bluuebunny/crossref_metadata_2025 huggingface dataset:
Mannitol Biosynthesis in Pyrenochaeta terrestris II. D‐Mannitol‐l‐phosphatase
Authors: Aitken W. Brent , Wright James R. , Letourneau Duane
Published: April 2006

Cell‐free extracts of mycelial mats of Pyrenochaeta terrestris contained an enzyme which hydrolyzed mannitol‐l‐phosphate to mannitol and inorganic phosphate. Greatest mannitol‐1‐phosphatase activity occurred early in the growth period when the mannitol content of the mats was at a maximum. The enzyme was active over a broad pH range with optimum activity between pH 6.5–7.0 in 0.05 M Tris‐maleate buffer. Maiinitnl‐1‐phosphatase was inhibited by reagents known to inhibit enzymes containing ‐SH groups. A 10‐fold purification was attained by a combination of (NII4)2 SO4 fractionation and gel filtration on Sephadex G‐100. The partially purified enzyme required Mg−2 for activity and did not hydrolyze a number of sugar phosphates. Km values for mannitol‐l‐phosphate and Mg−2 with the partially purified extract were 3 × 10−3 M and 1 × 10−4 M respectively.
Biochemical Aspects of Parasitism by the Angiosperm Parasites: Changes in Nucleic Acid Content of Infected Hosts
Authors: Setty Pravina N. , Beg M. U. , Singh Madhav , Krishnan P. S.
Published: April 2006

The acid‐insoluble phosphate in the tissues of three species of Cuscuta and of Orobanche cernua and in the infected hosts has been fractionated into phospholipids, RNA, DNA and phosphoprotein. Infection by parasites was attended, in general, by a decrease in RNA and an increase in DNA.
The Changes in Soluble Protein of Excised Barley Leaves during Senescence and Kinetin Treatment
Authors: Atkin Roger K. , Srivastava B. I. Sahai
Published: April 2006

Sterile detached barley leaves were floated on water or kinetin (10 mg/1)and supernatant extracts (30,000 x g for 30 min) were prepared from these leaves over an 8 day incubation period. Changes in selected total enzyme levels and in individual soluble protein components wore compared.

Ribonuclease, deoxyribonuclease and peptidase activities rose in senescing leaves, even as total protein levels fell. Kinetin to some extent depressed these activities. Evidence of considerable loss of ribonuclease and to a lesser extent of deoxyribonuclease into the surrounding medium was obtained.

Soluble supernatant ant extracts were resolved on DEAE‐Sephadex (A‐50) columns into about 15 components. While most components were degraded during senescence they did so at different rates. Kinetin lowered the rate of degradation of all components. Since no conclusive evidence of a new protein(s) was obtained in water and kinetin treated leaves, it was considered that any protein changes may have been of a quantitative rather than qualitative nature.
The Inhibition of Seedling Growth by Streptomycin Sulfate
Authors: Druhy Robert E. , Khan Anwar A.
Published: April 2006

The action of streptomycin sulfate (SS) on the growth of germinating seeds was investigated. It inhibited root growth more than shoot growth. Chemical analysis of roots indicated that nucleic acids decreased but their elution pattern from a column of methylated albumin kieselghur showed no qualitative differences. SS decreased the number of cells undergoing mitosis per root tip. This number was correlated with root length. One nM N5‐benzyladenine reversed the effect of SS on both root length and mitosis. Thus the effect of SS appears specific to cell division. SS failed to affect oxidative phosphorylation in isolated mitochondria so its effect on cell division would not be secondary to the inhibition of energy conservation. It s possible inhibition of enzyme activity is selective since it also failed to affect RNase activity in vitro.
Movement of Water and Solutes in Sieve Tubes of Willow in Response to Puncture by Aphid Stylets. Evidence against a mass flow of solution
Authors: Peel A. J. , Field R. J. , Coulson C. L. , Gardner D. C. J.
Published: April 2006

Experiments are described in which bark strips of willow were sealed to polythene tubes having two compartments. This allowed investigations to be made of the transport along the sieve tubes of tritiated water, 14C‐labelled sugars, and 32P‐phosphates from one compartment, towards a stylet situated in the bark over the other compartment.

Although activity from both 14C and 32p was detected in the stylet exudate usually within 1 hour from isotope application, tritium activity was never detected even after a period of 8 hours in most experiments, though in certain cases, very low activities were detected after 4 hours. Subsequent experiments in which stylets were sited over both compartments showed that tritium activity moved laterally into the punctured sieve element more rapidly than either 14C or 32P. Experiments using both live and dead bark in which stylets were not employed, showed that within 4 hours tritium activity had moved by diffusion along the whole length of a bark strip, therefore after this time tritium activity could have moved into the stylet exudate by a diffusional process.

The lack of rapid longitudinal movement of tritiated water along the sieve tubes, indicates that the transport process is unlikely to be a mass flow of solution.
Untersuchungen über Beziehungen zwischen Zellteilung und Morphogenese bei Gewebekulturen vou Daucus carota III. Der Eiufluss des Kinetins auf die Ultrastruktur der Zellen
Authors: Neumann K. H. , Cireli E. , Cireli B.
Published: April 2006

Relationship between cell division and morphogenesis of tissue culture of Daucus carota. III. The influence of kinetin on the ultrastructure of cells.— A previous paper reported a close correlation between cell division as influenced by kinetin and respiration, i.e. a high kinetin induced cell division rate corresponds with low oxygen consumption of the explants. This earlier observation was now confirmed. No significant differences between the ultrastructure of mitochondria of explants cultured with kinetin and those of explants cultured without kinetin could be observed, although the number of mitochondria per cell seems to be increased in explants cultured without kinetin. However, also the number of ribosomes in cells of explants cultured without kinetin seems to be increased as compared with those treated with kinetin. Kinetin apparently has no significant influence on the ultrastructure of cell organells under the conditions employed.
The Effect of Nonanal on Dipodascus aggregatus
Authors: Nyman Brita
Published: April 2006

Biotin can not replace nonanal for Dipodascus aggregatus. The growth‐promoting effect of nonanal (80 μW) remained unchanged when the concentration of biotin was increased from 2 μm per 1 to 200 μm per I. Oleic acid stimulated the growth of D. aggregates. However, unlike nonanal, oleic acid promoted growth even if cells from the exponential phase of growth were used as inoculum. The concentrations of oleic acid required to produce growth–stimulation were considerably higher than the concentrations of nonanal required to promote growth. The growth‐stimulating effect f nonanal seems to be different from t he effect of oleic acid. The incorporation of 1C‐ghtCOM by D. aggregates was stimulated by the addition of nonanal (80μm) to the growth medium. The uptake of glucosamine was not affected by nonanal (80 or 160 μM in the presence of ethanol, 0.8 to 100μ in the absence of ethanol). Hexokinase activity in cell‐free homogenates was not affected by the addition of nonanal over a concentration range from 0.0059 to 1250μM.
Arginine in Growing Cells of Sugarcane. Nutritional Effects, Uptake and Incorporation into Proteins
Authors: Maretzki A. , Nickell L. G. , Thom M.
Published: April 2006

The growth of sugarcane cell cultures derived from parenchyma tissues of three different varieties of sugarcane showed a marked dependence on the presence of arginine when the cells were cultured in a synthetic liquid medium containing a mixture of amino acids. The cells appeared lo have access to n normal biosynthetic pathway of arginine biosynthesis but took up exogenously supplied arginine rapidly and efficiently. Arginine was not limiting for protein formation, nor were proteins with AN unusually high number of arginine residues evident. The low level of arginine effective in bringing about the growth response is suggestive of a regulatory function for this amino acid in sugarcane cells.
Diurnal Periodicity and Plaut Growth
Authors: Ketellapper H. J.
Published: April 2006

The experiments were carried out to investigate whether other plant species, in addition to tomato plants, show injury symptoms when grown for 2 to 4 weeks in an aperiodic environment and to obtain information about physiological mechanisms involved in the response to the absence of environmental periodicity. The growth of seedlings of pea, peanut, and soybean, exposed to different daylengths at constant temperature, increased with Increasing length of the light period up to 16 to 20 hours, defending on the species. Further lengthening of the photoperiod did not result in significant increases in dry matter accumulated. The absence of environmental periodicity did not cause injury in these three species. Tomato plants responded in an entirety different manner. The optimal photoperiod for dry matter production by tomato plants was 18 hours and photoperiods longer than 20 hours caused interveinal chlorosis. Thus, tomato plants have an absolute requirement for a daily periodicity, white the other species do not in short‐term experiments. Under conditions of constant temperature development of chlorosis by tomato plants may be prevented by a daily dark period of 4 hours or longer or by a daily period of drastically lowered tight intensity. Complete darkness is not essential, however. This suggests that development of chlorosis is not mediated through a photoperiodic response system. Involvement of a circadian oscillation may also be excluded. Aperiodic environmental conditions appear to affect the physiology of the tomato plant in a direct manner, possibly by influencing chlorophyll synthesis or degradation.
Marine Brown Algae Requiring Vitamin B12
Authors: Pedersén Marianne
Published: April 2006

The brown algae Lithosiphon pusillus, Ectocarpus fasciculatus and Pylaiella litoralis were cultivated in bacteria‐free cultures in artificial sea water, ASP 6F. The growth was tested with different additions of vitamins and other metabolites. Lithosiphon pusillus and Ectocarpus fasciculatus were found to require vitamin B12 for optimal growth.

The zoospores of Pylaiella litoralis, when cultured in medium Asp 6F with kinetin added, had an absolute requirement for vitamin B12.
Growth Regulators and Wood Formation in Pinus silvestris
Authors: Hejnowicz A. , Tomaszewski M.
Published: April 2006

The formation of new xylem in the spring is preceded by bud development. In decapitated pine stem the formation of xylem is arrested until the outgrowth of interfascicular buds takes place. When indole‐3yl‐acetic acid (IAA) is applied to the cut surfaces of decapitated stems it induces the formation of a xylem ring on the whole length of 5‐ycar old trees. Naphthaleneacetic acid (NAA) causes the formation of xylem; however, the width of the growth ring is several times broader at the point of application than at the base of the leader. Cis‐ and trans‐cinnamic acids, coumarin, L‐tryptophan, kinetin (Kin), benzylaminopurine (BAP) and gibberellic acid (GA) alone do not induce cambial divisions; however, GA and the cytokinins given jointly with IAA or NAA accelerated the basipetal stimulus which has been induced by the auxins, resulting in normal xylem formation. 2,3,5‐Triiodobonzoic acid (TIBA) given jointly with IAA‐induced formation of compression wood in the apical part of the stem and narrow diameter tracheids at the base. When carboxyl labelled IAA or NAA are applied to pine segments it is found that the basipetal movement of IAA is much quicker than that of NAA. GA and the cytokinins increase the rate of transport of both auxins, whereas TIBA arrests the bulk of auxin in the apical part of the stem.
The Roles of the Cotyledons and Auxin in the Adventitious Root Formation of Hypocotyl Cuttings of Light‐Grown Cucumber Seedlings
Authors: Katsumi Masayuki , Chiba Yoshiko , Fukuvama Machi
Published: April 2006

Adventitious root formation in encumber hypocotyl cuttings was studied. Root formation was quantitatively related to the amount of the cotyledons attached to the hypocotyl. Complete removal of the cotyledons diminished root formation entirely. Hut the removal of the apical bud had no effect. Treatment of the hypocotyl with triiodobenzoic acid resulted in the inhibition of root formation. On t he other hand, IAA promoted root formation. Promoting concentration of IAA was 1 mg/1 for the cuttings with intact cotyledons and 10 mg/1 for those with l/8th of the cotyledons. The first two or three days of treatment was most effective. The presence of auxin (IAA‐like. substance) in cucumber seedlings was demonstrated by paper chromatography and the pea straight test. It is concluded that the cotyledon is necessary for root formation in cucumber hypocotyl cuttings and that auxin is at least one of the factors supplied from the cotyledons.
Interaction of Growth Retardants and Temperature in Growth, Flowering, Regeneration, and Auxin Activity of Begonia × cheimantha Everett
Authors: Heide Ola M.
Published: April 2006

Soil application of CCC reduced stem and leaf growth in Begonia plants. This effect was evident with all concentrations tested at 18°C, whereas at 21 and 24°C no growth–retarding effect was observed with 2 × 10−2 M CCC, and with 5 × 10−3 M growth was even stimulated. Flowering was promoted by CCC in long day and neur–critical temperature, particularly under low light intensity in the winter. The formation of adventitious buds in leaves of plants grown at 21 and 24°C was stimulated when the plants received 5 × 10−2 and 2 × 10−2 M CCC, while 8 7times; 10−2 M was inhibitory. In plants grown at 18°C bud formation was inhibited by all CCC concentrations. Root formation in the the leaves was usually stimulated by high CCC concentrations, while root elongation was reduced. The level of ether–extractable. acidic auxin (presumably IAA) in the leaves was lowered by CCC treatment of the plants, hut this required higher CCC concentrations at higt than at low temperature.

When applied to detached leaves CCC stimulated bud formation at concentrations ranging from 10−4 to 10−2 M in leaves planted at 18 and 21°C. At 24°C budding was inhibited by 10−2 M CCC, the lower concentrations being stimulatory also at this temperature. Root formation and growth were not much affected by CCC treatment of the leaves, but increased with the temperature.

Soil application of Phosfon (4 × 10−4 M) had no effect on growth and flowering, nov did it affect the subsequent regeneration of buds and roots in the leaves. In detached leaves Phosfon stimulated bud formation with au optimum at 10−6 M. Root formation was stimulated by Phosfon at all temperatures, the optimal concentration being 10−5 M, whereas root length was conversely affected. Foliar application of B‐995 to intact plants and treatment of detached leaves greatly inhibited the formation of buds and had little effect on root formation. B‐99D reduced the growth and delayed flowering in the plants.
Phytochrome Controlled RNA Changes in Terminal Buds of Dark Grown Peas (Pisum sativum cv. Alaska)
Authors: Jaffe M. J.
Published: April 2006

The terminal buds of intact dark grown Alaska pea plants (Pisum sativum) respond to low intensity red light by an enhanced rate of expansion of their leaflets. Twenty four hours after irradiation, red light was found to have increased the ribosomal fraction of the RNA content of the terminal buds. The increase in total RNA liter did not occur if the red light was immediately followed by irradiance with low intensity far red light.
Ribonuclease and Chlorophyllase Activities in Senescing Leaves
Authors: Phillips D. R. , Horton R. F. , Fletcher R. A.
Published: April 2006

The activities of two enzymes, ribonuclease and chlorophyllase were investigated during the senescence of leaves. Ribonuclease activities were measured in primary leaves of Phaseolus vulgaris, and related to the levels of nucleic acid, protein and chlorophyll. Similarly, changes in chlorophyllase activity during senescence of leaves of Raphanus sativus were measured and related to chlorophyll. During senescence the levels of each enzyme as well as its respective substrate declined. Retardation of senescence, by excision of young tissue from intact plants or by treatment of detached leaves with cytokinins resulted in a maintainace of both the substrate and enzyme levels. It was concluded that high levels of ribonuclease and chlorophyllase activity are not linked directly with the degradation of RNA and chlorophyll during leaf senescence.
Ethylene Production from Pardee's CO2 Buffers
Authors: Forsyth F. R. , Eaves C. A.
Published: April 2006

Fifteen milliliters of Pardee's CO2 buffer containing diethanolamine, thionrea, potassium bicarbonate and 6 N hydrochloric acid produces up to 108 μg of ethylene during a 42 hour period. Only 1/25 as much ethylene is produced from monoethanolamine and still less from triethanolamine. All components of the buffer with the exception of hydrochloric acid are necessary for maximum ethylene production. Increasing the level of hydrochloric acid depresses ethylene production.
The Effect of Methyl Glyoxal on Growth and Cell Division of Chlamydomonas reinhardii
Authors: Morris Ian
Published: April 2006

Methyl glyoxal, at concentrations of 1.0–2.0 mM, inhibits growth of the green alga, Chlamydomonas reinhardii. The photosynthetic assimilation of carbon dioxide is also inhibited by the glyoxal. At the lower concentrations (less than 1.0–1.5 mM) protein synthesis Is inhibited, whereas polysaccharide synthesis and assimilation of carbon dioxide into the alcohol–soluble fraction is stimulated; at higher concentrations fl.5–2.5 mM) these latter two processes are also inhibited. Cell division in synchonized cultures of the alga is more sensitive to methyl glyoxal when it is added at the start of the growth cycle than when added late in the growth cycle. However, when added late in the growth cycle, methyl glyoxal delays the onset of cell division by 2 hours. No such delay occurs when cycloheximide is added 4–6 hours before division.
Stimulation of Growth of Two Marine Green Algae by Organic Substances Excreted by Enteromorpha linza in Unialgal and Axenic Cultures
Authors: Berglund Hans
Published: April 2006

The alga Enteromorpha linza was cultivated in the artificial medium ASP 6F. Substances leaking out from the alga into the medium were extracted by ether and shown to stimulate the growth of two green algae. The amount of extract obtained was very small. One part was watersoluble, and the other part emulsive only in sodium hydroxide.
Studies on Cassava, Manihot utilissima. II. Biosynthesis of Asparagine‐14C from 14C‐labelled Hydrogen Cyanide and its Relations with Cyanogenesis
Authors: Nartey Frederick
Published: April 2006

Seeds and seedlings of Manihot utilissima were analysed for cyanogenic glycosides und free amino acids, with special reference to valine and isoleucine which serve as precursors of the aglycone moieties of linamarin and lotaustralin. Seeds contained traces of valine and isoleucine but no glycosides, whereas seedlings contained high concentrations of these amino acids and glycosides. Illumination of seedlings led to a steep increase in the concentration of glycosides followed by a decrease without excretion of detectable HCN. Seeds accumulated asparagine, while seedlings accumulated both asparagine and glutamine in the storage and transport of nitrogen. Seedlings incorporated 13.2 per cent of label from valine‐14C(U) and 2.4 per cent of label from isoleucine‐14C(U)into linamarin and lotaustralin, respectively. In both cases, appreciable amounts of label were also incorporated into asparagine. 49 per cent of label from H14CN was incorporated inio asparagine in which ca. 98 per cent of total radioactivity was located in the amide‐carbon atom. The different patterns of labelling which occurred during the assimilation of H14CN and 14CO2 showed that cyanide metabolism did not proceed via CO2, and that M. utilissima contains an efficient enzyme‐system which catalyses the conversion on high concentrations of HCN into asparagine, which subsequently enters different metabolic pools involved with respiration, protein and carbohydrate syntheses. Cyanogenesis in M. utilissima appears lo be directly influenced by available pools of valine and isoleucine, and the metabolism of HCN released from linamarin and lotaustralin by the action of linamarase may be directly related to respiratory and synthetic processes by way of the incorporation of HCN as a unit into asparagine.
The Auxinic Activity of Thioglycollic Acid Derivatives of β‐Di‐ketones
Authors: Barrett D. W. A. , George E. F.
Published: April 2006

2,2′‐Di(carboxymethylthio) pentan ‐4‐one was found to increase the stem height of intact tomato plants growing in pots under glass. Stem height was increased by 60 percent although this was accompanied by malformations in lamina development, leaf epinasty, and a final reduction in shoot weight. Stem growth of tobacco and potato were also stimulated by this compound but the deleterious effects on leaf development were less marked. Subsequent screening of chemical analogues, using as an assay the growth response of intact tomato plants revealed that 3,3′‐di(carboxymethylthio)heptan‐5‐one initially stimulated stem growth but then produced severe shoot damage, similar to that caused by phenoxyacetic acid herbicides. Both chemicals stimulated extension growth in a wheat coleoptile section test though to a lesser extent than indole‐3‐acetic acid.

Like the carboxymethyl‐N:N‐dialkyldithiocarbamates, these straight chain compounds appear to possess true auxin activity that could be related to the formation of an incomplete unsaturated “ring” system.
Effect of Various Light Treatments on Chlorophyll Formation in Excised Potato Roots
Authors: Bajaj Y. P. S. , McAllan J. W.
Published: April 2006

Potato root tips were grown in cultures and the effect of blue, red, and white light on chlorophyll formation was studied. The roots grown in white light turned green in 4–6 weeks, whereas in blue or red light, green colour occasionally appeared at places. The chlorophyll contents, as determined by the spectrophotometeric method, were found to be maximum in unfiltered light followed by blue and red light. In white and blue light treatments chlorophyll a contents were higher than chlorophyll b, however in red light this was reversed. The results are compared with earlier experiments on chlorophyll formation in excised roots.
Gibberellin and Protease Activity in Medicago sativa
Authors: Cohen Bat‐Sheba , Leshem Y. , Pinsky A.
Published: April 2006

During germination of the lucerne seed, proteolytic and gibberellinic activity increases. Exogenous GA added to the solution in which the seed was germinated caused an increment in proteolytic activity. CCC inhibited the biosynthesis of GA in the seed‐ ling, and had no effect on the proteases. This indicates that there are other factors Hum GA responsible for the increment in proteolytic activity during Medicago germination.
Palmelloid Formation of Chlamydomonas II. Mechanism of Palmelloid Formation by Organic Acids
Authors: Iwasa Kozo , Murakami Shohachi
Published: April 2006

To clarify the mechanism of palmelloid formation by organic acids, the dissociation of the suspension of palmelloids in different media was studied. It was found that the palmelloids can be dissociated by the calcium ion at the low concentration of 6.8 × 10‐5M, but not by the magnesium ion. The dissociation is suppressed by the phosphate ion. Furthermore, Chlamydomonas cells grown in media containing EDTA or GEDTA or in media deficient in calcium, are induced to form palmelloids. These results indicate that the effect of organic acids on the formation of palmelloids are due to their ability to chelate with calcium.
The Activity of α‐Amylase in the Shoot and its Relation to Gibberellin‐induced Elongation
Authors: Katsumi Masayuki , Fukuhara Masako
Published: April 2006

The activity of α‐analyses in various plant organs was examined and the relation‐ ship between the enzyme activity and the leaf sheath elongation of dwarf mutants of maize was investigated.

It has been shown that α‐amylase exists in various plant organs. Especially high activity was detected in the bean hypocotyl. The regional activity of a‐amylase in the epicotyl of the pea and the hypocotyl of the morning glory was examined. Higher activity was observed in the regions closer to the cotyledons. In the first leaf sheath of d5 mutants of maize, GA3‐treatment resulted in the promotion of α‐amylase activity, and there was a parallelism between GA3‐induced elongation and α‐amylase activity. Removal of the endosperm from seedlings did not influence the GA3‐indnced elongation of the leaf sheath or the promotion of α‐amylase activity. From these results it is concluded that at least some of the α‐amylase is actually formed in the leaf sheath, and that there exists a distinct parallelism between the GA3‐induced promotion of enzyme activity and leaf sheath elongation.
Adaptations of the Photosynthetic Mechanism of Sugar Maple (Acer saccharum) Seedlings Grown in Various Light Intensities
Authors: Logan K. T. , Krotkov G.
Published: April 2006

Sugar maple (Acer saccharum Marsh.) seedlings were grown in a nursery for three years in 13, 25, 45 and 100 per cent of full daylight. During the third year of growth, the rates of their apparent photosynthesis and respiration were measured periodically with an infra‐red gas analyzer at various light intensities and normal CO2 concentration. In addition, the rates of apparent photosynthesis of a single attached leaf of the same seedlings were measured at saturating light intensity, hut varying CO2 concentrations.

An increase in the light intensity in which seedlings were grown had no effect on their height or mean leaf area, hut resulted in thicker leaves, an increase in the total leaf area per seedling due to an increase in the number of leaves, an increase in the dry weight especially of roots and a decrease in the chlorophyll content of leaves.

Throughout the growing season seedlings grown in full daylight, as compared with those grown in lower light intensities, had the lowest rates of apparent photosynthesis measured at standard conditions (21,600 lux light intensity and 300 ul/l of CO2), when this was expressed per unit leaf area, hut the highest rates on a per seedling basis. Thus dry matter production attained at the end of the growing season correlated positively with the photosynthetic rate per seedling, but not per unit leaf area. The rates of apparent photosynthesis of seedlings grown at lower light intensities were more responsive to changes in light intensity or CO2 concentration than those of seedlings grown in full daylight intensity.
Studies on the Activity of Beta‐Analyses of the Chloroplasts of Stellaria media during Prolonged Illumination
Authors: Haapala Heikki
Published: April 2006

The changes in the activity of enzymes hydrolyzing starch were studied. Enzymes were extracted from the leaves of Stellaria media. Enzyme activity seems to be concentrated in the chloroplasts. Beta‐amylase has been identified as the main enzyme hydrolyzing starch in these leaves.

When Stellaria media plants are left in continuous illumination after a normal light‐dark‐rhythm), beta‐amylase activity remains essentially unchanged for some time. Alter an Illumination of 24–27 hours the activity suddenly increases. This phenomenon occurs at about the same time as the rapid disintegration of starch previously accumulated in the chloroplasts. In the light of present‐day knowledge the increase in the activity cannot be explained.
Studies on Deoxyribonucleotide Synthesis in Vicia faba
Authors: Odmark Göran
Published: April 2006

The incorporation of uniformly labelled [14C] cytidine into the nucleic acids was studied in root tips of Vicia faba. Cytidine was found to be incorporated into RNA and DNA and the specific activities of the individual mononucleotides were deter‐ mined. The pyrimidine nucleotides were degrade and the ratio between the specific activity of the pentose and the specific activity of the base was determined for each nucleotide.

CMP of RNA and deoxy CMP of DNA bad almost the same pentose: base ratios as The cytidine added to the incubation medium. It was concluded that the administered cytidine or a derivative of it was reduced to the corresponding deoxycytidine compound without breakage of the bond between pentose and base.

[14C)‐cytidine was transformed to UMP of RNA with some loss of radioactivity from the pentose and had almost the same pentose: base ratio as deoxy TMP of DNA. This indicates that the formation of thymidine phosphates involved The reduction of a uridine compound.

Furthermore the incorporation of 14C‐labelled thymidine, deoxyadenosine and deoxyguanosine into DNA was studied. Deoxyguanosine was found to be incorporated only to a slight extent. This finding has been discussed in relation to previous results.
Characterization of Boron Deficiency in Soybeans
Authors: Brown J. C. , Ambler J. E.
Published: April 2006

Boron‐deficient soybean roots have a rosette appearance at the terminals caused by the death of the root primordium and the initiation of new root primordia. The root tips show some darkening, swelling, and then a collapse of the tissue. The petiole s of B‐deficient plants are very brittle.

Physiologically, B‐deficiency in HA‐soybeans does not appear to involve an interference in the transport of photosynthate (C14 distribution) or precursors required for citrate synthesis in the roots.

More Ca 45 was found in the tops of B‐sufficient than B‐deficient plants, but the opposite trend existed in the root sap. Boron deficiency symptoms were accentuated by maintaining a relatively low pH of the prenutrient solution by the addition of K salts.
14C‐Studies on Apple Trees. IV. Photosynthate Consumption in Fruits in Relation to the Leaf‐Fruit Ratio and to the Leaf‐Fruit Position
Authors: Hansen Poul
Published: April 2006

The photosynthate consumption in apple fruits in relation to the leaf/fruit ratio was studied in sections of branches of the Graasten and Golden Delicious varieties by exposure to 14CO2during July and August. A significant, negative correlation was found between the fixation of 14C in the fruits in terms of percent of the total amount of 14C absorbed and the leaf/fruit ratio of the branch sections. The leaf area required for the saturation of one fruit was found to be ca. 190 and 230 cm2 (14 and 17 leaves) in the case of Golden Delicious, and ca. 400 and 670 cm2 (25 and 42 leaves) for Graasten in July and August, respectively, calculated under conditions of large leaf areas per fruit. In such cases a fairly good, reverse proportionality exists between the 14C fixation in the fruit in terms of percent and the leaf area expressed in multiples of saturation area. At low leaf/fruit ratios, however, the actual saturation area is found to be lower than the theoretically computed one.

The translocation of the 14C assimilated in the leaves of the extension shoots or of spurs without fruits to fruits on other spurs was on the whole promoted by a decreasing leaf/fruit ratio in the parts in question; similarly the greatest transport took place on the side where the leaf/fruit ratio was lowest. The fixation was often greatest in the fruit closest to the treated leaves, hut in a number of cases the value was higher for the second closest or even further removed fruits. In this connection the importance of the size of the fruit and the vascular connections is discussed.
Effect of Auxins and Light on Rooting Stem Cuttings of Populus nigra Salix tetrasperma, Ipomea fistulosa and Hibiscus notodus in Relation to Polarity
Authors: Nanda K. K. , Purohit A. N. , Kochhar V. K.
Published: April 2006

The apical and basal ends of stem cuttings of Populus nigra, Salix tetrasperma, Ipomoea fistulosa and Hibiscus notodus were treated with 10 mg/l solutions of IAA and IBA for 24 hours and were planted either erect or inverted both in light and dark. Observations for the number of cuttings that rooted and the roots produced on them were recorded at weekly intervals. In Salix, Ipomoea and Hibiscus rooting was more on cuttings planted erect, while in populus it did not differ much with the manner of planting. The reduced rooting in inverted cuttings may be ascribed to the low level of endogenous auxin at the apex due to polar transport. An exogenous application of auxins enhanced rooting on inverted cuttings. In dark, roots on Populus and Salix cuttings were produced both above and within the rooting medium. The weak polarity of these two plants may be due to the potential root primordia reported in their stem. The formation of callus occurred on the top of Populus cuttings whether planted erect or inverted but it differentiated into branches on erect cuttings only. In those planted in an inverted position the callus failed to differentiate in spite of the application of kinetin, auxins, TIBA, coumarin and sucrose, and dried ultimately.
Growth and Endogenous Gibberellin Content of Dormant Groundnut Embryonic‐axes as Influenced by Leaching and GA3
Authors: Sreeramulu N. , Rao I. M.
Published: April 2006

Leacthing the excised embryonic‐axes from dormant groundunt (Arachis hypogaea) seeds resulted in their growth. However, their growth was stunted compared to that of after‐ripened ones. It is attributed to (1) the lower amount of gibberellin‐like substances in the dry, dormant embryonic‐axes than in the after‐ripened ones, and (2) the inability of the former to sythesise tbe tibberetllin as indicated by the lower content compared to the after‐ripened ones kept in water. Exogenousty supplied GA3 (0.1 mg/1) increased both the endogenous gibberellin and growth of the dormant, leached embryonic‐axes to the level of after‐ripened ones.
Influence of the Maize Dwarf Mosaic Virns and Simazine upon the Buffer Soluble Proteins and Catalase Activity of a Virus‐susceptible and a Virus‐tolerant Variety of Zea mays
Authors: Millikan D. F. , Mann Don R.
Published: April 2006

Inbred corn varieties differing in their tolerance to the maize dwarf mosaic virus infection also differ in varietal character and host response to simazine. Oh 7B, a tolerant cv., has less total soluble and globulin proteins than the sensitive variety, H 55, but more Kjeldahl nitrogen, albumin protein and a doubling of catalase activity. Virus inoculation in Oh 7B causes a reduction in all three protein fractions, Kjeldahl nitrogen and catalase activity. Deleterious virus‐simazine interaction does not occur with either variety and the observed varietal and host response differences in protein may account for the conflicting reports of other workers.
The Effect of Light on Nitrate and Nitrite Assimilation by Chlorella and Ankistrodesmus
Authors: Morris L , Ahmed J.
Published: April 2006

Light stimulates the assimilation of nitrate and nitrite by two green algae, Chlorella pyrenoidosa and Ankistrodesmus braunii. Assimilation can be observed when the algae are illuminated in the absence of carbon dioxide under both aerobic and anaerobic conditions. The rates of assimilation by Chlorella do not depend on the presence of carbon dioxide, but Ankistrodesmus assimilates nitrate and nitrite more rapidly when cultures are illuminated in the presence of carbon dioxide than in its absence.

The ratios of O2: NO3′ and O2: NO2′ vary from one experiment to the other and, with the exception of Chlorella cultures reducing nitrite they are higher than the ‘expected’ values of 2.0 and 1.5 respectively.

Oxygen evolution accompanying nitrate and nitrite by algae illuminated in the absence of carbon dioxide is completely inhibited by DCMU at concentrations of 4 × 10‐6 M. However, nitrite assimilation by both Ankistrodesmus and Chlorella and nitrate assimilation by Ankistrodesmus are less sensitive to the inhibitor.
Inhibition of Nitrogen‐Fixing and Nitrifying Bacteria by Seed Plants
Authors: Rice Elroy L.
Published: April 2006

Euphorbia suinna occurs in the pioneer weed stage of succession in abandoned fields in several midwestern states of the United States. It was previously found to be very inhibitory to several test strains of nitrogen‐fixing and nitrifying bacteria and to several associated seed plants. The present project was concerned wilh the identification of the chief inhibitors produced by that species, using appropriate column and paper chromatographic techniques, and by tests of bacterial inhibition employing the diffusion technique on solid media. Three hydrolyzable tannins were consistently isolated from extracts of the species. All three tannins and purified reagent tannic acid from at least two commercial sources yielded ellagic acid, gallic acid, and glucose on hydrolj'sis by acid or tannase. All yielded one or more additional phenolics which were not identified. The tannins from E. supina were all slightly different from each other and from commercial reagent tannic acid as indicated by different Rf's on paper, elution sequence from polyamide columns, and relative amounts of glucose, ellagic acid and gallic acid produced on hydrolysis.
An Interaction between the Effects of Kinetin and Gibberellin in Retarding Leaf Senescence
Authors: Back A. , Richmond A.
Published: April 2006

The relation hetween the effects of kinetin and gibberellin on retardation of leaf senescence was studied. Leaf discs were incubated for five days in several hormone concentrations, the chlorophyll was extracted and its amount estimated spectrophotometrically. Investigation of leaves from actively growing plants of Taraxacum megalorrhizon and Tropaeolum majus showed that an interaction existed between the effect of both hormones. Leaf age, light intensity and day length had a marked effect on the degree of response to the hormonal treatments, hut the change in response effected by these conditions remained similar for both hormones. Possible interpretations of the interaction observed between the effects of kinetin and gibberellin are discussed.
Pathways of IAA Production from Tryptophan by Plants and by Tbeir Epipbytic Bacteria: a Comparison
Authors: Libbert Eike , Drawert Anneliese , Schröder Roswitha
Published: April 2006

Under nonsterile conditions, IAA can be extracted from pea stem sections infiltrated with buffer, IAA, or tryptophan. This IAA has microbial origin, since its occurrence is prevented by antibiotics. All infiltrated IAA disappears in the sections. Under sterile conditions, several inhibitors of IAA oxidase prevent the complete disappearance of infiltrated IAA. Some of them permit, by preventing the disappearance of produced IAA, the formation in vivo of extractable IAA amounts from tryptophan. This IAA production is further increased by pyridoxal (phospbate), and by α‐ketoglutarate.
Phase‐shift in Geotropical Oscillations – A Theoretical and Experimental Study
Authors: Johnsson A. , Israelsson D.
Published: April 2006

Geotropically induced phase‐shifts in circumnutations of Heliauthus annuus hypocotyls are studied. – Theoretical deductions from a previously developed theory for geotropical movements are made for the case of a short gravitational stimulation in different phase positions of an oscillating hypocotyl. – Experimental studies are performed to test the theoretical results. – The conclusions are drawn, that the theory mentioned can satisfactorily describe geotropically induced phase‐shifts. A comparison with phase‐shifts in photoperiodic systems is made.
An Investigation of Bidirectional Translocation in the Phloem
Authors: Peterson CarolA. , Currier H. B.
Published: April 2006

Patterns of 14CO2, assimilate movement in Vicia jaba plants having 7 nodes were studied. Bidirectional translocation occurred throughout most of the stem length when tracer was applied to leaves of various ages. To determine whether this bidirectional translocation occurs within single sieve tubes, a O.1 % solution of the fluorescent dye K‐fluorescein was applied to a lightly scraped area on the stem in the middle of a young internode. After one hour the dye was present short distances above and below the treated area. Free‐hand sections of the internode showed the dye to be localized in the traces of the larger leaves below tbe treated area and in the traces of the younger leaves above the treated area. The dye was never present in the same bundle both above and below the treated area, indicating that each bundle and sieve tube translocated the dye in only one direction. These results were confirmed using Phaseolus vulgaris, Vinca rosea, and Pelargonium hortum. A similar study in which petioles of young Ecballium elaterium leaves were treated showed that usually the phloem of one bundle translocated the dye in only one direction but in some cases the external phloem of the bicollateral bundles carried the dye toward the stem while the internal phloem carried the dye toward the blade. When longer time intervals were used in all these experiments, the dye sometimes appeared in the same phloem areas both above and below the treated area. This is explained by a lateral transfer of tracer within the phloem, either through secondary phloem or through bundle anastomoses at the nodes.
Callus Cultures of Tomato Mutants
Authors: Ulrich Jane M. , Mackinney G.
Published: April 2006

Callus from hypocotyl, stem, and fruit tissue of tomato mutants was grown on a complex pea extract medium. The genotypes responded differently to the levels of nutrients and stimulators or inhibitors in the medium. Hypocotyl callus of yellow (r) tomato required K2SO4 for quick establishment and continued steady growth for several months; callus of this mutant could also grow with 0.5 % dimethyl sulfoxide in the medium, although growth was less than the control. The red ghost (r+gh) mutant is sensitive to a toxic component in the pea extract, and makes its best growth with the standard minerals and vitamins, but in 1/2 concentration pea extract plus 5 % coconut water. Tangerine (t), red lutescent stem (r+l2), and r+gh are mutants which respond differently to thiourea: t grows about the same at all concentrations, r+gh grows best at low thiourea, and r+l2 grows best at the specific level of 20 mg/l thiourea. The recent active t or r+l1 and r+l2 isolates require supplementary auxin to which the older, slow‐growing isolates do not respond. However, there is variation in growth response of different isolates of the same mutant. The several red (r+) cultures are similar in their slow growth, but somewhat different in responses to specific nutrients. The recent + isolate is one of the most active cultures, in comparison to the slow growth of t callus isolated in 1964. It is therefore concluded that growth is affected both by the specific requirements of the mutant and by the age and vigor of isolates.
Influence of Light on Germination of Pinus palustris Seeds
Authors: McLemore B. F. , Hansbrough Thomas
Published: April 2006

Red light with a wavelength of 660 nm promotes germination of longleaf pine (Pinus palustris Mill.) seeds, and far‐red light (730 nm) inhibits germination. The promotion‐inhibition process is repeatedly reversible, indicating that germination is controlled by the photoreversible reaction of phytochrome. Response varied greatly between single‐tree lots and was dependent on the length of time seeds were imbibed at 5°C. Dry seeds did not respond to light treatments when they were subsequently imbibed and tested in darkness. Stratification for 28 days essentially removed the light requirements for germination.
The Adaptation of Plankton Algae
Authors: Jøsrgensen Erik G.
Published: April 2006

The variation in Skeletonema cells grown at 3 klux continuous illumination and 20°C is reported. Four different types of lamps gave no difference in the photosynthetic characteristics. The average diameter of the cells decreased from 8–3.5 μ during their six months vegetative period. The ratio between the pigment content in the largest and the smallest cells was about 2:1. A good correlation between cell volume and chlorophyll a content was found for this species. The content of chlorophyll c generally varied between 4 and 17 per cent of the chlorophyll a content. — A distinct correlation between the chlorophyll a content and the rate of photosynthesis per unit of cells at low light intensity was found. The rate of photosynthesis, in mg C per mg chlorophyll a and hour at 1 klux, varied between 0.40 and 0.70 for all 60 experiments with an average value of 0.56. The corresponding value for cells deficient in phosophorus was 0.19 and for cells deficient in nitrogen 0.09. — The material also showed a good correlation between the rate of photosynthesis per cell at 1 klux and the light‐saturated rate of photosynthesis. Ik varied between 7 and 13 klux.
The Chemical Induction of Supernumerary Shoots in the Developing Embryos of Wheat
Authors: Ferguson J. D. , McEwan J. M.
Published: April 2006

The induction of seedlings with multiple shoots by the in vivo treatment of embryos of wheat by herbicides such as 2,4‐D, 2,4,5‐T, MCPA and TBA as well as mixtures of these substances was studied. Treatment during the first week of embryo development was necessary for the production of additional shoots in the seedling; later treatment gave rise to callused seedlings. Other seedlings such as oats, barley and rye, and other species of wheat were treated, but seedlings with extra shoots were not produced, though callused seedlings were recovered.
Über den Einfluss hypotonischen Milieus auf den Stoffwechsel dereprimierter pflanzlicher Gewebe
Authors: Lange Horst , Kahl Günter , Rosenstock Günter
Published: April 2006

During investigations of their metabolism fragments of plant tissue are most commonly incubated in watery solutions in order to replace the conditions within the intact organ approximately. — This paper reports experiments performed to investigate the influence of a hypotonic medium on several parameters of importance in cell metabolism (protein synthesis, enzymatic activity, concentrations of metabolic intermediates, respiration and cell division). — It could be shown that protein synthesis is severely inhibited in hypotonically exposed potato tuber discs. As a consequence the activities of two dehydrogenases of the pentose phosphate shunt (glucose‐6‐phosphate‐ and 6‐phosphogluconate‐dehydrogenase) are very low as compared with tissue in air. Since the activated pentose shunt evidently contributes to the respiratory reaction after derepression of the tissue, lowered activities of these dehydrogenases must consequently result in lower respiratory activity. This is actually realized in washed tissue. Likewise the mitotic activity is inhibited to a considerable extent. — The destruction of permeability barriers within the cell as a consequence of slicing causes leakage of a variety of metabolites such as glucose, glucose‐6‐phosphate, fructose‐6‐phosphate and pyruvate. Thus leaching of metabolic active substances is certainly one of the causal factors in the complex reaction of tissue slices exposed to a hypotonic medium, although such important parameters as changed gas conditions and the various effects of altered hydration of cell cytoplasm must be considered.
Callus Cultures of Tomato Mutants II. Carotenoid Formation
Authors: Ulrich Jane M. , Mackinney G.
Published: April 2006

Carotenoid synthesis in the fruit of tomato mutants is under gene control. Since undifferentiated plant cells are presumably totipoltent, the callus tissue should be able to produce the carotenoids typical of the genotype. The carotenoids of masses of callus derived from hypocotyls of the red ghost and tangerine tomatoes were extracted and characterized by means of column and thin layer chromatography, chemical and spectral properties. The red ghost callus contained predominantly phytoene and phytofluene; the tangerine callus had primarily ζ‐carotene and prolycopene. Thus under our cultural conditions, carotenoids typical of the fruit rather than the leaf were produced, albeit in much reduced quantities.