bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Effect of a Non‐ionic Detergent on Some Plant Cells
Authors: Haapala Eva 
Published: April 2006

AbstractThe effects of a non‐ionic detergent. Triton × 100, on protoplasmic streaming in some plant cells, on plasmolysis, and on leakage of solutes from beet cells were investigated. The results of the different tests showed some features in common: (1) There is a critical range between 0.007 and 0.01 % v/v. (2) Above this concentration of the surfactant, that is at a concentration close to 0.01 %, the effect is manifested in the following ways. Plasmolysis with sucrose is anomalous or impossible. Protoplasmic streaming ceases within a short time. Definite leakage of ions and sugars starts from beet tissues. (3) At concentrations lower than 0.01 to 0.007 % there is enhanced retention of solutes in beet disks. — It is thought that the critical micelle concentration is of paramount importance. The micelle effect may consist in solubilizing or in forming mixed micelles or a complex with the globular lipoprotein units of the outermost plasma layer, the plasmalemma. The effect of the lower Triton concentrations is discussed.
Interaction of Epiphytic Bacteria and Activated Carbon on Root Growth
Authors: Burström H. G. , Persson P. I. , Stjernquist Ingrid 
Published: April 2006

AbstractThe influence of activated carbon and aseptic conditions has been studied on the growth of the primary root of wheat seedlings in order to ascertain whether or not the growth effect of activated carbon is connected with the occurrence of epiphytic bacteria. Growth was measured as mitotic activity, rate of cell elongation and duration of cell elongation. The surface infection of the septic roots probably consisted of common airborn and waterborn bacteria. Aseptic conditions increased the rate of cell elongation by ca 70 % but had no effect on the meristem activity. Activated carbon increased mitoses in the meristem and slightly augmented the duration of cell elongation but had no effect on the rate of elongation. The effects of sepsis and carbon were independent and appeared additative. Activated carbon removed inhibitors produced by the root tip itself but not those formed by the bacteria. In these experiments neither group of inhibitors seemed to contain IAA‐like substances.
Kinetics of Nicotinamide Adenine Dinucleotides during Dark‐Light Transients in Chlorella
Authors: Green W. G. E. , Israelstam G. F. 
Published: April 2006

AbstractNicotinamide adenine dinucleotides were extracted and assayed at frequent intervals for 30 seconds prior to and 60 seconds immediately following illumination of Chlorella cells. For these experiments a special illumination vessel was designed which dispensed 1 ml aliquots of algae with no dead volume. —White incandescent illumination of aerated Chlorella caused an immediate oxidation of its pyridine nucleotides. Under similar conditions blue light caused an initial reduction of these coenzymes. — White illumination of the alga perfused with CO2‐free air caused a transitory reduction of the pyridine nucleotide followed by an oxidation and a second reduction, Blue light, under similar conditions caused an immediate reduction but no oxidation as seen with white light. — When suspensions were perfused with N2, illumination produced a prompt and rapid oxidation of NADH. The extent of this oxidation was greater in white than in blue light. Under these conditions NADP+ was initially reduced and subsequently, temporarily oxidised. — The evidence offers some support for Lundegårdh's theory that blue light is more effective than red light in the photo‐reduction of NADP+. The results are discussed with referemce to the demonstrated in vitro reduction of nicotinamide adenine dinucleotides by chloroplasts and the conflicting reports from in vivo kinetic studies of living photosynthetic organisms. A scheme is proposed to explain the nicotinamide adenine dinucleotide kinetics as observed in these experiments.
Ribonuclease Activity and Auxin Effects in the Lens Root
Authors: Pilet P. E. , Braun R. 
Published: April 2006

AbstractIn Lens root tips, a direct proportionality between RNA and auxin levels and inverse proportionality between RNA content and RNase activity were found. IAA treatment of the Lens seedlings causes, in the root, both an increase of RNA and auxin content and a decrease of RNase activity. Addition of IAA to the excised roots produces an inhibition of both the decrease of the RNA levels and an inhibition of the increase of the RNase activity. The action of IAA on growth, related to the control of the RNA metabolism is discussed.
The Effect of Age and Chilling Temperature on the Concentration of Scopolin and Caffeoylquinic Acids in Tobacco
Authors: Koeppe D. E. , Rohrbaugh L. M. , Rice E. L. , Wender S. H. 
Published: April 2006

AbstractThrough the use of paper chromatographic separation, and fluorometric and spectrophotometric analysis, three caffeoylquinic acid isomers and scopolin have been quantilaed in tobacco as a function of age and chilling temperature. Coldchilled plants exhibited nitrate deficiency symptoms and 4‐5 fold increases over control plants in chlorogenic acid (CGA) concentration in all plant sections except the roots. Varying lesser increases in neochlorogenic acid, “Band 510”, and scopolin concentration were also observed in the above ground sections of chilled plants. Roots of cold‐chilled plants contained lesser concentrations of CGA and scopolin than control plants after 15 days of treatment. Leaves from the same control plant were found to decrease in CGA, Band 510 and scopolin concentration with age, while neochlorogenic acid concentrations changed little. In stem sections CGA concentration also decreased basipetally while the concentrations of scopolin increased. Similar leaf age studies done with cold‐chilled plants revealed phenolic concentration changes comparable to those of control plants, even though their concentrations were appreciably higher.
A Cellulase in Hevea Latex
Authors: Sheldrake A. R. , Moir G. F. J. 
Published: April 2006

AbstractUsing a viscometric method the latex of Hevea brasiliensis was found to contain a highly active cellulase capable of hydrolysing carboxymethyl cellulose. The enzyme has a pH optimum of around 6.3. It is present in the serum of the latex and is not membrane‐bound to any significant extent. Similar cellulase activities were detected in latex from old and new latex vessel rings and also in latex from regularly tapped vessels and newly tapped vessels. The possible role of the enzyme in the removal of cell wall material during the differentiation of latex vessels is discussed.
Pathways of IAA Production from Tryptophan by Plants and by Their Epiphytic Bacteria: A Comparison
Authors: Libbert Eike , Schröuder Roswitha , Drawert Anneliese , Fischer Elfriede 
Published: April 2006

AbstractMetabolites of indoleacetaldehyde (IAAld), indoleethnol (tryptophol, IAAoI), tryptamine (TNH2) and indoleacetamide (IAAm) were investigated using 2 systems; a baeterial (Pea stem homogenates containing the epiphytic bacteria) and a plant system (pea stem sections under sterile conditions). In both systems, indoleacetic acid (IAA), IAAol and indolecarboxylic acid (ICA) are produced from IAAld, and IAA and ICA are produced from IAAol (production of IAAld and ICAld not investigated). In the plant system TNH2 is converted to IAAld,IAA, IAAol and little ICA and ICAld. In the bacterial system TNH2 is converted to IAA, IAAol, the unknown substance Xb, and many ICA and ICAld. Xb is produced from IAAm, too. A nonacidie inhibitor extract from pea stems reduces the IAA gain from IAAld, IAAol and TNH2, and the IAAol and IAAld gain from TNH2; in the bacterial system it increases the IAAol gain from IAAld and the Xb gain from TNH2 and IAAm. Metabolic routes connecting Try, TNH2 and IAA are constructed for the plant tissue and for the epiphytic bacteria, respectively, including 4 sites of inhibitor action.
Studies on Protein Synthesis by Senescing and Kinetin‐treated Barley Leaves
Authors: Atkin R. K. , Sahai Srivastava B. I. 
Published: April 2006

AbstractUsing sterile conditions, changes in total protein synthesis were followed. over an 8 day incubation period, in detached first seedling leaves of barley from 8 day old plants during senescence and after kinetin treatment. In senescing leaves, total 14C‐alanine incorporation was enhanced by nearly 20% within 6 h of leaf detachment and by about 30 % after 24 h. Kinetin treatment stimulated protein synthesis even more, for total incorporation was promoted ca. 50 % after 6 h and by ca. 60 % after 24 h incubation. The leaf supernatant (30,000 ×g for 30 min) proteins were separated on DEAE‐Sephadex (A‐50) columns into approximately 14 fractions and changes in 14C labelling of these fractions were studied following leaf detachment and on incubation on water or kinetin for 6 days. In senescing leaves, 14C‐incorporation into supernatant proteins was sustained, even as protein levels declined rapidly The varied stabilities of the different leaf proteins was suggested by the characteristically changing specific activities of the different protein fractions. Although kinetin greatly promoted incorporation into all protein fractions, no evidence was surmised of specific effects on individual leaf proteins.Studies of changes in total protein synthesis in attached senescing first seedling leaves taken from plants aged 7 to 27 days revealed a relatively small increase in 14C‐incorporation. However, incorporation could be greatly increased in leaves up to 15 days old by detaching and preincubating such leaves for up to 2 days on water, prior to measurement. The promotion of 14C‐incorporation into protcins follwing leaf excision could result from early changes in permeability and precursor pool size.
Fixation of CO2 and Export of Photosynthate by the Carpel in Pisum sativum
Authors: Lovell Peter H. , Lovell Patricia J. 
Published: April 2006

AbstractPods of Pisum sativum cv. Meteor were supplied with 14CO2 and the fixation and distribution of the radiocarbon studied. A high fixation rate was found in all of the treated pods. In intact control plants about 60 per cent of the total radiocarbon fixed was exported from the carpet into the seeds of the treated pod in the 24 hour period following fixation. Almost all of the remainder was relained in the carpel itself. It was found that the seeds in the treated pod were the major sink for these fixation products and that the weight of the seed determined the level of import of radiocarbon from the carpel in both attached and detached pods. Removal of the seeds from the treated pod prior to 14CO2 treatment reduced export from the fed carpel from 60 to 15 per cent, this being distributed mainly in the other pods and stem fractions. It appears that carpet photosynthate is likely to be of great importance in the growth and development of seeds enclosed by the carpel. control of fixation and export of radiocarbon seemed to be a function of the carpel and the seeds enclosed by the carpel and to be relatively independent of the rest of the plant. This could explain the absence of effect of GA on these processes.
Synthèse des RNA au cours de la germination du radis
Authors: Julien R. , Grellet F. , Guitton Y. 
Published: April 2006

AbstractRNA synthesis in radish is studied during the first stages of germination. The radish seeds allowed to germinate in the dark, on distilled water, synthesize ribosomal RNA and accumulate a particular RNA, not incorporated in ribosomes. The results of 32P incorporation in RNA of radish seedlings indicate a progressive formation of ribosomal RNA. Two species of rapidly labelled RNA are synthesized. With labelling time, their chromatographic behaviour on MAK columus evolves, while their electrophoretic characteristics remain stable. It is assumed that these two species are involved in ribosome formation. In vivo experiments with chloramphenicol support this conclusion. RNA which accumulates during germination, could be a particular type of ribosomal RNA which could be enable, under the definite culture conditions, to enter into ribosomal structures.
Interaction entre Basidiomycètes mycorrhizateurs et racines de pin en presence d'acide indol‐3yl‐acetique
Authors: André Fortin J. 
Published: April 2006

Résumé Interaction between mycorrhizal Basidiomycetes and pine roots in presence of indol‐3yl‐acetic acid. — La croissance de deux Basidomycètes mycorrhizateurs, Suillus variegatus (Sw. ex Fr.) et S. granulatus (L. ex Fr.) O. Kuntze a été rendue possible dans un milieu contenant au départ des quantités d'acide indol‐3yl‐acétique (AIA) inhibitrices pour ces champignons. Pour obtenir ce résultat, il a suffi d'ajouter au miliceu, des racines isolées et vivantes de pin (Pinus sylvestris L. et P. resinosa Ait.).Plus la quantité d'AIA ajoutée au départ était grande, plus il fallait de racines pour renverser l'inhibition. L'exsudat des racines n'a produit aucun effet comparable.Des mesures effectuées sur une solution d'IAI ont montré que les racines isolées de pin peuvent accumuler rapidement cette substance. Le taux d'accumulation est maximum aux valeurs de pH inférieures à 4.0 et devient très faible au voisinage de la neutralité.L'auteur formule l'hypothèse qu'au cours de la formation des mycorrhizes ectotrophes chez le pin, la racine en accumulant l'AIA favorise la croissance du champignon en prévenant l'auto‐inhibition de son mycélium par l'AIA qu'il produit.
Effects of 6N‐Benzyladenine on Primary Leaves of Intact Bean Plants and on their Sodium Absorption Capacity
Authors: Jacoby B. , Dagan J. 
Published: April 2006

AbstractThe application of 6N‐benzyladenine (BA) to primary bean‐leaves attached to the intact plant resulted in increased leaf area. This was due to an extension of the duration of the period of leaf expansion.The dry‐weight percentage of untreated leaves decreased continuously from emergence to abscission. In BA treated leaves this decrease stopped with the cessation of leaf expansion. Net chlorophyll synthesis occurs in untreated leaves as long as they continue to expand, shortly afterwards net chlorophyll decomposition starts. Benzyladenine treatments diminished the rate of chlorophyll synthesis immediately after its first application, but prevented the loss of chlorophyll afterwards. The abscission of primary leaves was also delayed by BA.During the period of rapid leaf expansion in slices cut from BA treated leaves, sodium absorption rates were lower than in those from untreated leaves. From the age of 14 days after sowing, till abscission time of untreated primary leaves, the BA treatment did not significantly affect sodium absorption rates by leaf slices.
Regulation of Synthesis of Chlorophyll, Carotene, Ribulosel,5‐diP Carboxylase and Phosphoribulokinase in a Temperature‐sensitive Chlorophyll Mutant of Medicago sativa
Authors: Huffaker R. C. , Cox E. L. , Kleinkopf G. E. , Stanford E. H. 
Published: April 2006

AbstractThe activities of several enzymes were studied in a temperature‐sensitive chlorophyll mutant of alfalfa (Medicago saliva). In leaves grown at 10°C photosynthetic capacity was essentially nil with ribulose‐1,5‐diP carboxylase, chlorophyll, and carolene present in greatly limiting concentrations. The activity of phosphoribulokinase was 3.5 times lower at 10°C than at 27°C, but was still sufficiently high at 10°C to not limit the rate of CO2 fixation. Activities of phosphoriboisomerase, phosphoenolpyruvate carboxylase, glucose‐6‐P dehydrogenase and malate dehydrogenase were not different at 10°C and 27°C. The low fraction I protein content (which also accounts for the ribulose‐1,5‐dip carboxylase activity in alfalfa) indicated that synthesis of the carboxylase was effectively blocked at 10°C. A large, comparable increase in carboxylase activity and in concentration of fraction I protein in alfalfa leaves grown at 27°C indicated that the carboxylase was synthesized de novo.The initial induction of the carboxylase, chlorophyll, and carotene may be related, but after induction the carboxylase was not linearly correlated with the other two and had a different temperature optima. Nevertheless, the synthesis of each appeared to be regulated by the temperature‐sensitive gene of this mutant.
The Conversion of Protochlorophyllide636 to Protochlorophyllide630 in Leaves Treated with δ‐Aminolevulinic Acid
Authors: Sundqvist Christer 
Published: April 2006

AbstractAbsorbancy changes in dark‐grown, excised wheal leaves fed with δ‐aminolevulinic acid are measured in vivo. The treatment with σ‐aminolevulinic acid caused accumulation of protochlorophyllide, absorbing at 636 nm. After flashlight this form is found to convert in darkness to protochlorophyllide, absorbing at 650 nm. The conversion starts instantly after the leaves have been exposed to the flashlight, and the pre‐existent pool of protocholorophyllidc absorbing at 650 nm will become emptied. The conversion is completed after 15–20 minutes, when a new pool of protochlorophyllide has been filled up. This new pool is transformed to chlorophyllide by a second flash and the sequence is repeated. The conversion may be composed of two reactions, a conclusion which can be drawn from the behaviour at different temperatures. One of these reactions is fairly temperature independent while the other is temperature dependent. The action of the protochlorophyllide holochrome is discussed.
Interactions between Plants and Epiphytic Bacteria Regarding Their Auxin Metabolism
Authors: Libbert Eike , Silhengst Peter 
Published: April 2006

AbstractEpiphytic, IAA‐producing bacteria strains were fed with 14C‐tryptophan (Try). 14C‐Try absorption and, after transfer to a Try‐free medium, 14C‐IAA output were stated. Using 4 different methods, the 14C‐Try containing bacteria were applied to the tips of sterile corn coleoptiles and the ‘diffusible’ auxin collected at the coleoptile bases by means of agar blocks. 14C‐IAA was detected in the agar blocks. Sterile coleoptiles the tips of which were wupplied with 14C‐Try also deliver some 14C‐IAA at their bases, but much less than both sterile coleoptiles supplied with 14C‐Try‐containing bacteria and nonsterile supplied with 14C‐Try.
Seasonal Characteristics of the Daily Fluctuation in Nitrate Reductase Activity
Authors: Roth‐Bejerano Nurit , Herman Lips S. 
Published: April 2006

AbstractThe daily fluctuation of nitrate reductase activity in leaves of tobacco may be controlled by the relative amounts of endogenous cytokinin and gibberellin. While plants growing during the summer exhibit maximum nitrate reductase activity at midday, winter‐grown plants show minimum activity at that time. One reason for this phenomenon seems to be a relatively higher level of endogenous kinin in winter‐grown plants. Salt‐stress treatment of these plants changes the fluctuation pattern of nitrate reductase activity from a winter to a summer type. Kinetin addition to summer‐grown plants changes their fluctuation pattern from a summer to a winter type.
The Effect of Histones and Other Basic Macromolecules on Cell Permeability and Elongation of Barley Roots
Authors: Drew M. C. , McLaren A. D. 
Published: April 2006

AbstractLow exogenous concentrations of calf‐thymus histone, poly‐l‐lysine and lysozyme inhibit root elongation. These basic macromolecules (polycations) also affect cell permeability resulting in a leakage of ultraviolet light (UV)‐absorbing materials and chloride ion from cells. Adenosine 5′‐monophosphate was identified as one of the UV‐absorbing compounds in the root exudate, by thin layer chromatography. These deleterious effects of polycations on root growth and permeability are reduced in the presence of calcium and other divalent cations. Calcium ion‐histone interaction appears to exhibit competitive kinetics and suggests that both calcium and histone compete for attachment to negative sites on cell membrances.
14C‐Studies on Apple Trees. V. Translocation of Labelled Compounds from Leaves to Fruit and their Conversion within the Fruit
Authors: Hansen Poul 
Published: April 2006

AbstractFollowing application of 14CO2 to fruit spur leaves, the majority of the 14C absorbed is transfered to the fruit on the same spur, and the total content of 14C within the leaf‐fruit system as a whole remains virtually constant with time. The considerable reduction in activity in the leaves is accounted for mainly by a decrease in the amount of 14C‐sorbitol, although relatively speaking the decrease in 14C‐sucrose is also considerable. The major part of the activity of the sugar fraction in the conducting tissues between blade and fruit (petiol, spur) is found in sorbitol. Immediately following uptake of 14C yia the leaves a large part of the activity of the sugar fraction in the fruit is found in sorbitol; but this activity is rapidly reduced, accompanied by an increase in sucrose activity, and over longer periods of time increases in particular in glucose and fruclose activity, and in that of methanol insoluble compounds. The changes in activity distribution in the fruit vary with the variety of fruit and the dates within the growing season.By injecting labelled sorbitol directly into the fruit sorbitol is converted into sucrose, glucose and fructose, while injection of labelled sucrose, glucose and fructose has yielded proof of interconversions between these compounds but no measurable amounts of surbitol. After application of 14CO2 directly to the outer skin of the fruit considerably less of the activity is found in sorbitol than is the case in leaves following exposure to 14CO2.A minor, but significant, translocation of 14C away from the fruit was found to take place following the application of labelled 14C compounds to the fruit.The smallness of the respiratory loss of 14C in the leaf‐fruit system is discussed. It is concluded that in apple trees considerable translocation occurs in the form of sorbitol which in the fruits rapidly converted into other compounds.
Essai de localisation histochimique du zinc chez Hordeum gr. vulgare et toxicité
Authors: Gerebtzoff A. , Ramaut J. L. 
Published: April 2006

AbstractThe authors mention the importance of zine in plants, both as a toxic element in high concentration and as an indispensable one to some stages of cellular metabolism.They study the localization of this oligo‐element by means of histochemical methods in Hordeum vulgare.Zinc is found in the cytoplasm of the meristematic cells of the roots, in the cells of liber and on the grids of liber itserf. In the chlorophyllian parenchym, zinc is localized as minute particles in the near vicinity of chloroplasts.The authors suggest that zinc interferes with the growth of plants; it seems to be a co‐enzyme to carbo‐anhydrase and it modifies the physico‐chemical conditions of extractibility of chlorophyll.