bluuebunny/crossref_metadata_2025 huggingface dataset:
Growth‐Promoting Effects of Fatty Acids on Excised Wheat Roots and Oat Coleoptiles
Authors: GUdjónsdóttir Sigŕan
Published: April 2006

The growth action of some fatty acids and alcohols with carbon number from 1 to 4 was tested on excised wheat roots in aseptic cultures. Growth, cell length, and dry weight were measured after seven days. The tested substances were: Formic acid, acetic acid, propionic acid, n‐Butyric acid, isobutyric acid, acelaldehyde, propionaldohyde, ethanol, n‐propanol, isopropanol, n‐butanoL and isobutanol. The primary alcohols and all of the acids, except formic acid, promoted the cell elongation and the total growth, but the meristematic activity was inhibited in the higher concentrations. The concentrations with maximal growth‐promoting activity were 10−2M to 10−3M for the alcohols and 10−4M for the acids. Propionic acid was applied in darkness, red light, and white light and proved to increase the cell length from 215 μ, 180 μ, and 120 μ up to 240 μ in all three treatments. The growth rate was not affected, but the duration of the cell elongation was extended. The presence of iron proved to be necessary for the stimulation. The chlorophyll content in the light grown roots was relatively unaffected when the cell length was increased and the dry weight was not increased as long the cell number was normal.

The growth of Avena coleoptile segments was slightly promoted by propionic acid in the presence of IAA.
An Ion‐stimulated Adenosine Triphosphatase from Bean Roots
Authors: Gruener N. , Neumann J.
Published: April 2006

A soluble ATP‐ase from bean roots was discovered. The enzyme was assayed by measuring the release of inorganic P from 32P‐labelled ATP. The enzyme is strongly stimulated by hoth sodium and potassium ions, in the alkaline pH range. Its characteristics are compared to that of the animal membrnnal ATP‐ase which is presumably involved in the transport of ions in animal tissues.
Quantitative Determination of Indole‐3‐Acetaldehyde. II.
Authors: Lahsen Poul
Published: April 2006

The method by Larsen and Klungsöyr (1964) for the quantitative determination of indole‐3‐acetaldehyde (IAAld) was modified for the purpose of eliminating the need for filtration after oxidation of the IAAld to indole‐3‐acetic acid (IAA).

The essentials of the modified method are as follows: Samples of IAAld or IAA containing 0.015 to 0.15 μmol (ca. 2.5 to 25 μg) dissolved in peroxide‐free ether are evaporated to dryness and redissolved in 1.5 ml 0.02 M Ag2SO4. The oxidation is carried out in dim light by adding 0.5 ml 0.12 N NaOH. After 1.5 min, 2 ml of a modified Salkowski reagent are added. The optical density at 525 nm is read on a spectrophotometer after 75 min. The modified Salkowski reagent consists of 100 ml 0.05 M Fe2(SO4)3 in 1.5 N H2SO4; 240 ml H2O; and 160 ml cone. H2SO4 (sp. gr. 1.84). O.D. readings are identical for equal samples of IAAld and IAA (the latter used as a standard) up to 0.08 μmol (O.D. = 0.32). Larger quantities of IAAld may be determined when using pure IAAld as a standard, but at 0.20 μmol the O.D. for IAAld is lower than for IAA (0.69 as against 0.72).

Indole‐3‐acetonitrile, tryptophol, indole‐3‐carboxylic acid, and indole‐3‐aldehyde all give O.D. values lower than 0.1 when tested at 0.20 μmol under the same conditions as described for IAAld and IAA.
The Chemistry of Areneboronic Acids
Authors: Torssell Kurt
Published: April 2006

Benzeneboric acid causes a marked increase in the endogenous fermentation of pressed baker's yeast. It is shown that an increased leakage of trehalose occurs and it is suggested that benzeneboronic acid affects the permeability of the cytoplasmic membranes.
Breaking of Dormancy in Xanthium Seeds by Kinetin Mediated by Light and DNA‐dependent RNA Synthesis
Authors: Khan A. A.
Published: April 2006

Kinetin was able to break the dormancy of the “upper seed” (in bur) of Xanthium by antagonizing the endogenous inhibitor present in the embryo. Other growth substances like indoleacetic acid, gibberellic acid and cycocel were without effect. Breaking of dormancy by kinetin was dependent on reversible phytochrome system and DNA‐dependent RNA synthesis. Protein synthesis is possibly not involved in the act of dormancy breaking. Endogenous inhibitor possibly participates in the mechanism of repression of genie site(s). It is suggested that an interplay of endogenous inhibitors, kinins and other factors (light, temperature, etc.) regulate dormancy, germination and differentiation by repression and derepression of DNA sites.
The Germination of Avena fatua under Different Gaseous Environments
Authors: Hart J. W. , Berrie Alex. M. M.
Published: April 2006

The atmosphere in which seeds germinate can profoundly affect the level of germination and dormancy. Seeds were germinated in atmospheres containing various concentrations of carbon dioxide and oxygen. At the same time the effect of light on these systems was examined.

The germination of partially dormant populations of wild oat seed is inhibited by white light. This response to light is most apparent when the curyopsis is enclosed in the pales.

Investigations into the effect of the ambient atmosphere on germination have indicated that, while oxygen is a necessary factor in the germination of tliis species, carbon dioxide also has an effect. A lack of carbon dioxide increases the degree of light inhibition of germination; 3 per cent carbon dioxide (by volume) allows germination in light; 20 per cent carbon dioxide inhibits germination in light and darkness at all tested oxygen concentrations.
Phytochrome Levels Assayed by in vivo Spectrophotometry in Modified Underground Stems and Storage Roots
Authors: Koukkari Willard L. , Hillman William S.
Published: April 2006

In vivo spectrophotometric assays were conducted with sections of plant material cut from modified stems and storage roots. Phytochrome levels are highest in sections associated with growth such as buds and cambial regions. Interior tissues of tubers and the scale leaves of bulbs which are storage tissue contain low or no detectable phytochrome. However, in the storage root of Pastinaca saliva L. phytochrome is distributed in both the phloem and central regions, though it is highest in the cambial region. Total phytochrome in Gladiolus corm buds exposed to 5 minutes of red light followed by approximately 24 hours of darkness decreases more than 60 per cent. This rapid loss of detectable phytochrome in Gladiolus corm buds resembles phytochrome destruction in etiolated seedlings.
Spontaneous Movements in Plants Studied as a Random Walk Process
Authors: Johnsson Anders
Published: April 2006

A theory to describe spontaneous curvatures performed by different plant materials on the clinostat is put forward. The movements are proposed to follow the assumptions of a random walk process (statistically randomly distributed movements) and thus to give curvatures following the equations

E(α) = 0

V(α) = constant * time

where α is the curvature from the starting direction, E(α) is the expectation of α and V(α) is the variance ofα. These equations are experimentally shown to be valid for Lepidium roots and Helianthus hypocotyls. Results for roots reported in the literature are recalculated and are shown to support the theory.
Effect of UV Light on Lettuce Seed Germination and on the Unfolding of Grass Leaves
Authors: Wagné Claes
Published: April 2006

The effect of UV light on germination of lettuce seeds and on the unfolding of wheat leaves was studied.

A small improvement in germination was noted on exposure lo light of 254, 265, 334, 405 nm, and in unfolding on exposure to light of 254, 265, 313, 334, 360 and 405 nm.

The low germination rate at 238 nm shows, that light energy absorbed by the high‐absorbing protein part of the phylochrome (Siegelman and Butler 1965) cannot be used in the germination process.
Chemical and Physical Factors Influencing Growth of Phytophthora parasitica var. nicotianae on Vegetable Oils
Authors: Hendrix James W. , Norman Calvin , Appli J. L.
Published: April 2006

Factors influencing the growth of Phytophthora parasition var. nicotiona on vegetable oil liquid media were studied. This fungus grew poorly on oleic acid, triolein, and tristearin. Cholesterol and α‐tocopherol reversed the toxicity of oleic acid. Growth was often stimulated by addition of mineral oil to a glucose medium, and sterols dissolved in mineral oil frequently stimulated grwoth.

Shaking produced a 5‐fold or more increase in growth on either glucose or cottonseed oil media. Cholesterol (20 μ/ml further increased growth on glucose meidum in shake culture by at least 100%. Growth was usually better at pH 6.7 than at 5.4 or 7.7. Growth in shake culture on a glucose medium supplemented with cholesterol and α‐tocopherol approached that occuring on vegetable oil media.
Stem Internode Elongation in the Japanese Morning Glory (Pharbitis nil Choisy) in Relation to an Inhibitor System of Auxin Destruction
Authors: Stonier T. , Yoneda Y.
Published: April 2006

Further investigations on a wild‐type strain of the Japanese morning glory (Pharbitis nil Choisy) to ascertain the relationship between stem internode maturation, decreasing rate of internode elongation, and increasing auxin destruction, have established the following: There exists in young, elongating, internode tissue, substances which prevent the destruction of indoleacetic acid by enzymes normally found in stem tissue. Almost all of the protecting activity can be attributed to two substances, one of them possessing an apparent molecular weight in the 5000 to 10,000 g/mol range, the other, in the 1500–5000 g/mol range. Both are water soluble, and heat labile, at least in vitro. It is further suggested that associated with Japanese morning glory stem maturation, is the loss of these auxin‐protecting substances, and as a consequence of this loss, the loss of further endogenous auxin‐induced elongation.
Some Effects of Light on Excised Wheat Roots with Special Reference to Peroxide Metabolism
Authors: Björn L. O.
Published: April 2006

When excised wheat roots are exposed to blue light, catalase activity changes in a way to he expected as a result of photodestruction with first order kinetics. Wheat root catalase in vivo is less light sensitive than animal catalase in vitro, possibly due to internal screening. Illumination of the roots with red light causes some increase in catalasc activity. Peroxidase activity is much less affected by light. No relation has been found between catalase destruction and chlorophyll formation.

The ability of roots to oxidize pyrogallol to purpurogallin (by other workers interpreted as peroxide production) is decreased by light, especially blue light. On the contrary, one peroxide producing enzyme, glycolic acid oxidase, was detected only in roots grown in blue light.

The total flavin content, or the fraction present as FAD, is not affected by light. The ascorbic acid content is low, but slightly increased by blue light.
Growth, Turgor, Water Potential, and Young's Modulus in Pea Internodes
Authors: Burström H. G. , Uhrström Inger , Wurscher R.
Published: April 2006

The relations between longitudinal growth, Young's modulus, turgor, water potential, and tissue tensions have been studied on growing internodes of etiolated pea seedlings in an attempt to apply some physical concepts to the growth of a well‐known plant material. The modulus has been determined by the resonance frequency method and expressed as Etissue It increases nearly proportional to the turgor pressure and is at water saturation more than 50 times higher than at plasmolysis. Etissue is higher in the epidermis than in the ground parenchyma. Indoleacetic acid causes a decrease in Etissue Other properties have been studied on intact and split segments of internodes in solutions of graded mannitol additions. — The following tentative picture of the normal course of the growth has been obtained. Auxin induces growth both in the periphery (epidermis) and in the central core (parenchyma) under a decrease in Etissue This is followed by an increase of Etissue which is independent of auxin but depending upon the turgor pressure. It is assumed to involve internal structural changes of the cell walls of the type of creep. The rapid growth takes place in a dynamic system with a low water potential despite favourable water conditions. Epidermis and parenchyma grow equally rapid without tissue tensions. — Such can be produced artificially by splitting of segments and water uptake. The parenchyma thereby loses its sensitivity to auxin. This is the background of the split stem test for auxin. — Etissue increases when growth is slowing down, probably owing to both synthesis of wall substance and structural changes within the wall. The cells attain a more static condition with Etissue higher in epidermis than in parenchyma. This leads to the normal tissue tensions. — The result agrees with growth according to the multi‐net‐principle. The cause of the low water potential and low turgor is discussed with reference to the dynamic nature of both growth and water transport and a probably low matric potential of the streaming water. The decrease in Etissue following auxin addition is small but is the net difference between an auxin‐induced decrease and an increase through the assumed creep.
The Nutrition of Excised Wheat Roots
Authors: Ferguson J. D.
Published: April 2006

From an investigation of the nutrient requirements of Hilgendorf wheat roots, glucose emerged as the only suitable source of carbon and energy, and thiamine as the only vitamin necessary. The roots had the ability to utilise nitrogen from calcium nitrate, urea, alanine, glutamine, allantoin, and hydrolyzed casein.
The Promotion of the Immobilization of Auxin in Avena Coleoptiles by Triiodobenzoie Acid
Authors: Winter Alan
Published: April 2006

A study was made of the inhibition of auxin transport in Avena coleopliles by 2, 3, 5‐triiodobenzoic acid (TIBA), using carboxyl labelled 14C indole‐3‐acetic acid (IAA). A transport period of 1 hour followed by an export period of 2 hours was used routinely. Treatment with TIBA resulted in increased radioactivity remaining in the coleoptile sections after the export period. This radioactivity was distributed throughout the length of the coleoptile. The increase in radioactivity was shown to be due to an increase in the amount of IAA immobilized. The action of TIBA in inhibiting auxin transport is achieved by the promotion of the immobilization of IAA.
Respiration Rate, Adenosine Diphosphate and Triphosphate Concentrations of Leaves Showing Necrotic Local Lesions Following Infection by Tobacco Mosaic Virus
Authors: Sunderland D. W. , Merrett M. J.
Published: April 2006

The respiration rate of TMV‐infected leaves of Nicotiana tabacum L. variety Xanthi has been shown to be greater than the respiration rate of healthy leaves. 10−5M DNP gave maximum stimulation of the respiration rate of the healthy leaf but had no effect on the respiration of the virus‐infected leaf with dense lesion cover. The concentration of ATP increased with greater lesion density while the ADP concentration decreased. The increase in ATP concentration was greater than could be accounted for by the decrease in ADP concentration. Thus, increased respiration in the virus‐infected leaf is accompanied by a decrease in the ADP/ATP ratio. Illumination of the virus infected leaf increased the ADP/ATP ratio.
Primary Photosynthetic Induction Phenomena in Wheat
Authors: Egnéus Hans
Published: April 2006

The induction phenomena of photosynthesis in leaves of wheat were studied with a Beckman oxygen sensor. By special treatment prior to illumination, e.g. long dark and anaerobic periods the oxygen evolution could be divided into two parts, one consisting of two or three transients appearing under the first minute of illumination and one consisting of the main oxygen evolution. One or two transients could be observed when the plant was placed in darkness after an illumination period. The oxygen evolution had the same appearance in monochromatic as in white light. KCN‐treatment inhibited only the main oxygen evolution.

The transients are interpreted as being manifestations of the primary processes connected with the start of photosynthesis. The main oxygen evolution is assumed to be closely related to the processes connected to the Calvin‐cycle.

Experiments were also performed to ascertain that the observed induction phenomena were not connected with the stomatal movements in the leaves.
Effects of Ultraviolet and X‐Ray Radiation on in vitro Cultivated Cells of Haplopappus gracilis
Authors: Eriksson Tage
Published: April 2006

A cell strain of Haplopappus gracills was used for investigations of the effects of UV (2537 A) and X‐ray irradiation.

Mitotic inhibition and killing after UV exposure were studied. A survival curve of UV treated and then plated cells is presented. The LD50 seems to be about 2000 erg. mm−2 under the experimental conditions used. All types of chromosome aberrations are induced by UV irradiation, but the frequency is relatively low at doses which do not completely inhibit cell division.

A mutant strain of chromosome type is isolated after UV treatment and then plating.

Mitotic inhibition and killing after X‐ray treatment were studied. A survival curve is presented and the LD50 under the culture conditions used seems to be about 2000 R.

The frequency of chromosome aberrations induced by X‐rays is highly increased by aeration during X‐ray treatment which indicates that some degree of cell anoxia exists in a cell suspension.

There arr indications that chromosome aherrations may not cause growth inhibition to such an extent as is usually believed.
Growth and Development of Pelargonium Pith Cells in vitro
Authors: Chen Hwa‐Ruey , Galston Arthur W.
Published: April 2006

Pelargonium pith callus cultured in media containing auxin and cytokinin will not differentiate formed organs if monthly subcultures are made into fresh medium. Left on semisolid medium for prolonged periods, such callus gives rise to nodules containing lignified cells. Such nodules can be stimulated to produce shoots and roots if cultured for one month in shaken liquid medium or for longer times on semisolid mediium lacking both auxin and cytokinin. The subsequent development of organs is best on semisolid medium. Entire plants have heen produced in this way from initial pith explants containing several hundred cells.
Influence of Gibberellic Acid and Gibrel on Fruit Set and Yield in Vaccinium macro‐carpon cv. Early Black
Authors: Devlin Robert M. , Demoranville I. E.
Published: April 2006

The influence of gibberellic acid (GA) and Gibrel on the parthenocarpic development of cranberries (Vaccinium macrocarpon cv. Early Black) was investigated. Application of GA or Gibrel at 25 % bloom, 50 % bloom, 100 % bloom and after bloom resulted in a much higher than normal percentage fruit set and large increases in yield. However, treatment of cranberry vines with these compounds also resulted in an abundance of small, commercially undesirable berries. In addition, application of GA caused abnormal elongation of the vines and inthibited terminal bud development. Gibrel caused only slight vine elongation and did not retard terminal bud development. The possible use of Gibrel in the commercial production of cranberries is discussed.
Occurrence of Indoleacetaldehyde and Tryptophol in the Extracts of Etiolated Shoots of Pisum and Helianthus Seedlings
Authors: Rajagopal R.
Published: April 2006

Presence of a non‐acidic, growth‐promoting indole compound, identical in Rf and colour reaction and closely similar in UV spectrum to synthetic indoleacetaldehyde (IAAId) has been demonstrated in extracts of etiolated shoots of Pisum and Helianthus. On chemical as well as enzymic oxidation of this neutral extract, activity passes over into the acidic fraction. This neutral substance is believed to be IAAId and occurs in the free state as short‐term, low temperature extractions indicate. On the basis of Rf, colour reaction and UV spectrum, tryptophol has also been identified in Helianthus extracts. Its identification in pea extracts, however, rests only on Rf, colour reaction and inactivity in Avena bioassays.
Initiation of Flowering and Changes in Endogenous Inhibitors and Promoters in Olive Buds as a Result of Chilling
Authors: Hartmann Hudson T. , Fadl Mostafa S. , Hackett Wesley P.
Published: April 2006

Olive trees require a period of chilling temperatures, either diurnally fluctuating, or at a constant—but definite—level before inflorescences develop. In this study, bud and leaf samples were taken at weekly intervals during this critical period from trees receiving temperatures favorable for flowering and from trees under temperature conditions known to prevent flowering. Extracts were obtained from these samples, separated by paper chromatography and the different growth‐active materials were bioassayed by the mung bean rooting test for the presence of promoters and inhibitors.

Extracts from buds on trees under conditions unfavorable for flowering generally consisted only of promoters. Extracts from buds on trees placed under conditions favorable for flowering showed a definite and consistent pattern for the presence of rooting inhibitors and promoters. Within one or two weeks after being placed under such conditions a strong inhibitor band appeared from Rf 0.50 to 0.70. This persisted for 6 to 7 weeks, gradually decreasing in intensity, followed by promoters at these bands. During this period all other bands, at different Rf values, showed strong promoters.

Extracts from leaves on shoots under temperature regimes favorable for flowering showed a pattern like the buds in the appearance and disappearance of inhibitors and at the same Rf values but with about one week lag in time. Bud extracts from defoliated shoots on trees under temperature conditions known to result in inflorescence production failed to show the characteristic inhibitor pattern associated with flowering. Such defoliated shoots do not form inflorescences.
Effect of Intercalated Long Days and Light Interruption of Dark Period on Flowering, Extension Growth and Senescence of impatiens balsamina
Authors: Krishnamoorthy H. N. , Nanda K. K.
Published: April 2006

Plants of Impatiens balsamina L. grown under long days were divided into 5 lots to receive 1, 2, 4, 8 and 16 consecutive short day (SD) cycles respectively. Each lot was divided into 5 groups to receive 1, 2, 4, 8 and 16 long day (LD) cycles subsequent to SD regime and the cycles were repeated till the end. Observations on the number, position and time of emergence of floral buds, flowers and extension growth were recorded.

The floral buds are initiated and these develop into flowers even when Individual SDs are intercalated with 16 LD cycles, showing that the sub‐threshold stimulus is not wiped off but becomes effectively summated through a long non‐inductive period.

The floral bud initiation in lots receiving less than 4 and flowering in those receiving less than 8 consecutive SD cycles are delayed with decreasing number of consecutive SDs and increasing number of intercalating LDs. This progressive delay is probably due to the delay that is caused by these treatments in the completion of requisite number of SD cycles.

The first node to show floral bud initiation is shifted up with increasing intercalated LDs only in plants receiving less than 4 SD cycles and not in those receiving more. Some of the lower floral buds in plants receiving less than 8 consecutive SD cycles either abort or revert to vegetative growth. The first node to flower is, therefore, shifted up. The number of such buds increases either with a decrease in the number of consecutive SDs or an increase in the number of intercalated LDs.

The number of floral buds produced in plants receiving 2 or more and flowers in those receiving 4 or more consecutive SD cycles does not differ much with the number of intercalated LDs, but decreases in those receiving less number of SDs. Some nodes bear more than one floral bud and flower. Such nodes are observed in plants receiving individual SD cycles only when intercalated with individual LDs but in all groups in plants receiving 16 consecutive SD cycles.

The rate of extension growth increases with an increase in the number of consecutive SDs. The rate in plants receiving individual SDs closely resembles that of plants grown under continuous LDs and that of consecutive 16 SDs with that of control SD plants. The attainment of maximum and the consequent steep fall preceding senescence is successively delayed with an increase in the number of intercalated LDs in plants receiving 16 consecutive SD cycles.

Light interruption of the dark period inhibits both the initiation of floral buds and their development Into flowers. showing that in this plant. short days are necessary both for the initiation of floral buds and their development into flowers.
Nitrogen Metabolism of Tamarindus indica: Changes in γ‐Methyleneglutamine and its Corresponding Acid γ‐Methyleneglutamic Acid During Seedling Growth
Authors: Pal Ravindra N. , Laloraya Manmohan M.
Published: April 2006

Changes in γ‐methyleneglulamine, a third non‐protein amide, γ‐methyleneglutamic acid, its corresponding acid, other free aminoacids and amides, and protein and soluble‐nitrogen during the seedling growth of tamarind (Tamarindus indica L.), were studied. The changes in the prolein‐N content in different parts of the seedling, during growth parallel closely the growth pattern expressed as changes in fresh weight. γ‐Meythyleneglutamine is the principal amide during the early stages of seedling growth, but later on when its content starts declining, asparagini’ takes over its function. Thus, γ‐methyleneglutamine seems to spare the utilization of amide asparagine, during the early growth period. During later stages of seedling growth, asparagine content also shows a decline, indicating that during this period, asparagine contributes to the protein synthesis and growth. γ‐Methyleneglutamic acid was also recorded in large amounts in various parts of the seedling and its concentration was not found to be less than the amide at any stage of seedling growth. The two peaks observed for some of the key aminoacids including γ‐methyleneglulamic acid, γ‐methylglulamic acid, α‐alanine, glutamic acid, aspartic acid, glycine and serine, are interesting, in that the first corresponds to the active growth period of roots and the hypocotyl in the first eleven days, and the second with the active growth of the epicotyl.
Growth and Enzyme Activity of Myxococcus virescens in Liquid Medium
Authors: Haskå Guno , Norén Börje
Published: April 2006

The object of this work was to develop a method for determination of the growth of Myxocuccus virescens in liquid medium. The bacteria were grown in N III‐B medium in 100 ml Kjeldahl flasks, which were fixed on a disc forming an angle of 50 degrees with the horizontal plane. The disc was rotated two full revolutions per minute. The total nitrogen content of the washed swarms, developing on the glass walls of the flasks, was used as an expression for the myxobacterial growth.

After a lag the bacteria grown in total darkness had a growth phase, approximately exponential, of about 270 hours, which was followed by a steep phase of decline. When the bacteria were illuminated daily for a short period, a lag of 50–200 hours appeared in the middle of the exponential growth phase, after which a new exponential growth phase began. This second growth seemed to depend on variants insensitive to light induced lysis.

The increase of enzymes, active on casein and autoclaved aerobacter cells, closely followed the first part of the growth curve. However both activities began to decrease before the growth maximum. No sign of proteolytic activity or lytic activity on autoclaved aerobacter cells could be detected after about 700 hours' incubation.

In illuminated flasks it is shown that the production of yellow pigments in culture solution is sharply increased at the end of the exponential growth phase.

The lytic enzymes of M. virescens seem to be extracellular, secreted during the exponential phase of growth. No activity was exhibited by washed cell swarms, even if they were sonically disintegrated.
Fine Structure of Healthy and TMV‐Infected Tobacco Cells Grown in Tissue Culture
Authors: Nakata Kazuo , Hildebrandt A. C.
Published: April 2006

Three types of tobacco (Nicotiana tabacum cv. Havana 38) callus: 1) healthy stem callus, 2) TMV‐infected stem callus, 3) TMV‐infected leaf callus; and leaves differentiated from healthy stem callus, and from TMV‐infected leaf callus were compared for fine structure. In addition, the fine structure was observed of plastids in cells of leaves differentiated from callus isolated from stem sections of TMV‐infected hybrid tobacco plants (N. tabacum cv. Havana 38 ×N. glutinosa) grown under high temperature. The cytoplasmic organelles in tissue cultured cells were similar to those in cells of greenhouse‐grown tobacco plants. Except for plastids, TMV infection did not noticeably affect morphologically other cellular organelles in tissue culture cells. In TMV‐infected leaf callus, numerous small bodies were seen in plastid‐like bodies, while vesicle‐like structures were observed in the stroma of plastids in leaves differentiated from callus of hybrid tobacco inoculated with TMV. Morphological variations of mitochondria, such as swelling and vacuolization of the inner matrix, occurred frequently in TMV‐infected leaf callus. Needle‐like crystalline inclusions or looped inclusions composed of many fine, long filaments were considered TMV particles orientated parallel to each other. The TMV particles were detected in the cytoplasm of tissue culture cells.
Carbon Dioxide Efflux from Leaves in Light and Darkness
Authors: Holmgren Paul , Jarvis Paul G.
Published: April 2006

Efflux of carbon dioxide in light and darkness was measured at low ambient CO2 concentrations in leaves of Rumex acetosa. Light carbon dioxide production (photo‐respiration) was found to depend on irradiance and to differ from dark production as to the response to temperature and ambient concentrations of O2 and CO2. These observations support previously made suggestions that photorespiration follows a different metabolic pathway to dark respiration.
The Effects of Phosphate on the Development of Phytase in the Wheat Embryo
Authors: Sartirana Maria Luisa , Bianchetti Renato
Published: April 2006

The effects of experimentally induced changes of inorganic phosphate concentration in the tissues of isolated wheat embryos during germination, were investigated in order to study the control mechanisms of the phytin‐phytase system.

The supply of inorganic phosphate at concentrations from 5 × 10−3M to 3 × 10−3M does not alter growth, respiration, hexose phosphate level and protein synthesis, measured both as 14C leucine incorporation and as increase of several enzymatic activities.

Experiments with 32P inorganic phosphate indicate that the rate of phvtin breakdown is controlled in vivo by the concentration of inorganic phosphate, through the inhibition of phytase activity.

Phytase increases during germination: this increase, sensitive to puromycin, is specifically repressed by inorganic phosphate.

An interpretation of the behaviour of the phytin‐phytase system during germination under physiological conditions is tentatively given on the basis of the results obtained.
Experimental Modification of Pigment Content and Phototropic Sensitivity in Excised Avena Coleoptiles
Authors: Bara Metin , Galston Arthur W.
Published: April 2006

Avena seedlings were imbibed and germinated in the presence of inhibitors of carotenoid biosynthesis. After excision and defoliation, the coleoptiles were cultured in the presence of these basally supplied inhibitors and their growth, phototropic behavior and pigment content were subsequently measured. Total carotenoids could be reduced to ca. 20 percent of the control value without marked influence on the dose‐response curve for the first positive curvature. Chromatographic analysis of extracted carotenoids on alumina columns revealed that the inhibitors produced both qualitative and quantitative changes, reducing one fraction and virtually eliminating two others. The total riboflavin content of the coleoptiles was almost completely unaffected by these treatments. The data are applied to an analysis of the nature of the photoreceptor in phototropism of the Avena coleoptile.
Some Properties of Unpurified Chitinase from the Crayfish Plague Fungus, Aphanomyces astaci
Authors: Unestam Torgny
Published: April 2006

The culture filtrate of the crayfish plague fungus, Aphanomyces astaci (Saprolegniaceae), incubated in a peptone glucose medium was tested for chitinase activity under different conditions. The activities were assayed turbidimetrically using low‐polymerized chitin as a substrate.

Adsorption of chitinase was found to occur on chitin and probably on cellulose and sulphomethyl cellulose but not at all or only a little on some other cellulose derivatives.

The pH optimum of the enzyme activity was found to lie at about pll 5.0–5.5. The stability was greatest near pH 6.5 and the highest degree of adsorption occurred at still higher pH values. Enzyme adsorption on the substrate seemed to protect the enzyme against inactivation by heating, shaking, and extreme pH‐conditions.

The chitinase activity was positively affected by the rest of the culture filtrate.

Mercury, cobalt, and copper chlorides, and to a lesser degree some other metal salts, lowered the enzyme activity when present in the test medium. Cellobiose, but neither glucose nor N‐acetyl glucosamine had a pronounced inhibiting effect on the activity. Neither cellobiose nor N‐acetyl glucosamine seemed to affect chitinase adsorption on chitin. Some chelating and reducing compounds inactivated the culture filtrate. This activity‐reducing effect of chelators was strongly prevented by EDTA in some cases.
Variations du taux en composés sulfhydrilés acidosolubles de tissus cultivés in vitro
Authors: Pilet Paul‐Emile , Dubois Jean
Published: April 2006

Variations of the Level of the Nitrogen and Thiol Groups in Tissues Culture.—Distribution of nitrogen and thiol compounds was analysed in the fragments of carrot roots cultivated in vitro. A typical gradient of –SH groups was observed: high level in the callus, low level in the base of the fragment (in contact with the medium). In discontinuous light, callus—which have a great amount of chlorophylls—contain less sulfhydric compounds than in continuous dark. With increasing age of the tissues, the concentration of the endogenous –SH groups was decreasing. The probable biochemical relations between –SH level, auxin content and auxin‐oxidase activity are discussed.
Lipids in Cruciferae
Authors: Appelqvist Lars‐Åke
Published: April 2006

The effect of nitrogen, phosphorus and potassium nutrition on average seed weight, oil content and fatty acid composition of rape seed (Brassica napus) grown in soil‐free culture has been studied. Nitrogen effected an increase in seed weight and a decrease in oil content, while the average amount of oil per seed remained constant. A small, but highly significant, decrease in palmitic and eicosenoic acid content, a significant decrease in oleic acid and a highly significant increase in erucic acid content were observed. This suggests that a decrease in the extent of elongation of oleic acid to erucic acid occurs in seeds developing on plants with sub‐optimal levels of nitrogen nutrition. Phosphorus and potassium had very limited effects on fatty acid composition. Significant differences were found only in oleic acid content for phosphorus alone, the nitrogen‐phosphorus interaction and the phosphorus‐potassium interaction. The effect of various levels of sulfate at optimal levels for nitrogen, phosphorus and potassium, was studied in a separate experiment. Seed from sulfur‐starved plants had decreased oil content; oleic acid percentages were increased and erucic acid percentages decreased. Excessive amounts of sulfate had no effect on fatty acid composition.
Rhythmic Growth in Excised Sprout‐leaves of Onion Bulbs
Authors: Jaffe M. J. , Isenberg F. M. R.
Published: April 2006

Sprout leaf preparations, consisted of the inner 6 or 7 sprout leaves attached to the base plate of bulbs of Allium cepa cv. Downy Yellow Globe. The preparations excised from dormant bulbs were capable of sprouting. The elongation of the sprout leaves in the light was inhibited by a field pretreatment of 2000 mg/1 M.H.‐30 (30% maleic hydrazide) and stimulated by incubation in the dark. Rapid cooling of the bulbs prior to excising of the preparations had no effect on sprouting. The ability of the sprout leaf preparations to elongate followed a cyclical time course, displaying maxima 8 to 12 weeks apart. Pretreatment with M.H.‐30 inhibited this periodicity.
Isoenzyme Polymorphism in Flowering Plants
Authors: Mákinen Yrjö , Macdonald Timothy
Published: April 2006

Esterases, leucine aminopeptidases, catalases and acid phosphatases from pollen of Oenothera organensis were studied electrophoretically. A study was made using several different extraction media to see the effect it had on esterase migration and stainability. It was found that different extraction media resulted in significant changes in migration rates and stainabilities of the esterase isozymes.

Anodal esterases and leucine aminopeptidases from 13 inbred lines of maize were studied and are reported. Preliminary genetic studies of two of the esterase isozymes from maize pollen are reported.

A survey of anodal esterases and leucine aminopeptidases from the pollen of 11 genera of diverse angiosperms is presented.
Comparative Physiology of Respiration in Aquatic Fungi
Authors: Gleason Frank H. , Unestam Torgny
Published: April 2006

A comparative study of terminal respiration was undertaken in five genera of aquatic fungi in the Leptomitales. The cytochrome system in this group of fungi contained cytochrome a‐a3 (605 nm), cytochrome c (551 nm), cytochrome b (557 nm), and cytochomo b (564 nm). A representative of each of three aerobic genera, Leptomitus, Apodachlya, and Sapromyces, had a total cytochrome content of about 2×10−10 mol/mg dry weight. An endogenous respiration rate of 21 μl O2 uptake/ (h × mg dry weight) at 21.7°C was found in Leptomitus and Apodmhlya and 14 in Sapromyces. The strain belonging to the fermenlative genus Mindeniella had approximately one‐third of the total cytochrome content and one‐third of the endogenous respiration rate observed in Leptomitus and Apodachlya. Mindeniella and Sapromyces contained less total cytochrome when grown under reduced oxygen tension than when grown in air. Only about one‐half of the b‐type cytochrome was redueible by endogenous substrates. Both cytochrome a3 and an unidentified pigment bound CO. The endogenous respiration of Leptomitus, Apodachlyo, and Sapromyces was strongly Inhibited by sodium cyanide, sodium azide, antimycin A, and sodium fluoroacetate.
Cyclic Variations in Plant Properties under Constant Environmental Conditions
Authors: Barrs H. D. , Klepper Betty
Published: April 2006

Cyclic fluctuations in stomatal aperture, transpiration rate and leaf water potential under constant environmental conditions have been investigated in intact plants of cotton, pepper, and sunflower. Stomatal aperture and transpiration rate were least when leaf water potential was high and were greatest when leaf water potential was low.

Lowest leaf water potential values lagged behind the occurrence of highest transpiration rates, and high overall resistance to water flow occurred in cycling plants. Both of these are considered essential for the occurrence of persistent cyclic behaviour. Hydropassive opening of stomates as the leaves wilted facilitated cycling in cotton and pepper, but not in sunflower, where hydropassive opening did not occur.

The roots were identified as the site of the major resistance to water flow in the plant and further experiments directly showed the importance of this root resistance in initiating cycling by causing water stress in the leaves as the stomates opened.

Root resistance varied diurnally, becoming increasingly important at night. Root resistance naturally rose to high levels in cotton. High levels were induced in pepper or sunflower by having the roots in deionized water for several days or by anoxia.

Quantitative measurements of overall plant resistance were made from leaf water potential and transpiration rate data.

The results are discussed and it suggested that plant resistance may indirectly be of importance in the movement of water from the plant to the air.
Evidence for a Tumor‐associated Factor Active in the Promotion of Crown‐gall Tumor Growth on Primary Pinto Bean Leaves
Authors: Lippincott James A. , Lippincott Barbara B. , El Khalifa M. D.
Published: April 2006

The growth of crown‐gall tumors on primary pinto bean leaves (Phaseolus vulgaris L. cv. “Pinto”) between day 3 and day 6 after inoculation was found to be proportional to the number of tumors on the leaves. Similar differences observed in the growth of tumors induced by adenine, methionine and asparagine requiring mutants of Agrobacterium tumefaciens (Smith and Town.) Conn appear to be due to the same phenomenon. Tumors induced by these auxotrophs thus show no obvious growth differences from those induced by the prototrophic strain despite the lower specific infectivity and the existence of a mutational lesion in these bacteria. A diffusible growth factor(s) produced by the tumor tissue is proposed to account for the relation between tumor number and early tumor growth.
Extraction of Auxin and of Other Growth Regulators from Citrus Steins by Centrifugal Force
Authors: Goldschmidt E. E. , Monselise S. P.
Published: April 2006

A method is described whereby diffusible native growth substances are forcibly extracted by centrifugation. Centrifugates are relatively pure, highly active when tested for auxins and gibberellins, and contain far less inhibitors than solvent extracts.
The Effect of Some Promoters and Inhibitors on the Light Controlled Germination of Strawberry Seeds; Fragaria vesca semperflorens Ehr.
Authors: Thompson P. A.
Published: April 2006

Seed of Fragaria vesca semperflorens Ehr. fails to germinate if kept in continuous darkness after sowing, but responds to short periods of exposure (5 to 10 min) of low intensity red light. Sensitivity increases with increasing time between sowing and light treatment. The promotive effect of light was inhibited by coumarin, but the inhibitory effects of low levels of coumarin could be removed by increasing the quantity of red light given. Thio‐urea induced a percentage of seeds to germinate in the dark, but the effect could not be correlated with the light effect. Seven gibberellins were tested at concentrations between 1 and 50 nig/1. A 4 showed very high activity fully replacing the light requirement at 10 mg/l, but none of the others did so.
The Relationship between Growth and Proline Incorporation after Auxin Treatment of Mung Bean Hypocotyls
Authors: Kuraishi Susumu , Kasamo Kunihiro , Yamaki Toshio
Published: April 2006

Indoleacetic acid (IAA) stimulates the incorporation of 14C‐proline into both the cyloplasmic and the cell wall fractions of the hypocotyl of mung bean (Phaseolus aureus Roxb. cv. Black). It neither stimulates the transfer of 14C‐proline from the cyloplasmic fraction into the cell wall fraction, nor the retention of 14C‐proline in the wall or cytoplasmic fractions. Moreover, the stimulation of growth caused by IAA parallels the stimulation of the incorporation of proline into the cytoplasmic fraction, but does not parallel the stimulation into the cell wall fractions.

The stimulation of the incorporation into the cyloplasmic fraction seems to appear within 30 minutes after auxin treatment, at about the same time the increase in the growth is observed in response to IAA, suggesting a connection between these effects. On the other hand, the stimulation of the proline incorporation into the cell wall fraction seems to require more than 90 minutes after auxin treatment, suggesting no close connection between growth and proline incorporation into the cell wall fraction.
Nitrogen Metabolism of Vicia faba
Authors: Olsson R. , Boulter D.
Published: April 2006

Vicia faba plants were grown for four and six weeks without externally supplied nitrogen. Some nitrogen was transported to the plant axis from the cotyledons throughout this period, but the amount available was insufficient to support maximum shoot growth. During this period the protein content of the shoot declined whilst the free amino acids, especially aspartic acid, glutamic acid, histamine and the combined pool for threonine, serine, asparagine and glutamine and ammonia, increased in amount. In contrast to the shoot the protein content of the root increased as did their free amino acid content, but the increase in the latter was less than in the shoot and only the combined value for threonine, serine, asparagines and glutamine increased significantly. During tbe last two weeks growth, some soluble non‐amino acid compound appeared to donate nitrogen to the pool of free amino acids in the root and shoot.
Action de solvants basiques sur le spectre d'absorptiou des complexes pigmentes extraits de la bactérie pourpre Rhodospirillum rubrum
Authors: Aghion Jacques , Crevier Louise
Published: April 2006

Absorption spectrum of Rhodospirillum rubout pigment complexes in basic solvents. — The adsorption and aggregation of bacteriochlorophyll are studied in various polar solvents, at different concentrations. It is shown that 3 absorption bands exist in these conditions, duplicating 3 of the absorption bands found in vivo: the 772 nin, the 830 nm and the 890 nm‐bands. The 800 nm‐band cannot be formed in vitro. The relations between the respective concentrations of the 3 states of bacteriochlorophyll found In vitro are calculated and discussed.
Effects of Photodynamic Action on the Cell Membrane of Euglena
Authors: Bellin Judith S. , Ronayne M. E.
Published: April 2006

The effects of photodynamic action on the cell membrane of Euglena gracilis were investigated by means of studies on dye binding and electrophoretic mobility. Molecular species of alkaline or acid dyes can penetrate the membrane to about the same extent. Once the cell has been injured by pbotodynamic action, ils ahility to exclude large ions is partially lost; it becomes greatly more permeable to dye anions. Binding of rose bengal induces an increased negative charge on Euglena cells which is reversed by subsequent photosensitized damage to the cells.