWAS P. K. 
Published: April 2006

AbstractThe seeds of loblolly pine (Pirns taeda L.) were cold‐stratified for 0, 14, 28, 42, and 56 days. Endogenous growth regulators were extracted from these seeds, and also from the germinating and the 28‐day warm stratified seeds. Partially purified extracts were separated on chromatographic paper. The chromatograms were cut into 10 equal segments, and these were tested for biological activity using three different btoassays.The results indicated that the unstratified seeds and those stratified up to a period of 28 days contained very little or no growth promoter (GA‐like substances), and a relatively high concentration of an inhibitor (presumably abscisic acid), Following 42‐day stratification, the promoter concentration gradually increased while the inhibitor level fell almost to zero. A high level of promoter but no inhibitor was detected in germinating seeds.No auxin‐like activity was noted in the unstratified seeds. This activity slowly increased up to a period of 28 days and remained at this level for the subsequent stratification periods. However, the activity greatly increased in the germinating seeds.Very little changes in the levels of growth regulators were noted in warm‐stratified seeds as compared to the unstrati‐fied controls.
The After‐effect of Wind on the Photosynthesis and Transpiration of Festuca arundinacea
Authors: GRACE J. , THOMPSON J. R. 
Published: April 2006

AbstractThe after‐effect of wind on photosynthesis and transpiration of Festuca arundinacea Schreb, was determined. Following a period of exposure In a controlled environment wind tunnel the wind‐treated plants showed reduced rates of photosynthesis when compared with the controls under standard conditions. Evaporation from paper model tillers was measured and the boundary layer resistance was shown to be low in all but very low wind speeds. Analysis of CO2 and H2O diffusion pathways indicated that mesophyll resistance in wind‐treated plants was higher whilst leaf surface resistance was lower than in the controls. The high mesophyll resistance in the wind‐treated plants was attributed to reduced water content.
In Vivo Measurements of the Photo‐Oxidation of Chlorophyll Pigments in Dark Grown Wheat Leaves after Treatment with δ‐Aminolevulinic Acid
Authors: AXELSSON LENNART 
Published: April 2006

AbstractDark‐grown leaves of wheat fed with δ‐aminolevulinic acid accumulate protochlorophyllide636 in excess. After the leaves had been illuminated with high intensity red light (154 W × m−2) for half a minute, a treatment which blocks the phototrans‐formation protochlorophyllide chlorophyllide, the sensitivity of chlorophyllide and protochlorophyllide to light was examined.The decrease in pigment content, caused by photo‐oxidation was found to be very close to a second order reaction. The second order “rate constant” for decrease in absorbance was found to be eight times greater for the formed chlorophyllide than for protochlorophyllide. The light intensity dependence of the decomposition was found to be linear within the intensity range used (E= 25 – 154 W × m−2). In samples in which the pigments had been heat denatured, it was possible to photodecompose the chlorophyllide without affecting the protochlorophyllide.The results are discussed in connection with the theory of a photodynamic action involving oxygen in the singlet state (1ΔO2).
Carbonic Anhydrase Activity and Localization in Some Plant Species
Authors: TRIOLO L. , BAGNARA D. , ANSELMI L. , BASSANELLI C. 
Published: April 2006

AbstractThe aim of this work concerned the study of the differences in the carbonic anhydrase activity and localization between plant species, the photosynthesis of which is carried out according to the C3 and C4 pathways respectively.The measurement of enzymatic activity was made with a titrimetric evaluation of the rate of the reaction CO2+ H2O ⇆ H++ HCO−3. The C3 plant species showed higher activities than the C4 species.The localization of carbonic anhydrase was carried out with a histochemical method.The carbonic anhydrase appeared in the chloroplasts both in the mesophyll and the bundle sheath without any difference between C3 and C4 plants.
Water Content and the Responsivity of Lettuce Seeds to Light
Authors: BERRIE ALEX. M. M. , PATERSON J. , WEST H. R. 
Published: April 2006

AbstractLettuce seed (Lactuca sativa L. cv. Grand Rapids) prevented from attaining maximum water content are still able to respond to irradiation if the seed moisture content is above 6%. When the limitation to water uptake is by immersion in a solution of either polyethylene glycol 400 (PEG 400), mannitol, or sucrose, the responsiveness of the seed is lessened.With PEG 400 the molarity which reduces germination by about 50% is 0.03 while mannitol and sucrose must be present at 0.07M and 0.05 M respectively to bring about the same reduction.While red light overcomes any additional effect 0.1 M mannitol and 0.025 M PEG 400 have on lettuce seed at 30°C (at which temperature the sample was positively photoblastic), irradiation did not overcome the effect of 0.1 M sucrose. Gibberellic acid did not have any effect on any of the treated seed.The solutes used cannot be considered as inert. Some chemical activity is associated with them and it is unwise to consider using these molecules to establish a particular level of water potential in the liquid bathing the seed.
Rooting and the Metabolism of Nicotine in Tobacco Callus Cultures
Authors: PETERS J. E. , WU P. H. L. , SHARP W. R. , PADDOCK E. F. 
Published: April 2006

AbstractThe usefulness of exogenous nicotine as a factor in the induction of morphogenesis in a tobacco tissue culture medium has been demonstrated. Nicotiana rustica callus cell cultures were grown on a modified Murashige and Skoog medium with 2 mg/l indoleacetic acid (IAA) and 0.2 mg/l kinetin (MMS). Root morphogenesis was induced in roller tube callus cell cultures and solid callus cell cultures grown on MMS without kinetin supplemented with 10–100 mg/l nicotine.Optimal nicotine concentration for root induction was 50 mg/l. Other tests using varying combinations of IAA, kinetin and nicotine produced no obvious morphogenesis, although some changes in the amount of callus growth and endogenous protein concentration did correlate with nicotine concentration relative to the presence of IAA and/or kinetin.In liquid MMS medium, 14C‐nicotine was primarily incorporated into the protein fraction of cultured cells while primarily incorporated into the cell wall and/or cell membrane fraction of cells cultured on MMS without kinetin in the medium. In MMS without IAA and MMS without both IAA and kinetin, there was incorporation, but to a lesser extent in both the protein and the cell wall and/or cell membrane fractions.
Oscillatory Transpiration and Water Uptake of Avena Plants
Authors: BROGÅRDH T. , JOHNSSON A. 
Published: April 2006

AbstractThe action of D2O on oscillatory transpiration of Avena plants was investigated. D2O affects the amplitude and the period of the oscillations when given as a root medium to intact plants. The period is then dependent on the amplitude. From such experiments it is not possible to conclude whether the period change is simply due to the changed amplitude or to a change in the stomatal parameters.When given to xylem compressed, excised plants without roots, the D2O hardly affects the amplitude of the oscillations but the period is increased. Thus, the period of the self‐sustained transpiratory oscillations is lengthened by D2O action on the stomatal parameters.Phase and amplitude changes of the oscillatory transpiration caused by short D2O pulses given both to intact and excised plants, are discussed.The following conclusion is emphasized: a substance which affects the root system can also cause profound changes in the stomatal water regulation.
A Broad Spectrum Tissue Culture Experiment with Tobacco (Nicotiana tabacum) Pith Tissue Callus
Authors: de FOSSARD R. A. , MYINT AUNG , LEE EDWARD C. M. 
Published: April 2006

AbstractThe composition and rationale of a broad spectrum tissue culture experiment involving 81 different media are described. Tobacco calluses sub‐cultured on media in this experiment were induced to form six main types of callus depending on the concentration levels of minerals, auxins, cytokinins, and sucrose, growth factors and amino acids in the medium. Only nine of the 81 media inhibited callus growth, and growth (increase in mass divided by initial mass of fresh matter) varied considerably reaching a maximum of nearly 200 after eight weeks on a medium high in minerals, cytokinins, sucrose, growth factors and amino acids and low in auxins. Five media induced regeneration from the calluses. This experiment is suggested as a potentially fruitful introductory test for many new or unresolved tissue culture situations.
Growth and Dormancy in Norway Spruce Ecotypes
Authors: HEIDE OLA M. 
Published: April 2006

AbstractHeight and radial growth of spruce in years n+ 1, n+ 2, and n+ 3 as affected by photoperiod and temperature in year n have been studied in controlled environments and in the field.In agreement with common opinion apical shoot growth in year n+ 1 was strongly dependent on the temperature conditions prevailing in the period following budset in year n. This was found mainly to be a direct effect upon the differentiation of the shoot and needle primordia for next year's growth. A similar, although less pronounced effect, was found also on radial growth, possibly an indirect effect elicited through the effect on apical growth.A rather wide temperature optimum of 18 to 24°C was found in three Norwegian ecotypes and a somewhat lower optimum (15 to 18 C) in an Austrian high altitude ecotype. The shorter the bud differentiation period, the higher was the temperature optimum in all ecotypes (heat sum effect). Photoperiod which is the main factor controlling the time of budset, thus had a great after‐effect.The after‐effect was strongly modified by photoperiod and to a lesser extent also by temperature in the current growing season. It is concluded that in second‐year or older spruce plants the important effect of photoperiod in the current growing season is to control quantitatively and qualitatively the amount of secondary (lammas) shoot formation, and to modify shoot extension in the main growth flush. Longer photoperiods were needed for continuation or resumption of growth in second‐year plants than for maintenance of uninterrupted growth in first‐year seedlings.Delayed flushing was observed in plants maturing at high temperatures, indicating that these plants had entered a deeper state of dormancy than those maturing at lower temperatures.Also in years n+ 2 and n+ 3 apical and radical growth was significantly related to photoperiod and temperature conditions in year n. This effect gradually became an indirect one through the effects on general plant size (leaf and root area).The results are discussed in the light of previous work in the field.
Guaiacyl Lignin Associated with Vessels in Aspen Callus Cultures
Authors: WOLTER KARL E. , HARKIN JOHN M. , KIRK T. KENT 
Published: April 2006

AbstractLignin from aspen (Populus tremuloides Michx.) tissue cultures containing only mature vessels and undifferentiated parenchymatous cells is exclusively of the guaiacyl type normally associated with gymnosperms. This supports the theory that the guaiacyl and syringyl lignin in angiosperm wood is compartmentalized, with guaiacyl lignin in vessels and syringyl lignin in fibers and ray cells.