bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Cullural Conditions on the Growth of Agrostemma githago Cells in Suspension Culture and the Concomitant Production of an Anti‐Plant Virus Substance
Authors: TAKAYAMA SHINSAKU , MISAWA MASANARU , KO KEIDO , MISATO TOMOMASA 
Published: April 2006

AbstractAn extract of cultured Agroxieinma githago L. cells was found to show potent inhibitory activity against plans virus infection. The effects of cultural conditions on the growth of the cell suspension and on the production of the inhibitor were examined. Since the production of substance was dependent on growth. experiments were made to improve growth. The optimum temperature was 26 to 30°C and optimum pH of the medium before autoclaving was between 5 and 7. In a medium of higher osmotic pressure, the water content of the cultured cells was lowered markedly. The growth rate in a small volume of the medium was higher than that in a larger volume at an early stage of the cultivation, but it was not changed by different inoculum sizes.The cells required thiamine and 2,4‐D for growth but no other vitamins or growth regulators. The optimum level of 2,4‐D was 0.1 mg/l.Higher sucrose concentration in the medium gave higher production of cell mass and of the inhibitor. However, 3% of sucrose was selected as the most economical concentration. For normal cell growth, the presence of both NH4NO3 and KNO3 as nitrogen sources was required. The use of a single nitrogen source caused a long lag period or inhibition of the cell growth. KH2PO4 stimulated the growth when in was used in the level of 2.5 to 5 mM.The cell adhesion on the surface of the fermentor sometimes causes trouble in a large‐scale cultivation. It was found that reducing the Ca2+ level in the medium prevented the cell adhesion and foaming remarkably.Based on the results obtained, a modified medium was established which was excellent for shortening the culture period and for efficient production of the anti‐plant virus inhibitor.
Boron Uptake by Excised Barley Roots
Authors: BOWEN JOHN E. , NISSEN PER 
Published: April 2006

AbstractActive uptake of boron (B) by excised barley roots is linear with time for at least 1.5 h. Although no evidence was found for accumulation of B against a concentration gradient. this component of B uptake does satisfy other criteria for an active transport process. Transport is inhibited by 0.05 mM 2,4‐dinitrophenol, 0.05 mM azide, 5 mM arsenate and 5 mM dicoumarol. Also, uptake is temperature‐sensitive, being nil at 2°C and maximal at 34 to 38°C. Boron uptake by barley roots increases with time when they are washed in aerated 0.5 mM CaSO4 solution.A double reciprocal plot of the B uptake data manifests a series of phases separated by sharp transitions or “jumps”, and is compatible with the concept of multiphasic uptake mechanisms. Kinetic constants and transition points for the various phases were calculated accordingly. The fit of these data was compared statistically to three other relevant models, viz, the dual model, the “single + diffusion” model (a Michaelis–Menten term and a diffusion term), and the negative cooperativity model. In each case, the data were better represented by the multiphasic model.
Carbon Isotope Ratios (13C/12C) in Fractions of Field‐Grown Grape
Authors: DI MARCO G. , GREGO S. , TRICOLI D. , TURI B. 
Published: April 2006

AbstractThe carbon isotope ratio (δ13C%) in leaves and berries of Vitis vinifera L. was determined during the fruiting season.The δ13C was from −24.6 to −26.3 in total leaf tissue, while it is from −22.7 to −24.3 in the aqueous extract of leaves. The δ13C in the berries was more stable, around −24, with no change during ripening. Malic and tartaric acid, isolated from the berries at the onset of ripening, showed a δ13C of −23.5 and −23.0 respectively. It was concluded that malic acid accumulated in the berries at the onset of ripening is not formed directly through β‐carboxylation.
Changes in Auxin and Cytokinin Activity in Roots of Red Oak, Quercus rubra, Seedlings during Lateral Root Formation
Authors: CARLSON WILLIAM C. , LARSON M. M. 
Published: April 2006

Abstract Quercus rubra L. seedlings were partially root pruned to induce formation of new laterals. Auxins in root extract fractions that cochromatographed with IAA, and cytokinins in root xylem sap fractions that cochromatographed with zeatin and zeatin riboside, were quantified by bioassays at 24 h intervals after pruning. Auxin activity sharply increased in the first 24 h and then decreased to prepruning levels. Cytokinin activity also increased during the first 24 h. New laterals appeared 4 to 5 days after pruning. The possible sources and role of these two hormones in root initiation are discussed.
Tissue Culture of Maize
Authors: SHERIDAN WILLIAM F. 
Published: April 2006

AbstractCallus of 12 strains of maize (Zea mays L.) was grown on a basal medium and on media supplemented singly with 0.3, 1.0 or 3.0 mM of either the glutamate, aspartate, or aromatic families of amino acids. Groth rate on basal medium difrered significantly among strains with Black Mexican Sweet corn growing most rapidly. Although there were three cases of simulation of callus growth at the 0.3 mM level and one case at the 1.0 mM level, generally the addition of amino acid families had either no effect or were inhibitory to growth rate. The sensitivity of inhibition varied among the strains tested at the 3.0 mM level except for the strain Ibadan B. Strains of the sweet, flint, pop and dent types of maize were all represented among the more fapidly growing strains and among those significantly inhibited by inclusion of amino acids in the cultural media. It remains to be determined as to whether the differences in growth response of the callus from the different strains is strain specific since, in all cases but one, callus was obtained from a single seedling of each strain.
Relations polyphénols — croissance: Mise en évidence d'un effet inhibiteur des composés phénoliques sur le transport polarisé de l'auxine
Authors: MARIGO GÉRARD , BOUDET ALAIN M. 
Published: April 2006

Abstract Polyphenols and Growth: Inhibition of Polar Auxin Transport by Phenolic Compounds.The possible effects of polyphenols on auxin transport in tomato plants (Lycopersicum esculentum Mill.) were investigated. For this purpose, the phenolic content of the material was stimulated by exogenously supplied quinic acid. After the apical bud had been excised, labelled compounds were applied to the cut surface, and the radioactivity transported to the roots was measured. Quinic acid treatment significantly delayed polar transport of labelled auxins (IAA or NAA). It did not affect the migration rate of sucrose−14C and leucine−3H. A number of evidences seems to demonstrate that the phenolics are responsible for these modifications, since similar results were recorded when the labelled compounds were supplied simultaneously with polyphenols from tomato. Moreover, a decreased polarity of NAA transport could be observed when the plants were submitted to treatments which lead to an increased level of phenols (boron deficiency, infection by Fusarium oxysporum). The data presented in this paper suggest that phenolic compounds could act on growth processes via the regulation of polar auxin transport.
Induced Protein Synthesis during the Adaptation to H2 Production in Chlamydomonas moewusii
Authors: KLEIN UWE , BETZ AUGUSTIN 
Published: April 2006

AbstractGas production by Chlamydomonas moewusii in the light has been followed by manometric techniques during the adaptation to anaerobiosis. The only detectable gases produced are CO2 and H2 CO2 is produced at a rather constant rate whereas H2 evolution increase with time. This increase of H2 evolution during the adaptation period can be inhibited by cycloheximide and by chloral hydrate, two inhibitors of protein synthesis. If the inhibitors are added to already adapted cells there is no effect on H2 evolution. Adapted cell suspensions are sensitive to oxygen. Incubation under O2 for 10 min inhibits the H2 evolution to 100%. After removal of oxygen the capability to evolve H2 can be restored only by a new adaptation period. This second adaptation to H2 evolution can also be inhibited by cycloheximide.
Indoleacetic Acid Oxidase Activity in Two High‐Peroxidase Tomato Mutants
Authors: PALMIERI S. , ODOARDI MIRIAM , SORESSI G. P. , SALAMINI F. 
Published: April 2006

AbstractHomogenates of tomato (Lycopersicon esculentum Mill.) tissues oxidize IAA at a rate proportional to their peroxidase activity. Moreover, isoproteins with peroxidase activity catalyze also the oxidation of IAA. Two monogenic recessive mutations, olivacea and monstrosa, are involved in the control of the peroxidase‐IAA oxidase activity. In olivacea leaflets this activity is 15 times that of the normal; all the aerial organs of monstrosa show high activities, particularly the midrib. These high activities depend on the enhancement of the organ‐specific isoenzymes and on the derepression of the root isoenzyme band C2. This latter peroxidase‐IAA oxidase band is present in olivacea and monstrosa leaflets, in monstrosa stems and, less intensely stained, in monstrosa midribs. The reduction in length and weight of mutant organs and their epinastic and geotropic‐like behavior are associated with high peroxidase‐IAA oxidase activities and with the derepression of the root‐specific band C2. These results suggest an important role of the peroxidase‐IAA oxidase system in controlling the metric relationships among different organs of the plant. Olivacea and monstrosa are to be viewed as auxin‐related mutations controlling the synthesis of a group of proteins related in function.
Lipids from Bean, Barley and Sugar Beet in Relation to Salt Resistance
Authors: STUIVER C. E. E. , KUIPER P. J. C. , MARSCHNER H. 
Published: April 2006

AbstractA comparison was made between the lipid and fatty acid composition of the salt‐sensitive bean (Phaseolus vulgaris L. cv. Saxa), the less salt‐sensitive barley (Hordeum vulgaris L. cv. Wisa) and the salt‐tolerant sugar beet (Beta vulgaris L. cv. Kawemono). Sugar beet roots showed a higher content of sterol components and sulfolipid as compared with bean and barley roots. The lipids of sugar beet roots contained more linoleic acid and less linolenic acid than those of bean and barley roots. For barley and sugar beet roots a higher amount of extra‐long chain fatty acids was observed than for bean roots. It was concluded that differences in membrane structure are correlated with differences in membrane permeability to sodium and chloride and in salt‐resistance of the studied species.
Leaf Response to Water Deficits in Soybeans
Authors: SIVAKUMAR M. V. K. , SHAW R. H. 
Published: April 2006

AbstractSoybeans [Glycine max (L.) Merrill cv. Wayne] plants were subjected to an extended drying cycle in the field to investigate the leaf sensitivity to water deficits. Soybeans in irrigated plots were superior to those in non‐irrigated plots in the average size and number of leaflets per plant. Apparent differences in the leaf area distributions in the canopy seemed to be mediated by moisture stress effects associated with leaf senescence and light penetration in the lower depths of the canopy. A major decrease in leaf enlargement occurred near a leaf‐water potential of ‐8 bars, and at ‐ 12 bars, the growth was completely halted. Similar decreases were observed at a stomatal conductance of 0.4 cm/s and at 0.2 cm/s no enlargement was observed.
A Relationship between Length of Basis and Adventitious Root Formation in Pea Cuttings
Authors: VEIERSKOV BJARKE 
Published: April 2006

AbstractA positive correlation between the length of the basis and the ability of the cuttings to form adventitious roots was observed in pea cuttings. Plants with a different basis length (the third internode) were obtained in different ways: Regulation by the level of irradiance, dark treatment or gibberellic acid. The length of the basis was also regulated by excision of the cuttings at different places on the stock plants. With increasing basis length an increase was found in the number of roots subsequently formed. The results were similar in cuttings from plants grown at different levels of irradiance or from dark treated plants. Optimal rooting was obtained by cutting the plants just above the second scale leaf. Cuttings from plants treated with 10−3M GA3 showed the same correlation between the length of the third internode and root formation as found in the other experiments, but the number of roots were at a lower level.
The Effect of Source—Sink Manipulations on Nitrogen Fixation in Peas
Authors: BETHLENFALVAY GABOR J. , ABU‐SHAKRA SALAH S. , FISHBECK KATHLEEN , PHILLIPS DONALD A. 
Published: April 2006

AbstractThe effect on nitrogen fixation of excising leaves or pods in pea (Pisum sativum L. cv. Alaska) was determined over a 60‐day period. Flower buds or their subtending leaves were removed, and C2H2 reduction, H2 evolution and N accumulation were measured at weekly intervals. Highest percentage nitrogen content in all treatments coincided with time of maximal C2H2‐reduction rates. Nitrogen fixation, calculated from C2H2 reduction and H2‐ evolution data, was significantly lower in the partially defoliated and generally higher in the depodded plants than in the controls. Total N accumulation was greatest in the depodded plants and least in the defoliated ones. Percentage nitrogen content and N2‐fixation rates in the depodded plants were maximized approximately 10 days later than in the defoliated or control plants. The absolute rates of C2H2 reduction and H2 evolution were significantly altered by plant organ removal, but the relative rates were proportional. As a result the ratios of H2/C2H4 production and the related relative efficiency of N2 fixation in the treatments were not significantly different from the controls.
Sensitivity of Cultured Tissue of Arabidopsis thaliana Races to Sulfanilamide
Authors: SCHOLL R. L. , DENNISON K. M. 
Published: April 2006

AbstractCallus of Arabidopsis thaliana (L.) Heynh. was examined for the kinetics of sulfanilamide inhibition of growth. Two geographic races of this species were compared for relative sulfanilamide sensitivity (as assessed by dry weight increase on drug‐containing medium) and rate of drug uptake.It was found that low concentrations of sulfanilamide in the culture medium (∼ 100 μM) inhibited callus growth and that low concentrations of p‐aminobenzoate (20 μM) competitively antagonized the sulfanilamide effect.Racial variation for sulfanilamide sensitivity was demonstrated. A partially drug‐resistant race had greater sulfanilamide uptake (per gram fresh weight) than a sensitive race. suggesting that relative drug‐sensitivity was not determined by the capacity to exclude sulfanilamide.
Seasonal Changes in Translocation of 14C from Different Age‐Classes of Needles on 20‐Year‐Old Scots Pine Trees (Pinus silvestris)
Authors: ERICSSON ANDERS 
Published: April 2006

AbstractNeedles of 20‐year‐old Scots pine trees (Pinus silvestris L.) were permitted to photoassimilate 14CO2 for 1 h on different dates during the growing season. The loss of radioactivity from current, 1‐year‐old, and 2‐year‐old needles was followed, and the translocation of photoassimilated 14CO2 from older needle age‐classes to the elongating new needles studied. The effects of good mineral and water supply on translocation were also considered.In the spring, 1‐year‐old and 2‐year‐old needles accumulated 14C. These reserves, together with current photosynthate, were utilized when the trees started growing. The 1‐year‐old needles exported 14C to the current needles during the first weeks of elongation of the later, while no such translocation occurred from the 2‐year‐old needles. Removal of the 1‐year‐old needles resulted in translocation of assimilates from the 2‐year‐old needles to the current needles. The general pattern of translocation observed in the control trees was not changed when the trees were fertilized and irrigated.The new needles started to export assimilates in the middle of July when the photosynthetic rate per needle was comparable with that of the older age‐classes. This occurred about 4 weeks after positive net photosynthesis was first measured for the current shoot. The current needles of trees with good nutrient and water supply seemed to become self‐sufficient in photoassimilates earlier than the current needles of the control trees.
Nitrogenase Activity Measurements in Intact Plants of Alnus incana
Authors: HUSS‐DANELL KERSTIN 
Published: April 2006

AbstractA technique for C2H2‐reduction assay on intact plants of Alnus incana (L.) Moench was evaluated. Cloned plants were grown, in pots, on fine gravel. During assay only the pot was inserted into a Perspex incubation chamber of simple construction. The incubation volume was rather small, plants with various shoot heights could be used, and the shoot was not exposed to the C2H4 produced. Intact plants showed high and constant C2H2‐reduction rates during several hours of incubation. In comparison, excised nodulated roots conventionally incubated in test tubes showed low and decreasing rates, due to removal of the photo‐synthesizing shoot and injury to the root nodules when drawn from the pot. Repeated nitrogenase activity assays on the same intact individual plants did not affect growth. The technique thus proved useful in studies. where repeated nitrogenase activity measurements are important.
The in vivo response of corn mitochondria to Bipolaris (Helminthosporium) maydis (race T) toxin
Authors: MALONE CARL P. , MILLER RAYMOND J. , KOEPPE DAVID E. 
Published: April 2006

AbstractThe addition of 2‐deoxyglucose to tissue elicits an in vivo mitochondrial conformation response (contraction) that can be viewed ultrastructurally and is indicative of the phosphorylative capability of mitochondria. Utilizing this technique toxin from Bipolaris (Helminthosporium) maydis race T was found to penetrate leaf and root tissue of Texas male‐sterile cytoplasm corn (Zea mays L. W64A) only slowly, but once in cells the toxin had a rapid deleterious effect on mitochondrial function. It is concluded that B. maydis (race T) toxin has effects on in vivo mitochondria similar to those reported after in vitro experimentation and that mitochondria are a primary site of toxin action. These observations are followed by the suggestion that susceptibility or resistance to B. maydis (race T) is conferred in corn by a cytoplasmically inheritable character associated with mitochondria.
The Aetiology of Vascular Discoloration in Cassava Roots after Harvesting: Association with Water Loss from Wounds
Authors: MARRIOTT J. , BEEN B. O. , PERKINS C. 
Published: April 2006

AbstractWhen root pieces of cassava, Manihot esculenta Crantz (cv. Yellow Heart or cv. Cuba Sweet), with an area of periderm removed or with a transverse cut uncovered, were held at low humidity and at 22°C, vascular discoloration consistently developed within 2 days. Vascular discoloration was prevented when injured pieces were stored at high humidity or when wounds were covered by a semi‐permeable film. When pieces were injured by removal of periderm, at high humidity the respiratory rate was unaltered but at low humidity an increase in respiratory rate occurred after 1 day. When pieces were injured by a transverse cut, at high humidity respiratory rate increased during the first day but decreased thereafter, whereas at low humidity the initial increase was followed by a further increase in respiratory rate after 2 days. It is suggested that vascular discoloration and a respiratory increase may occur in freshly harvested cassava roots as a result of stress produced locally by high rates of water loss at cuts and abrasions.
Cold Hardiness of Pine Needles and Apple Bark as Affected by Alteration of Day Length and Temperature
Authors: BERVAES J. C. A. M. , KETCHIE D. O. , KUIPER P. J. C. 
Published: April 2006

AbstractCold hardiness of pine needles and apple bark was determined in a series of experiments. Plants were exposed to 0°C and 20°C and exposed to day length conditions of 9 and 14 h. All 16 possible combinations were investigated by transfer of the plants from the original condition to each of the other conditions. In order to interpret the results, it was necessary to distinguish between a single and a dual environmental factor change. In pine plants at 20°C, a change in two factors decreased cold hardiness contrary to a single change in temperature or day length. In plants at 0°C, the effects of a change in day length and temperature were additive. Differences in pine and apple are discussed in relation to natural conditions and to geographical distribution. It is suggested that for increased hardiness shortening of day length should precede a low temperature regime and that reversal of this order may upset the signal system, resulting in dehardening.
Cytokinin Production by Tomato Root: Occurrence of Cytokinins in Staled Medium of Root Culture
Authors: KODA YASUNORI , OKAZAWA YOZO 
Published: April 2006

AbstractCytokinins were released into the medium by cultures of excised tomato (Lycopersicon esculentum Mill.) root tips. A large portion was directly released from the proximal cut‐end of the roots. The most active substance was found to co‐chromatograph with zeatin riboside in both paper and Sephadex column chromatographies. The cytokinin activity after 7 days of growth was found about eight times higher in the medium as compared with that in the root tissues. When freshly excised root tips were subcultured throughout eight passages, the accumulation of cytokinin in the medium of each passage was approximately the same. These results show that the root tip is a main site of cytokinin synthesis.
Tissue Culture of Cassava on Chemically Defined Media
Authors: PARKE DONNA 
Published: April 2006

AbstractDefined media that promote the initiation and undifferentiated growth of callus derived from stem explants of four cultivars of cassava, Manihot esculenta Crantz, are described. Growth rates and yields of cassava callus after 4 weeks of culture are shown to be comparable to those of callus of Nicotiana tabacum L. cv. Wisconsin No. 38. Nitrogen sources of ammonium nitrate or of ammonium chloride plus succinate supported growth of all four cultivars. Sucrose was superior to glucose as a carbon source. The cassava cultivars differed in their response to increasing concentrations of sucrose between 0.5% (w/v) and 3%, two of them increasing in dry matter with increasing sucrose concentrations of up to 3%. When cultured in the light on defined media that contained higher ratios of cytokinin to auxin, callus of the latter two cultivars turned green. Roots but not shoots differentiated from the callus of all cultivars. The influence of hormone concentrations, sucrose level, and nitrogen source on greening and root formation is summarized.
Low Pressure and Ethylene in Lettuce Seed Germination
Authors: RUDNICKI RYSZARD M. , BRAUN JOSEPH W. , KHAN ANWAR A. 
Published: April 2006

AbstractThe extent and manner of ethylene involvement in germination of lettuce (Lactuca Sativa L. cv. Mesa 659) seed at a moderate temperature (20°C) were investigated. Inhibition of germination at low pressure of 150 mmHg in an oxygen flow‐through system was alleviated to a marked extent by ethylene. Carbon dioxide was ineffective by itself but caused further alleviation of inhibition in presence of ethylene and oxygen. Other seed treatments which partially alleviated the inhibition caused by low pressure included soaking in 10μM of fusicoccin and a prior treatment with acetone. Of the two ethylene adsorbents used, Purafil was more effective in inhibiting germination in a closed container. Although the ethylene biosynthesis inhibitor, 8‐hydroxyquinoline (1.0 mM). showed no effect on ethylene production, it markedly inhibited germination and the effect was partially reversed by ethylene and GA3. An ethoxy analog of rhizobitoxine, on the other hand, had little or no effect on germination but strongly inhibited the ethylene production. Although no causal relation of ethylene to germination was established, the evidence presented here implicates ethylene, together with other gases, in the regulation of germination.