bluuebunny/crossref_metadata_2025 huggingface dataset:
Metabolism of Indole‐3‐acetaldehyde
Authors: Rajagopal R.
Published: April 2006

Infiltration of indolcacelaldehyde (IAAId) into living tissues of sonic lower and higher plants gives rise simultaneously to both indoleacetic acid (IAA) and Iryptophol (T‐ol). But on a molar basis, there is no correlation between the products indicating a disimitation. Expressed juice of Avena coleoptiles by itself, exhibits only IAA forming activity. Approximately two moles of IAAld are consumed for each mole of IAA formed at pH 4.5, but only if necessary corrections are made for losses of substrate and products. Addition of reduced NAD or NADP readily induces tryptophol formation. But even at pH 4.5, adding reduced NADP causes greater tryptophol formation, leading to a marked divergence in the acid‐alcohol ratio. Varying the pH in the presence of reduced coenzymes also alters the ratio, with alcohol formation predominating. NAD and NADP have no influence on the formation of IAA from IAAld by the whole cytoplasm of Avena coleoptiles. Whole cytoplasm of Asparagus shoots forms both IAA and tryptophol from IAAld, but in widely varying amounts, devoid of any suggestive stoichiometry between the products.

With the acetone powder of Avena coleoptiles including the first leaf, data indicating an apparent disimitation of IAAld are obtainable only at pH 4.5. On altering the pH however, unequal amounts of the two products, namely IAA and tryptophol, are formed and hence a different ratio results. Acetone powders of wheat coleoptiles and Asparagus shoots do not yield data supporting disimitation either at pH 4.5 or 7.2.

IAA formation in Avena is aerobic while tryptophol formation is seemingly independent of oxygen supply. The former activity is selectively abolished by 10−3M dithionite while the latter activity suffers a similar suppression in the presence of 10−3M manganese sulphate. Varying the IAAld concentration results in unequal amounts of the two products, revealing the dissimilar affinity of the two activities for the common substrate

Saturation to a level of 30 percent with ammonium sulphate throws out most of the acid‐forming activity whereas the alcohol‐forming system appears mostly in the protein fraction precipitated between 30 and 40 percent saturation. The enzyme system of Avena coleoptiles oxidizing IAAld to IAA can also be easily separated by Sephadex gel filtration and its independent activity demonstrated in the total absence of tryptophol formation.

Based on the heterogeneous properties of the two activities, metabolism of IAAld in Avena coleoptiles is believed to be mediated by two independent enzyme systems without the intervention of a mutase or a dismutation mechanism.
Wirkung von Wuchs– und Hemmstoffen auf die Kambiumtätigkeit und Reaktionsholzbildung
Authors: Casperson Gerhard
Published: April 2006

Effects of Growth Promoters and Inhibitors on Cambium Activity and Formation of Reaction Wood. — The cambium activity of horizontal bent apicotyls of Aesculus hippocastanum can be stimulated by auxins (2,4‐D) or kinetin applied artificially. The effect of kinetin was equal on the upper and lower side of the stem. Applied in high concentration to the upper side 2,4‐D acted as inhibitor of cell division on this side but as promoter on the lower side. TIBA was active at the spot of application only. The formation of reaction wood was influenced remarkably by auxins but only slightly by TIBA or kinetin. The results are discussed in term of the theory of growth substances of Went and Cholodny.
The Amount of γ‐Amino Butyric Acid and the Activity of Glutamic Decarboxylase in Aging Leaves
Authors: Lähdesmäki P.
Published: April 2006

The amount of γ‐amino butyric acid as measured by thin‐layer chromatography, and the specific activity of glutamic decarboxylase as measured both by Warburgapparatus (CO2) and by thin‐layer chromatography (γ‐ABA) were determined in leaves of different ages. Datura suaveolens, Medicago sativa and Salvinia natans were used as experimental plants.

The amount of γ‐ABA increases in the leaves of Salvinia natans, Medicago sativa and Datura suaveolens in proportion to the age of the leaves. In the case of Salvinia natans, the amount of γ‐ABA in old leaves is about twice as much as in young ones: in the case of Medicago sativa and Datura suaveolens the increase is slightly less. In Salvinia natans the amount of γ‐ABA reaches its greatest value in the third to fifth leaf, in Medicago sativa and Datura suaveolens later. This increase in the amount of γ‐ABA with respect to the age variation of the leaves, is reflected in the growth of leaves. In Salvinia natans the third or fourth leaf is full‐grown, in Medicago sativa and Datura suaveolens this stage is reached in the seventh or eighth leaf.

The activity of glutamic decarboxylase parallels the γ‐ABA accumulation in that it increases when the leaves grow. The increase of glutnmic decarboxylase activity takes place more rapidly in the aging leaves of Medicago sativa than in those of Datura suaveolens. The activities observed are somewhat higher when the amounts of γ‐ABA are analysed than when the CO2 evolved is measured.

KM‐values for glutamic decarboxylase were calculated using various substrate concentrations to test the enzyme activity. The KM‐values obtained were 7.0 · 10−3M in the case of Medicago sativa, and 7.9 · 10−3M in the case of Datura suaveolens.
The Time Effect of Auxin and Calcium on Growth and Elastic Modulus in Hypocotyls
Authors: Uhrström Inger
Published: April 2006

The relationship between Young's modulus and longitudinal growth has been studied on growing segments of etiolated sunflower hypocotyls. The modulus was determined by means of the resonance frequency method. IAA in a concentration of 2.8 10−5 M produces a decrease in the modulus with a time lag of 4 minutes, while an increase in growth is observable only after 6 minutes. Addition of IAA results in a stronger decrease in the modulus if the segments are placed in a solution of 0.1 M mannitol rattier Hum in water. Through plasmometric measurements it has been found that the elastic extensibility is insignificant compared with the growth. After the addition of IAA, there occurs a marked elongation both in 0.1 M mannitol and in water, and at the same time a decrease in the elastic extensibility of the segments is observed. In the growing segments an increased modulus causes an in creased elastic extensibility, a matter which is directly contrary to the relationship found in a physical system with an applied external force. An explanation of this discrepancy has been given. With an excess of calcium the modulus increases, while the elongation decreases. Calcium deficiency implies both a decreased modulus and a decreased growth. With the addition of 10−3 M Ca(NO3)2 to segments raised without calcium the modulus increases after only 10 minutes, while an increase in longitudinal elongation is observable after 30 minutes. With the addition of IAA to the calcium deficient segments the modulus decreases to the same extent as in an optimal supply o f calcium. The results are discussed with reference to other investigations about elasticity and growth. It has been concluded that plastic extensibility cannot he of great importance in longitudinal growth. Time studies of the auxin effect and I he interaction between auxin and calcium have confirmed the hypothesis that one of the primary actions of auxin consists in a loosening of the cell wall matrix. Calcium always increases Youngs modulus and gives the cell wall a more rigid structure. Furthermore, calcium in a certain concentration is necessary for longitudinal growth.
Gibberellin Induced Changes in Diffusible Auxins from Savoy Cabbage
Authors: Andersen A. Skytt , Muir Robert M.
Published: April 2006

Diffusates from apices of young plants of savoy cabbage treated with gibberellie acid (GA) and apices of control plants have been examined with respect to their content of Indole auxins. Three indole Compounds were detected and identified on the basis of their chromatographic characteristics in several systems. These compounds were: glucoubrassicin, indole‐3‐acetic acid (IAA) and indole‐3‐acetonitrile (IAN).

An effect of GA on the total auxin activity of the diffusate was noted 90 hours after treatment, while an increase in stem height occurred 48 hours later. This increase in auxin effect of the entire diffusates was shown bv chromogenic development and bioassay of chromatograms of diffusates to be a result of an increase in level of the IAA content. A concomitant decrease in I the glucobrassicin content was indicated.

Since GA was found to have no effect on the enzymatic conversion of tryptophan or tryptamine to IAA, it is proposed that the effect of GA is on the conversion of glucobrassicin to IAA.
Physiological and Biochemical Studies of Chilling Injury in Bananas
Authors: Murata Takao
Published: April 2006

The physiological changes in green bananas (cv. Sin‐zun), which are very sensitive to chilling injury, were studied during and after exposure to low temperatures (4±1°C, 6±0.5°C) for various periods. While the fruits injured by chilling did not fail to produce CO2 and ethylene, the pattern of both CO2‐ and ethylene production in these chilled fruits (9 and 15 days at 6°C) after transfer to 20°C was not normal. The contents of acetaldehyde and ethanol in chilled fruits, both in peels and pulps, increased with the advance of chilling, injury. There was an accumulation of α‐keto acids in the peels of chilled fruits. Only half the conversion of 14C (fed as succinic acid‐1, 4‐14C) to citric acid and isocitric acid was observed in chilled tissues as compared with healthy ones; the activity of citrate synthase in banana peels appears therefore to be inhibited by chilling injury. A histological study of the tissues showed that the browning substances (polyphenols) present in chilled fruits accumulate around the vascular tissues.
Effect of Green and White Flashes on the Activity of the Enzyme Ribulose‐diphonphate Carboxylase in Darkgrown Barley Plants
Authors: Dasstou C. , Akoyunoglou G.
Published: April 2006

The effect of short impulses of white and green light on the activity of ribulosediphosphate carboxylase in dark‐grown barley leaves has been studied Intermittent white light induces an increase in the activity of the enzyme. After 90 flashes a 30% increase in the activity is observed. Intermittent green light has no effect on the activity of the enzyme.

A correlation between the increase in the activity of the enzyme and the accumulation of chlorophyll under the effect of intermittent white light has been observed.
Biochemical Aspects of Parasitism by the Angiosperm Parasites: Host‐parasite Interrelationship in Phosphatase Activity
Authors: Mattoo R. L. , Viswanathan P. N. , Krishnan P. S.
Published: April 2006

Infection by Cuscuta and Orobanche causes significant losses in dry solids and protein content in host plant or plant part. Changes occur in phosphatase activity towards fructose‐1,6‐diphosphate at alkaline pH and β‐glycerophosphate at acid pH, expressed per mg protein or g fresh tissue. The leaves of all hosts infected by Orobanche show an increase in the alkaline fructosediphosphatase activity, whereas as far as the infection by Cuscuta is concerned the general response is a decrease in the enzyme in the shoots. The alterations in the phosphatase activity towards β‐glycerophosphate at acid pH in the shoots are not consistent. However, there is a marked increase in the acid phosphatase activity against β‐glycerophosphatase in the roots of the infected hosts. The significance of these findings has been discussed in the light of host‐parasite interrelationship.
The Effect of Nonanal on Dipodascus aggregatus II. Influence of the Prehistory of the Inoculum and of the Presence of Ethanol
Authors: Nyman Brita
Published: April 2006

Nonanal, added in ethannlic solution, in concentrations lower than 40 to 80 μM did not affect the growth of Dipodascus aggregatus, provided the inoculum had been harvested from the exponential phase of growth. Growth could even be inhibited by 80 μM.

If the inoculum had been grown to the exponential phase and then for another period, to the acceleration phase, in fresh liquid medium, growth was strongly promoted by 80 μM nonanal. If cells from the exponential phase were grown for another period in the supernatant fluid of centrifuged cultures from the exponential phase, 80 μM affected growth in the following way: in five different experiments growth was not stimulated, in one experiment undoubtedly promoted, and weakly stimulated in another one.

The growth of cultures inoculated with cells grown only on malt agar was not affected by 80 μM nonanal.

Pretreatment of cells, harvested from the acceleration phase, with nonanal (80 μM) in the presence of ethanol did not diminish the growth‐promoting action of nonanal on the cultures inoculated with these cells.

Nonanal, in the absence of ethanol, in a concentration of 10 μM did not affect the growth of cells, harvested from the acceleration phase, whereas 100 μM nonanal strongly inhibited growth.

An attempt is made to explain the results starting from the endogenous metabolism.
Some Physical‐kinetic Considerations in Penetration of Naphthaleneacetic Acid through Isolated Pear Leaf Cuticle
Authors: Norris Robert F. , Bukovac Martin J.
Published: April 2006

The penetration of naphthaleneacetic acid (NAA) through enzymatically isolated pear leaf cuticle (Pyrus communis L. cv. Bartlett) is reported herein. Penetration of NAA increased with increasing lime and attained a steady state in approximately 20 minutes. The quantity of NAA penetrating was directly related to the concentration of the donor solution. NAA that penetrated the cuticle was shown to he unaltered. The Penetration of NAA from inside to outside is similar to that from outside to inside. Isolated stomatous lower cuticle permitted approximately 10‐foId greater penetration of NAA than the astomatous upper cuticle. The penetration of NAA through isolated pear leaf cuticle is highly temperature dependent, exhibiting a temperature coefficient (Q10) of about 5.6 between 15° and 25 C. The low quantities of chemicals penetrating through the isolated cuticle reported herein and elsewhere are considered to he a characteristic of the technique and not an absolute limitation of the cuticle. Cuticular penetration could account for physiological quantities of NAA entering the plant.
The Ultrastructure of a Cyanophage Attack on Anabaena variabilis
Authors: Granhall Ulf , Hofsten Angelica V.
Published: April 2006

Cyanophages multiplying on the nitrogen fixing blue‐green alga Anabaena variabilis Kütz. were revealed by electron microscopy.

Severe ultrastructural changes have been observed in the vegetative cells, whereas the heterocysts appeared resistant to the cyanophage. A lytic cycle was observed from adsorption to lysis.
Factors Affecting Spore Germination of Volvariella volvacea
Authors: Chang Shu‐Ting , Chu Sze‐Shuen
Published: April 2006

Environmental factors affecting basidiospore germination were studied with Volvariella volvacea, the edible straw mushroom which is common in South East Asia. A relatively mild heal shock is necessary for spore germination. The spores give best germination at 40°C although early hyphal growth is better at 35°C the germination of spores is affected by temperature. pH. a presoaking treatment and spore density. Higher pH supports more germination but seems unfavourable for early mycelial growth. Presoaking treatment in phosphate buffer solution or distilled water also stimulates germination markedly.
An Adenosine Triphosphatase in Agrobacterium tumefaciens
Authors: Gainor C. , Phillips P. G.
Published: April 2006

Cell‐free extracts from the phytopathogen Agrobacterium tumefaciens contained an enzyme(s) capable of cleaving nucleoside triphosphates, showing highest specific activity toward adenosine triphosphate. Differences are indicated between the adenosine triphosphate phospbohydrolase described hero and other microbial adenosine triphosphatases previously reported. The adenosine trit)hosphatasc activity was stimulated by Mg2+ and Mn2+ and inhibited by other divalent cations. Enzymatic activity was inhibited 100% by mercuric chloride, 38% by p‐chloromercuribenzoate, 22% by potassium fluoride, 12% by sodium azide, and 10% by iodoacetic acid, all at a final concentration of 10−2 M. The enzyme (s) had an optimal PH range of 7.8 to 8.0, and an optimal temperature for hydrolysis at 40deg;C.
On the Relationship Between Soil Moisture and Osmotic Potential in Maize and Sugar Beet Plants
Authors: Padurariu Alexandra , Horovitz C. T. , Paltineanu Rodica , Negomireanu V.
Published: April 2006

Investigations on the relationship between soil moisture and maize and sugar beet plant osmotic potential were carried out during three years under field trial conditions. It was established that between soil moisture and osmotic potential there is an inverse ratio dependence, expressed in significant correlation coefficients (r =−0.84** for maize and r =−0.88** for sugar beet on an average). The correlation appears more striking in the lower third of the active moisture range, where slight variations in soil moisture determine important changes in osmotic potential. The possibility of using the osmotic potential as an index in estimating plant water requirement is asserted and the limit values indicating a good water supply in maize and sugar beet plants are established according to growth stages.
Mediated and Residual Methionine Transport by Brewer's Yeast
Authors: Balogh Esther , Böszörményi Z. , Cseh Edith
Published: April 2006

The characteristics of methionine uptake by brewer's yeast (S. carlsbergentis “Schwehat No. 2”) and the regulation of the process have been studied. The methionine uptake by brewer's yeast grown on wort is a complex process Composed of a mediated transport process saturating at low concentration and permeation that is in linear dependence on the concentration. The mediated transport process is under regulated control and can be repressed by (a) certain amino acids added to wort media or applied to phosphate buffer in shorter pre‐treatment, (b) ammonium ions added to a synthetic nutrient solution or, in shorter pre‐treatment, by ammonium ions applied to a synthetic nutrient solution containing glutamic acid.
The Utilization of Carbohydrate and Nitrogen Reserves in the Spring Growth of Lilac
Authors: Meyer Martin M. , Splittstoesser Walter E.
Published: April 2006

The spring flush of growth and the utilization of reserve materials in this growth was studied in lilac plants 0, 2, 4 and 6 weeks after bud break. The influence of nitrogen applied the previous season on the storage and utilization of carbohydrate and nitrogen reserves was determined. The plants were separated into buds, stems and roots and analyzed for changes in total available carbohydrates, sugars, hemi‐celluloses, total nitrogen, basic and non‐basic amino acids and organic acids.

The bulk of the carbohydrate reserves occurred as soluble sugars in the roots, although the reserves of sugars and hemicellulose in the stem was important during the first two weeks after bud break.

The bulk of the nitrogen reserves were stored as non‐basic amino acids in the stems and roots. However, the roots of plants grown under high nitrogen levels contained twice us much total nitrogen as roots grown under low nitrogen. This additional nitrogen which was stored in the roots of high nitrogen plants was released as arginine.

The dry weight of buds increased 3–10 fold during the initial two week period and during the next four weeks doubled again. This bud growth was correlated with the stored nitrogen reserves. The high nitrogen plants grew twice as much and utilized more of the reserve carbohydrates in spring growth than low nitrogen plants. Carbohydrates were synthesized in this new growth and the high nitrogen plants utilized this carbohydrate for additional growth while low nitrogen plants transported it to the stems and roots.
The Effect of Ethanol on the Growth of Dipodascus aggregatus
Authors: Nyman Brita
Published: April 2006

Ethanol (68.2 mM) did not appreciably affect the growth of Dipodascus aggregatus with glucose (55.5 mM] as carbon source. Growth with fructose was inhibited whereas growth with galactose was stimulated by ethanol in this concentration. The fungus could grow with ethanol as the sole carbon source. D. aggregatus did not grown with maltose as the sole carbon source. Growth with maltose + ethanol started much earlier than growth with ethanol alone. The maltose concentration of the medium did not measurably decrease during growth with maltose‐n ethanol. D. aggregatus did not grow with sucrose as the sole carbon source
Root Formation by Detached White Mustard (Sinapis alba) Cotyledons
Authors: Moore Keith G. , Lovell Peter H.
Published: April 2006

Rooting is shown to occur in excised cotyledons of Sinapis alba when grown in petri dishes on moist filter paper. Cotyledons were excised at intervals from 6 hours after the start of imbibition, when they were yellow, unexpanded and enclosed within the testa, to 27 days after sowing when the cotyledons were green and fully expanded and on plants possessing up to 3 foliage leaves. Rooting generally began 5 or 6 days after excision and was completed dining the following 5 days. The age of cotyledons at t ho time of excision had three effects on rooting: the lag period be‐fore rooting began and the period during which rooting took place both increased with age: but the most marked effect was on the total number of cotyledons which were able to form roots, which increased until cotyledon expansion was almost complete, then decreased as the mature cotyledons became older. Optimal rooting was shown by cotyledons detached 8 days alter sowing, when they were half expanded. At this age S5 % of them formed roots between 6 days and 8 days after excision.
Physiological Studies with Heavy Water
Authors: Bhattacharya (née Bose) S. , Bhandarkar M. K. , Gaur B. K.
Published: April 2006

The absorption of H2O and D2O was studied in seeds with different reserve food materials represented by barley and rice (starch), linseed and mustard (fat) and mung, and kidney beans (protein). Respiration rate and respiratory quotient during absorption were also measured. The results indicate that the water absorption profiles of the starchy and fatty seeds are essentially similar but differ from that of The proteinaceous type. Initial hydration is relatively incomplete in D2O in all The seeds to varying degrees the latter being maximum in The proteinaceous and minimum in The starchy seeds. The respiration rate is lower in D2O while The R.Q. values are higher for The first hour but lower later on. The results, in part, help explain The varying effects of D2O on The germination of different types of seeds. These studies also support The earlier reported preference (Cope et al. 1965) by the higher plant systems for protium.
The Effect of Growth Regulatory Chemicals on Abscission and IAA–Oxidizing Enzyme System of Dwarf Bean Seedlings
Authors: Jain M. L. , Kadkade P. G. , Huysse Patrick Van
Published: April 2006

The effects of certain carcinogenic agents, a growth retardant, and kinetin on abscission, IAA, IAA–oxidase and peroxidase on dwarf bean seedlings were studied. The results indicate significant changes in the levels of IAA, IAA–oxidase and peroxidase brought about by the treatment with the carcinogens, growth retardant, and kinetin.
Action Spectra for Transformation and Fluorescence of Protochlorophyll Holochrome from Bean Leaves
Authors: Björn L. O.
Published: April 2006

The action spectrum from 232 to 687 nm was determined for the transformation of protochlorophyllide into chlorophyllide a in solutions of protochlorophyll holochrome Fran bean leaves. The whole ultraviolet region is effective. The peaks at 445 and 639 nm have a height ratio of 4.0. Only radiation absorbed in the protochlorophyllide itself is effective in transformation (absorption in aromatic amino acids of the protein and in carotenoids is ineffective).

The activation spectra for fluorescence at 643 and 683 nm are measured for the holochrome before and after transformation, as well as the change in absorption spectrum that takes place upon transformation. By combining the various measurements the spectrum of inactive (non‐transformable) protochlorophyllide (peak at 440 nm) and the holochromatic chlorophyllide a are derived. In the latter spectrum the peaks at 419 and 435 nm are of about the same height.
Effects of Age on Sodium Fluxes in Primary Bean Leaves
Authors: Jacoby B. , Dagan J.
Published: April 2006

The effects of age on sodium fluxes in primary‐leaf sections from control and decapitated bean plants were determined. It was assumed that at high external salt concentrations the measurements represent mainly fluxes through the tonoplast, and that in brief efflux experiment subsequent to free‐space exchange efflux from the cytoplasma is essentially measured. Net‐ and influxes to the vacuoles increase during the period of leaf expansion and net chlorophyll synthesis. Both fluxes and amount of chlorophyll decrease rapidly in senescing leaves. The exchangeability of previously absorbed sodium also increased in senescing leaves. Decapitation delayed senescence and very much reduced the decreases in net flux and influx, and the exchangeability of sodium. The results are discussed in relation to solutes redistribution in the plant.
Interactions between Plants and Epiphytic Bacteria Regarding Their Auxin Metabolism
Authors: Libbert Eike , Risch Hannelore
Published: April 2006

Using hydrocultured pea plants, 109 bacterial strains (42 from shoots) were isolated from shoots, roots, and from the hydroculture medium. 58 different strains (26 from shoots) were able to produce IAA from tryptophan, 15 different strains (7 from shoots) were able lo destroy IAA. (Included are 13 strains possessing both properties.) As far as they could be identified, the IAA‐producing and ‐destroying strains belong to Pseudomonas (by far dominating), Achromobacter, Alcaligenses, Bacillus, and Flavobacterium. The IAA‐destroying activity strongly depends on the physiological state of the bacteria and the milieu conditions. Bacterial IAA production (but not IAA‐degradation) is supposed to be important for the plant.
Zoospore Chemotaxis in the Watermold Allomyces
Authors: Machlis Leonard
Published: April 2006

The chemotactic response of the mitospores and meiospores of Allomyces macrogynus and A. abuscula to casein hydrolysate was shown to he caused by the combined action of leucine and lysine in the hydrolysate. The testing was done by counting the zoospores that attached to a membrane through which substances diffused downward. The action of leucine and lysine was shown to be synergistic and to be specific for the L, forms. The optimum concentration above the membrane was 5 × 10‐2M for each amino acid. An effect was detectable down to approximately 10‐55 M. The addition of L‐proline to the mixture increased the response. Proline in combination with leucine caused good attachment, although less than that by leucine and lysine, of the zoospores of A. arbuscula but not of those of A. macrogynus.
Photoenhancement by Blue Light of Organogenesis in Tobacco Pith Cultures
Authors: Weis J. S. , Jaffe M. J.
Published: April 2006

Agar‐grown cultures of tobacco pith tissue (Wisconsin 38) were incubated in the dark or in the light for 36 days. With 1 μM indole‐3‐acetic acid (IAA) in the medium, considerable differentiation, including organogenesis occurred in the light, but not in the dark. Such photoenhancement of differentiation did not occur when 2.4‐dichlorophenoxy acetic acid (2,4‐D) or naphthalene acetic acid (NAA) was substituted for IAA. Blue light of greater than 12 days duration was responsible for the photoenhancement effect.
Relation between Anion Transport and Water Flow in Tomato Plants
Authors: Greenway H. , Klepper Betty
Published: April 2006

Lowering the water potential of culture solutions from −0.4 to −5.4 atm reduced both phosphorus and bromide transport to the shoot, hut the content in the roots was not affected. Reductions in phosphorus transport to the shoot were measured during the first four hours of treatment and were related to concurrent decreases in water flow and not to an impairment of active phosphorus transport. The effect of low water potential on phosphorus transport to shoots was similar at external phosphorus concentrations between 0.6 and 15 mg/l.

Phosphorus transport was greater in the dark at −0.4 atm than in the light at −5.4 atm even when these treatments gave the same overall rates of water flow; this is attributed to a different pattern of water flow through the various root zones. The results suggest that the main effect of water flow on anion transport to shoots occurred after the ions had been actively adsorbed by the roots and was not due to mass flow increasing ion delivery to sites of active uptake.
Microbiology of Saturated Salt Solutions and Other Harsh Environments
Authors: Siegel S. M.
Published: April 2006

The study of chemical stress tolerance in a Penicillium mutant was continued using KCl‐ and H3BO3‐saturated glucose peptone broth as a basic growth medium. Growth was completely restricted to the mutant. Variations were the presence or absence of inosine‐5′‐phosphate (inosinic acid, IMP) and choice of carhohydrate which was substituted for glucose. All six monosaccharides used‐three hexoses, three pentoses – were essentially equivalent hence data are presented only for D‐glucose and D‐xylose. The other carbohydrates, sucrose, lactose, maltose and starch differed in their suitability as carbon sources. In the presence of the nionosaccharides the mutant can grow both in KCl and H3BO3 media, but growth rates are greatly enhanced by IMP. Boric acid blocked sporulation under all conditions. KCl permitted spores of abnormal color to form without IMP, whereas spores of normal green color appeared in its presence. Media containing H3BO3 and disaccharides or starch supported no growth, but addition of IMP stimulated growth without sporulation. In KCl media sucrose alone among the disaccharides and starch permit limited growth without IMP, but the nucleotide is required for sporogenesis. These results show that the role of nucleotides, especially IMP, is not limited to recovery from exposure to extreme salt effects, but also applies to growth in the continuing presence of quite different chemical stress conditions.
Effets de l'acide gibbérellique et de la kinétine sur le développement de l'activitéα‐amylasique durant la croissance de l'Orge
Authors: Verbeek Rita , Van Onckelen Henri , Gaspar Thomas
Published: April 2006

Effects of gibberellic acid and kinetic on α‐amylase production during the germination of barley. ‐ The action of gibberellic acid and kinetin, alone or combined at different concentrations, has been studied on α‐amylase production in whole barley seedlings and in embryoless endosperms in course of the six first days of development in the dark. The classic activation of α‐amylase synthesis by gibberellic acid has been confirmed both in whole seeds and in embryoless endosperms. Kinetin inhibits α‐amylase synthesis after the third day of germination but has no effect on isolated endosperms. When gibberellic acid and kinetin are given simultaneously gibberellic acid stimulated during the three first days just as it does alone, kinetin inhibits after the third day also as it was alone so that the two regulators act, without interactions, at different stages in the time. These effects of kinetin are be independent. A critical examination of the techniques used in the literature in the stud of amylase is made.
Variations de quelques aclivités enzymatiques (peroxydase, catalase, AIA‐oxydase) et de la teneur en polyphénols au cours de la germination de I'Orge. Influence de la kinétine
Authors: Gaspar Thomas , Verbeek Rita , Van Onckelen Henki
Published: April 2006

Peroxidase catalase, IAA‐oxidase and polyphenol content of growing barley coleoptile. Effect of kinetin. ‐ Kinetin strongly inhibits root and coleoptile growth of germinating barley in the dark. Treated coleoptiles become senescent before the untreated ones. Soluble proteins content, peroxidase, catalase and IAA‐oxidase activity were greatly increased in treated coleoptiles while the level of polyphenols was reduced. These biochemical effects joined with the other property of kinetin to diminish α‐amylase synthesis in the endosperm are discussed in relation to growth and in connection with the classic view of a cytokinin retarded senescence.
Further Studies on Regulation of Betacyanin efflux from Beetroot Tissue Ca‐Ion‐Reversible Effects of Hydrochloric Acid and Ammonia Water
Authors: Siegel S. M.
Published: April 2006

The Ca‐ion‐reversible effects of aqucous NH3 and HCL on betacyanin leakage from beetroot sections were studied as simple models for complex polycations such as polylysines.— From kinetic evidence, the competitive character of Ca‐ion antagonism in all these cases, and general chemical arguments, it is suggested that ammonia, hydrogen chloride and polylysine all act as osurees of [H H2O]+ which can compete with Ca‐ion for electronegative sites on the membrane. The Ca‐reversibility of alcohol‐induced leakage is then explained as a lowering of diclectric constant at the membrane resulting in reduced charge at electronegative sites with concomitant loss of ion binding capacity. Biological illustration of the antagonism between Ca‐ion and ammonia, and of H‐ion dependent NaCl sensitivity are presented.
The Growth of Acer pseudoplatanus Cells in a Synthetic Liquid Medium: Response to the Carbohydrate, Nitrogenous and Growth Hormone Constituents
Authors: Simpkins I. , Collin H. A. , Street H. E.
Published: April 2006

A synthetic culture medium which supports a high level of growth of a scrially propagated cell suspension culture of Acer pseudoplatanus is described. The sucrose of this medium can be effectively replaced by glucose or fructose or a mixture of glucose and fructose or galactose or maltose or soluble starch. When the carbohydrate is glucose or fructose no other sugars appear in the culture medium in significant amounts. Glucose is absorbed in greater quantity than fructose from an equimolar mixture of these sugars. When sucrose is supplied both glucose and fructose appear in the medium. Glucose appears in maltose medium, and maltose and glucose in soluble starch medium. Under the standard conditions of culture, media containing 2 % sucrose or 2 % glucose become depleted of sugar before the 25th day of incubation. Enhanced yield of the cultures can be obtained by raising the initial sucrose concentration to 6 %. – A supply of nitrate is essential for maximum yield and healthy growth. Growth, in the presence of nitrate, is significantly enhanced by a supply of urea. Addition of casein hydrolysate or of a mixture of amino acids enhances growth in the presence of nitrate and urea and particularly when nitrate is omitted. – When kinetin is omitted or incorporated at the standard level (0.25 mg/I), 2,4‐dichlorophenoxyacetic acid (2,4‐D) at 1.0 mg/l is essential for continuation of growth at a high level. It cannot be replaced by indol‐3yl‐acetic acid (IAA). 1‐naphthaleneacetic acid (NAA) at 10 mg/l permits of a low level of growth with abnormal aggregation. When the level of kinetin is raised to 10 mg/l a high level of growth occurs in the absence of added auxin but the cultures become brown and tend to show increasing aggregation on subculture.
Effects of Stratification, Gibberellic acid and Germination Temperature on the Germination of Betula nana
Authors: Junttila Olavi
Published: April 2006

Experiments were carried out with three seed lots of Betula nana collected in 1967 from different localities in Norway. Seeds were stratified for 0‐20 days in dark at +2‐+3 °C on filter papers moistened with distilled water, or treated with solution of GA3 for 24 h at room temperature, and then moved into special germination boxes that were placed in different temperature conditions.

All the seed lots had conditional dormancy. Quantitatively, the dormancy was different in the different seed lots (pronenances), but there were no qualitative difference in the reaction to stratification gibberellic acid and to germination temperature. Differences between seed lots may have been due to different stage of seed development.

The dormancy was deepest at low temperatures(12 and 15°C) decreasing gradually with increasing temperature (to 24 °C). The dormancy was effectively broken by a short stratification (from 5 to 15 days), and by treatment with gibberellic acid. The deeper the dormancy and the lower the germination temperature the longer the stratification that was needed for maximum germination. Similarly, the concentration of GA3 needed for maximum germination increased with decreasing temperature and with increasing dormancy.
Photomophogenesis in the Blue‐green Alga Nostoc commune 584
Authors: Robinson Beatrice L. , Miller John H.
Published: April 2006

The blue‐green alga Nostoc commune 584 displays a photocontrolled developmental cycle similar to that described for N. muscorum A by Lazaroff and Vishniac (1961). In both species white fluorescent light acts at the same stage, ragulating the development of motile trichomes from sheathed aseriate colonies. However white light blocks this step in N. commune 584, whereas the formation of motile trichomes is promoted by white light in N. muscorum A. Light‐grown (aseriate) cultures in N. commune 584 were used to determine the action spectra for photomorphogenesis. Green light (max 520 nm) inhbited aseriate colony breakage, and red light (max 640 nm) promoted colony breakage and the differentiation of motile trichomes. On a quantum basis green light was about 3 times more effective than red light. The morphogenetic effects of either red or green light were reversible by irradiation with the other color of light. Repeated photoreversibility was observed, and the algal culutres responded only to the color of the last irradiation in a sequence. An unidentified substance is excreted into the media of motile cultures of both N. commune 584 and N. muscorum A which promotes motility in non‐motile cultures. The motility‐promoting substances from both species are reciprocally active. Activity is lost when the media are autoclaved.
Conversion of Indolylglycerol Phosphate into Tryptophan by Extracts of Pisum
Authors: Schiewer U. , Erdmann N. , Libbert E.
Published: April 2006

Dialyzed extracts from sterile and nonsterile pea seedlings perform the synthesis of tryptophan from indole‐3‐glycerol‐1‐phosphate (IGP) and L‐serine. Compared with the analogous indole methabolism, there are similar dependences with regard to pH and to serine and pyridoxal‐5‐phosphate requirements, but the IGP conversion rate only amounts to one third of that measured for indole. Indole‐3‐glycerol is not metabolized by both tissues and homogenates.
The Influence of Protochlorophyllide, Formed from Exogenous δ‐Aminolevulinic Acid, on Chlorophyll Synthesis in Leaves during Flash Illumination
Authors: Steer B. T.
Published: April 2006

In the presence of large accumulations of protochlorophyllide, derived from exogenous δ‐aminolevulinic acid, chlorophyll synthesis in excised leaves of two varieties of barley was less than in untreated leaves. In oat leaves the accumulated protochlorophyllide, from exogenous δ‐laminolevulinic acid, stimulated chlorophyll synthesis to above the control level. — These relationships could only be demonstrated when phtodestruction of pigments was minimised by the use of flash illumination (2 milliseconds every 3 minutes). — These was no evidence from in vivo absorption spectra that the pigments in the barley leaves were different to those in leaves studied by other workers. However, the presence of the accumulated protochlorophyllide appeared to prevent the shift of the chlorophyll absorption maximum from 673 nm to 677 nm. — Possible mechanisms of inhibition are discussed.
Changes in Uptake Capacities of Phosphorus and Calcium during Callus Induction in Rice
Authors: Nishi Toyoyuki
Published: April 2006

Changes in the uptake capacities of phosphorus and calcium during callus induction in rice were examined as the first approach to the understanding for the possible mechanism of callus induction. A decrease in the capacity of phosphorus uptake and an increase in that of calcium was found during callus induction.
Eisen‐ und manganhaltige Verbindungen im Blutungssaft von Helianthus annuus
Authors: Höfner W.
Published: April 2006

Bleeding sap of sunflower seedlings (Helianthus annuus) which had been transferred to 59Fe‐ or 54Mn‐labelled nutrient solution 16 hours before decapitation, was fractionated by gelfiltration on Sephadex G‐15.

In both the 59Fe‐ and the 54Mn‐labelled bleeding sap three fractions could be determined, containing the microelement together with amino acids and carbohydrates.

According to the results of gelfiltration, the molecular weight of these compounds ranges below 1500.
Ultraviolet Inactivation and Photoreactivation in Synchronized Chlorella
Authors: Taube ÖRn
Published: April 2006

Synchronous cultures of Chlorella pyrenoidosa have been used in studies of the action of UV‐irradiation during different stages in the life cycle on cell division capacity. These experiments show that there is a considerably higher sensitivity to UV‐irradiation during the first hours of the life cycle.

The variations in photoreactivating capacity of UV‐damaged cells during a life cycle have been investigated. The results from these investigations show that the photoreactivating capacity varies and that it is higher in young daughter cells (autospores) and 12–15 hour cells. These variations can be due to variations in the activity of the photoreactivating enzyme during the life cycle.
Studies on Cytokinins in Watermelon Seeds
Authors: Prakash Ritu , Maheshwari S. C.
Published: April 2006

Extracts of immature seeds of watermelon contain three cytokinins which are adsorbed on Dowex 50W ion exchange resin. The Rf of the fastest moving factor is similar to that of zeatin. The slowest moving factor is insoluble in n‐butanol and shows some resemblance to zeatin ribotide. The chromatographic properties of the second factor are, however, different from those of any of the known cytokinins and is believed to be new to literature.
Promotion of Growth and Flowering and Increase in Content of Endogenous Gibberellins in Gladiolus Plants Treated with the Growth Retardant CCC
Authors: Halevy A. H. , Shilo Ruth
Published: April 2006

Application of the growth retardant CCC to gladiolus plants resulted in stimulation of stem lenth, increased number of flowers per spike and a slight advancement of anthesis date. Leaves of treated plants were heavier than control and contained a higher amount of water and chlorophyll. The anthocyanin content in petals was also greatly increased. CCC had little or no effect on the content of the endogenous gibberellins in the acidic ethyl acetate fraction, but markedly increased the content of the native gibberellins in the aqueous fraction. The mode of action of CCC in plants is discussed on the basis of these results and a review of the literature.
Regulative Systems in the Developing Citrus Fruit I. The Hormonal Balance in Orange Fruit Tissues
Authors: Goren R. , Goldschmidt E. E.
Published: April 2006

The regulative systems of auxins, gibberellin‐like substances and their inhibitors in citrus fruit were studied. Masking caused by a high content of inhibitors was eliminated by using a refined method of solvent partition. Considerable amounts of auxins and gibberellin‐like substances were detected in all stages of fruit development. The auxin system of the citrus fruit is highly complex and consists of various elements which undergo dynamic changes throughout the growth period. The identity of the auxins was studied using IAA‐2‐14C, and 88% of the radioactivity specifically migrated into the etheric pH 6.0 fraction. Although the prominent zones of promotion do not coincide with IAA, it can be concluded that the auxin promoters are probably not the “citrus auxin”. Abscisic acid‐like inhibitors were found to accumulate in the external layers of the fruit, increasing in content as time advances.
Control of Rooting and the Pattern of Senescence in Detached White Mustard Cotyledons
Authors: Moore Keith , Lovell Peter
Published: April 2006

Senescence of detached mustard cotyledons was greatest in full light or at low light intensity but was reduced at intermediate light intensities. The location of yellowing in the blade depended on the conditions in which it was maintained after excision. Cotyledons cultured at full light intensity in the absence of exogenous nutrients formed roots at the base and yellowed around the margins. Reduction in light intensity and increasing nutrient concentrations resulted in an increasing proportion of the cotyledons yellowing from the base upwards, and fewer developed roots. At low light intensity with high nutrient levels rooting was suppressed and basal senescence predominated.

The location of yellowing in the cotyledon may be associated with mobilisation gradients induced by the differential effects of light and mineral nutrient level on root initiation and blade growth.
Diffusion and Quasi‐diffusion Resistances in Relation to the Carboxylation Kinetics of Maize Leaves
Authors: Gifford R. M. , Musgrave R. B.
Published: April 2006

A “quasi‐diffusion resistance”, rq, is defined to accommodate the role which the thermochemical and photochemical phenomena of photosynthesis play in the control of CO2 fixation to the terminology and approach of the diffusion resistance analogue for the CO2 exchange of leaves. The relationship of rq to Rabinowitch's classical rectangular hyperbolic model of photosynthesis rate as a function of CO2 concen‐tration at the carboxylating surface is discussed. Examination of Kmapp for phos‐phopyruvate carboxylase (the predominant carboxylase in maize) suggests, as a reasonable hypothesis for light‐saturated maize leaves, that rq may be essentially independent of ambient CO2‐concentration up to at least 300 μ1/l. A corollary of the hypothesis is that an increase of diffusion resistance, rather than of rq, may account for the observed curvature of the response curves of light‐saturated maize leaf photosynthesis to ambient CO2‐concentration. An experiment carried out on fieldgrown maize plants, using a well controlled leaf chamber as a nitrous oxide diffusion porometer, gave evidence which strongly supported the hypothesis.
Cytokinin Production by Rhizobium japonicum
Authors: Phillips Donald A. , Torrey John G.
Published: April 2006

Possible hormonal interactions between soybean roots and the Rhizobium initiating nodule proliferation in this genus were studied. A cytokinin has been isolated by column and paper chromatography from an effective strain of Rhizobium japonicum grown in pure culture. The substance promotes cell proliferation in a cytokinin‐requiring soybean callus tissue. The bacteria are capable of conditioning a cylokinin‐free soybean culture medium so that it is able to support the cytokinin‐requiring tissue. It is concluded that the substance is a product of the bacteria rather than an artifact of purification. This unidentified cytokinin or a substance moving to a similar Rf value on the paper chromalogram produces polyploid divisions when tested on cultured pea root segments. Some of the division figures exhibit the diploclirornosomes typical of the root nodule primordium in pea.
Seasonal Variations in GA3 Effects on Flowering of Impatiens balsamina, a Qualitative Short Day Plant
Authors: Nanda K. K. , Tory K. L. , Sawhney S.
Published: April 2006

The effectiveness of GA3 in inducing floral‐bud initiation in Impatiens balsamina under non‐inductive photopcriods varies considerably at different parts of the year and appears to be determined by the prevailing temperature conditions. The period of floral‐bud initiation is shortest in October and February and increases both with decreasing temperatures in November and with increasing temperatures in August and September. Floral buds do not initiate in March and April, during which time the temperature increases considerably subsequent to the start of experiment.