bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of Ultraviolet and X‐Ray Radiation on in vitro Cultivated Cells of Haplopappus gracilis
Authors: Eriksson Tage 
Published: April 2006

AbstractA 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

Abstract 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

AbstractThe 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

AbstractPresence 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

AbstractOlive 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

AbstractPlants 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

AbstractChanges 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

AbstractThe 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

AbstractThree 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

AbstractEfflux 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

AbstractThe 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

AbstractAvena 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

AbstractThe 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

Abstract 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

AbstractThe 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

AbstractSprout 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

AbstractEsterases, 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

AbstractA 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.