Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| [myotrophic and myotonic effects of a new preparation, betul, a combination of sodium glycerophosphate, vitamin b1 and white birch]. | 1952 | 14919353 | |
| [association of white birch, sodium glycerophosphate, and vitamin b1 in the treatment of sequels of hemiplegia, lumbar arthrosis, and neuritis; preliminary observations]. | 1952 | 14937254 | |
| [triterpenes of betula pendula roth and betula pubescens ehrh. comparative study of the bark]. | 1966 | 5220364 | |
| [cytokinins of parasitic origin. i. cytokinin activity in leaves of betula pendula roth caused by an infecion by stigmella argentipedella zeller (lep.)]. | 1970 | 5537265 | |
| [cherry leaf-roll virus from birch (betula pendula roth)]. | 1972 | 5068493 | |
| naturally-occurring growth regulators in leaf washings of picea sitchensis (bong.) carr and betula pendula roth. | leaf washings were collected during and immediately after periods of rainfall ('natural') from picea sitchensis (bong.) carr and betula pendula roth., growing in the field. they contained acidic and non-acidic ethyl acetate-soluble growth regulating factors, including a gibberellin-like compound and an inhibitor resembling abscisic acid (aba). similar ranges of growth regulators were obtained when needles of picea sitchensis were intermittently sprayed with a fine water mist ('artificial') in gl ... | 1974 | 24458991 |
| the decomposition of branch-wood in the canopy and floor of a mixed deciduous woodland. | the pattern of decomposition of branch-wood greater than 2 cm diameter is described for a one hectare site at meathop wood, cumbria, based on studies carried out as part of the ibp between 1967 and 1972. three phases of decomposition are recognised. following the death of branches in the canopy and their colonisation by fungi, decomposition proceeded at an average annual loss rate of about 8.4%. wood at branch-fall had on average lost about 40% of its original dry weight. on the forest floor the ... | 1976 | 28309258 |
| tree host range and world distribution of the extomycorrhizal fungus pisolithus tinctorius. | the natural occurrence of pisolithus tinctorius has been confirmed in 33 countries of the world and in 38 states in the united states. this ectomycorrhizal fungus is found associated with various tree species in nurseries, urban areas, orchards, forests, and strip-mined spoils. experiments have proved that this fungal symbiont forms ectomycorrhizae with abies procera, betula pendula, carya illnoensis, 11 species of eucalyptus, 30 species of pinus, pseudotsuga menziesii var. meniziesii, 2 species ... | 1977 | 856419 |
| the influence of plant water stress on stomatal control of gas exchange at different levels of atmospheric humidity. | leaves of well-watered and mildly water-stressed seedlings of betula pendula roth. and gmelina aroborea l. were subjected to a range of vapour pressure deficits (vpd) between 10 and 24 kpa. the stomatal conductance of birch seedlings decreased as vpd was increased and at least in mildly-stressed seedlings this response seemed to be closely linked to the water status of the air rather than to the bulk water status of the plant. mild water stressing enhanced the degree of the stomatal humidity-res ... | 1980 | 28310617 |
| the influence of water stress on the photosynthetic performance and stomatal behaviour of tree seedlings subjected to variation in temperature and irradiance. | seedlings of betula pendula roth. and gmelina arborea l. were subjected to variation in temperature and irradiance. the influence of a mild water-stressing treatment on the photosynthetic performance and stomatal behaviour of these plants was assessed. for both species, the shape of the relationships between irradiance and photosynthesis and temperature and photosynthesis resembled those reported for other species. the effect of water stress was to reduce the rate of photosynthesis, particularly ... | 1980 | 28310929 |
| water permeability of betula periderm. | the water permeability of periderm membranes stripped from mature trees of betula pendula roth was investigated. the diffusion of water was studied using the system water/membrane/water, and transpiration was measured using the system water/membrane/water vapor. betula periderm consists of successive periderm layers each made up of about 5 heavily suberized cell layers and a varying number of cell layers that are little suberized, if at all. it is shown that these layers act as resistances in se ... | 1980 | 24311086 |
| root growth and water relations of oak and birch seedlings. | first year seedlings of english oak (quercus cobur) and silver birch (betula pendula) were subjected to pressure-volume analysis to investigate the water potential components and cell wall properties of single leaves. it was hoped that this rapid-drying technique would differentiate between reductions in plant solute potential resulting from dehydration and the effects of solute accumulation.comparison of results from these experiments with those of slow drying treatments (over a number of days) ... | 1981 | 28310018 |
| the role of coprophagy in the feeding strategies of terrestrial isopods. | the hypothesis that faeces recycling in isopods evolved as an adaption to facilitate maintenance of an adequate copper balance in terrestrial environments is examined. experimental observations on the consumption, absorption and growth rates of porcellio scaber fed betula pendula leaf litter varying in copper content and extent of microbial decay are reported. preventing the isopods from reingesting their faeces caused a reduction in the growth rates of experimental animals fed their natural low ... | 1982 | 28311744 |
| electron microscopic localization of concanavalin a receptor sites in pollen surface material after fixation with glutaraldehyde-cetylpyridinium chloride. | pollen from birch trees (betula pendula) was fixed in glutaraldehyde containing 0.5% cetylpyridinium chloride (cpc), incubated with concanavalin a (con a)-ferritin, postfixed in osmium, dehydrated, and embedded in epon. on ultrathin sections, ferritin particles were observed closely associated with the electron-dense material precipitated by cpc on the surface of the pollen grains. controls for cpc, which were fixed in glutaraldehyde alone, showed no electron-dense material on the surface. in co ... | 1984 | 6430993 |
| immunoelectron-microscopic localization of diffusible birch-pollen antigens in ultrathin sections using the protein-a/gold technique. | pollen grains from betula pendula were fixed in a mixture of p-formaldehyde and cetylpyridinium chloride (cpc) for the precipitation of soluble pollen glycoproteins. after dehydration and embedding at low temperatures in the water-soluble resin, lowicryl k4m, ultrathin sections of the pollen grains were incubated using specific antibodies against birch-pollen extract and protein-a/gold complexes. antigen activity was found in the cpc-precipitated surface material and within the exine (bacular ca ... | 1984 | 6520024 |
| differentiation--a consequence of idiotype-environment interaction. | the present paper deals with a model of idiotype-environment interaction and its application to a tissue culture experiment with birch (betula pendula roth.). the data of the experiment are characterized with respect to the physiological reactions and are discussed in the light of the model. the main results of the paper are: with respect to the environmental action one has to discriminate between the environment inside and outside the cell (external and internal environment). the environmental ... | 1984 | 6743790 |
| metabolic response of river birch and european birch and european birch roots to hypoxia. | flood tolerance of woody plants has been attributed to internal oxygen diffusion from shoot to root, metabolic adaptation within the root, or both. the purpose of this study was to compare several biochemical and physiological responses of birch roots to hypoxia in order to determine the nature of root metabolic adaptation to low oxygen tension. one-year-old seedlings of flood-tolerant river birch (betula nigra l.) and flood-intolerant european birch (betula pendula roth) were transferred to sol ... | 1984 | 16663817 |
| chemical defense in birch: inhibition of digestibility in ruminants by phenolic extracts. | the biological activity of phenolic extracts originating from winter twigs of birch (betula pendula roth.) was measured using the ruminant in vitro method and the nylon bag technique. different extracts were prepared by extraction with organic solvents, removing phenols of corresponding solubility. the extract of birch twigs (diameter <1.5 mm) contained about 19% phenol equivalents, corresponding to 6% of twig dry matter (dm). coarse birch twigs (diameter 1.5-5 mm) contained about 3% in the dm p ... | 1985 | 28310902 |
| seasonal variation of phenols, crude protein and cell wall content of birch (betula pendula roth.) in relation to ruminant in vitro digestibility. | birch twigs of diameter ≦1.5 mm exhibit seasonal trends in ruminant in vitro organic matter digestibility (ivomd), and in the contents of crude protein, cell walls (neutral detergent fibre, ndf), and phenolic compounds. the ivomd is low in winter twigs, increases in spring, and reaches a maximum in early summer. crude protein behaves similarly. on the other hand, the proportion of hydrophilic phenols and cell walls (cellulose, hemicellulose, and lignin) to dry weight decreases dramatically in sp ... | 1985 | 28310434 |
| cytokinins in the spring sap of curly birch (betula pendula f. carelica) and the non-curly form. | the different forms of cytokinins in the spring sap fo curly (f. carelica) and non-curly birch (betula pendula) were determined by two preparation methods, with (1) or without (2) acid hydrolysis, and were fractionated using a column of sephadex lh-20 eluted with 35 % ethanol. the levels of cytokinins in the fractions were estimated with theamaranthus caudatus explant bioassay and the total cytokinin contents were calculated on amino nitrogen, total sugar and sap volume bases. using method 1, th ... | 1985 | 23195929 |
| rapid wound-induced resistance in white birch (betula pubescens) foliage to the geometrid epirrita autumnata: a comparison of trees and moths within and outside the outbreak range of the moth. | two strains of a geometrid defoliator, epirrita autumnata, were used in bioassays to test existence and relative efficacy of rapid, wound-induced foliage resistance in two provenances of the white birch. one birch and one moth strain originated in the outbreak range of the moth and another outside it. both birch provenances responded to manual leaf damage by changes in foliage quality which significantly retarded growth of the insects, reducing their pupal weights and protracting larval periods. ... | 1985 | 28310669 |
| leaf growth of betula and acer in simulated shadelight. | leaves of birch (betula pendula roth) and sycamore (acer pseudoplatanus l.) were initiated and grown either in a simulated shadelight (80 μmol m(-2) s(-1), r/fr ratio 0.28)/dark photoenvironment or a white light (250 μmol m(-2) s(-1), r/fr>1)/dark photoenvironment. until the leaves were more than 50% expanded, growth rates (measured every 24 h) were the same for both species in both environments. after this time, growth rate slowed and this correlated well with a decrease in wall extensibility ( ... | 1986 | 28311620 |
| uptake of carbon and nitrogen at decreased nutrient availability in small birch (betula pendula roth.) plants. | uptake of carbon and nitrogen in relation to mineral nutrient supply was investigated in small birch (betula pendula roth.) plants grown in solution culture. a step-decrease in nutrient availability (from near-optimal to a low rate of supply) caused an immediate and temporary cessation in net uptake of nitrogen to leaves and a sharp reduction in rate of leaf expansion. both net uptake of nitrogen to leaves and leaf area expansion subsequently resumed but at a rate matching the decreased nutrient ... | 1986 | 14975842 |
| visualization of birch pollen allergens using ige-containing sera from human atopic individuals in immunogold labelling experiments. | pollen from birch trees (betula pendula) was fixed in paraformaldehyde with or without the addition of 0.5% cetylpyridinium chloride, dehydrated and embedded in lowicryl k4m in the cold. ultrathin sections were incubated using the following sequence of antibodies and antisera: ige-containing serum from an atopic human individual allergic to birch pollen allergens, rabbit anti-human ige antibodies, and colloidal gold-labelled goat anti-rabbit antibodies. controls were performed by replacing the s ... | 1986 | 3486858 |
| [hemostatic system function as affected by thromboplastic agents from higher plants]. | it has been determined that the thromboplastic agents from the inflorescence of the birch betula pendula roth, blossoms of the willow salix daphnoides vill., seeds of the pea pisum sativum l. provoke protective reaction of the animal's anticoagulation system, though weaker expressed than the reaction of thromboplastin from brain. the mechanisms of action of thromboplastic agents of plant origin is similar to the mechanism of action of tissue thromboplastin. | 1986 | 3708030 |
| young's modulus of sections of living branches and tree trunks. | young's modulus along the grain (elasticity, e) was measured on 10 sections of branches and three tree trunks, with bark, of picea sitchensis (bong.) carr., pinus contorta dougl. ex loud., larix decidua mill. and betula pendula roth. syn. verrucosa ehrh. the sections were simply supported and corrections were made for taper and deflection due to shear. the e values for trunks were at the lower end of the range reported for green timber (2.4-7.5 gpa), and those for branches were still lower (0.7- ... | 1987 | 14975919 |
| effects of sulphur dioxide and nitrogen dioxide, singly and in mixture, on the macroscopic growth of three birch clones. | an investigation of some aspects of the effects of low concentrations of the gases, sulphur dioxide and nitrogen dioxide, singly and in mixture, was made on the growth of three birch clones, two of betula pendula roth. (silver birch) and one of betula pubescens ehr. (downy birch). comparative measurements of the growth form and dry mass increment were made over one year in glasshouses supplied with charcoal-filtered ambient air, and so(2) and no(2), singly or in mixture, at mean concentrations o ... | 1987 | 15092731 |
| effects of different types of damage on the chemistry of birch foliage, and the responses of birch feeding insects. | 1. we collected insect-grazed, mined, and holepunched leaves of betula pendula roth, and assessed their palatability to four species of birch-feeding lepidopteran caterpillars (apocheima pilosaria d. & s., erranis defolaria clerck, epirrita dilutata d. & s., and euproctis similis fuessly) in laboratory preference tests. the palatability of hole-punched leaves of different ages was also determined, using apocheima pilosaria only. 2. the total phenolic content and protein-precipitating ability of ... | 1987 | 28312484 |
| a parenchymatic medium solidifier for plant in vitro culture. | a new material for the solidification of liquid culture media was prepared from plant parenchyma tissues by mechanical subdivision, solute extration and dessication from ethanol. it is suitable for in vitro culture and propagation of callus as well as shoot tip cultures. the following plant materials have been grown by means of the new medium solidifier: shoot cultures of betula pendula roth, gerbera jamesonii h. bolus ex hook and floribunda rose "triumph", callus tissues of daucus carota l. and ... | 1987 | 24248936 |
| effects of terrestrial isopods on the decomposition of woodland leaf litter. | the indirect contribution terrestrial isopods make to decomposition processes by stimulating microbial activites has been quantified in laboratory experiments. the extent to which microbial metabolism is enhanced as a result of the passage of betula pendula leaf litter through the alimentary system of isopods was measured for both freshly fallen and decayed leaves. faeces derived from 1 g freshly fallen litter lost 75 mg g(-1) d.w. more than did intact leaves, as a result of enhanced microbial m ... | 1987 | 28312524 |
| the inhibition of phenolic biosynthesis in damaged and undamaged birch foliage and its effect on insect herbivores. | 1. the leaves of betula pendula roth trees were damaged artificially, or by insect-grazing. both induced an increase in phenolic levels in damaged leaves, larger in the case of insect attack.-2. some of the damaged trees were sprayed with an inhibitor of phenolic biosynthesis, (aminoxy) acetic acid, which led to a reduction in phenolic levels in both undamaged and damaged leaves. hence both the effects of damage per se and damage-induced changes in foliage phenolic levels on insect feeding prefe ... | 1988 | 28312381 |
| chemical defense in birch. platyphylloside: a phenol frombetula pendula inhibiting digestibility. | extracts of scandinavian birch (betula pendula roth) buds and internodes of varying twig diameters have been investigated for their inhibitory effect on ruminant digestibility in vitro. the predominant inhibitory effect was observed in extracts containing the phenol platyphylloside, 5-hydroxy-1,7-bis-(4-hydroxy-phenyl)-3-heptan-one-3-o-β-d-glucopyranoside. isolation of the pure compound and incubation with rumen inocula showed that digestibility was negatively related to the concentration. signi ... | 1988 | 24276001 |
| diameters and dry weights of tree shoots: effects of young's modulus, taper, deflection and angle. | the structural theory for cantilever beams was used to calculate the diameters and dry weights of wood that unbranched shoots must produce to support their own weights. the study was done on picea sitchensis (bong.) carr., pinus contorta dougl., larix decidua mill. and betula pendula roth. syn. verrucosa ehrh. the weights of wood increased in a non-linear fashion with increase in shoot length. a large investment in wood (as measured by diameter and dry weight) was required to maintain a small en ... | 1988 | 14972812 |
| micropropagation of a mature colchicine-polyploid and irradiation-mutant of betula pendula roth. | tetraploid plantlets were regenerated from cultured apical and axillary buds of a 23-year-old colchicine-polyploid and irradiation-mutant betula pendula roth tree. bud explants were grown on modified murashige and skoog medium supplemented with 2.0 mg l(-1) benzylaminopurine (bap) and 0.01 mg l(-1) 1-naphthaleneacetic acid (naa). the medium allowed both induction of adventitious buds and development of shoots. the cut ends of new shoots produced new buds and shoots during a 4-week culture period ... | 1988 | 14972827 |
| isolation and characterization of messenger rna from male inflorescences and pollen of the white birch (betula verrucosa). | a glycoprotein with a molecular weight (mw) of 17 kilodaltons (kd), bet v i, represents the major allergen of the white birch (betula verrucosa, bv) and plays an important role in tree-pollen-induced type i allergic reactions. in order to characterize the major and also some minor allergens of bv, we investigated the ige-binding properties of these allergens using immunoblot techniques. normal and patients' sera were employed for this study. furthermore, rna from male inflorescences and from pol ... | 1988 | 3170006 |
| the gene coding for the major birch pollen allergen betv1, is highly homologous to a pea disease resistance response gene. | pollen of the white birch (betula verrucosa) is one of the main causes of type i allergic reactions (allergic rhinoconjunctivitis, allergic bronchial asthma) in middle and northern europe, north america and the ussr. type i allergies are a major threat to public health in these countries, since 10-15% of the population suffer from these diseases. betvi, an allergenic protein with an mr of 17 kd is a constituent of the pollen of white birch and is responsible for ige binding in more than 95% of b ... | 1989 | 2571499 |
| [a new rapid test for the detection of ige antibodies in inhalation allergies]. | we compared the results of the skin-prick-test, phadezym-rast and ige-quick, developed by quidel, obtained from 75 patients suffering from an inhalant allergy and 25 controls. the ige-quick is a qualitative eia dipstick test designed for the rapid visual detection of allergen-specific ige. the ige-quick contained nine test pads coated with one of the following purified allergens: betula pendula, phleum pratense, secale cereale, artemisia vulgare, felis domestica, canis familiare, d. pteronyssinu ... | 1989 | 2742661 |
| phenolic biosynthesis, leaf damage, and insect herbivory in birch (betula pendula). | the effect of both caterpillar herbivory and artificial damage on phenylalanine ammonia lysase (pal) activity of birch foliage was measured, using an intact cell assay. after artificial damage there was a small increase in pal activity in damaged leaves but no change in adjacent undamaged ones. insect grazing produced a larger increase in pal activity, and the enzyme activity was also increased in adjacent undamaged leaves. artificial damage increased the phenolic levels of the damaged leaves. i ... | 1989 | 24271442 |
| changes in the water relations of balsam fir and white birch saplings after thinning. | in the autumn of 1987, young balsam fir (abies balsamea (l.) mill.) and white birch (betula papyrifera marsh.) trees were thinned and their water relations followed during the next two growing seasons. at the beginning of the first summer following treatment, thinned trees of both species had lower osmotic potentials at full saturation (psi(pi,sat)) and at turgor loss point (psi(pi,tlp)) compared with controls. at this time, psi(pi,sat) was linearly related to the percentage of full sunlight rea ... | 1990 | 14972929 |
| autotetraploid plants from callus cultures of betula pendula roth. | autotetraploid plants with 2n = 56 chromosomes were found in a population of plants derived from callus cultures of stem internodes of silver birch (betula pendula roth) with 2n = 28 chromosomes. these plants were readily identified by their twisted, pubescent foliage and slow rate of growth, and by cytological examination. the frequency of autotetraploidy varied with the auxin used in the culture medium. when indole-3-butyric acid was used, autotetraploids accounted for 3.8% of the total study ... | 1990 | 14972954 |
| the utilization of old phenological time series of budburst to compare models describing annual cycles of plants. | a phenological time series of the date of budburst of birch (betula pendula) was constructed using data from the years 1907-1950. data for the years 1908, 1910-1915 and 1930 are missing. the phenological observations were made at saarijärvi (62 degrees 42' n, 25 degrees 44' e) in central finland. different models describing the rate of development in the spring were analyzed using temperature data from the city of jyväskylä about 60 km to the southeast of saarijärvi. the models based on temperat ... | 1991 | 14972878 |
| sequence of a cdna encoding the bi-specific nad(p)h-nitrate reductase from the tree betula pendula and identification of conserved protein regions. | nitrate reductase (nr) assays revealed a bispecific nad(p)h-nr (ec 1.6.6.2.) to be the only nitrate-reducing enzyme in leaves of hydroponically grown birches. to obtain the primary structure of the nad(p)h-nr, leaf poly(a)+ mrna was used to construct a cdna library in the lambda gt11 phage. recombinant clones were screened with heterologous gene probes encoding nadh-nr from tobacco and squash. a 3.0 kb cdna was isolated which hybridized to a 3.2 kb mrna whose level was significantly higher in pl ... | 1991 | 1675424 |
| identification of profilin as a novel pollen allergen; ige autoreactivity in sensitized individuals. | a complementary dna encoding a pollen allergen from white birch (betula verrucosa) that was isolated from a pollen complementary dna library with serum immunoglobulin e from a birch pollen-allergic individual revealed significant sequence homology to profilins. the recombinant protein showed high affinity to poly-l-proline. immunoglobulin e antibodies from allergic individuals bound to natural and recombinant birch profilin and also to human profilin. in addition, birch and human profilin induce ... | 1991 | 1857985 |
| a low molecular weight allergen of white birch (betula verrucosa) is highly homologous to human profilin. | cloning of allergens has contributed substantially to the understanding of mechanisms in allergic diseases by providing information about the sequence and hence biological functions of allergens. the major birch pollen allergen, bet v i [breiteneder h, et al: embo j 1989;8:1935-1938] and the white-faced hornet venom allergen (antigen 5) [si yun fang k, et al: proc. natl. acad. sc. usa 1988;85:895-899] were shown to be highly homologous to pathogenesis-related proteins of plants. in the case of t ... | 1991 | 1937902 |
| do birch-feeding caterpillars make the right feeding choices? | the effects of leaf quality on caterpillar performance are frequently investigated, as are the feeding preferences of caterpillars, but rarely are the two considered together to see how preferences match performance. i looked at the preferences and performance of the specialist feeder achlya flavicornis and the generalist spilosoma luteum on betula pendula leaves which were artificially damaged, mined or left undamaged, and on leaves of different ages. often feeding preferences were not for the ... | 1991 | 28313843 |
| sequence of a cdna encoding nitrite reductase from the tree betula pendula and identification of conserved protein regions. | the sequence of an mrna encoding nitrite reductase (nir, ec 1.7.7.1.) from the tree betula pendula was determined. a cdna library constructed from leaf poly(a)+ mrna was screened with an oligonucleotide probe deduced from nir sequences from spinach and maize. a 2.5 kb cdna was isolated that hybridized to an mrna, the steady-state level of which increased markedly upon induction with nitrate. the nucleotide sequence of the cdna contains a reading frame encoding a protein of 583 amino acids that r ... | 1992 | 1347145 |
| distribution of allergens and allergen-coding mrnas in various tissues of white birch. | the distribution of allergenic proteins was investigated in various tissues of white birch, betula verrucosa (pollen, leaves and male inflorescences containing immature pollen). in addition, callus and suspension culture cells were investigated for expression of ige-binding proteins. furthermore, rna was extracted from all these tissues and subjected to in vitro translation in a cell-free wheat germ system. bet v i, the major birch pollen allergen, could be extracted easily from pollen, and in l ... | 1992 | 1406724 |
| [immunological study of the hla class ii antigen associated with birch pollen allergy]. | pollinosis is known as a hereditary disease. recently, association of hla antigens and pollinosis caused by several pollen allergens has been reported. furthermore, hla antigens are considered to have a very important role in the development of pollinosis. we performed an hla population study and tested the lymphocyte proliferative response (lpr) to birch pollen allergens with birch pollen allergic patients and healthy control subjects. the results of the hla population study indicated that hla- ... | 1992 | 1602355 |
| pcr based cloning and sequencing of isogenes encoding the tree pollen major allergen car b i from carpinus betulus, hornbeam. | cloning of the gene encoding the major allergen, car b i, from carpinus betulus (hornbeam) pollen was performed using the polymerase chain reaction (pcr) to specifically amplify the gene of interest using single stranded cdna as template. specific primers, deduced from the aminoterminal sequence of the purified protein, were tailored to facilitate direct expression of plasmic clones, and the large fraction of positive clones obtained, revealed the presence of isogenic variation. three clones wer ... | 1992 | 1603091 |
| effects of copper and cadmium on uptake and leakage of k(+) in birch (betula pendula) roots. | uptake and leakage experiments were performed to study the effects of copper and cadmium on k(+) fluxes in birch (betula pendula roth) roots. labeled rubidium ((86)rb(+)) was used as a tracer for k(+). plants were pretreated with cu or cd (0, 2, 5 or 25 microm) for 0-300 min and then transferred to radiolabeled nutrient solution (150 microm k(+)) with or without 2,4-dinitrophenol (dnp) to separate the effects of heavy metal on active and passive k(+) influxes. passive k(+) influx was decreased b ... | 1992 | 14969953 |
| induction of nitrate assimilatory enzymes in the tree betula pendula. | the coordinate appearance of the bispecific nad(p)h-nitrate reductase (nr; ec 1.6.6.2) and nitrite reductase (nir; ec 1.7.7.1) was investigated in leaves and roots from european white birch seedlings (betula pendula roth). induction by nitrate and light of both enzymes was analyzed by in vitro assays and by measuring nr- and nir-encoding mrna pools with homologous cdnas as probes. when birch seedlings were grown on a medium containing ammonium as the sole nitrogen source, low constitutive expres ... | 1992 | 16669009 |
| variations in leaf morphometry and nitrogen concentration in betula pendula roth., corylus avellana l. and lonicera xylosteum l. | relations between leaf dry weight to leaf area (lwa), leaf nitrogen concentration and irradiance inside a natural canopy were studied in betula pendula roth., corylus avellana l. and lonicera xylosteum l. in all species, lwa increased with increasing irradiance. relative variability in lwa was smaller in betula pendula than in the other two species. in corylus avellana, lwa also depended on total plant height. foliar nitrogen concentration (on a dry weight basis) increased with increasing irradi ... | 1993 | 14969921 |
| foliar injury in young betula pendula roth., salix purpurea l. and ilex aquifolium l. trees and in propagated taxus baccata l. shoots exposed to intermittent fog at a range of acidities. | the occurrence of various visible symptoms of foliar injury was assessed on a 5-point scale for each of the species. there was a distinct increase in the incidence of most types of injury in plant material which has been exposed to ph 2.5 acid fog. no clear ph-related trend in foliar injury occurred in plants exposed to acid fog at ph 3.5, ph 4.5 and ph 5.6, indicating that a threshold for a range of different types of visible injury may exist between ph 2.5 and ph 3.5 for all four species. | 1993 | 15091854 |
| classification of plant somatic embryos by computer vision. | this article deals with the automation of the process of somatic embryogenesis for the propagation of plants. an important problem is the monitoring of the embryo production process in order to decide the time to start harvesting embryos for further processing. the classification algorithm development for somatic embryos of birch (betula pendula roth) showed that automated recognition of embryos at different developmental stages is possible. no globular stage embryos were classified to be heart ... | 1993 | 18601243 |
| characterization of a birch (betula pendula roth.) embryogenic gene, bp8. | we have isolated the birch homologue (bp8) for the carrot embryogenic gene dc8 by heterologous hybridization. the birch bp8 gene encodes a putative protein of 53 kda, showing 52% sequence identity with the dc8 gene at the amino acid level. the putative bp8 protein contains 20 repeats of 11 amino acids and thus belongs to the group of lea proteins isolated from such plants as carrot, cotton and wheat. northern hybridization of mrna isolated from birch cells representing different stages of somati ... | 1993 | 8219076 |
| characterization of recombinant bet vi, the major pollen allergen of betula verrucosa (white birch), produced by fed-batch fermentation. | the gene encoding the major allergen, bet v i, from betula verrucosa (white birch) pollen was cloned by application of the polymerase chain reaction with double-stranded cdna as template and specific primers based on the published nucleotide sequence of the gene. the gene was inserted into plasmid pkk223-3 and expressed in escherichia coli k-12 strain jm105 grown to high cell density in a fermenter using a fed-batch procedure. ample material was provided for a thorough characterization of the ep ... | 1993 | 8219778 |
| saponins in the leaves of birch? hemolytic dammarane triterpenoid esters of betula pendula. | three hemolytic dammarane triterpenes, esterified with malonate at c-3 and acetate at c-12, were isolated from the leaves of betula pendula. their structures were elucidated by chemical and spectroscopic means. former reports on the presence of saponins in birch leaf extracts could not be confirmed. the hemolytic activity of the extracts, which was ascribed to saponins, is caused by the dammarane esters instead. a fraction containing a mixture of the dammarane esters did not exhibit diuretic act ... | 1993 | 8441786 |
| [molecular and functional characterization of allergens: fundamental and practical aspects]. | well-defined allergens are a prerequisite for the exact diagnosis and immunotherapy of type i (ige-mediated) allergic diseases. the allergens have to be available in highly purified form and in sufficient quantities. by applying molecular cloning methods this goal can be achieved with respect to both characterization and reproducibility of allergen preparations. moreover, this technique leads to the deduction of primary structures of allergens, which allows computer-aided comparisons with alread ... | 1993 | 7507286 |
| growth and nutrition of small betula pendula plants at different relative addition rates of manganese. | in a series of experiments, growth of small birch plants (betula pendula roth) was controlled by the relative addition rate of manganese, r(mn) (day(-1)). the r(mn) treatments were 0.05, 0.10, 0.15 and 0.20 day(-1) with free access to all other nutrients. in an additional treatment, fa, there was free access to all nutrients including mn. the ph of the nutrient solution ranged between 3.9 and 4.1, and the conductivity was between 100 and 200 micro s cm(-1). after an adjustment phase to steady-st ... | 1994 | 14967693 |
| growth and branching habit of rooted cuttings collected from epicormic shoots of betula pendula roth. | patterns of shoot growth and branching were studied over two growing seasons in rooted cuttings collected from both epicormic shoots and seedlings of betula pendula roth. epicormic shoots were induced to sprout on stumps and small logs of 5-, 10- and 30-year-old trees. the use of epicormic shoots enhanced the rooting capacity of stem cuttings collected from these shoots but did not appear to reverse the process of maturation. in this study, maturation was based on characteristics typical of matu ... | 1994 | 14967697 |
| association between hla-drb3*0101 and immunoglobulin-e responsiveness to bet v i. | the relationship between hla-drb3 antigens and specific ige responsiveness to highly purified major allergen from white birch (betula verrucosa), bet v i, was studied in 43 patients, who were skin-prick test positive to birch pollen extract. specific ige to bet v i was measured using an assay based on the principle of the magic lite method. hla-dr and -dq typings were performed by standard restriction fragment-length polymorphism techniques and hla-drb3 typing by the use of polymerase chain reac ... | 1994 | 7910161 |
| landfill site restoration: the inimical challenges of ethylene and methane. | vertically migrating landfill gases pose inimical challenges to site revegetation strategies. laboratory studies were made to examine the efficacy of ectomycorrhizae and soil cover to obviate the challenges of ethylene and methane. in the presence of ethylene concentrations </= 640 ppm the mean colony radial extension rates of the fungal isolates laccaria proxima, paxillus involutus and hebeloma crustuliniforme were comparable with the non-ethylene controls. h. crustuliniforme afforded no protec ... | 1994 | 15091739 |
| the effect of elevated carbon dioxide and fertilization on primary and secondary metabolites in birch,betula pendula (roth). | seedlings of european white birch (betula pendula roth) were grown in growth chambers for one growth season under four carbon dioxide regimes (350, 700, 1050 and 1400 ppm) and at three fertilization levels (0, 100 and 500 kg ha(-1) monthly). the soluble carbohydrates and secondary phenolics in the leaves and stems were analysed. it was found that fertilizer addition reduced the amounts of glucose and fructose while sucrose remained almost unaffected. the sugar content of leaves increased at 700 ... | 1994 | 28313886 |
| composition of larval secretion ofchrysomela lapponica (coleoptera, chrysomelidae) and its dependence on host plant. | the defensive secretion ofchrysomela lapponica larvae, which is produced by nine pairs of exocrine dorsal glands, has been chemically analyzed. thec. lapponica larvae were kept in the laboratory on leaves of either birch (betula pendula), alder (alnus glutinosa), or willow (salix fragilis). larvae developed normally on birch and willow, whereas those on alder died within a few days. gc-ms analyses of the secretion of larvae on birch and willow revealed that the composition of this secretion diff ... | 1994 | 24242305 |
| the influence of ozone and nutrition on δ(13)c in betula pendula. | in the cellulose of stems and leaves, δ(13)c was investigated in a birch clone (betula pendula), which was exposed throughout the growing season to either <3 (control) or 90/40 nl o3 1(-1) (day/night). each regime was split into plants under high or low nutrient supply. δ(13)c was increased (becoming less negative), in stems rather than leaves, by both high nutrition (+2‰) and o3 stress (+1‰). whereas high nutrition raised the wateruse efficiency (wue) while lowering the co2 concentration in the ... | 1995 | 28306987 |
| allocation of mass in trees subject to nitrogen and magnesium limitation. | it has previously been shown that lack of magnesium, potassium or manganese depresses allocation of new mass to roots in trees, and that these elements often occur in low amounts in declining forest stands. a model for tree growth and nutrient uptake was used to examine the effect of allocation pattern of new plant mass on growth and development in soils with low nutrient concentrations. growth parameters and empirical allocation functions from steady-state experiments with birch (betula pendula ... | 1995 | 14965958 |
| nighttime exposure to ozone reduces whole-plant production in betula pendula. | for 20 weeks during the growing season, cuttings of one birch clone (betula pendula roth.) were exposed in the birmensdorf fumigation chambers to o(3)-free air (control) or 75 nl o(3) l(-1). ozone was supplied either from 1900 until 0700 h (nighttime regime), from 0700 until 1900 h (daylight regime), or all day (24-h regime). by autumn, reductions in whole-plant biomass production, root/shoot biomass and stem weight/length ratios were evident in all three o(3) regimes. the reductions in cuttings ... | 1995 | 14965971 |
| growth and nutrition of birch seedlings at varied relative addition rates of magnesium. | growth and nutrition of hydroponically cultivated birch seedlings (betula pendula roth.) were investigated at various magnesium (mg) availabilities. suboptimum mg conditions were created by adding mg once per hour in exponentially increasing amounts at one of four relative addition rates (r(mg)): 0.05, 0.10, 0.15 or 0.20 day(-1). seedlings given free access to mg were used as controls. after an acclimation period, the relative growth rate of the seedlings attained the same value as the correspon ... | 1995 | 14965980 |
| dormancy release and chilling requirement of buds of latitudinal ecotypes of betula pendula and b. pubescens. | bud burst and dormancy release of latitudinal ecotypes of betula pendula roth and b. pubescens ehrh. from denmark ( approximately 56 degrees n), mid-norway ( approximately 64 degrees n) and northern norway ( approximately 69 degrees n) were studied in controlled environments. dormant seedlings were chilled at 0, 5 or 10 degrees c from october 4 onward and then, at monthly intervals from mid-november to february, batches of seedlings were held at 15 degrees c in an 8-h (sd) or 24-h (ld) photoperi ... | 1995 | 14965987 |
| methods for combining phenological time series: application to bud burst in birch (betula pendula) in central finland for the period 1896-1955. | we compared four methods for combining separate fragmentary phenological time series into a single long reliable series. the systematic linear effect of differences in observers, genotypes, geography and climate at the observation points produces disturbing variation in the observations and bias in the means of some time points. the three methods based on the adjustment of individual series eliminated the disturbing variation and bias. the methods were compared based on phenological observations ... | 1995 | 14965990 |
| photosynthesis and canopy characteristics in genetically defined families of silver birch (betula pendula). | net photosynthetic rates (a) of leaves in upper and lower crown layers (a(upper) and a(lower)), leaf area index (lai), mean tilt angle (mta), several leaf characteristics, and volume growth were observed in fast- and slow-growing families of a 14-year-old full-sib and half-sib family progeny test of betula pendula roth. each measure of net photosynthetic rate was calculated after correcting measured net photosynthesis for the effects of environmental variables. the differences in a(upper) and la ... | 1995 | 14966000 |
| heterogeneity of pollen proteins within individual betula pendula trees. | to determine the variation of antigenic water soluble proteins in white birch (betula pendula) pollen, extracts of pollen from different sides of individual trees were analyzed by isoelectric focusing (ief), crossed immunoelectrophoresis, and crossed radioimmunoelectrophoresis. ige-antibody-binding patterns were also studied in samples analyzed by ief by probing with serum pooled from patients with birch pollen allergy, followed by radiolabelled anti-ige. antigenic proteins and allergens per uni ... | 1995 | 7580310 |
| the choice of reducing substrate is altered by replacement of an alanine by a proline in the fad domain of a bispecific nad(p)h-nitrate reductase from birch. | differences in the amino acid sequence between the bispecific nad(p)h-nitrate reductase of birch (betula pendula roth) and the monospecific nadh-nitrate reductases of a variety of other higher plants have been found at the dinucleotide-binding site in the fad domain. to pinpoint amino acid residues that determine the choice of reducing substrate, we introduced mutations into the cdna coding for birch nitrate reductase. these mutations were aimed at replacing certain amino acids of the nad(p)h-bi ... | 1995 | 7784504 |
| discovery of betulinic acid as a selective inhibitor of human melanoma that functions by induction of apoptosis. | as a result of bioassay-guided fractionation, betulinic acid, a pentacyclic triterpene, was identified as a melanoma-specific cytotoxic agent. in follow-up studies conducted with athymic mice carrying human melanomas, tumour growth was completely inhibited without toxicity. as judged by a variety of cellular responses, antitumour activity was mediated by the induction of apoptosis. betulinic acid is inexpensive and available in abundant supply from common natural sources, notably the bark of whi ... | 1995 | 7489361 |
| a natural experiment on plant acclimation: lifetime stomatal frequency response of an individual tree to annual atmospheric co2 increase. | carbon dioxide (co2) has been increasing in atmospheric concentration since the industrial revolution. a decreasing number of stomata on leaves of land plants still provides the only morphological evidence that this man-made increase has already affected the biosphere. the current rate of co2 responsiveness in individual long-lived species cannot be accurately determined from field studies or by controlled-environment experiments. however, the required long-term data sets can be obtained from co ... | 1996 | 11607712 |
| preseasonal intranasal immunotherapy in birch-alder allergic rhinitis. a double-blind study. | a double-blind, placebo-controlled study was carried out to test the clinical efficacy and safety of local nasal immunotherapy (lnit) in powder form. twenty-two patients suffering from allergic rhinitis strictly associated with early spring symptoms, with positive skin prick tests and rast for birch-alder, all responders to a specific nasal provocation test (npt), received randomly active or placebo treatment for 4 months. immunotherapy consisted of administration of a set of capsules containing ... | 1996 | 8836333 |
| characterization of purified recombinant bet v 1 with authentic n-terminus, cloned in fusion with maltose-binding protein. | a gene encoding the pollen major allergen bet v 1 from betula verrucosa (white birch) has been cloned and expressed in escherichia coli as a fusion with maltose-binding protein and a factor xa proteolytic cleavage site. a generally applicable cloning strategy based on polymerase chain reaction was designed to position the factor xa proteolytic site so that the authentic amino terminus of bet v 1 was generated after cleavage. fusion protein was isolated by amylose affinity chromatography and enzy ... | 1996 | 8936599 |
| crystallization and preliminary x-ray investigation at 2.0 a resolution of bet v 1, a birch pollen protein causing ige-mediated allergy. | the 17 kda protein from betula verrucosa (white birch) pollen, bet v 1, is the clinically most important birch pollen allergen causing immediate type i ige-mediated allergy. the three-dimensional structure of bet v 1 and its ige-binding epitopes are at present not known. in addition, the biological function of bet v 1 in birch pollen is not fully established. in this work, bet v 1 has been expressed in escherichia coli as a recombinant protein, purified and crystallized. the space group of recom ... | 1996 | 8953655 |
| [standardization of the birch leaf]. | dried leaves of betula pendula roth (14 batches) and b. pubescens ehrh. (3 batches) present a similar flavonoid pattern. the mean levels of the principal flavonoid compounds were respectively: total flavonoids 3.29 and 2.77%, hyperoside 0.80 and 0.77%, avicularin (two forms) 0.57 and 0.26%, galactosyl-3 myricetol 0.37 and 0.18%, glucuronyl-3 quercetol 0.25 and 0.36%, quercitrin 0.14 and 0.12%. the flavonoid levels were higher in young leaves and lower in old leaves of b. pendula. 14 batches of c ... | 1996 | 8953799 |
| growth responses and related biochemical and ultrastructural changes of the photosynthetic apparatus in birch (betula pendula) saplings exposed to low concentrations of ozone. | saplings of ozone-sensitive and ozone-tolerant birch (betula pendula roth.), clones b and c, respectively, were exposed to ozone concentrations that were 1.7-fold higher than ambient for one growing season under open-field conditions. ambient air was used as the control treatment. in the ozone-sensitive clone b, there was an initial stimulation of leaf area growth in response to the ozone treatment, but further ozone exposure caused reductions in leaf and stem biomass growth, rubisco and chlorop ... | 1996 | 14871697 |
| improving the reliability of a combined phenological time series by analyzing observation quality. | collecting phenological data is a slow process. although such data have been collected by a number of organizations, the reliability of these data is not known because the data-generating process cannot be repeated. no further observations to improve the reliability can be obtained. however, the data usually consist of several overlapping observation series and this overlap can be utilized to construct a combined phenological time series and to improve its reliability. we have developed two tech ... | 1996 | 14871705 |
| micropropagation of adult birch trees: production and field performance. | we compared the growth of trees produced by micropropagation from nodal stem sections or callus tissue of a 20-year-old silver birch (betula pendula roth) tree with that of seedlings; growth was monitored for 17 months in pots followed by six years in the field. micropropagated trees from both nodal stem sections and callus tissue grew at a similar rate to seedling trees and no obvious mutant types were observed. however, micropropagated trees were more uniform in height and trunk girth than see ... | 1996 | 14871723 |
| comparison of the photosynthetic capacity of siberian and japanese birch seedlings grown in elevated co(2) and temperature. | the effects of increased co(2) and temperature on the photosynthetic capacity of siberian white birch and japanese white birch (betula platyphylla sukatch. and b. platyphylla sukatch. var. japonica hara) were measured. birch seedlings were raised with a co(2) partial pressure of 36 +/- 0.3 pa (i.e., ambient) or 70 +/- 0.6 pa at day/night temperatures of either 30/16 degrees c or 26/12 degrees c. siberian birch leaves were smaller and thicker than japanese birch leaves. water use efficiency and n ... | 1996 | 14871740 |
| impacts of water and nitrogen supplies on the physiology, leaf demography and nitrogen dynamics of betula pendula. | we determined the response of betula pendula roth. trees to a restricted water supply, and quantified the interactions between tree n and water status on leaf demography and internal n cycling. in april 1993, 3-year-old trees were planted in sand culture and four treatments applied: high-n supply (56 mg tree(-1) week(-1)) with either 2 dm(3) water week(-1) (hn+) or 0.9 dm(3) water week(-1) (hn-), or low-n supply (14 mg tree(-1) week(-1)) with 2 dm(3) (ln+) or 0.9 dm(3) (ln-) water week(-1). unti ... | 1996 | 14871759 |
| herbivore-induced resistance in betula pendula: the role of plant vascular architecture. | we studied the role of plant vascular architecture in the determination of the spatial extent of herbivore induced responses within betula pendula roth saplings. the induced responses were measured in bioassays in terms of the relative growth rate of larvae of a geometrid moth, epirrita autumnata. we hypothesised that the level of induced resistance of a certain leaf would be determined by the degree of vascular connectivity between the leaf in question and a damaged leaf, as suggested by recent ... | 1996 | 28307807 |
| elevated co2 reduces field decomposition rates of betula pendula (roth.) leaf litter. | the effect of elevated atmospheric co2 and nutrient supply on elemental composition and decomposition rates of tree leaf litter was studied using litters derived from birch (betula pendula roth.) plants grown under two levels of atmospheric co2 (ambient and ambient +250 ppm) and two nutrient regimes in solar domes. co2 and nutrient treatments affected the chemical composition of leaves, both independently and interactively. the elevated co2 and unfertilized soil regime significantly enhanced lig ... | 1996 | 28307453 |
| allozyme variation in populations, full-sib families and selfed lines in betula pendula roth. | changes in genetic variability in populations (stand origins), full-sib (fs) families and three generations of selfed lines of betula pendula were observed based on 15 allozyme loci. growth vigour, measured as stem volume, and its relationship with heterozygosity was studied to determine the effect of inbreeding. pooled fs families showed a higher percentage of polymorphic loci (p) and allelic numbers per locus (a) than those of natural populations, but no difference in heterozygosity. there was ... | 1996 | 24166635 |
| effects of bilberry (vaccinium myrtillus l.) litter on seed germination and early seedling growth of four boreal tree species. | laboratory and greenhouse bioassays were used to test for inhibitory effects of senescent and decomposed leaves and aqueous extract from bilberry (vaccinium myrtillus l.) against seed germination and seedling growth of aspen (populus tremula l.), birch (betula pendula roth.), scots pine (pinus sylvestris l.), and norway spruce [picea abies (l.) karst.]. aqueous extracts from bilberry leaves were inhibitory to aspen seed germination and seedling growth and also induced root damage and growth abno ... | 1996 | 24227618 |
| effect of birch (betula pendula) bark and food protein level on root voles (microtus oeconomus): ii. detoxification capacity. | the effect of protein and birch bark powder (bbp) content of forage on detoxification capacity of root voles (microtus oeconomus) was studied. young voles were fed with eight different diets for two weeks. individuals on low (3%) protein diets had significantly lighter livers and kidneys than those on moderate (6%) or high (12%) protein diets. birch bark powder addition did not have significant effect on organ weight. detoxification was significantly induced, apparently due to secondary compound ... | 1996 | 24227580 |
| effect of birch (betula pendula) bark and food protein level on root voles (microtus oeconomus): i. food consumption, growth, and mortality. | the effect of protein and birch bark powder (bbp) content of forage on food consumption and growth of root voles (microtus oeconomus) was studied by feeding young voles with eight different diets for two weeks. voles ate more when the protein content of forage was moderate (6%) or low (3%), and when bbp was added to the diets, as compared to a high (12%) protein diet without bbp addition. on high and moderate protein diets voles gained weight, whereas on low protein diets they lost weight. addit ... | 1996 | 24227579 |
| xylem dysfunction during winter and recovery of hydraulic conductivity in diffuse-porous and ring-porous trees. | xylem embolism in winter and spring as well as the occurrence of positive xylem pressure were monitored in several diffuse-porous and one ring-porous tree species (fraxinus excelsior). in acer pseudoplatanus and betula pendula embolism reversal was associated with positive (above-atmospheric) xylem pressures that frequently occurred during a 2-month period prior to leaf expansion. in acer high stem pressures were occasionally triggered on sunny days after a night frost. the other species investi ... | 1996 | 28307135 |
| growth performance of hybrid families by crossing selfed lines of betula pendula roth. | hybrid breeding is an effective approach in many agricultural crops. in allogamous tree species severe inbreeding depression and long reproductive cycles generally prohibit its use. however, three generations of selfing in silver birch (betula pendula roth) were obtained by forcing trees to flowering under greenhouse conditions. hybrids were produced by crossing first-, second and third-generation selfed lines. the effects of different levels of parental inbreeding on the growth performance of h ... | 1996 | 24166273 |
| regenerating temperate forest mesocosms in elevated co2: belowground growth and nitrogen cycling. | the response of temperate forest ecosystems to elevated atmospheric co2 concentrations is important because these ecosystems represent a significant component of the global carbon cycle. two important but not well understood processes which elevated co2 may substantially alter in these systems are regeneration and nitrogen cycling. if elevated co2 leads to changes in species composition in regenerating forest communities then the structure and function of these ecosystems may be affected. in mos ... | 1997 | 28307286 |
| effects of light quality on growth and n accumulation in birch seedlings. | we studied the effects of light quality and nutrient supply on growth and nitrogen accumulation in silver birch (betula pendula roth) seedlings to test three hypotheses: (1) growth of birch seedlings is sensitive to changes in light quality; (2) the response of birch seedling growth to light quality depends on nutrient supply; and (3) assimilation and allocation of nitrogen by birch seedlings are affected by light quality. the two light regimes simulated the spectral quality of sunlight and shad ... | 1997 | 14759882 |
| differences in growth, leaf senescence and injury, and stomatal density in birch (betula pendula roth.) in relation to ambient levels of ozone in finland. | the differences in growth, leaf senescence, visible ozone injuries and stomatal density between one coastal site (natural ozone) and two inland sites (natural and elevated ozone) in finland were determined for saplings of betula pendula clones grown under open-field conditions during two growing seasons. responses in growth, leaf senescence, visible injuries, and stomatal density were determined in relation to cumulative ozone exposure accumulated over the thresholds of 30, 40 and 50 ppb (10(9)) ... | 1997 | 15093411 |
| antioxidant responses to simulated acid rain and heavy metal deposition in birch seedlings. | this study measured the responses of different anti-oxidants in 2-year-old birch (betula pendula roth) seedlings subjected to simulated acid rain (ph 4.0) and heavy metals (cu/ni), applied alone or in combination for 2 months. the applied concentrations of pollutants did not significantly affect seedling biomass or total glutathione levels. acid rain alone increased superoxide dismutase (sod) activity both in leaves and roots, while heavy metals alone inhibited sod activity in roots. both acid r ... | 1997 | 15093466 |
| variation in ozone sensitivity among clones of betula pendula and betula pubescens. | forty clones of betula pendula and 6 clones of betula pubescens, originating from southern and central finland, were ranked in order of ozone sensitivity according to visible injuries, growth and leaf senescense under low ozone exposure. the plants were fumigated in natural climatic conditions using an open-air exposure system during two growing seasons. control plants were grown under ambient air, and the elevated-ozone exposures were 1.6x the ambient in 1994 and 1.7x the ambient in 1995. the d ... | 1997 | 15093472 |
| isolation and characterization of cdna for a plant mitochondrial phosphate translocator (mpt1): ozone stress induces mpt1 mrna accumulation in birch (betula pendula roth). | we have isolated by ddrt-pcr (differential-display reverse-transcription polymerase chain reaction) and cdna library screening a 1.3 kb cdna corresponding to a strongly ozone-inducible transcript from birch (betula pendula roth). nucleotide sequence analysis suggests that it encodes a mitochondrial phosphate translocator protein (pic), the first one isolated from plants. the isolated birch mitochondrial phosphate translocator cdna (designated mpt1) contains an open reading frame of 1092 bases en ... | 1997 | 9349251 |
| effects of air pollution and other environmental factors on birch pollen allergens. | to determine the effects of anthropogenic pollution on water-soluble proteins and specifically allergens in birch (betula pendula and b. pubescens) pollen, we analyzed extracts of pollen from the pollution gradient around a factory complex (emitting sulfur oxides and heavy metals) by sodium dodecyl sulfate (sds)--polyacrylamide gel electrophoresis (page) and ige immunoblotting. in addition, tree density-associated shading of the tree habitat, and quantity and quality of proteins and allergens in ... | 1997 | 9450140 |
| new dammaranes, esterified with malonic acid, from leaves of betula pendula. | three known and five new dammarane triterpenes, esterified with malonic acid at c-3 with hemolytic activity were identified from the ethanol-water extract of leaves of betula pendula roth: 12-o-acetyl-3alpha,12beta,20(s),24(r)-tetrahydroxydammar-25-en-3-yl hydrogen propanedioate, 12-o-acetyl-3alpha,12beta20(s),24(s)-tetrahydroxydammar-25-en-3-yl hydrogen propanedionate, 12-o-acetyl-3alpha,12beta,17alpha,20(s),24(r)-pentahydroxydammar-25-en-3-yl hydrogen propanedioate, [12beta-acetoxy-4,4,8,10,14 ... | 1997 | 17252393 |