characteristics of pollen diffusates and pollen wall cytochemistry in poplars.pollen diffusates, known to be important in pollen-stigma interactions controlling interspecific incompatibility between populus deltoides and populus alba, have been partly characterized and shown to contain more than 20 protein bands by polyacrylamide gel electrophoresis, at least 4 of these being glycoproteins. seven fractions had antigenic activity in rabbits and several enzyme activities were also present. peroxidase and leucine aminopeptidase isoenzymes were detected in the diffusates, dem ...19807440650
transient expression of goat growth hormone gene in poplar (populus alba l.) protoplasts: a quick method for detection of foreign gene expression in mrna level.we developed a sensitive, accurate, and fast method to detect foreign gene expression using reverse transcriptase-mediated polymerase chain reaction (rt-pcr) in poplar tree (populus alba l.) protoplasts. template total rna was purified by removing the transfected foreign gene vector completely with dnase i treatment before the rt reaction. expression of cdna that encodes goat growth hormone was confirmed at the mrna level 24 h after electroporation mediated dna transfer.19979339563
manipulation of glutathione and amino acid biosynthesis in the chloroplastpoplars (populus tremula x populus alba) were transformed to overexpress escherichia coli gamma-glutamylcysteine synthetase (gamma-ecs) or glutathione synthetase in the chloroplast. five independent lines of each transformant strongly expressed the introduced gene and possessed markedly enhanced activity of the gene product. glutathione (gsh) contents were unaffected by high chloroplastic glutathione synthetase activity. enhanced chloroplastic gamma-ecs activity markedly increased gamma-glutamyl ...19989765532
lignification in transgenic poplars with extremely reduced caffeic acid o-methyltransferase activity.transgenic poplars (populus tremula x populus alba) were obtained by introduction of a sense homologous transgene encoding caffeic acid o-methyltransferase (comt) under the control either of the cauliflower mosaic virus double 35s promoter or of the eucalyptus cinnamyl alcohol dehydrogenase promoter. although these constructs conferred a moderate overexpression of comt in some lines, a transgenic line with the double 35s promoter was found where comt activity in woody tissues was close to zero d ...200010938354
thermodynamic analysis of diffusion of non-electrolytes across plant cuticles in the presence and absence of the plasticiser tributyl phosphate.solute mobility in cuticular membranes (cms) of 14 plant species (citrus aurantiumn l., citrus grandis l., hedera helix l., ilex aquifolium l., ilex paraguariensis st.-hil., malus domestica borkh. cv. golden delicious, populus alba l., prunus laurocerasus l., pyrus communis l. cv. bartlett, conference and gellerts butterbirne, pyrus pyrifolia (burm. f.) nakai, schefflera actinophylla (endl.) harms and strophanthus gratus baill.) was measured over the temperature range 25-55 degrees c. the five o ...200011219574
first isolation of an isoprene synthase gene from poplar and successful expression of the gene in escherichia coli.for the first time, the complete functional gene for isoprene synthase has been isolated from poplar (populus alba x populus tremula). the gene was quite similar to known limonene and other monoterpene synthases, but was found to specifically catalyze the formation of isoprene from the precursor dimethylallyl diphosphate with only a marginal activity for the formation of the monoterpene limonene from geranyl diphosphate as compared with limonene synthases. omitting the part of the gene that puta ...200111506373
bacterial disease resistance of transgenic hybrid poplar expressing the synthetic antimicrobial peptide d4e1.important losses in poplar productivity occur because of susceptibility to microbial pathogens. to enhance disease resistance in susceptible genotypes, the gene coding for d4e1, a synthetic antimicrobial peptide consisting of 17 amino acid residues, was introduced into poplar (populus tremula l. x populus alba l.) via agrobacterium-mediated transformation. four kanamycin-resistant transformants were selected based on significant accumulation of the d4e1 transcript and confirmed by reverse transc ...200312642242
significant increases in pulping efficiency in c4h-f5h-transformed poplars: improved chemical savings and reduced environmental toxins.the gene encoding ferulate 5-hydroxylase (f5h) was overexpressed in poplar (populus tremula x populus alba) using the cinnamate-4-hydroxylase (c4h) promoter to drive expression specifically in cells involved in the lignin biosynthetic pathway and was shown to significantly alter the mole percentage of syringyl subunits in the lignin, as determined by thioacidolysis. analysis of poplar transformed with a c4h-f5h construct demonstrated significant increases in chemical (kraft) pulping efficiency f ...200314518941
evidence that sucrose loaded into the phloem of a poplar leaf is used directly by sucrose synthase associated with various beta-glucan synthases in the stem.sucrose (suc) synthase (susy) is believed to function in channeling udp-glc from suc to various beta-glucan synthases. we produced transgenic poplars (populus alba) overexpressing a mutant form (s11e) of mung bean (vigna radiata) susy, which appeared in part in the microsomal membranes of the stems. expression of susy in these membranes enhanced the incorporation of radioactive suc into cellulose, together with the metabolic recycling of fructose (fru), when dual-labeled suc was fed directly int ...200414988476
enhancement of growth and cellulose accumulation by overexpression of xyloglucanase in poplar.because the loosening of xyloglucan in the cell wall promotes plant growth (takeda et al. (2002) proc. natl. acad. sci. usa 99, 9055-9060; park et al. (2003) plant j. 33, 1099-1106), we expressed aspergillus xyloglucanase constitutively in populus alba. the expression increased the length of stem even in the presence of sucrose. increased stem growth was accompanied by a decrease in young's elastic modulus in the growth zone but an increased elasticity in mature tissue. the increased internode l ...200415094064
sensitization to common allergens, especially pollens, among children with respiratory allergy in the trakya region of turkey.asthma and allergic rhinitis are common problems in children and the causative pollen allergens vary according to the geographical area. the aim of this study was to investigate patterns of sensitization to common inhalant allergens, especially pollens, in turkish children living in the trakya region and to determine differences between rural and urban areas. allergen skin testing was prospectively performed on 539 children aged between 4 and 17 years with respiratory allergy. the reaction was c ...200415783130
chemical composition and antibacterial activity of propolis collected by three different races of honeybees in the same region.the chemical analysis and antibacterial activity of three types of propolis collected three different races of apis mellifera bee in the same apiary were investigated. propolis samples were investigated by gc/ms, 48 compounds were identified 32 being new for propolis. the compounds identified indicated that the main plant sources of propolis were populus alba, populus tremuloides and salix alba. the antimicrobial activity against staphylococcus aureus, escherichia coli, pseudomonas aeruginosa an ...200515848022
gene expression and characterization of isoprene synthase from populus alba.isoprene synthase cdna from populus alba (paisps) was isolated by rt-pcr. this paisps mrna, which was predominantly observed in the leaves, was strongly induced by heat stress and continuous light irradiation, and was substantially decreased in the dark, suggesting that isoprene emission was regulated at the transcriptional level. the subcellular localization of paisps protein with green fluorescent protein fusion was shown to be in plastids. paisps expressed in escherichia coli was characterize ...200515848197
poplar pollen-related allergy in ankara, turkey: how important for patients living in a city with high pollen load?the impact of high pollen load of particular plants on sensitized subjects is a topic of interest. we aimed to detect the clinical importance of poplar allergy in subjects with seasonal allergy living in ankara, capital city of turkey, having a high poplar pollen load. the subjects with seasonal allergy and demonstrating allergy to populus alba in skin-prick tests (spts) (n = 20) underwent a specific nasal provocation test with p. alba allergen extract and were requested to fill in symptom-medic ...200515971469
dimethylallyl diphosphate and geranyl diphosphate pools of plant species characterized by different isoprenoid emissions.dimethylallyl diphosphate (dmadp) and geranyl diphosphate (gdp) are the last precursors of isoprene and monoterpenes emitted by leaves, respectively. dmadp and gdp pools were measured in leaves of plants emitting isoprene (populus alba), monoterpenes (quercus ilex and mentha piperita), or nonemitting isoprenoids (prunus persica). detectable pools were found in all plant species, but p. persica showed the lowest pool size, which indicates a limitation of the whole pathway leading to isoprenoid bi ...200616461390
[isolation and characterization of a dre-binding transcription factor from yinxin poplar (populus alba x p. alba var. pyramidalis)].dehydration-responsive element binding ( dreb) transcription factors, specifically binding with dehydration reponsive element (dre), activate a variety of stress-responsive genes in plants under abiotic stresses (dehydration, high salt and low temperature). using pcr and homologous est search, we isolated a dreb-like gene from yinxin poplar (populus alba x p. alba var. pyramidalis) named padreb2. yeast one-hybrid experiment demonstrated that padreb2 protein could function as a dreb transcription ...200516468344
factors influencing the tissue culture and the agrobacterium tumefaciens-mediated transformation of hybrid aspen and poplar clones.tissue culture conditions and transformation have been established for both aspen and poplar. the use of previously described culture conditions resulted in shoot tip necrosis in the shoot cultures and necrosis of stem and leaf explants. shoot tip necrosis could be overcome by buffering the medium with 2-(n-morpholino)ethanesulfonic acid and ca-gluconate and by growing the shoots below 25 degrees c. necrosis of the explants was probably due to an accumulation of ammonium in the explants and coul ...199016667565
admixture in european populus hybrid zones makes feasible the mapping of loci that contribute to reproductive isolation and trait differences.the use of admixed human populations to scan the genome for chromosomal segments affecting complex phenotypic traits has proved a powerful analytical tool. however, its potential in other organisms has not yet been evaluated. here, we use dna microsatellites to assess the feasibility of this approach in hybrid zones between two members of the 'model tree' genus populus: populus alba (white poplar) and populus tremula (european aspen). we analyzed samples of both species and a central european hy ...200716985509
rhizobium cellulosilyticum sp. nov., isolated from sawdust of populus alba.during a study of polysaccharide-hydrolysing bacteria present in different plant sources, two strains were isolated from pulverized decaying wood of populus alba and classified in the genus rhizobium on basis of their almost complete 16s rrna gene sequences. their closest phylogenetic relatives were rhizobium galegae usda 4128(t) and rhizobium huautlense s02(t), with 98.2 and 98.1 % 16s rrna gene sequence similarity, respectively. reca and atpd sequence analysis showed that these species have le ...200717392217
a molecular timetable for apical bud formation and dormancy induction in poplar.the growth of perennial plants in the temperate zone alternates with periods of dormancy that are typically initiated during bud development in autumn. in a systems biology approach to unravel the underlying molecular program of apical bud development in poplar (populus tremula x populus alba), combined transcript and metabolite profiling were applied to a high-resolution time course from short-day induction to complete dormancy. metabolite and gene expression dynamics were used to reconstruct t ...200717693531
arbuscular mycorrhizal fungi differentially affect the response to high zinc concentrations of two registered poplar clones.the effects of a high concentration of zinc on two registered clones of poplar (populus alba villafranca and populus nigra jean pourtet), inoculated or not with two arbuscular mycorrhizal fungi (glomus mosseae or glomus intraradices) before transplanting them into polluted soil, were investigated, with special regard to the extent of root colonization by the fungi, plant growth, metal accumulation in the different plant organs, and leaf polyamine concentration. zinc accumulation was lower in jea ...200817888550
enhanced phytoremediation of volatile environmental pollutants with transgenic trees.small, volatile hydrocarbons, including trichloroethylene, vinyl chloride, carbon tetrachloride, benzene, and chloroform, are common environmental pollutants that pose serious health effects. we have developed transgenic poplar (populus tremula x populus alba) plants with greatly increased rates of metabolism and removal of these pollutants through the overexpression of cytochrome p450 2e1, a key enzyme in the metabolism of a variety of halogenated compounds. the transgenic poplar plants exhibit ...200717940038
downregulation of cinnamoyl-coenzyme a reductase in poplar: multiple-level phenotyping reveals effects on cell wall polymer metabolism and structure.cinnamoyl-coa reductase (ccr) catalyzes the penultimate step in monolignol biosynthesis. we show that downregulation of ccr in transgenic poplar (populus tremula x populus alba) was associated with up to 50% reduced lignin content and an orange-brown, often patchy, coloration of the outer xylem. thioacidolysis, nuclear magnetic resonance (nmr), immunocytochemistry of lignin epitopes, and oligolignol profiling indicated that lignin was relatively more reduced in syringyl than in guaiacyl units. t ...200718024569
growth-phase-dependent gene expression profiling of poplar (populus alba x populus tremula var. glandulosa) suspension cells.complex sequences of morphological and biochemical changes occur during the developmental course of a batch plant cell culture. however, little information is available about the changes in gene expression that could explain these changes, because of the difficulties involved in isolating specific cellular events or developmental phases in the overlapping phases of cell growth. in an attempt to obtain such information we have examined the global growth phase-dependent gene expression of poplar c ...200718251851
determination of as in tree-rings of poplar (populus alba l.) by u-shaped dc argon-stabilized u-shaped dc arc with a system for aerosol introduction was used for determination of as in poplar (populus alba l.) tree-rings. after optimization of the operating parameters and selection of the most appropriate signal integration time (30 s), the limit of detection for as was reduced to 15.0 ng/ml. this detection limit obtained with the optimal integration time was compared with those for other methods: inductively coupled plasma-atomic emission spectrometry (icp-aes), dire ...200918351436
overexpression of poplar cellulase accelerates growth and disturbs the closing movements of leaves in this study, poplar (populus alba) cellulase (papopcel1) was overexpressed in a tropical leguminosae tree, sengon (paraserianthes falcataria), by the agrobacterium tumefaciens method. papopcel1 overexpression increased the length and width of stems with larger leaves, which showed a moderately higher density of green color than leaves of the wild type. the pairs of leaves on the transgenic plants closed more slowly during sunset than those on the wild-type plants. when main veins from each gen ...200818417637
evaluating ascorbate oxidase as a plant defense against leaf-chewing insects using transgenic poplar.ascorbate is the major water-soluble antioxidant in plants and animals, and it is an essential nutrient for most insect herbivores. therefore, ascorbate oxidase (ao) has been proposed to function as a plant defense that decreases the availability of ascorbate to insects. this hypothesis was tested by producing transgenic poplar (populus tremula x populus alba; salicaceae) with 14- to 37-fold higher foliar ao activities than control (wild type) leaves and feeding these leaves to lymantria dispar ...200818773241
the origin of clonal diversity and structure of populus alba in sardinia: evidence from nuclear and plastid microsatellite markers.populus alba is a thermophilic forest tree present in the mediterranean basin. its habitat is highly fragmented and its distribution range has been subject to long-term human interference, resulting in debate surrounding whether certain populations are native or exotic in origin. in particular, populations from the islands of corsica and sardinia are of uncertain origin. while populations of p. alba mainly reproduce sexually, clonal reproduction is also common. the aims of this study were to loc ...200818845663
biological method to quantify progressive stages of decay in five commercial woods by coriolus versicolor.biologic agar-block method was developed that allowed wood samples to be evaluated and monitored in terms of colonization and development of the decay by basidiomycetes fungi (coriolus versicolor) and to be directly classified based on mean mass loss. in this research, the in vitro decay of five commercial woods by coriolus versicolor was studied by the agar-block method. the selected wood samples were abies alba, populus alba, fagus orientalis, platanus orientalis and ulmus glabra. the results ...200719070053
fungal pathogen (mis-) identifications: a case study with dna barcodes on melampsora rusts of aspen and white poplar.wide variation and overlap in morphological characters have led to confusion in species identification within the fungal rust genus melampsora. the melampsora species with uredinial-telial stages on white poplar and aspens are especially prone to misidentification. this group includes the melampsora populnea species complex and the highly destructive pine twisting rust, melampsora pinitorqua, which alternates between hosts in populus section populus and pinus. our objective was to compare morpho ...200919249365
expression of jasmonic ethylene responsive factor gene in transgenic poplar tree leads to increased salt tolerance.the stress resistance of plants can be enhanced by regulating the expression of multiple downstream genes associated with stress resistance. we used the agrobacterium method to transfer the tomato jasmonic ethylene responsive factors (jerfs) gene that encodes the ethylene response factor (erf) like transcription factor to the genome of a hybrid poplar (populus alba x populus berolinensis). eighteen resistant plants were obtained, of which 13 were identified by polymerase chain reaction (pcr), re ...200919203952
the cytokinin type-b response regulator ptrr13 is a negative regulator of adventitious root development in populus.adventitious root formation at the base of plant cuttings is an innate de novo organogenesis process that allows massive vegetative propagation of many economically and ecologically important species. the early molecular events following shoot excision are not well understood. using whole-genome microarrays, we detected significant transcriptome remodeling during 48 h following shoot removal in populus tremula x populus alba softwood cuttings in the absence of exogenous auxin, with 27% and 36% o ...200919395410
expression of the psmta1 gene in white poplar engineered with the mat system is associated with heavy metal tolerance and protection against 8-hydroxy-2'-deoxyguanosine mediated-dna damage.marker-free transgenic white poplar (populus alba l., cv 'villafranca') plants, expressing the psmt (a1) gene from pisum sativum for a metallothionein-like protein, were produced by agrobacterium tumefaciens-mediated transformation. the 35scamv-psmt (a1)-nost cassette was inserted into the ipt-type vector pmat22. the occurrence of the abnormal ipt-shooty phenotype allowed the visual selection of transformants, while the yeast site-specific recombination r/rs system was responsible for the excisi ...200919506883
ogataea populialbae sp. nov., a yeast species from white poplar.during a survey of methylotrophic yeasts in natural habitats in hungary, the yeast community associated with the exudates of white poplar (populus alba) was found to be unique among the tree exudates hitherto investigated. nineteen methanol-assimilating yeast strains representing an undescribed ascomycetous species were isolated from tree exudates of p. alba collected at different locations in hungary. analysis of the d1/d2 large subunit rrna gene sequences placed the strains in the ogataea clad ...200919645773
characterization and expression analysis under bending and other abiotic factors of ptazfp2, a poplar gene encoding a cys2/his2 zinc finger plants, mechanoperception and transduction of mechanical signals have been studied essentially in arabidopsis thaliana l. and lycopersicon esculentum l. plants, i.e., in nonwoody plants. here, we have described the isolation of both the full-length cdna and the regulatory region of ptazfp2, encoding a member of cys2/his2 zinc finger protein (zfp) family in populus tremula l. x populus alba l. time course analysis of expression demonstrated that ptazfp2 mrna accumulated as early as 5 min in re ...200919203938
a novel plant cysteine-rich peptide family conferring cadmium tolerance to yeast and plants.we have identified a novel cdna clone, termed dccdt1, from digitaria ciliaris, that confers cadmium (cd)-tolerance to yeast (saccharomyces cerevisiae). the gene encodes a predicted peptide of 55 amino acid residues of which 15 (27.3%) are cysteine residues. we found that monocotyledonous plants possess multiple dccdt1 homologues, for example rice contains five dccdt1 homologues (designated oscdt1~5), whereas dicotyledonous plants, including arabidopsis thaliana, brassica rapa, poplar (populus tr ...200919816106
the ectomycorrhizal fungus laccaria bicolor stimulates lateral root formation in poplar and arabidopsis through auxin transport and signaling.the early phase of the interaction between tree roots and ectomycorrhizal fungi, prior to symbiosis establishment, is accompanied by a stimulation of lateral root (lr) development. we aimed to identify gene networks that regulate lr development during the early signal exchanges between poplar (populus tremula x populus alba) and the ectomycorrhizal fungus laccaria bicolor with a focus on auxin transport and signaling pathways. our data demonstrated that increased lr development in poplar and ara ...200919854859
type 3 metallothioneins respond to water deficit in leaf and in the cambial zone of white poplar (populus alba).the involvement of metallothioneins (mts) in response to plant water stress and recovery was assessed by analyzing gene expression in leaves and in the cambial zone of white poplar. one-year-old plants were submitted to two different watering regimes: irrigation was withheld for 9d and then resumed until day 17, or soil moisture was maintained to field capacity by irrigation during the experiment. changes in leaves and stem water relations, gas exchange and co(2) assimilation were recorded. the ...200918845361
isolation and characterization of osmotic stress-induced genes in poplar cells by suppression subtractive hybridization and cdna microarray analysis.osmotic stress induces changes in the expression of various genes including those associated with drought tolerance, cell wall metabolism and defense. we isolated 852 cdna clones, the expression of which is induced by osmotic stress, from cells of a hybrid poplar (populus alba x populus tremula var. glandulosa) by suppression subtractive hybridization after mannitol treatment. we examined how stress affected their expression using cdna microarray analysis, which identified 104 genes significantl ...201019962907
ozone-induced changes in photosynthesis and photorespiration of hybrid poplar in relation to the developmental stage of the leaves.young poplar trees (populus tremula michx. x populus alba l. clone inra 717-1b4) were subjected to 120 ppb of ozone for 35 days in phytotronic chambers. treated trees displayed precocious leaf senescence and visible symptoms of injury (dark brown/black upper surface stippling) exclusively observed on fully expanded leaves. in these leaves, ozone reduced parameters related to photochemistry (chl content and maximum rate of photosynthetic electron transport) and photosynthetic co(2) fixation [net ...200818823329
poplar vulnerability to xylem cavitation acclimates to drier soil conditions.xylem vulnerability to cavitation differs between tree species according to their drought resistance, more xerophilous species being more resistant to xylem cavitation. variability in xylem vulnerability to cavitation is also found within species, especially between in situ populations. the origin of this variability has not been clearly identified. here we analyzed the response of xylem hydraulic traits of populus tremula x populus alba trees to three different soil water regimes. stem xylem vu ...201020210873
recovery of useful traits from isolates inhabiting an agricultural soil cultivated with herbicide-resistant poplars.the aim of this study was to investigate the culturable bacteria living in soil cultivated with basta-tolerant transgenic white poplars (populus alba l. 'villafranca'). plate count agar medium containing phosphinothricin, the active component of basta, was used to isolate the herbicide-resistant bacteria (hrb). no significant changes in the size of the soil microbial flora following herbicide treatment were observed. the characterization of hrb isolates by 16s rdna-based taxonomy revealed a pred ...200818388991
changes in composition, structure and aboveground biomass over seventy-six years (1930-2006) in the black rock forest, hudson highlands, southeastern new york state.we sought to quantify changes in tree species composition, forest structure and aboveground forest biomass (agb) over 76 years (1930-2006) in the deciduous black rock forest in southeastern new york, usa. we used data from periodic forest inventories, published floras and a set of eight long-term plots, along with species-specific allometric equations to estimate agb and carbon content. between the early 1930s and 2000, three species were extirpated from the forest (american elm (ulmus americana ...200818244941
[photosynthetic characteristics of five arbor species in shenyang urban area].by using li-6400 infrared gas analyzer, this paper studied the diurnal and seasonal variations of the photosynthetic rate of main arbor species (populus alba x p. berolinensis, salix matsudana, ulmus pumila, robinia pseudoacacia and prunus davidiana) in shenyang urban area. the correlations between net photosynthetic rate and environmental factors (photosynthetic active radiation, temperature, and stomatal conductance) were assessed by multivariate regression analysis, and related equations were ...200717974233
limited impact of elevated levels of polyphenol oxidase on tree-feeding caterpillars: assessing individual plant defenses with transgenic poplar.polyphenol oxidase (ppo) is commonly believed to function as an effective antiherbivore defense in plants. ppo is induced in plants following herbivory, and insect performance is often negatively correlated with ppo levels. however, induced defenses create numerous changes in plants, and very little work has been done to test the direct effects of ppo on insect herbivores separately from other changes. this study examined the impacts of high levels of ppo on the performance of two species of tre ...200717724619
[morphological-ecological characters and growth patterns of main tree species leaves in urban forest of shenyang].the study with statistic and multivariate analyses showed that the main meteorological factors affecting the growth and development rhythms of main tree species leaves in urban forest of shenyang were > or = 5 degrees c accumulated temperature, accumulated sunshine hours, and mean temperature in the middle ten days of each phenological period. the meteorological factors needed by the tree species varied with their phenological period. necessary low temperature and ci were required in germination ...200617269315
expression of bt-cry3a in transgenic populus alba × p. glandulosa and its effects on target and non-target pests and the arthropod community.during the growing seasons of 2006-2008, feeding tests and field studies were conducted in beijing, china, to investigate the effects of transgenic bacillus thuringiensis (bt) poplar (bga-5) expressing the cry3a protein (0.0264-0.0326% of the total soluble protein) on target and non-target pests and the arthropod community. the effects of bga-5 on the target pest plagiodera versicolora (coleoptera, chrysomelidae) and a non-target pest clostera anachoreta (lepidoptera, notodontidae), were assesse ...201120703808
barrier to gene flow between two ecologically divergent populus species, p. alba (white poplar) and p. tremula (european aspen): the role of ecology and life history in gene introgression.the renewed interest in the use of hybrid zones for studying speciation calls for the identification and study of hybrid zones across a wide range of organisms, especially in long-lived taxa for which it is often difficult to generate interpopulation variation through controlled crosses. here, we report on the extent and direction of introgression between two members of the "model tree" genus populus: populus alba (white poplar) and populus tremula (european aspen), across a large zone of sympat ...200515773935
morphological-anatomical characterization and molecular identification of tomentella stuposa ectomycorrhizae and related anatomotypes.species in the genus tomentella (thelephoraceae) belong to the most frequent and widespread ectomycorrhizal (em) fungi found in temperate and boreal forests. although several unidentified tomentelloid morphotypes have been presented as common members of em communities in coniferous and broad-leaved forests, few tomentelloid em have been identified and described in detail. in this study, ten tomentelloid em isolates collected from populus alba, quercus cerris and picea abies stands in hungary and ...200515517422
activation tagging of a dominant gibberellin catabolism gene (ga 2-oxidase) from poplar that regulates tree stature.we identified a dwarf transgenic hybrid poplar (populus tremula x populus alba) after screening of 627 independent activation-tagged transgenic lines in tissue culture, greenhouse, and field environments. the cause of the phenotype was a hyperactivated gene encoding ga 2-oxidase (ga2ox), the major gibberellin (ga) catabolic enzyme in plants. the mutation resulted from insertion of a strong transcriptional enhancer near the transcription start site. overexpression of the poplar ga2ox gene (ptaga2 ...200312857810
[dust removal effect of urban tree species in harbin].dust removal by plants was proposed as an important basis of designing urban green space system for future urbanization. dust removal measurement and leaf surface electron-microscopic scanning were taken for 28 tree species in harbin city. the results showed that there were obviously different effects of dust removal among different tree species. picea koraiensis and juniperus rigida were the ideal conifers for dust removal, and their dust removal abilities were 5.7 g.m-2 and 4.4 g.m-2 after 4 w ...200212561175
the vascular expression pattern directed by the eucalyptus gunnii cinnamyl alcohol dehydrogenase egcad2 promoter is conserved among woody and herbaceous plant species.cinnamyl alcohol dehydrogenase (cad; ec catalyses the last step in the synthesis of the monomeric precursors of lignin. here, we demonstrate that the vascular expression pattern conferred by the eucalyptus gunnii egcad2 promoter in transgenic poplar (populus tremula x populus alba) is conserved in another perennial woody angiosperm of economic interest (vitis vinifera l.), as well as in a model herbaceous plant (nicotiana tabacum l.). furthermore, promoter deletion analysis performed ...200212369625
red xylem and higher lignin extractability by down-regulating a cinnamyl alcohol dehydrogenase in poplar.cinnamyl alcohol dehydrogenase (cad) catalyzes the last step in the biosynthesis of the lignin precursors, the monolignols. we have down-regulated cad in transgenic poplar (populus tremula x populus alba) by both antisense and co-suppression strategies. several antisense and sense cad transgenic poplars had an approximately 70% reduced cad activity that was associated with a red coloration of the xylem tissue. neither the lignin amount nor the lignin monomeric composition (syringyl/guaiacyl) wer ...199612226459
synthesis of glutathione in leaves of transgenic poplar overexpressing [gamma]-glutamylcysteine synthetase.internode stem fragments of the poplar hybrid populus tremula x populus alba were transformed with a bacterial gene (gshl) for [gamma]-glutamylcysteine synthetase ([gamma]-ecs) targeted to the cytosol. lines overexpressing [gamma]-ecs were identified by northern analysis, and the transformant with the highest enzyme activity was used to investigate the control of glutathione synthesis. whereas foliar [gamma]-ecs activity was below the limit of detection in untransformed plants, activities of up ...199612226433
An efficient Agrobacterium-mediated transformation and regeneration system for leaf explants of two elite aspen hybrid clones Populus alba-á+ù-áP. berolinensis and Populus davidiana-á+ù-áP. bolleana.Transgenic technology has been successfully used for gene function analyses and trait improvement in cereal plants. However, its usage is limited in woody plants, especially in the difficult-to-transform but commercially viable hybrid poplar. In this work, an efficient regeneration and transformation system was established for the production of two hybrid aspen clones: Populus alba-á+ù-áP. berolinensis and Populus davidiana-á+ù-áP. bolleana. A plant transformation vector designed to express the ...201121717184
cellulose in cyanobacteria. origin of vascular plant cellulose synthase?although cellulose biosynthesis among the cyanobacteria has been suggested previously, we present the first conclusive evidence, to our knowledge, of the presence of cellulose in these organisms. based on the results of x-ray diffraction, electron microscopy of microfibrils, and cellobiohydrolase i-gold labeling, we report the occurrence of cellulose biosynthesis in nine species representing three of the five sections of cyanobacteria. sequence analysis of the genomes of four cyanobacteria revea ...200111598227
production of 7-o-methyl aromadendrin, a medicinally valuable flavonoid, in escherichia coli.7-o-methyl aromadendrin (7-oma) is an aglycone moiety of one of the important flavonoid-glycosides found in several plants such as populus alba and eucalyptus maculata with various medicinal applications. to produce such valuable natural flavonoids in large quantity, e. coli cell factory has been developed to employ various plant biosynthetic pathways. here, we report the generation of 7-oma from its precursor p-coumaric acid in e. coli for the first time. primarily, naringenin (nrn) (flavanone) ...201122101053
optimized refolding and characterization of s-peroxidase (cwpo_c of populus alba) expressed in e. coli.cationic cell wall peroxidase (cwpo_c) from poplar tree (populus alba l) was heterologously expressed in escherichia coli as an inclusion body. the insoluble inclusion body was solubilized and reactivated via a refolding procedure. the condition for this procedure was optimized by varying the refolding ph, and the concentrations of the oxidizing agent (gssg), denaturing agent (gndcl), and hemin, respectively. the optimal conditions for refolding cwpo_c were 100 mm tris-hcl at ph 8.5, 0.6mm gssg, ...201121856428
bio-isoprene production using exogenous mva pathway and isoprene synthase in escherichia this paper, an original strategy is employed to biosynthesize the isoprene by heterologously co-expressing the saccharomyces cerevisiae mva pathway and isoprene synthase (isps) from populus alba in the escherichia coli bl21 (de3) strain, which was screened from three different isps enzymes. the finally genetic strain yjm13 harboring the mva pathway and isps(pa) gene could accumulate isoprene up to 2.48mg/l and 532mg/l under the flask and fed-batch fermentation conditions, respectively, which ...201222133602
identification of tyr74 and tyr177 as substrate oxidation sites in cationic cell wall-bound peroxidase from populus alba l.cationic cell wall-bound peroxidase (cwpo-c) has the capability to oxidize sinapyl alcohol, ferrocytochrome c, and synthetic lignin polymers, unlike most peroxidases that have been characterized in flowering plants, such as horseradish peroxidase and arabidopsis thaliana peroxidase a2. it has been suggested that the oxidation site is located on the cwpo-c surface, and homology modeling and chemically modified cwpo-c studies suggest that tyr74 and/or tyr177 are possible participants in the cataly ...201122099451
microautoradiographic localization of phosphate and carbohydrates in mycorrhizal roots of populus tremula x populus alba and the implications for transfer processes in ectomycorrhizal associations.microautoradiographic studies were carried out to examine the distribution and exchange of phosphate and labeled carbohydrates in mycorrhizal roots of populus tremula x populus alba l. following application of 33p-orthophosphate (pi) and 14co2. labeled pi was not homogeneously distributed along the mycorrhizal longitudinal axis. the fungal sheath and the hartig net contained more 33pi in the median parts of the root than in the apical or basal root zones, indicating that uptake and transfer of p ...200111303640
sucrose synthase affects carbon partitioning to increase cellulose production and altered cell wall ultrastructure.overexpression of the gossypium hirsutum sucrose synthase (susy) gene under the control of 2 promoters was examined in hybrid poplar (populus alba x grandidentata). analysis of rna transcript abundance, enzyme activity, cell wall composition, and soluble carbohydrates revealed significant changes in the transgenic lines. all lines showed significantly increased susy enzyme activity in developing xylem. this activity manifested in altered secondary cell wall cellulose content per dry weight in al ...200919625620
transgenic poplars: expression of chimeric genes using four different constructs.leaf or stem explants of a hybrid poplar clone (populus tremula x populus alba), sensitive to agrobacterium tumefaciens, were co-cultivated either by an octopine or a nopaline disarmed a. tumefaciens modified strain. transformed poplar shoots were readily regenerated from explants. the protocol was improved using the nopaline disarmed strain c58/pmp90 with the binary vector pbi121. this protocol was then used to test three other vectors. the first one, possessing a nptii gene fused to the camv 1 ...199224213546
essential role of caffeoyl coenzyme a o-methyltransferase in lignin biosynthesis in woody poplar plants.caffeoyl coenzyme a o-methyltransferase (ccoaomt) has recently been shown to participate in lignin biosynthesis in herbacious tobacco plants. here, we demonstrate that ccoaomt is essential in lignin biosynthesis in woody poplar (populus tremula x populus alba) plants. in poplar stems, ccoaomt was found to be expressed in all lignifying cells including vessel elements and fibers as well as in xylem ray parenchyma cells. repression of ccoaomt expression by the antisense approach in transgenic popl ...200011027707
regulation of sulfur nutrition in wild-type and transgenic poplar over-expressing gamma-glutamylcysteine synthetase in the cytosol as affected by atmospheric h2s.this study with poplar (populus tremula x populus alba) cuttings was aimed to test the hypothesis that sulfate uptake is regulated by demand-driven control and that this regulation is mediated by phloem-transported glutathione as a shoot-to-root signal. therefore, sulfur nutrition was investigated at (a) enhanced sulfate demand in transgenic poplar over-expressing gamma-glutamylcysteine (gamma-ec) synthetase in the cytosol and (b) reduced sulfate demand during short-term exposure to h2s. h(2)s t ...200010982459
enhancing production of bio-isoprene using hybrid mva pathway and isoprene synthase in e. coli.the depleting petroleum reserve, increasingly severe energy crisis, and global climate change are reigniting enthusiasm for seeking sustainable technologies to replace petroleum as a source of fuel and chemicals. in this paper, the efficiency of the mva pathway on isoprene production has been improved as follows: firstly, in order to increase mva production, the source of the "upper pathway" which contains hmg-coa synthase, acetyl-coa acetyltransferase and hmg-coa reductase to covert acetyl-coa ...201222558074
identification of novel isoprene synthases through genome mining and expression in escherichia coli.isoprene is a naturally produced hydrocarbon emitted into the atmosphere by green plants. it is also a constituent of synthetic rubber and a potential biofuel. microbial production of isoprene can become a sustainable alternative to the prevailing chemical production of isoprene from petroleum. in this work, sequence homology searches were conducted to find novel isoprene synthases. candidate sequences were functionally expressed in escherichia coli and the desired enzymes were identified based ...201526275749
silver nanoparticles synthesised using plant extracts show strong antibacterial this study, three plants populus alba, hibiscus arboreus and lantana camara were explored for the synthesis of silver nanoparticles (snps). the effect of reaction temperature and leaf extract (le) concentration of p. alba, h. arboreus and l. camara was evaluated on the synthesis and size of snps. the snps were characterised by ultra-violet-visible spectroscopy, scanning electron microscopy and atomic force microscopy. the synthesis rate of snps was highest with le of l. camara followed by h. ...201526023158
significantly enhanced production of isoprene by ordered coexpression of genes dxs, dxr, and idi in escherichia coli.we constructed a biosynthetic pathway of isoprene production in escherichia coli by introducing isoprene synthase (isps) from populus alba. 1-deoxy-d-xylulose 5-phosphate synthase (dxs), 1-deoxy-d-xylulose 5-phosphate reductoisomerase (dxr) and isopentenyl diphosphate (ipp) isomerase (idi) were overexpressed to enhance the isoprene production. the isoprene production was improved 0.65, 0.16, and 1.22 fold over the recombinant bl21 (pet-30a-isps), respectively, and idi was found to be a key regul ...201323143466
cell-specific and conditional expression of caffeoyl-coenzyme a-3-o-methyltransferase in poplar.caffeoyl coenzyme a-3-o-methyltransferase (ccoaomt) plays an important role in lignin biosynthesis and is encoded by two genes in poplar (populus trichocarpa). here, we describe the expression pattern conferred by the two ccoaomt promoters when fused to the gus-coding sequence in transgenic poplar (populus tremula x populus alba). both genes were expressed similarly in xylem and differentially in phloem. in xylem, expression was preferentially observed in vessels and contact rays, whereas expres ...200010889235
structural alterations of lignins in transgenic poplars with depressed cinnamyl alcohol dehydrogenase or caffeic acid o-methyltransferase activity have an opposite impact on the efficiency of industrial kraft pulpingwe evaluated lignin profiles and pulping performances of 2-year-old transgenic poplar (populus tremula x populus alba) lines severely altered in the expression of caffeic acid/5-hydroxyferulic acid o-methyltransferase (comt) or cinnamyl alcohol dehydrogenase (cad). transgenic poplars with cad or comt antisense constructs showed growth similar to control trees. cad down-regulated poplars displayed a red coloration mainly in the outer xylem. a 90% lower comt activity did not change lignin content ...19999880356
overexpression of glutathione reductase but not glutathione synthetase leads to increases in antioxidant capacity and resistance to photoinhibition in poplar trees.a poplar hybrid, populus tremula x populus alba, was transformed with the bacterial genes for either glutathione reductase (gr) (gor) or glutathione synthetase (gs) (gshii). when the gor gene was targeted to the chloroplasts, leaf gr activities were up to 1000 times greater than in all other lines. in contrast, targeting to the cytosol resulted in 2 to 10 times the gr activity. gr mrna, protein, and activity levels suggest that bacterial gr is more stable in the chloroplast. when the gshii gene ...19958552710
clonal differences in survival capacity, copper and zinc accumulation, and correlation with leaf polyamine levels in poplar: a large-scale field trial on heavily polluted soil.three ex situ collections of poplar clones from natural populations of populus alba and p. nigra growing in northern italy were assessed for their genetic dissimilarity (gd) by means of amplified fragment length polymorphism (aflp). the high gd evidenced within populations was exploited for screening 168 clones in a field trial on heavy metal-polluted soil. after one growth season, clonal differences in plant survival and growth were observed. on the basis of performance, six clones were singled ...200919285369
nonmicrobial aerobic methane emission from poplar shoot cultures under low-light conditions.the aerobic formation of methane in plants has been reported previously, but has been questioned by a number of researchers. recently, isotopic evidence demonstrated that ultraviolet irradiation and heating lead to photochemical or thermal aerobic methane formation mainly from plant pectin in the absence of microbial methane production. however, the origin of aerobic methane formation from plant material observed under low temperature and low-light/dark conditions is still unclear. here we show ...200919281477
leaf-associated bacteria from transgenic white poplar producing resveratrol-like compounds: isolation, molecular characterization, and evaluation of oxidative stress tolerance.the aim of this study was the isolation and characterization of the culturable bacteria inhabiting the leaves of transgenic white poplars (populus alba l. 'villafranca') engineered with the stsy gene for the production of resveratrol-like compounds. resveratrol glucosides are available in small amounts from natural sources or by expensive chemical synthesis procedures. an alternative approach for the large-scale production of these relevant pharmaceuticals is the use of transgenic plants as bior ...200919767855
effects of fosmidomycin on plant photosynthesis as measured by gas exchange and chlorophyll higher plants, many isoprenoids are synthesised via the chloroplastic 1-deoxy-d-xylulose 5-phosphate/2-c-methyl-d-erythritol 4-phosphate (mep) pathway. attempts to elucidate the function of individual isoprenoids have used the antibiotic/herbicidal compound fosmidomycin (3-[n-formyl-n-hydroxy amino] propyl phosphonic acid) to inhibit this pathway. examination of the effect of fosmidomycin on the major components of photosynthesis in leaves of white poplar (populus alba) and tobacco (nicotiana ...201019915954
over-expression of bacterial gamma-glutamylcysteine synthetase (gsh1) in plastids affects photosynthesis, growth and sulphur metabolism in poplar (populus tremula x populus alba) dependent on the resulting gamma-glutamylcysteine and glutathione levels.we compared three transgenic poplar lines over-expressing the bacterial gamma-glutamylcysteine synthetase (gsh1) targeted to plastids. lines lggs6 and lggs12 have two copies, while line lggs20 has three copies of the transgene. the three lines differ in their expression levels of the transgene and in the accumulation of gamma-glutamylcysteine (gamma-ec) and glutathione (gsh) in leaves, roots and phloem exudates. the lowest transgene expression level was observed in line lggs6 which showed an inc ...201020199621
spore-forming bacteria in soil cultivated with gm white poplars: isolation and characterization.the impact of transgenic white poplars (populus alba l. cv. 'villafranca') was assessed on the soil aerobic spore-forming bacteria (sfb). the genetically modified poplars, expressing either the stsy gene for resveratrol production or the bar gene for herbicide tolerance, were cultivated in greenhouse. the occurrence of sfb was monitored in soil samples collected at eight different timepoints over a two-year period. the total culturable bacterial population of the stsy and bar trials underwent si ...201020336503
genetic structure and regulation of isoprene synthase in poplar (populus spp.).isoprene is a volatile 5-carbon hydrocarbon derived from the chloroplastic methylerythritol 2-c-methyl-d: -erythritol 4-phosphate isoprenoid pathway. in plants, isoprene emission is controlled by the enzyme isoprene synthase; however, there is still relatively little known about the genetics and regulation of this enzyme. isoprene synthase gene structure was analysed in three poplar species. it was found that genes encoding stromal isoprene synthase exist as a small gene family, the members of w ...201020467886
changes in sulphur metabolism of grey poplar (populus x canescens) leaves during salt stress: a metabolic link to photorespiration.the poplar hybrid populus x canescens (syn. populus tremula x populus alba) was subjected to salt stress by applying 75 mm nacl for 2 weeks in hydroponic cultures. decreasing maximum quantum yield (fv/fm) indicated damage of photosystem ii (ps ii), which was more pronounced under nitrate compared with ammonium nutrition. in vivo staining with diaminobenzidine showed no accumulation of h(2)o(2) in the leaf lamina; moreover, staining intensity even decreased. but at the leaf margins, development o ...201020516486
tyloses and phenolic deposits in xylem vessels impede water transport in low-lignin transgenic poplars: a study by cryo-fluorescence microscopy.of 14 transgenic poplar genotypes (populus tremula × populus alba) with antisense 4-coumarate:coenzyme a ligase that were grown in the field for 2 years, five that had substantial lignin reductions also had greatly reduced xylem-specific conductivity compared with that of control trees and those transgenic events with small reductions in lignin. for the two events with the lowest xylem lignin contents (greater than 40% reduction), we used light microscopy methods and acid fuchsin dye ascent stud ...201020639405
feeding on poplar leaves by caterpillars potentiates foliar peroxidase action in their guts and increases plant resistance.peroxidases (pods) are believed to act as induced and constitutive defenses in plants against leaf-feeding insects. however, little work has examined the mode of action of pods against insects. putative mechanisms include the production of potentially antinutritive and/or toxic semiquinone free radicals and quinones (from the oxidation of phenolics), as well as increased leaf toughness. in this study, transgenic hybrid poplar saplings (populus tremula × populus alba) overexpressing horseradish p ...201020680646
antisense down-regulation of 4cl expression alters lignification, tree growth, and saccharification potential of field-grown poplar.transgenic down-regulation of the pt4cl1 gene family encoding 4-coumarate:coenzyme a ligase (4cl) has been reported as a means for reducing lignin content in cell walls and increasing overall growth rates, thereby improving feedstock quality for paper and bioethanol production. using hybrid poplar (populus tremula × populus alba), we applied this strategy and examined field-grown transformants for both effects on wood biochemistry and tree productivity. the reductions in lignin contents obtained ...201020729393
endogenous overexpression of populus myb186 increases trichome density, improves insect pest resistance, and impacts plant growth.trichomes are specialized epidermal cells that generally play a role in reducing transpiration and act as a deterrent to herbivory. in a screen of activation-tagged populus tremula × populus alba 717-1b4 trees, we identified a mutant line, fuzzy, with increased foliar trichome density. this mutant also had a 35% increase in growth rate and a 200% increase in the rate of photosynthesis as compared with wild-type poplar. the fuzzy mutant had significant resistance to feeding by larvae of the white ...201020807210
growth responses and metal accumulation capabilities of woody plants during the phytoremediation of tannery sludge.five woody plants species (i.e. terminalia arjuna, prosopis juliflora, populus alba, eucalyptus tereticornis and dendrocalamus strictus) were selected for phytoremediation and grow on tannery sludge dumps of common effluent treatment plant (cetp), unnao (uttar pradesh), india. concentration of toxic metals were observed high in the raw tannery sludge i.e. fe-1667>cr-628>zn-592>pb-427>cu-354>mn-210>cd-125>ni-76 mg kg(-1) dw, respectively. besides, physico-chemical properties of the raw sludge rep ...201120889325
differential impact of chronic ozone exposure on expanding and fully expanded poplar leaves.populus tremula l. × populus alba l. (populus ×c anescens (aiton) smith) - clone inra 717-1-b4 saplings (50 cm apex to base and carrying 19 leaves on average) - were followed for 28 days. half of the trees were grown in charcoal-filtered air while the other half were exposed to 120 ppb ozone for 11 h a day during the light period. the expanding leaf number 4 was tagged at the beginning of the experiment and finished expansion between 7 and 14 days. these leaves were harvested weekly for biochemi ...201021030406
members of the lateral organ boundaries domain transcription factor family are involved in the regulation of secondary growth in populus.regulation of secondary (woody) growth is of substantial economic and environmental interest but is poorly understood. we identified and subsequently characterized an activation-tagged poplar (populus tremula × populus alba) mutant with enhanced woody growth and changes in bark texture caused primarily by increased secondary phloem production. molecular characterization of the mutation through positioning of the tag and retransformation experiments shows that the phenotype is conditioned by acti ...201021097711
laboratory and field evaluation of the transgenic populus alba x populus glandulosa expressing double coleopteran-resistance genes.expression of the two coleopteran-resistant proteins (bt-cry3a and oryzacystatin i) was detected in the leaves of field-grown transgenic poplar (boga-5) in two or three subsequent years. the boga-5 contained ∼10 μg g(-1) of cry3a over the individual years with no detection in the control, and protein extracts from boga-5 displayed a higher reduction in papain activity (∼42%) compared with ∼21% in the control. laboratory feeding experiments showed that the total mortality of the target pes ...201121561923
genetic analysis of post-mating reproductive barriers in hybridizing european populus species.molecular genetic analyses of experimental crosses provide important information on the strength and nature of post-mating barriers to gene exchange between divergent populations, which are topics of great interest to evolutionary geneticists and breeders. although not a trivial task in long-lived organisms such as trees, experimental interspecific recombinants can sometimes be created through controlled crosses involving natural f(1)'s. here, we used this approach to understand the genetics of ...201121587301
Overexpression of constitutively active Arabidopsis RabG3b promotes xylem development in transgenic poplars.An Arabidopsis small GTPase, RabG3b, was previously characterized as a component of autophagy and as a positive regulator for xylem development in Arabidopsis. In this work, we assessed whether RabG3b modulates xylem-associated traits in poplar in a similar way as in Arabidopsis. We generated transgenic poplars (Populus alba × Populus tremula var. glandulosa) overexpressing a constitutively active form of RabG3b (RabG3bCA) and performed a range of morphological, histochemical and molecular analy ...201121895694
lignin engineering in field-grown poplar trees affects the endosphere bacterial microbiome.cinnamoyl-coa reductase (ccr), an enzyme central to the lignin biosynthetic pathway, represents a promising biotechnological target to reduce lignin levels and to improve the commercial viability of lignocellulosic biomass. however, silencing of the ccr gene results in considerable flux changes of the general and monolignol-specific lignin pathways, ultimately leading to the accumulation of various extractable phenolic compounds in the xylem. here, we evaluated host genotype-dependent effects of ...201626755604
bioprofiling of salicaceae bud extracts through high-performance thin-layer chromatography hyphenated to biochemical, microbiological and chemical detections.the buds of poplars (populus l.) and willows (salix l.), both from the same family (salicaceae mirbel), are increasingly used in gemmotherapy and importantly contribute to the production of the physiologically active propolis by european bee apis mellifera l. in order to study their phenolic profiles, polar extracts of buds from p. nigra l. were compared to those of p. alba l. and s. alba l. through high-performance thin-layer chromatography (hptlc). five chemotypical patterns were distinguished ...201728222858
expression of the stilbene synthase (stsy) gene from grapevine in transgenic white poplar results in high accumulation of the antioxidant resveratrol glucosides.when present, stilbene synthase leads to the production of resveratrol compounds, which are major components of the phytoalexin response against fungal pathogens of the plant and are highly bioactive substances of pharmaceutical interest. white poplar (populus alba l.) was transformed with a construct containing a cdna insert encoding stilbene synthase from grapevine (vitis vinifera l.), under the control of the cauliflower mosaic virus (camv) 35s promoter, and a chimeric kanamycin resistance ge ...200415359598
metal uptake by young trees from dredged brackish sediment: limitations and possibilities for phytoextraction and phytostabilisation.five tree species (acer pseudoplatanus l., alnus glutinosa l. gaertn., fraxinus excelsior l., populus alba l. and robinia pseudoacacia l.) were planted on a mound constructed of dredged sediment. the sediment originated from a brackish river mouth and was slightly polluted with heavy metals. this preliminary study evaluated the use of trees for site reclamation by means of phytoextraction of metals or phytostabilisation. although the brackish nature of the sediment caused slight salt damage, ove ...200415142776
[leaf litter decomposition and nutrient release of different stand types in a shelter belt in xinjiang arid area].from october 2007 to november 2008, an in situ mesh bag experiment was conducted to study the leaf litter decomposition and nutrient release of forest stands populus alba var. pyramidalis, amorpha fruticosa, and p. alba var. pyramidalis + a. fruticosa in a shelter belt in karamay, xinjiang. it was observed that the mass loss rate of leaf litter differed with tree species, and was significantly affected by leaf litter composition. the leaf litter of p. alba var. pyramidalis + a. fruticosa was mor ...201121941735
an ecophysiological study of plants growing on the fly ash deposits from the "nikola tesla-a" thermal power station in serbia.this ecophysiological research on the ash deposits from the "nikola tesla-a" thermal power station in serbia covered 10 plant species (tamarix gallica, populus alba, spiraea van-hauttei, ambrosia artemisifolia, amorpha fruticosa, eupatorium cannabinum, crepis setosa, epilobium collinum, verbascum phlomoides, and cirsium arvense). this paper presents the results of a water regime analysis, photosynthetic efficiency and trace elements (b, cu, mn, zn, pb, and cd) content in vegetative plant parts. ...200415503386
altering carbon allocation in hybrid poplar (populus alba × grandidentata) impacts cell wall growth and development.galactinol synthase is a pivotal enzyme involved in the synthesis of the raffinose family of oligosaccharides (rfos) that function as transport carbohydrates in the phloem, as storage compounds in sink tissues and as soluble metabolites that combat both abiotic and biotic stress in several plant species. hybrid poplar (populus alba × grandidentata) overexpressing the arabidopsis thaliana gols3 (atgols3) gene showed clear effects on development; the extreme overexpressing lines were stunted and h ...201627998032
engineering monolignol p-coumarate conjugates into poplar and arabidopsis lignins.lignin acylation, the decoration of hydroxyls on lignin structural units with acyl groups, is common in many plant species. monocot lignins are decorated with p-coumarates by the polymerization of monolignol p-coumarate conjugates. the acyltransferase involved in the formation of these conjugates has been identified in a number of model monocot species, but the effect of monolignol p-coumarate conjugates on lignification and plant growth and development has not yet been examined in plants that d ...201526511914
nitrogen deprivation promotes populus root growth through global transcriptome reprogramming and activation of hierarchical genetic networks.we show a distinct and previously poorly characterized response of poplar (populus tremula × populus alba) roots to low nitrogen (ln), which involves activation of root growth and significant transcriptome reprogramming. analysis of the temporal patterns of enriched ontologies among the differentially expressed genes revealed an ordered assembly of functionally cohesive biological events that aligned well with growth and morphological responses. a core set of 28 biological processes was signific ...201323795675
sucrose phosphate synthase expression influences poplar phenology.the objective of this study was to manipulate the intracellular pools of sucrose, and investigate its role in regulating plant growth, phenology (leaf senescence and bud break) and fibre development. this objective was achieved by differentially expressing an arabidopsis (arabidopsis thaliana l. heynh.) sucrose phosphate synthase (sps) gene in hybrid poplar (populus alba l.xpopulus grandidentata michx.), a model system for tree biology with substantial industrial relevance in the context of shor ...200919429901
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