bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effect of kinetin on the level of an indoleacetylaspartic acid like substance in germinating seeds and young plants of Phaseolus vulgaris
Authors: SALEH ADIRUKMI NOOR , HEMBERG TORSTEN 
Published: April 2006

AbstractKinetin treatment increased the level of an extractable indoleacetyl conjugate, apparently indoleacetylaspartic acid (IAAsp) in germinating seeds and young plants of Phaseolus vulgaris L. cv. Alabaster. The level of this substance in extracts of treated seeds was always higher than that from water treated seeds irrespective of whether the seeds had been extracted 24, 48 or 72 h after the beginning of the treatment. In all parts of young bean plants treated with kinetin there was more of the substance than in the corresponding parts of water treated plants.
Chromosomal proteins of conifers
Authors: PITEL J. A. , DURZAN D. J. 
Published: April 2006

AbstractDuring imbibition and germination of jack pine seeds, the composition of the total extractable chromatin varied. Relative to DNA, the histone levels decreased as the nonhistone chromosomal proteins (NHCP) increased. New chromosomal proteins were synthesized after 2 days of imbibition as judged by recovery of 14C‐amino acids from the major protein fractions. Phosphorylation of histones from 32P‐phosphoric acid was detected before the incorporation of 14C‐amino acids. In the seed the synthesis and relative changes of chromatin coincided with a fall in total soluble protein and free arginine N. By contrast, adenylate energy charge, free glutamine N and in vitro template activity of chromatin increased during chromatin protein synthesis.When seeds had germinated for 4 days after the start of imbibition more radioactivity, derived from free 14C‐amino acids, was recovered from the NHCP than from the histones. The percentage amino acid composition of most histone fractions remained stable, whereas the composition of NHCP changed more with time. The phosphorylation of NHCP was 8‐ to 41‐fold greater than that of the histones. Phosphorylation of histone H4 was not detected at any stage of germination. Correlations between recovery of radioactivity (32P and 14C) from chromosomal proteins and higher adenylate energy charge were positive.
The influence of the extraction procedure on yield of indole‐3‐acetic acid in plant extracts
Authors: HEMBERG TORSTEN , TILLBERG ELISABETH 
Published: April 2006

AbstractDifferent types of plant material, including both dry and swollen maize kernels, swollen bean seeds, bean seedlings and dry rose seeds, were extracted by different methods and the yield of IAA was determined with the indolo‐α‐pyrone method.Extraction of dry maize kernels during short time experiments, varying from 3 to 24 h, gave the highest IAA yield when methanol was the extractant and a significant lower yield when diethyl ether or dichloromethane were used. The duration of the extraction period increased the yield with all the extractants. Progressive extractions for several days or weeks had little effect on the yield when 100% acetone was used in contrast to methanol and ether as extractants, which increased the yield during prolonged extraction. Extractions of tissue treated to 100°C for 1 h contradicted the hypothesis that IAA is enzymatically liberated during ether extraction. Water in the extractant solvents increased the yields. This was most pronounced when aqueous acetone was used instead of 100% acetone. Increased extraction temperature augmented the IAA yields.The yield of IAA from other types of tissue extracted with methanol for periods of 3 or 24 h was, however, independent of the duration of the extraction time. This indicates that some tissues contain less not easily extractable IAA than dry maize kernels. The terms “free” and “bound” IAA are discussed; they should be replaced by “easily extractable” and “not easily extractable” IAA.The results also show that IPyA in vitro can partly be converted to IAA during extraction and fractionation.
Reassociation of cytoplasmic ribosomal subunits of barley and its virescens mutant to form active hybrids
Authors: KOUNDAL KIRPA R. , COHEN ABE S. , ZALIK SAUL 
Published: April 2006

AbstractPolyphenylalamine synthesis by cytoplasmic ribosomes of Gateway barley (Hordeum vulgare) and its virescens single gene nuclear mutant was compared. The cytoplasmic 80S ribosomes were isolated from unimbibed embryo material and the ribosomes were dissociated into their component 60S and 40S subunits by centrifugation through sucrose gradients containing high KCl‐to‐MgCl2 buffer. These separated subunits could be reassociated by resuspension in buffer having about equimolar concentrations of MgCl2 and KCl. Both homologous and heterologous combinations of the subunits reassociated to give monomeric 80S ribosomes, and the derived monomers as well as various combinations of the individual subunits showed equivalent activity in an in vitro system for poly (U)‐directed polyphenylalanine synthesis.
Growth rate and phosphate utilization of some Carex species from a range of oligotrophic to eutrophic swamp habitats
Authors: VEERKAMP MIRJAM T. , CORRÉ WIM J. , ATWELL BRIAN J. , KUIPER PIETER J. C. 
Published: April 2006

AbstractIn a growth experiment at phosphate levels varying between 0,0005 and 0.1 mM phosphate, relative growth rates and other growth parameters were determined in Carex species (C. rostrata Stokes, C. limosa L., C. lasiocarpa Ehrh., C. diandra Schrank, and C. acutiformis Ehrh., listed in order of increasing nutrient availability of their natural habitats). In all species, more efficient utilization of the phosphate was observed with decreasing phosphate levels, together with reduced fresh shoot ratio. In addition, each species shows characteristics which may help it to grow under low phosphate conditions: relatively high phosphate level in the plant (C. rostrata), a low fresh shoot ratio (C. limosa) and regulation of uptake and translocation of phosphate in such a way that relative growth rate during the first two weeks is maintained or even increased for a longer period (C. rostrata, C. limosa, and C. diandra). In the studied Carex species, the contribution of fresh shoot ratio to relative growth rate is much larger than that of net assimilation rate. C. acutiformis, a species of eutrophic areas, had the highest relative growth rate.
Factors affecting 14C‐sucrose uptake by single‐node explants of rose flower stems
Authors: JACOBS GERARD , ZIELIN NAFTALY , HALEVY ABRAHAM H. 
Published: April 2006

AbstractSingle node explants of ‘Baccara’ rose were fed through the basal cut surface with 14C‐sucrose in agar. Accumulation of 14C‐metabolites by buds is a steady process, while a quick uptake occurs in the stem piece during the initial stage of incubation suggesting a passive uptake at this stage. The uppermost 5‐leaflet node buds had an initially higher 14C‐uptake than the lowest bud. This difference disappeared after 2–3 days when growth started in both buds. Light enhanced uptake of 14C‐sucrose by both stem pieces and buds. Accumulation of 14C‐metabolites by buds was in direct relationship to buds deviation from the direction of gravity. This phenomenon was not evident in the stem part of the explant.
Ultrastructure and movements of cell structures in normal pea and an ageotropic mutant
Authors: OLSEN GUNN MARI , IVERSEN TOR‐HENNING 
Published: April 2006

AbstractThe pea mutant (Pisum sativum ageotropum) and the normal pea (P. sativum cv. Sabel) were compared in order to see if there were any differences in root anatomy or submorphology which could explain the presumed ageotropic behaviour of the mutant. In both types the root cap consists of a central core (columella) distinct from the peripheral part. The core contains five to six rows of columella cells, each consisting of 10 to 16 storeys of statocytes. The ultrastructure of the columella cells in the two types is very similar; the main difference is confined to the distribution of rough endoplasmic reticulum (ER), which in the mutant statocytes is evenly distributed throughout the cell, while in the normal pea statocytes it is mainly concentrated in the distal part at the “floor” of the cell.Using light micrographs, the movement of amyloplasts and nuclei have been followed in detail during a 40 min inversion period. The pattern of movement of the amyloplasts is apparently identical in the two types and the distances moved during the inversion period are 39 μm and 44 μm in the normal and mutant statocytes, respectively. The nucleus has not been observed to move in normal pea; a slight rearrangement of the nucleus position can be observed during the period 30 to 40 min after the start of inversion of the mutant.Based on magnified electron micrographs of the statocytes a morphometrical analysis was made of five cell structures – amyloplasts, nuclei, mitochondria, vacuoles and ER – which appeared to be freely movable or redistributable under the influence of the gravitational force.
Growth and zinc accumulation in spinach
Authors: DESMET G. M. , DIRKSE W. G. 
Published: April 2006

AbstractZinc accumulation in spinach (Spinacea oleracea L. cv. Verbeterd Breedblad), especially in the leaves, has been studied in plants grown on nutrient solutions. The extent of accumulation depends on, but is not proportional to the external zinc supply. Zinc uptake by water flow does not account for the concentrations observed in the various plant parts. The relative accumulation rate is related to the relative growth rate, but depends also on leaf position and leaf age.The data suggest that the midribs act as sinks for the nutrient solution, whilst the leaf blades in turn act as sinks for the midribs. We suggest that strong binding of zinc occurs to specific organic compounds in the cell, thus, diminishing the concentration of the free zinc ions in the biological tissue.
15N2 fixation, H2 evolution and C2H2 reduction relationships in Phaseolus vulgaris
Authors: SAITO S. M. T. , MATSUI E. , SALATI E. 
Published: April 2006

AbstractIn a study of N2 fixation in nodules of beans (Phaseolus vulgaris L.) cv. Venezuela‐350 of different ages and kept under controlled light and temperature conditions, three parameters ‐ 15N2 fixation, C2H2 reduction and H2 evolution—were measured.C2H2 reduction was positively related to the N fixed. A standardization of sampling is necessary to keep experimental errors to a minimum. To decrease the variation between replications, the nodules should be carefully incubated (adequate time and temperature), and the samples for chromatography should also be carefully stored. No significant difference was found in C2H2 reduction in the systems studied ‐ nodulated roots, disturbed whole plants and intact plants—during the first hour of measurement.H2 evolution was detected in nodules over 20 days of age and was positively related to N2 fixation and C2H2 reduction. This measurement was essential to account for the equilibrium between the three parameters in the electron balance ratio. Under phytotron conditions, maximum H2 evolution occurred 20–30 days after planting.Nodulated roots from different plants were used to determine the N2 fixed and C2H2 reduction, and on average the ratios C2H2:N2 varied between 7.3 and 8.3 for all ages. In vivo C2H4/(3N2+ H2) electron balance values were over 1, varying from 1.32 to 1.43. These data suggest that overestimation of actual N2 fixation might be occurring when using the C2H2 reduction technique, even if taking account for H2 evolution. In this case, this method should be used with great care to avoid an overestimation of on average 32‐43% of the actual value. Variation was smaller between the measures of the three parameters when younger nodules were used.
Respiratory pathways in aged soybean seeds
Authors: LEOPOLD A. C. , MUSGRAVE MARY E. 
Published: April 2006

AbstractRespiratory activities in soybean seeds (Glvcine max (L.) Merr. cv. Chippewa 64) have been examined in the first minutes after water imbibition and after three hours of imbibition, using either particles or intact axes. Cyanide and azide were utilized as inhibitors of the cytochrome oxidase pathway of respiration, and SHAM inhibitions were interpreted as effects on the alternative pathway, since in unaged axes inhibitions by SHAM were obtained only when respiratory activity had either been restricted with inhibitors of the cytochrome oxidase pathway or expanded by an uncoupler (CCCP). From the experiments with these inhibitors, it is suggested that unaged seeds utilize both respiration pathways in the cotyledon but only the cytochrome pathway in the axis. Accelerated aging causes a marked deterioration of respiration, especially that through the cytochrome pathway, and there is an associated engagement of the alternative pathway in the seed axis. It is suggested that the lowering of respiratory activity and the shift in respiratory pathways may play a major role in the decline of germinability and vigor.
Influence ?une alimentation continue avec une solution glucosée sur ľévolution des glucides et des protéines dans les divers organes de la rose coupée (Rosa hybrida cv. Carina)
Authors: PAULIN ANDRÉ 
Published: April 2006

Abstract Influence of continuous supply with a solution of glucose on the changes in the content of soluble sugars and proteins in various organs of the cut rose (Rosa hybrida cv. Carina).Exogenous glucose continuously supplied to the cut rose is immediately converted into saccharose in the stem tissues. This saccharose migrates to the flower, where it is immediately hyd‐rolysed, and to the leaves where its hydrolysis occurs more slowly. The reducing sugars resulting from the hydrolysis of saccharose in the flower and, therefore, possibly from the hydrolysis of saccharose in leaves, induce a large accumulation of hexoses (glucose and fructose) in the flower. The protein content does not depend on the level of reducing sugars in the flower.
Prevention of auxin‐induced epinasty by α‐aminooxyacetic acid
Authors: AMRHEIN NIKOLAUS , SCHNEEBECK DIRK 
Published: April 2006

AbstractElhylene production and epinastic growth of leaf petioles of tomato (Lycopersicon esculentum Mill. cv. Moneymaker) plants sprayed with 0.1 mM naphthyl‐1‐acetic acid were suppressed when 1 mMα‐aminooxyacetic acid (AOA) was simultaneously sprayed on the plants. AOA had no effect on ethylene evolution and epinastic growth resulting from the application of 5 mM 1‐aminocyclopropane‐1‐carboxylic acid, the immediate precursor of ethylene.
Effects of lithium and potassium on recovery of solute uptake capacity of Acer pseudoplatanus cells after gas‐shock
Authors: THELLIER MICHEL , THOIRON BERNARD , THOIRON ARLETTE , GUIEL JEANNE LE , LÜTTGE ULRICH 
Published: April 2006

AbstractAt concentrations of 10‐−3M, Li+ inhibits the recovery of solute uptake capacity of Acer pseudoplatanus L. cell suspension cultures after gas‐shock (i.e. after rapid exchange of the atmosphere in the culture flasks for ambient air). It also reduces solute uptake capacity of cells having already attained high rates of uptake during recovery from gas‐shock. The effects of Li+ are much greater in cells which have been cultivated in 7 mM K+ solution than in cells cultivated with higher K+ levels (19 mM). Increasing K+ concentration during recovery reverses the effect of 10–3M Li+ and, with sufficiently high concentrations of K+ (≥ 10‐−2M) during recovery, the solute uptake capacity of the fully recovered cells can even become greater than that of the control, at least for the low values of substrate concentration (here sulphate 10‐−5M). Since Li+ does not affect the time course of solute uptake measured over 15–20 min, it is thought that it interacts with the synthesis and turnover of the solute uptake machinery of the Acer pseudoplatanus cells. Thermodynamic analysis of the flux data also supports the hypothesis that Li+ inhibits the biosynthesis of specific sites of solute permeation, but it does not rule out the possibility that K+ interferes rather on the forces acting on the transport of the considered solutes than on the catalytic structures of permeation.
Kinetic analysis of root growth and georeaction
Authors: Baehler William , Pilet Paul‐Emile 
Published: April 2006

The kinetics of growth and georeaction of horizontal or vertical maize (cv. ORLA 264) apical root segments were analysed. Elongation and curvature data were fitted to a mathematical function and the effect of both light and decapitation reported. Elongation of horizontal segments was found to be more sensitive to light than to decapitation. A light treatment or the decapitation presented several effects on the shape of the growth curves. Growth of vertical segments was affected much more by decapitation than by light treatment. The shape of the curves was clearly different for decapitated and intact segments.Curvature is affected both by light and decapitation but the shape of the bending curves is modified principally by decapitation.Under the present conditions used, growth and georeaction of root segments do not seem to be strictly correlated.
Cellular changes during boron‐deficient culture of the diatom Cylindrotheca fusiformis
Authors: Smyth Douglas A. , Dugger W. M. 
Published: April 2006

The effects of boron‐deficient culture were studied on the unicellular diatom. Cylindrotheca fusiformis Reimann and Lewin. After 24 to 30 h, cell division was almost completely inhibited in boron‐deficient cultures. By 48 h of culture, boron‐deficient diatoms had approximately twice the modal cell volume of control cells, and at least twice the amount of organic constituents such as protein (2.0x), insoluble carbohydrate (2.4x), total phenols (2.6x), and chlorophyll at (2.1x). Boron deficiency led to irreversible damage after this time.Dark respiration was 1 nmol O2/min × 106 cells for both control and boron‐deficient diatoms prior to 40 h of culture. By 48 h, the respiratory rate of boron‐deficient diatoms was double that of controls. The proportion of 14C‐glucose metabolized by the pentose phosphate pathway was similar in both control and boron‐deficient diatoms after 24 and 48 h of culture. After 24 h, the in vitro activity of glucose‐6‐phosphate dehydrogenase was similar in both control and boron‐deficient cells, although the pool size of its substrate, glucose‐6‐phosphate, was 26% greater in boron‐deficient cells. The cellular amount of glucose‐6‐phosphate dehydrogenase continued to increase once mitosis was arrested in boron‐deficient diatoms. Boric acid (1 mM) inhibited 6‐phosphogluconate dehydrogenase by 18% in diatom homogenates.During the early stages of boron deficiency, the uptake of silicate, nitrate, and phosphate, and the in vitro activity of β‐glucosidase were similar to control diatoms. After cell division was inhibited, boron‐deficient diatoms accumulated more nitrate and phosphate, and retained a higher level of β‐glucosidase than control cells.
Auxin‐induced changes in the cell wall structure: Changes in the sugar compositions, intrinsic viscosity and molecular weight distributions of matrix polysaccharides of the epicotyl cell wall of Vigna angularis
Authors: Nishitani Kazuhiko , Masuda Yoshio 
Published: April 2006

Rapid effects of indole‐3‐acetic acid (IAA) on the mechanical properties of cell wall, and sugar compositions, intrinsic viscosity and molecular weight distribution of cell wall polysaccharides were investigated with excised epicotyl segments of Vigna angularis Ohwi et Ohashi cv. Takara.

IAA caused cell wall loosening as studied by stress‐relaxation analysis within 15 min after the IAA application.
IAA stimulated the decrease in the content of arabinose and galactose in the hemicellulose 1 h after its application. The amounts of other component sugars in the cell wall polysaccharides remained constant during the IAA‐induced segment growth.
The intrinsic viscocity of the pectin increased as early as 30 min after the IAA application. This effect was not prevented when elongation growth of the segment was osmotically suppressed by 0.15 M mannitol.
Gel permeation chromatography of the pectin on a Sepharose 4 B column demonstrated that IAA caused increase in the mass‐average molecular weight of the pectin. Analysis of the sugar compositions of the pectin eluted from the Sepharose 4 B column indicated that IAA increased the molecular weight of the polysaccharides composed of uronic acid, galactose, rhamnose and arabinose. This effect became apparent within 30 min after the IAA application. Furthermore, IAA increased the molecular weight of the pectin when elongation growth of the epicotyl segments was osmotically suppressed by 0.15 M mannitol.
Hemicellulose of the cell wall chromatographed on a Sepharose CL‐4 B column. Analysis of the neutral sugar compositions and the iodine staining property (specific for xyloglucans) of the polysaccharide solution eluted from the column indicated that the hemicellulose consisted of xyloglucans, arabinogalactans and polysaccharides composed of xylose and/or mannose. IAA caused a decrease in the arabinogalactan content and depolymerization of xyloglucans. These IAA effects became apparent within 30 min after the IAA application. These changes occurred even when elongation growth of the epicotyl segments was osmotically suppressed by 0.15 M mannitol.

Polymerization of the pectin, degradation of arabinogalactans and depolymerization of xyloglucans appear to be involved in the mechanism by which IAA induces cell wall loosening and therefore extension growth of cells.
Root surface phosphatase activity in ecotypes of Aegilops peregrina
Authors: Silberbush Moshe , Shomer‐Ilan Adiva , Waisel Yoav 
Published: April 2006

The relationships between root surface phosphatase activity and the edaphic factors of their native habitats were investigated in four ecotypes of Aegilops peregrina (Hack.) Maire et Weil. In one set of experiments plants were grown in phosphate‐deficient nutrient solution cultures (5 μM) with three pH values: 5.5, 6.5 and 7.5. In a second series, plants were grown in both P‐poor and P‐rich soils.Results showed an optimal activity of the commonly‐described root surface acid phosphatase of pH 4.5–5.0 in the ecotypes Meron (a P‐poor montmorillonitic, typical mediterranean Terra‐Rossa soil) and Har‐Hurshan (a P‐rich calcareous soil). However, in the ecotypes Malkiya (a P‐rich kaolinitic Terra‐Rossa) and Bet‐Guvrin (a P‐rich calcareous soil) the optimal activity of the phosphatase occurred at pH 6.0. The pH level of the growth solution had no effect on the pH of optimal activity of the phosphatase in the ecotypes Malkiya and Bet‐Guvrin, but it somewhat affected their level of activity.Phosphatase activity was stimulated when plant roots were grown in a P‐poor soil, as compared to the activity of those which were grown in a P‐rich soil. Plants of the Malkiya ecotype exhibited the strongest activation of phosphatase as compared to the other three ecotypes. It seems that ecotypes which have evolved in P‐rich soils may regulate their root surface phosphatase activity better than those which have evolved in P‐poor soils.