bluuebunny/crossref_metadata_2025 huggingface dataset:
The Effect of Kinetin on the Occurrence of Acid Auxin in Coleus blumei
Authors: HEMBERG TORSTEN
Published: April 2006

Excised shoots and potted plants of Coleus blumei Benth, were subjected to different treatments with kinetin solutions. Control treatments were made with water. Free and bound auxin were extracted with ether. The acid fractions were purified by electrophoresis to remove all traces of kinetin, and were then analyzed with the Avena straight‐growth test.

As compared with the controls, kinetin treatment increases the bound auxin, whereas the corresponding free auxin is unchanged. Also methanol extracts of treated stems contain more acid auxin than corresponding extracts of water‐treated stems. This indicates that on methanol extraction not only free auxin but also some bound auxin is obtained. The extracted auxin behaves like indoleacetic acid in paper chromatography with four different solvent systems, as well as in gel filtration through Sephadex.

New formation or decreased breakdown of auxin seem the most likely explanations for the observed effects of kinetin.
Interaction of Kinetin and Indoleacetic Acid in the Avena Straight‐Growth Test
Authors: HEMBERG TORSTEN , LARSSON ULF
Published: April 2006

Kinetin has a stimulating effect in the Avena straight‐growth test. The action of different concentrations of kinetin, 2.5 × 10−7, 2.5 × 10−6 and 2.5 × 10−5M, in combination with different concentrations of IAA was studied in this test. It was shown that the effect of low IAA concentrations, 0.25 × 10−7 and 1 × 10−7M, was strongly enhanced by the addition of all the kinetin concentrations investigated. The effect of the highest IAA concentrations, 25 × 10−7 and 100 × 10−7M, on the other hand, was inhibited relatively strongly by the highest employed concentration of kinetin. The results are explained as due to a kinetin‐produced increase of auxin in the coleoptile segment, which in combination with low IAA concentrations can lead to a growth stimulation and with high IAA concentrations to a growth inhibition.

Since kinetin in purification and chromatography of auxin can partly follow IAA, thereby affecting the quantitative yield, it is emphasized that, prior to the test, auxin extracts containing cytokinins should be freed from the latter by, for example, gel filtration or paper electrophoresis.
Changes in Amino Acid Content and the Metabolism of γ‐Aminobutyrate in Cucurbita moschata Seedlings
Authors: CHOU KUO‐HOWERE , SPLITTSTOESSER WALTER E.
Published: April 2006

Ungerminated pumpkin (Cucurbita moschata Poir.) cotyledons contained 30 % of their dry weight as lipid and 26 % as protein, of which 93 % was globulin. There was a rapid degradation of these reserves 4 to 8 days after planting when the cotyledons had their maximum metabolic activity. About half of the mole percent of amino acids found in the globulin reserve was in arginine, glutamate, aspartate, and their amides. The cotyledons had a large soluble pool of arginine, glutamine, glutamate, and leucine. Most amino acids increased steadily in amount in the cotyledons during germination, except glutamine, ornithine, alanine, serine, glycine, and γ‐aminobutyrate and these appeared in large amounts in the translocation stream to the axis tissue. Little arginine or proline was translocated. By 10 days, when translocation had decreased, amino acids accumulated. Ornithine, γ‐aminobutyrate, and aspartate were rapidly utilized in the hypocotyl, while glutamine, glycine, and alanine accumulated there. Cysteine and methionine levels were low in the reserve, trans‐location stream and soluble fractions. γ‐Aminobutyrate‐U−14C injected into cotyledons or incubated with hypocotyls was utilized in a similar fashion. The label appeared in citric acid cycle acids and in the amino acids closely related to this cycle, but the bulk of the label appeared in CO2. The labeling pattern suggests that γ‐aminobutyrate was utilized via succinate, and thus entered the citric acid cycle. A close relationship between arginine, ornithine, glutamate, and γ‐aminobutyrate exists in the cotyledon with all but arginine being translocated rapidly to the axis tissue where these amino acids are rapidly metabolized.
Isoenzyme Activities during the Early Stages of Allium Radicle Germination
Authors: MALLERY CHARLES H.
Published: April 2006

As a continuation of a study of the molecular events surrounding the establishment of a mature root apex, changes in the pattern and specific activity of the isoenzymes of aminopeptidase (AmP), esterase (EST), glucose‐6‐phosphate de‐hydrogenase (G6PD) and glutamic‐oxaloacetic transaminase (GOT) were investigated during the early germinative growth of the Allium radicle tip.

Polyacrylamide disc gel electrophoresis revealed a total of 9 EST fractions. A shift in pattern and reactivity characteristic of pre‐emergence to those characteristic of post‐emergence was demonstrated.

G6PD electropherograms displayed 5 isoenzyme bands. Relative specific activity analyses indicated that this enzyme may be more important during the very early stages of germination.

Only quantitative differences were noted in the 3 AmP isoenzymes detected. The progressive increase in AmP isoenzyme activity during the period of maximal protein body degradation suggested a role for these exopeptidases in the degradation of reserve proteins.

The 3 isoenzyme bands of GOT exhibited only quantitative changes during germination. Parallel increases in the quantity of soluble protein and GOT specific activity suggest that this isoenzyme is involved in the onion's nitrogen metabolism during germination.
Effects of Ethylenediaminetetraacetic Acid, Auxin and Gibberellic Acid on Phytochrome Controlled Nyctinasty in Albizzia julibrissin
Authors: McEVOY ROBERT C. , KOUKKARI WILLARD L.
Published: April 2006

Nyctinastic closure of Albizzia julibrissin pinnules is inhibited by 5 × 10−2M ethylenediaminetetraacetic acid. At least two hours of incubation are required for maximum inhibition and destruction of the phytochrome effect.

Concentrations of 10−3 to 10−5M naphthaleneacetic acid reduced the nyctinastic closure of pinnules but not the phytochrome response. Similar results were obtained with indoleacetic acid and gibberellic acid. No appreciable differences in pinnule movements could be attributed to pH. Chelation or the inhibition of ion transport resulting in, or caused by, changes in membrane permeability are suggested as possible mechanisms involved in these effects.
Incorporation of Labeled Precursors into, and Accumulation of, Triglycerides and Phosphoglycerides at Selected Stages of Fungal Growth
Authors: JACK CECIL , ANEKWE GREGORY E.
Published: April 2006

There was greater incorporation of [2−14C] acetate and of [6−14C] glucose into phosphoglycerides than into triglycerides, of 1 1/2, 2, 3, 4 and 6 day old mycelial sample of the fungus Glomerella cingulata. Maximum incorporation into both classes of lipids occurred in young mycelial samples (2 to 3 days of age) which had a high content of total nitrogen. The five sets of mycelial samples all contained somewhat larger quantities of phosphoglycerides than triglycerides, and changes in content of both classes of lipids were similar in pattern to changes in content of total nitrogen. Incorporation, accumulation and total nitrogen of the mycelial samples, decreased at 4 days but increased again by 6 days. The apparent turnover of the triglycerides and phosphoglycerides was qualitatively similar although there was greater apparent turnover of phosphoglycerides than triglycerides; the similarity in patterns of apparent turnover was inferred to be a consequence of acyl exchange between labeled and unlabeled triglycerides and phosphoglycerides. There was greater incorporation of [2−14C] acetate into the acyl than into the glyceryl moieties of both classes of lipids but greater incorporation of [6−14C] glucose into the glyceryl than acyl moieties. With both precursors, the glyceryl and acyl moieties of the phosphoglycerides were more heavily labeled than corresponding moieties of the triglycerides.
Pénétration et migration du 59Fe appliqué sur les feuilles de Maïs; effet du dimáthylsulfoxyde
Authors: CHAMEL A.
Published: April 2006

The uptake and translocation of 59Fe applied to leaves of Zea mays L. is studied with special reference to the effect of dimethylsulfoxide (DMSO). 59Fe is deposited on corn leaves as droplets of solution of ferrous sulfate or ferric nitrate (1 mM. The uptake of 59Fe is affected by the associated anion; the penetration is more important with the nitrate than with the sulfate. The translocation of 59Fe from the treated part during 24 hours is very low in all the experiments. The exsorption of 59Fe taken up, from the site of application in different solutions (FeSO4, 7H2O; EDTA Na) concerns only a low percentage of 59Fe present in the treated part. DMSO (0.5 and 1 %) increases the uptake but not the translocation of 59Fe applied as sulfate; it seems to have no effect when iron is applied as nitrate. The increase during 24 hours reaches between 32 % and 53 % in seven experiments with sulfate. The effect also appears in an experiment conducted during four weeks, with several applications of ferrous sulfate during this time. This effect of DMSO is discussed: it is mainly explained by the great hygroscopicity of this solvent, therefore the effect would in part depend on the solubility of salts in concentrated DMSO and of the climatic conditions: relative humidity and temperature of the air.
Specific Structural Alterations of the Chloroplasts of Spinach Leaves by Neutral Salts
Authors: YAO VIVIANA J. , STERLING CLARENCE , STOCKING C. RALPH
Published: April 2006

Freshly isolated spinach (Spinacea oleracea) chloroplasts were treated with 4 different neutral salt solutions at concentrations of 1 and 2 M for ultrastructural study. Each salt induces a specific pattern of structural disorganization. In KCl, there is principally swelling of the fret‐canal and end‐granal‐compartment loculi. With KI, there is removal of green pigment, loss of some stainability, swelling, and separation of the individual membranes of the granal partition layers. Sodium trichloracetate causes apparent end‐to‐end fusion of granal stacks and their curvature; and in KSCN there is a great volume increase, related to the separation of the membranes of the partition region and extensive swelling of all the loculi.

This work has been rendered possible through a grant from the National Science Foundation (GB 12906).
Changes in Nicotinamide Nucleotide Coenzymes in Cucumber Leaves during Ammonium Toxicity
Authors: WAKIUCHI N. , MATSUMOTO H. , KONDO S. , TAKAHASHI E.
Published: April 2006

Nicotinamide nucleotide coenzymes were estimated enzymatically in cucumber leaves (Cucumis sativus L. cv. Suisei No. 2) during ammonium toxicity. The contents of all the coenzymes (NAD(H) and NADP(H)) were found to be higher in the ammonium‐treated plants than in the control plants, and the difference attained a maximum at 5 days after the initiation of ammonium treatment. Thereafter, the contents of NAD and NADH returned towards the control level, but NADP and NADPH levels were lowered in injured plants. The ratios of NAD/NAD + NADH and NADP/NADP ++ NADPH were little altered by the ammonium treatment.

Changes of nicotinamide nucleotide coenzymes are discussed in relation to respiratory metabolism in cucumber leaves during ammonium toxicity.
The Effect of Red and Far‐red Light on Subsequent Enzyme Activity in Arena Coleoptiles
Authors: SPEER HENRY L. , PALMER DOUGLAS S.
Published: April 2006

The effect of red light (660 nm), far‐red light (730 nm) and dark treatment on the subsequent enzyme activity in homogenates of Avena coleoptiles was investigated. The activities of succinic dehydrogenase (SDH), lactic dehydro‐genase (LDH) and glucose‐6‐P dehydrogenase (GDH) were investigated. The activity of SDH was greatest in material receiving continuous darkness. LDH and GDH activity was stimulated by both light treatments compared with the dark values. Little or no difference in enzyme activity was found using either a single 15 min flash of light or continuous light for 24 h. Admixtures of extracts from dark treated and light treated material in a 1:1 ratio gave unexpected levels of enzyme activity. In all cases such admixtures gave much less than the anticipated enzyme activity.
The Influence of Potassium on the Transpiration Rate and Stomatal Opening in Triticum aestivum andPisum sativum
Authors: BRAG HOLGER
Published: April 2006

The investigation concerns the influence of potassium on the transpiration rate of Triticum aestivum and Pisum sativum grown in nutrient solutions. Plants with high amounts of potassium were found to have the lowest transpiration rates. Shoot/root ratio, stomatal frequency, and stomatal aperture were correlated with the potassium concentration in the leaves. In Triticum no correlations with leaf concentration of Na were evident.

Short term experiments were carried out in order to investigate the effects on the transpiration rate of a sudden increase in potassium concentration in the nutrient solution. An addition of potassium chloride to potassium deficient wheat plants resulted in a decrease in the transpiration rate of up to 50% within two hours. Comparative tests with sodium chloride resulted in a decrease in transpiration rate of the same magnitude, indicating that the short‐time reaction is not specific to potassium.

The experiments show that the transpiration rate can be regulated by varied potassium and sodium concentrations. The observed effect is supposed to be due to changes in the stomatal aperture.
Changes in Amounts of Chloroplast and Cytoplasmic Ribosomal‐RNAs and Photomorphogenesis in Dryopteris Gametophytes
Authors: ROWLAND GARY P.
Published: April 2006

The basis for the difference in total‐RNA base composition between the filamentous and the prothallial gametophytes of the fern Dryopteris has been examined. Analyses of the relative amounts of chloroplast rRNA (i.e. chloroplast rRNA/chloroplast + cytoplasmic rRNA) indicate a shift to a higher level of chloroplast rRNA in the transition from filamentous to prothallial growth. This increased level of chloroplast rRNA is of sufficient magnitude to be entirely responsible for the observed change in total‐RNA base composition. Time‐lapse analysis of the photomorphogenetic transition to prothallial growth shows that a 2–3 h lag proceeds the first response (tip swelling). Pulse‐labelling experiments reveal an increased synthesis of chloroplast rRNA during the transition to prothallial growth; but this increase occurs after the onset of the photomorphogenetic change and therefore cannot be considered causally involved. These results provide a biochemical correlate for the cytological observations on size changes in the nucleoli and chloroplasts of these gametophytes.
Scanning Electron Microscopy of the Nematode‐trapping Organs in Arthrobotrys oligospora
Authors: NORDBRING‐HERTZ BIRGIT
Published: April 2006

The three‐dimensional capture organs of the nematodetrapping fungus Arthrobotrys oligospora are presented in scanning electron micrographs.

The fungus was grown directly on agar substrates or on millipore filters or glass cover slips placed on agar substrates. To avoid shrinkage of the soft‐walled mycelial material, a fixation in OsO4‐vapour was performed, before freeze‐drying and coating with Au‐Pd alloy.

When capture organs were prepared in this way, it was possible to visualize them in their erect position in the scanning electron microscope. Young capture organs, both spontaneously formed and nematode‐induced, remained standing better than old ones.

An adhesive substance on the capture organs, with the aid of which nematodes are trapped, seems to be visible in these pictures.
Responses of Populus tremula to Picloram and Other Translocated Herbicides
Authors: ELIASSQN LENNART
Published: April 2006

Whole aspen plants and isolated aspen root segments were three to ten times more sensitive to the growth‐inhibitory and toxic effects of picloram than to those of 2,4‐D, 2,4,5‐T and dicamba.

The activity of picloram in the inhibition of root growth was about ten times higher than that of 2,4‐D and dicamba when tbe substances were added to the nutrient solution. Epinastic responses indicated a very rapid translocation of picioram from the roots to the growing shoot parts. When the herbicides were applied to the mature leaves dicamba rapidly caused a complete inhibition of root growth indicating a rapid translocation of this compound from the leaves to the root tips. Leaf‐applied picloram, 2,4‐D and 2,4,5‐T affected root growth considerably more slowly. Dicamba, 2,4‐D and 2,4,5‐T rapidly killed the directly treated leaf tissue due to high acute toxicity while picloram did not show this type of toxicity. It is concluded that the higher activity of picloram in killing the plant and in inhibition of root and shoot growth can only partly be explained as a result of greater uptake and translocation of this compound.
Control of Auxin‐induced Stem Elongathn by the Epidermis
Authors: MASUDA YOSHIO , YAMAMOTO RYQICHI
Published: April 2006

Segments of the 4th and 5th internodes of light‐grown pea seedlings were used for the study of control of stem elongation. With 5th internodes, at low turgor as well as at water saturation auxin primarily appeared to cause a change in cell wall properties of the epidermis but it showed little effect on expansion af the inner tissue. This was confirmed by comparison of expansion between peeled and unpeeled segments, split tests and by measurements of stress‐relaxation properties of the epidermal cell wall. Segments with the central part re‐moved elongated well in response to auxin, but the isolated epidermis showed neither auxin‐induced elongation nor cell wall loosening. A fungal β‐1,3‐glucanase appeared, at least partly, to have a similar effect as that of auxin on elongation, by changing cell wall properties of the epidermal cell wall. Peeled segments of 4th internodes expanded very little and auxin had little effect on their epidermal cell wall properties.
Activation and Inactivation of Alcohol Dehydrogenase in Germinating Pea Cotyledons
Authors: SUZUKI YONEZO , KYUWA KUMIKO
Published: April 2006

Alcohol dehydrogenase (E.C.1.1.1.1.) activity increases markedly in the germinating pea cotyledon in the first 2 days. The activity was not suppressed by the administration of actinomycin D, 6‐methylpurine, DL‐p‐fluorophenylalanine, and D‐chloramphenicol. The compounds rather depressed the decrease of alcohol dehydrogenase activity in cotyledons after 3 days of germination. The alcohol dehydrogenase activity in ungerminated pea seeds was activated by treatment with sodium lauryl sulphate, sodium dioctyl sulfosuccinate, dithiothreitol, 2‐mercaptoethanol and NADH. The inhibitory effect caused by the extract from 7 day‐old cotyledons was diminished markedly in the presence of dithiothreitol and 2‐mercaptoethanol, as well as by addition of bovine serum albumin. If dithiothreitol was added to the extraction medium, the enzyme activity from older cotyledons was greatly enhanced.
Characterization of Copper Texicity in Lettuce Seedlings
Authors: MUKHERJI SUBHENDU , GUPTA BISHNUPRIYA DAS
Published: April 2006

This paper provides information on the effects of toxic concentrations of cupric sulphate on the growth of lettuce (Lectuca sativa) seedlings. Root growth is completely inhibited at 5 x 10‐2M and germination stops altogether at 10‐1M. The relative inhibition of root growth is stronger than that of hypocotyl growth. Various metabolites and hormones are partially capable of relieving copper inhibition.

Catalase, peroxidase and IAA‐oxidase activity shows increments directly proportional to the concentration of copper. It is obvious that growth is inversely proportional to enzyme activity. The increased level of these enzymes is probably due to an accelerated protein synthesis.
Translocation and Complex Formation of Picloram and 2,4‐D in Wheat Seedlings
Authors: HALLMÉN ULF , ELIASSON LENNART
Published: April 2006

Uptake, translocation and metabolism of 14C‐labelled 4‐amino‐3,5,6‐trichloropicolinic acid (picloram) and 2,4‐dichlorophenoxyacetic acid (2,4‐D) in seedlings of wheat (Triticum aestivum L.) were studied.

The uptake of the herbicides through the upper surface of the first leaf was slow but was almost complete after nine days. Picloram was absorbed faster than 2,4‐D. Picloram was also translocated into the stem and the untreated leaves to a greater extent than 2,4‐D. Only small fractions of the activity were recovered from the roots and from the nutrient solution.

Picloram and 2,4‐D formed water‐soluble conjugates in the tissues. These conjugates were very labile and hydrolyzed under release of the unchanged herbicides. The isotope from 2,4‐D was also incorporated in an insoluble fraction, containing cell walls and proteins. Also from this fraction biologically active 2,4‐D could be released by hydrolysis. The formation of the complexes was partly prevented by cycloheximide.

It is suggested that herbicide detoxification through complex formation is of importance for the relatively low sensitivity of wheat to auxin herbicides.
Peroxidase and IAA Oxidase Activity and Isoenzyme Patterns in Cucumber Plants, as Affected by Sex Expression and Ethephon
Authors: RETIG NIRA , RUDICH J.
Published: April 2006

Peroxidase and IAA‐oxidase activity, electrophoretic patterns of total proteins and isoenzymes and the effect of Ethephon (= Ethrel, 2‐chloroethane phosphonic acid) on these patterns were compared in extracts of monoecious and gynoecious cucumber plants. The activity of both peroxidase and IAA oxidase was greater in gynoecious than in monoecious plants. Ethephon treatments given at the 2‐leaf stage increased peroxidase activity, especially in monoecious plants, and decreased IAA‐oxidase activity. Ethephon treatment did not affect total protein or isoenzyme patterns, but increased band intensity, especially that of one band in monoecious plant extracts. No differences between monoecious and gynoecious plants were found in total protein, peroxidase and IAA‐oxidase isoenzyme patterns. Peroxidase and IAA‐oxidase activity sites on the gel were similar.
Effect of Temperature and Some Antimetabolites on the Interaction Effects of Auxin and Nutrition in Rooting Etiolated Stem Segments of Salix tetrasperma
Authors: JAIN M. K. , NANDA K. K.
Published: April 2006

Rooting on 2.5 cm long stem segments of Salix tetrasperma was optimal when cultured in 5.0 mg/I IAA in combination with 1.0 % glucose at 30°C, and in combination with 0.1 % glucose at 15°C. 5‐Fluorodeoxyuridine (FUDR), actinomycin‐D and cycloheximide all inhibited rooting and the inhibitory effect in each case increased with concentration. 5‐Fluorouracil (FU), on the other hand, was ineffective. The results show that auxins probably act as a triggering agent for the synthesis of specific enzyme proteins that are required for the initiation of root primordia at the transcriptional level and that a correct balance of auxin and nutrition which may vary with the environmental conditions, is necessary for optimal rooting.
The Influence of Inorganic Ions on the Heat Stability of a Thermophilic Bacteriophage
Authors: LJUNGER CLAES , EDEBO MARGARETA
Published: April 2006

A thermophilic bacteriophage was isolated from soil. Heat inactivation of this phage, suspended in tryptone starch broth at 65°C and 70°C, was found to be a monomolecular reaction. The phage was more heat stable in tryptone broth than in tris buffer. When the tris buffer was supplemented with calcium or magnesium ions, the survival percentage increased from 0.0 to 18.0 after two hours of heating at 65°C. The addition of sodium or potassium ions to the tris buffer had no significant effect. Equimolar solutions of calcium and magnesium chloride had the same effect on the heat stability of the phage. Maximum stability was attained in 2.5 mM solutions of these salts, and a further increase in the concentration up to 10.0 mM did not increase the percentage of surviving phages.
Swelling in Bean Shoot Mitochondria Induced by a Series of Potassium Salts of Organic Anions
Authors: LEE DANIEL C. , WILSON RICHARD H.
Published: April 2006

A series of potassium salts of organic anions were examined for their effect on the volume change of bean shoot mitochondria as measured by spectrophotometric light scatterings. A passive osmotic swelling (substrate independent) as well as an active osmotic swelling (substrate dependent) was shown with a series of organic anions. Both oxidizable substrates and non‐oxidizable substrates induce swelling. The monocarboxylic acids including acetate, β‐OH‐butyrate, propionate, and pyruvate induce active swelling which is partially inhibited by the presence of an ATP generating system or the uncoupler 2,4‐dinitrophenol (DNP). Dicarboxylic acids produce less extensive rates and amounts of active swelling. Moreover, the swelling induced by dicarboxylic acids is inhibited less completely by an ATP generating system or by DNP. Metabolizable substrates including citrate, pyruvate, glutarate, and α‐oxo‐glutarate induced swelling despite their poor rates or lack of oxidation. It was concluded that with these anions, penetration across the inner membrane as measured by osmotic swelling of isolated mitochondria is not the rate limiting step in their metabolism.
Short‐ and Long‐term Effects of High Temperatures (47–49 °C) on Tobacco Leaves. I. Photosynthesis
Authors: ZIONI ALIZA BEN , ITAI CHANAN
Published: April 2006

Detached Nicotiana rustica leaves were exposed for 2 minutes to temperatures in the range 36° to 51°C. Above 45°C, 14CO2 fixation was reduced by half as compared with controls. The fall in 14CO2 fixation continued for 2 1/2 h. Recovery was completed 45 h after the treatment. Above 45°C there was an increase in the labeled cationic and anionic fractions and a decrease in the neutral fractions, both increase and decrease being associated with the impaired CO2 fixation. However, these changes in products were also demonstrated when leaves were exposed to the high temperature after labeling.
The Relationship between Exogenous Growth Inhibitors and Endogenous Levels of Ethylene, and Tuberization of Dahlias
Authors: BIRAN I. , GUR I. , HALEVY A. H.
Published: April 2006

Treatments with abscisic acid (ABA), succinic acid‐2,2‐dimethylhydrazide (SADH), or 2 chlorethyl phosphonic acid (ethephon) promoted the tuberization of dahlia plants in long‐days. This effect was smaller, however, than the effect short days have on tuberization. In contrast, gibberellic acid (GA) treatments inhibited tuberization. SADH and ethephon treatments of budless leaf‐cuttings inhibited tuberization whereas ABA treatments slightly enhanced it. Evolution of endogenous ethylene reached a peak between the second and third week after the start of short‐day treatments, and then decreased to the low level found in plants growing under long days. The peak in ethylene evolution occurred one week before the onset of tuberization.
Recherches sur les enzymes catalysant la biosynthèse des acides phénoliques chez Quercus pedunculata. III. Formation séquentielle, à partir de la phénylalanine, des acides cinnamique, p‐coumarique et caféique, par des organites cellulaires isolés
Authors: ALIBERT GILBERT , RANJEVA RAOUL , BOUDET ALAIN
Published: April 2006

The reactions leading to cinnamic acids from phenylalanine as only substrate were investigated in organelles from Quercus pedunculata Ehrh. roots.

–“F 10 000′” fraction, including mitochondria and micro‐bodies, catalyses the first reaction, i.e., cinnamate formation by deamination of phenylalanine.

– Microsomal fraction catalyses all the steps from phenylalanine to caffeic acid via cinnamate and p‐coumarate. These results suggest that microsomes are the intracellular site of the cinnamic units synthesis. The enzymes involved in these reactions, associated in the same cellular compartment, does not form a multienzyme system. The formation of caffeic acid by isolated microsomes is demonstrated for the first time; the reaction may be realised by an enzyme different from phenolase.

– The free phenolic acids are the metabolically active forms.
The Fate of Exogenously Applied Indoleacetic Acid in Light Grown Stems
Authors: DAVIES P. J.
Published: April 2006

Elongating segments from light grown pea (Pisum sativum L. cv. Alaska) and bean (Pbaseolus vulgaris L. cv. Red kidney) stems were incubated in 10‐5M indoleacetic acid (IAA)‐1‐14C,and ‐5‐3H in the light. Radoactive derivatives, extracted in water, ethanol or ether, and 1 N sodium hydroxide at three different times were chromatographed in three separate systems and the different metabolites identified by their labeling and chromatographic characteristics. Major metabolites included indoleacetyl aspartate, possibly indoleacetyl glucoside, hydroxymethyloxindole, and in bean a further major unidentified compund. Other compounds occurred in lesser amounts. Indole aldehyde was present only in very small quantities. IAA breakdown commenced between 1 and 6 h of incubation, following which IAA decreased and most metabolites increased, though IAA was still present after 24 h. Alkaline hydrolysates contained mainly IAA at a level which changed little between 6 and 24 h.
Morphogenetic Investigations in Callus Cultures of Tylophora indica
Authors: RAO P. S. , NARAYANASWAMI S.
Published: April 2006

Callus cultures derived from stem explants of Tylophora indica (Fam. Asclepiadaceae) show a broad spectrum of tissue differentiation and regenerative potentialities over a wide range of nutrient conditions resulting in the production of roots, shoots, bipolar embryos and plantlets. This has been investigated and interpreted on a histological basis. Studies on the morphogenesis of embryos have shown that only such embryonal cells which were deeply embedded with in the callus parenchyma showed an ontogenic development reminiscent of ovular embryogeny whereas in those organized in the superficial layer of the callus the sequence of embryogeny was entirely different. Free cells growing in agitated liquid media first developed into filamentous structures and eventually, by repeated intercalary divisions, organized into bipolar embryos. Development of accessory embryos through cleavage and budding in the callus, differentiation of amphicribral vascular nodules, and meristematic colonies organized into spheres of parenchyma were also observed. These alternative morphogenetic events probably reflect the biochemical subtleties occurring within the callus as a result of an inadequacy or an imbalance of the various constituents in the culture medium.
Growth Hormones and Propagation of Cymbidium in vitro
Authors: FONNESBECH MOGENS
Published: April 2006

Protocorms of Cymbidium (Orchidaceae) were grown on solid or liquid medium with macro‐nutrients according to Wimber (van Raalte 1967) and iron, micro‐nutrients and vitamins according to Nitsch (1968) the medium also contained 2% sucrose. The effects of 1) the auxins; indol‐3yl‐acetic acid (IAA), α‐naphthaleneacetic acid (NAA) and 2,4‐dichlorophenoxyacetic acid (2,4‐D); 2) the cytokinins; 6‐furfurylaminopurine (kinetin) and benzyladenine (BA) and 3) the gibberellin; gibberellic acid (GA) were examined alone or in combinations.

IAA had no effect alone. NAA resulted in optimal fresh weight at 10 μM and the protocorms were vigorous, but lighter green than usual. 2,4‐D caused a high weight increase at 1 μM, but the protocorms were abnormal. Higher concentrations of NAA and 2,4‐D inhibited chlorophyll synthesis. On solid medium kinetin (100 μM) induced a growth of many small shoots, but had no effect on the fresh weight. In liquid medium, kinetin promoted a callus formation and fresh weight increase. BA had effects similar to kinetin, but at lower concentrations. GA alone promoted shoot and leaf growth.

Combinations of kinetin and NAA resulted in a maximal fresh weight increase at kinetin concentrations one tenth of the NAA concentrations. The optimal growth and the best development occurred at 10 μM NAA and 1 μM kinetin. NAA and kinetin together could limit the shoot and leaf growth induced by GA.
Influence of Two Phenoxy Growth Regulators on the Uptake and Accumulation of Naptalam by Bean Plants
Authors: DEVLIN ROBERT M. , YAKLICH ROBERT W.
Published: April 2006

Bean plants (Phaseolus vulgaris L. cv. Black Valentine) treated with 2,4‐dichlorophenoxyacetic acid (2,4‐D) and 4‐chlorophenoxyacetic acid (PCPA) absorb and accumulate considerably more N‐1‐naphthylphthalamic acid (naptalam) than untreated plants. All concentrations of 2,4‐D from 5 x 10‐8 to 5 x 10‐4M were effective, peak stimulation occurring at 3 x 10‐5M. Plants treated with this concentration took up 186% more naptalam than control plants. It was shown that the leaf area (on a per g dry weight basis) was influenced most by growth regulator treatment. The leaf area of plants treated with 5 x 10‐5M 2,4‐D contained 575% more naptalam than the leaf area of untreated plants. The influence of PCPA on naptalam uptake by bean plants was similar to that of 2,4‐D but less effective.
The Effect of Plant Growth Substances on the Hyperchromicity of DNA
Authors: SPANG HENRY A. , PLATT ROBERT S.
Published: April 2006

Deoxyribonucleic acid (DNA) was isolated from four day old, dark grown corn seedlings according to the procedure of Bonner for the isolation of chromatin followed by separation and purification according to Marmur. The purified DNA was dissolved in dilute saline‐citrate and the absorbance at 260 nm of the solution measured as the solution was slowly heated in a quartz cuvette. The degree of increase in absorbance of the DNA in solution as it is thermally denatured was used to assess the interaction of the DNA with plant hormones. Concentrations of 4 x 10‐5M NAA, IAA, 2,4‐D, and GA3 increased the hyperchromicity of the DNA when added to the DNA. Conversely, the same concentrations of CCC, AMO 1618, TIBA, and ABA decreased the hyperchromicity of the DNA. Kinetin, IAN, and tryptophan at 4 x 10‐5M had no measurable effect on the hyperchromicity of the DNA. Deoxyribonucleic acid from Escherichia coli and salmon sperm showed no change in hyperchromicity with added NAA at 4 x 10‐5M. The effect of these plant growth substances is most likely either on the thermally disrupted single strands or on the process in which the double strand opens up to single strands since only the high temperature portion was affected. It is postulated that if the plant growth substances act to alter the binding of the double strands of DNA in an isolated system and if this effect has a relationship to the DNA in an intact cell then this effect may be important in the control of plant growth and development.
The Effect of Photoperiod on Levels of Endogenous Cytokinins in Xanthium strumarium
Authors: VAN STADEN J. , WAREING P. F.
Published: April 2006

The cytokinin content of Xanthium strumarium L. plants decreased markedly when they were exposed to short days (SD). There was a significant decrease in the content of the butanol‐soluble cytokinins of the mature leaves after only 5 SD cycles, and after 10 SD there was no significant cytokinin activity in butanol extracts; the changes in the young leaves were less marked. Most of the cytokinin activity in mature leaves appears to be present in the aqueous fraction, whereas in young leaves most activity occurs in the butanol‐soluble fraction. SD treated plants produced less root exudate than LD plants, but there were no significant differences in the amounts of cytokinin in the root exudates from LD and SD plants collected over an equivalent time period. The cytokinin levels of SD‐induced leaves remained low even when transferred back to LD. The observed differences in cytokinin levels did not appear to be the result of photosynthetic differences. Exposure of detached leaves to LD or SD did not result in differences in cytokinin content. It is not clear whether the observed changes in cytokinin levels in the leaves under SD are involved in the flowering response, but they may be causally related to a reduced chlorophyll content observed in SD‐induced leaves.
Accumulation of (2,4‐dichlorophenoxy) acetic acid and (2,4,5‐trichlorophenoxy) acetic acid by Parenchyma Tissue as Influenced by Metabolic Inhibitors and Lecithin
Authors: SMITH A. E.
Published: April 2006

Parenchyma tissue from potato (Solanum tuberosum L. cv. Russet) tubers was treated with inhibitors to the release of metabolic energy in order to determine the importance of an active transport system for (2,4‐dichlorophenoxy)acetic acid (2,4‐D) and (2,4,5‐trichlorophenoxy)acetic acid (2,4,5‐T) accumulation. Results from treatments with carbonylcyanide m‐chlorophenylhydrazone, an inhibitor of oxidative phosphorylation, and N,N'‐dicyclohexylcarbodiimide, an inhibitor of membrane‐bound adenosine triphosphatase, indicated 2,4‐D and 2,4,5‐T accumulation to be independent of available energy as influenced by these metabolic inhibitors. Lecithin treated parenchyma tissue accumulated more 2,4‐D and 2,4,5‐T than untreated tissue indicating possible binding of the herbicide to the lecithin moiety.
Studies on the Physiology of Host‐parasite Relationship in Orobanche. III. Carbohydrate and Nitrogen Metabolism of Host and Parasite
Authors: SINGH JAGDISH NARAIN , RAI TEJ BAHADUR , SINGH JAI NARAIN
Published: April 2006

Determination of different carbohydrate and nitrogen fractions was made in tomato (Lycopersicum esculentum Mill.) and mustard (Brassica campestris L.) serving as hosts for Orobanche cernua and O. aegyptiaca respectively. Shoots of Orobanche were also subjected to such analyses. Infection raised the level of total reducing and total sugar in the host with a simultaneous decrease in the level of acid‐hydrolyzable and total carbohydrates in the constituent organs of infected hosts. This has been explained to be due to predominance of hydrolytic activity in the infected host. Infection also brought about a depression in the proportion of sucrose to the pool of total sugar in the host. This was also possibly due to predominance of hydrolytic processes and retardation in the synthetic processes. Higher concentration of acid‐hydrolyzable and total carbohydrates in Orobanche than in the host indicated a high demand for sugars by the parasite.

The insignificant differences between the relative proportions of different nitrogen fractions to the pool of total nitrogen in healthy and infected hosts indicated that nitrogen metabolism was not deranged in any way due to infection. Orobanche always had a lower concentration of total soluble and total nitrogen than the host root.
Effect of 4‐Amino‐3,5,6‐trichloropicolinic acid on Protein Synthesis
Authors: BAUR J. R. , BOWMAN J. J.
Published: April 2006

The effects of 4‐amino‐3,5,6‐trichloropicolinic acid (picloram) on protein synthesis in bean (Phaseolus vulgaris L. cv. ‘Astro’) hypocotyl and hook tissues were studied. Picloram (10‐4M) was shown to have a stimulatory effect on 14C‐1‐DL‐leucine uptake in hook but not hypocotyl tissues. Maximum leucine incorporation and maximum total protein concentration occurred in hook tissues treated with 10‐4M picloram. Inhibition of protein synthesis with cycloheximide (CH) and erythromycin (ERY) indicates that endogenous and picloram‐stimulated protein synthesis is a function of the 80S cytoplasmic ribosomes rather than 70S chloroplast or mitochondria ribosomes.
Starch Metabolism, Respiration, and Shoot Formation in Tobacco Callus Cultures
Authors: THORPE TREVOR A. , MEIER DONALD D.
Published: April 2006

The starch content of shoot‐forming and non‐shoot‐forming tobacco callus cultured in light and darkness was determined. A variety of carbohydrates and cytokinins incorporated into the culture medium were effective in bringing about starch accumulation and shoot formation in the tissue. In addition, the respiratory activity of the callus, grown in the presence or absence of gibberellic acid, was measured. A strong correlation between the starch content of the tissue, its rate of respiration, and shoot formation was observed.
Titration with 3‐(3,4‐dichlorophenyl)‐1,1‐dimethylurea (DCMU) as Evidence for Several Photophosphorylation Sites in Scenedesmus
Authors: KYLIN A. , SUNDBERG I. , TILLBERG J.‐E.
Published: April 2006

Photophosphorylation was measured in intact cells of Scenedesmus obtusiusculus, which were made phosphate starved before the start of the experiments. Photophosphorylation was titrated with narrow intervals of 3‐(3,4‐dichlorophenyl)‐1,1‐dimethylurea (DCMU) from 10‐7M upwards. Plots of the reciprocal of photophosphorylation against concentration of DCMU gives three essentially straight lines; one between 10‐7 and 10‐6M DCMU; one between 10‐6 and 6 · 10‐6M DCMU; and one for more than 6 · 10‐6M DCMU, the last‐mentioned line being parallel to the abscissa. The stoichiometry between the three reactions is roughly 2: 1: 1. At least three sites for photophosphorylation are indicated, and the assumption that all sites work with approximately the same efficiency would make them four.
Translocation of Shoot‐Applied Indolylacetic Acid into the Roots of Populus tremula
Authors: ELIASSON LENNART
Published: April 2006

Application of 10 to 100 μg indol‐3‐ylacetic acid to the leaves of rooted cuttings of aspen caused inhibition of root growth after three hours. Root growth recovered within 24 hours after IAA treatment. Swelling of the root tips occurred during the period of inhibition. The roots responded in the same way if IAA was applied in solution to the cut stem surface above the mature leaves.

IAA‐1‐14C applied through a cut stem surface or to mature leaves was translocated downwards in the plants and labelled IAA could be isolated from the roots 3 to 24 hours after application. The ethanol‐soluble activity decreased rapidly indicating a rapid metabolism or binding of IAA. IAA‐1‐14C applied to growing leaves was not translocated.

From the rapid response of root growth it was concluded that IAA was translocated into the roots at a rate of about 7 cm per hour. This rate of translocation indicates that the sieve tubes are involved in the translocation. Implications of the results for the translocation of endogenous auxin into the roots are discussed.
Cyclic Purine Mononucleotides: Induction of Gibberellin Biosynthesis in Barley Endosperm
Authors: KESSLER BEZALEL , KAPLAN BINA
Published: April 2006

The de novo synthesis of α‐amylase in barley endosperm and isolated aleurone layers is induced by 3′,5′‐cyclic purine mononucleotides and gibberellic acid.

The induction of α‐amylase by cyclic purine mononucleotides is prevented by 2,4‐DNP, inhibitors of RNA and protein syntheses, CCC, AMO‐1618 and phosfon. The induction of α‐amylase formation by 3′,5′‐cyclic purine mononucleotides, but not by gibberellic acid, is also blocked by inhibitors of DNA synthesis.

Extracts from cyclic AMP‐treated endosperm halves exhibit a characteristic gibberellin‐like activity which is detectable within 12 hours from the addition of the cyclic AMP. On paper chromatograms this gibberellin‐like activity is located at the Rf typical for GA3. Its formation is prevented by inhibitors of DNA synthesis, CCC and AMO‐1618.

Glucose inhibits the formation of α‐amylase induced by gibberellic acid. Glucose has no effect on the cAMP‐induced gibberellin biosynthesis.

The evidence shows that the cyclic purine mononucleotides induce DNA synthesis, which results in gibberellin biosynthesis, which in turn activates the synthesis of α‐amylase.
The Regulatory Role of Inflorescence Leaves in Fruit‐setting by Sweet Orange (Citrus sinensis)
Authors: MOSS G. I. , STEER B. T. , KRIEDEMANN P. E.
Published: April 2006

Inflorescence leaves improve fruit set on sweet orange trees. We sought an explanation for this effect in terms of carbon demand by developing fruit versus potential supply from adjacent leaves. Our assessment was based upon measurements of fruit growth, leaf photosynthesis and 14C distribution patterns in plants grown under controlled conditions.

Leafy inflorescences had sufficient foliar surface (1.24 dm2) and photosynthetic capacity (CO2 10.1 mg · dm‐2· h‐1) to support early development of fruits on the same shoot, and to make a substantial contribution towards subsequent growth. 14C‐assimilates derived from new leaves were distributed towards adjacent fruit which showed strong competition for labelled substrate.

By contrast, fruit borne on leafless inflorescences had to obtain all their assimilates from older leaves whose photosynthetic capacity (CO2 3.5–4.6 mg · dm‐2· h‐1) and individual area (0.2 dm2) were generally insufficient to wholly sustain fruit growth, so that a large number of old‐leaves were needed; these fruit would be more susceptible to competition from other sinks.
14C‐Studies on Apple Trees. VIII. The Seasonal Variation and Nature of Reserves
Authors: HANSEN POUL , GRAUSLUND JØRGEN
Published: April 2006

The nature, seasonal variation and mobilization of reserves in Malus × domestica have been studied by means of 14C, carbohydrate analyses and extractions of xylem sap.

Following exposure to 14CO2 in the autumn, the majority of the 14C absorbed is found in the root. During the winter and in particular the spring the amounts of 14C in the top and root are reduced to approximately 40 per cent of the autumn values; in the root the amount of dry matter was also considerably reduced. In the tops, most of the 14C absorbed was found as methanol (80 %)‐soluble 14C which also showed the greatest seasonal reduction; sorbitol, sucrose or glucose in particular are responsible for the decrease in concentration within this fraction. Maximum values for methanol‐insoluble 14C were found in March. In the root, the highest values for absolute changes were found for methanolinsoluble 14C. Hydrolysis of this fraction showed considerable activity in glucose. In the root there was also considerable activity in a precipitated fraction of the methanol extract.

Eluates of xylem sap from apple branches contained primarily sorbitol, the highest concentration of which was found at the beginning of March.

For a tree with a dry matter weight of about 300 g, the utilization of reserves from the tree in the spring was calculated to be at least 13 g of dry matter. However, only a minor part (less than 25 per cent) of the latter appears to serve as building material for new growth.
Protoplast Cultures from Cell Suspensions of Daucus carota
Authors: WALLIN ANITA , ERIKSSON TAGE
Published: April 2006

Protoplasts, enzymatically isolated from cell suspension cultures of Daucus carota, have been grown in small Petri‐dishes. After enzyme treatment and washing the protoplasts were plated in agar media. Growth and divisions were viewed through the bottom of the Petri‐dishes with a light microscope. Different osmotic stabilizers were tested with respect to their ability to promote wall formation and growth of the protoplasts. Combinations of sucrose, sorbitol and “Modopeg” gave the best results. Electron micrographs of cultured protoplasts revealed normal as well as abnormal nuclear conditions.
Rhizomorph Formation in Fungi
Authors: ALLERMANN K. , SORTKJÆR O.
Published: April 2006

The effect on growth and rhizomorph formation of 12 alcohols (methanol, ethanol, 1‐propanol, 2‐propanol, 1‐butanol, 2‐butanol, iso‐butyl alcohol, tert‐butyl alcohol, 1‐pentanol, iso‐amyl alcohol, ethylene glycol and glycerol) at different concentrations has been examined for 2 isolates of Armillaria mellea (Vahl ex Fr.) Quél. and 1 of Clitocybe geotropa (Bull. ex Fr.) Quél. The fungi were cultivated for 28 days on a synthetic, liquid glucose medium with the alcohols as supplement.

The following alcohols strongly stimulated growth and rhizomorph formation: ethanol, 1‐propanol and 1‐butanol. A great variation was demonstrated between the isolates in relation to rhizomorph production, morphology, and ability to be stimulated by different alcohols.