| poplar-root knot nematode interaction: a model for perennial woody species. | plant root-knot nematode (rkn) interaction studies are performed on several host plant models. though rkn interact with trees, no perennial woody model has been explored so far. here, we show that poplar (populus tremula × p. alba) grown in vitro is susceptible to meloidogyne incognita, allowing this nematode to penetrate, to induce feeding sites, and to successfully complete its life cycle. quantitative reverse transcription-polymerase chain reaction analysis was performed to study changes in p ... | 2016 | 27135257 |
| dual targeted poplar ferredoxin nadp(+) oxidoreductase interacts with hemoglobin 1. | previous reports have connected non-symbiotic and truncated hemoglobins (hbs) to metabolism of nitric oxide (no), an important signalling molecule involved in wood formation. we have studied the capability of poplar (populus tremula × tremuloides) hbs ptthb1 and ptttrhb proteins alone or with a flavin-protein reductase to relieve no cytotoxicity in living cells. complementation tests in a hb-deficient, no-sensitive yeast (saccharomyces cerevisiae) δyhb1 mutant showed that neither ptthb1 nor pttt ... | 2016 | 27095407 |
| two iron-regulated transporter (irt) genes showed differential expression in poplar trees under iron or zinc deficiency. | two iron-regulated transporter (irt) genes were cloned from the iron chlorosis resistant (ptg) and susceptible (pty) populus tremula 'erecta' lines. nucleotide sequence analysis showed no significant difference between ptg and pty. the predicted proteins contain a conserved zip domain with 8 transmembrane (tm) regions. a zip signature sequence was found in the fourth tm domain. phylogenetic analysis revealed that ptirt1 was clustered with tomato and tobacco irt genes that are highly responsible ... | 2015 | 26373309 |
| symplastic phloem loading in poplar. | sap is driven through phloem sieve tubes by an osmotically generated pressure gradient between source and sink tissues. in many plants, source pressure results from thermodynamically active loading in which energy is used to transfer sucrose (suc) from mesophyll cells to the phloem of leaf minor veins against a concentration gradient. however, in some species, almost all trees, correlative evidence suggests that sugar migrates passively through plasmodesmata from mesophyll cells into the sieve e ... | 2014 | 25056922 |
| in vitro dermo-cosmetic evaluation of bark extracts from common temperate trees. | wood residues produced from forestry activities represent an interesting source of biologically active, high value-added secondary metabolites. in this study, 30 extracts from 10 barks of deciduous and coniferous tree species were investigated for their potential dermo-cosmetic use. the extracts were obtained from fagus sylvatica, quercus robur, alnus glutinosa, prunus avium, acer pseudoplatanus, fraxinus excelsior, populus robusta, larix decidua, picea abies, and populus tremula after three suc ... | 2016 | 27352384 |
| selective behaviour of honeybees in acquiring european propolis plant precursors. | honey bees harvest resins from various plant species and use them in the hive as propolis. while there have been a number of studies concerning the chemical composition of this antimicrobial product, little is known about selective behavior and bee preference when different potential plant sources of resin are available. the main objective of this paper was to investigate some aspects of behavioral patterns of honeybees in the context of resin acquisition. samples of propolis originating from te ... | 2016 | 27294416 |
| the melliferous potential of forest and meadow plant communities on mount tara (serbia). | the apiflora of 34 forest and meadow plant communities in tara national park was studied with the aim of assessing their melliferous potential and their contribution to bee pasture during the vegetation period. the melliferous plants were analyzed individually from the aspect of their flowering phenology, abundance, and the intensity of nectar and pollen production, as well as the production of honeydew. the melliferous potential of each investigated plant community was theoretically assessed on ... | 2013 | 23905735 |
| norwood: a gene expression resource for evo-devo studies of conifer wood development. | the secondary xylem of conifers is composed mainly of tracheids that differ anatomically and chemically from angiosperm xylem cells. there is currently no high-spatial-resolution data available profiling gene expression during wood formation for any coniferous species, which limits insight into tracheid development. rna-sequencing data from replicated, high-spatial-resolution section series throughout the cambial and woody tissues of picea abies were used to generate the norwood.congenie.org web ... | 2017 | 28186632 |
| low temperatures are required to induce the development of fertile flowers in transgenic male and female early flowering poplar (populus tremula l.). | until now, artificial early flowering poplar systems have mostly led to the development of sterile flowers. in this study, several strategies aimed at inducting fertile flowers in phsp::atft transgenic poplar were evaluated, in particular the influence of temperature and photoperiod. our results provide evidence that temperature, and not photoperiod, is the key factor required for the development of fertile flowers in early flowering poplar. fertile flowers were only obtained when a cold treatme ... | 2016 | 27052434 |
| pad4, lsd1 and eds1 regulate drought tolerance, plant biomass production, and cell wall properties. | arabidopsis and poplar with modified pad4, lsd1 and eds1 genes exhibit successful growth under drought stress. the acclimatory strategies depend on cell division/cell death control and altered cell wall composition. the increase of plant tolerance towards environmental stresses would open much opportunity for successful plant cultivation in these areas that were previously considered as ineligible, e.g. in areas with poor irrigation. in this study, we performed functional analysis of proteins en ... | 2016 | 26754794 |
| transgenic hybrid aspen trees with increased gibberellin (ga) concentrations suggest that ga acts in parallel with flowering locus t2 to control shoot elongation. | bioactive gibberellins (gas) have been implicated in short day (sd)-induced growth cessation in populus, because exogenous applications of bioactive gas to hybrid aspens (populus tremula × tremuloides) under sd conditions delay growth cessation. however, this effect diminishes with time, suggesting that plants may cease growth following exposure to sds due to a reduction in sensitivity to gas. in order to validate and further explore the role of gas in growth cessation, we perturbed ga biosynthe ... | 2015 | 25382585 |
| phytoalexin deficient 4 affects reactive oxygen species metabolism, cell wall and wood properties in hybrid aspen (populus tremula l. × tremuloides). | the phytoalexin deficient 4 (pad4) gene in arabidopsis thaliana (atpad4) is involved in the regulation of plant--pathogen interactions. the role of pad4 in woody plants is not known; therefore, we characterized its function in hybrid aspen and its role in reactive oxygen species (ros)-dependent signalling and wood development. three independent transgenic lines with different suppression levels of poplar pad expression were generated. all these lines displayed deregulated ros metabolism, which w ... | 2015 | 24943986 |
| monitoring seasonal bud set, bud burst, and cold hardiness in populus. | using a perennial model plant allows the study of reoccurring seasonal events in a way that is not possible using a fast-growing annual such as arabidopsis thaliana (arabidopsis). in this study, we present a hybrid aspen (populus tremula × p. tremuloides) as our perennial model plant. these plants can be grown in growth chambers to shorten growth periods and manipulate day length and temperature in ways that would be impossible under natural conditions. in addition, the use of growth chambers al ... | 2014 | 24792061 |
| 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 ... | 2013 | 23795675 |
| shortening tobacco life cycle accelerates functional gene identification in genomic research. | definitive allocation of function requires the introduction of genetic mutations and analysis of their phenotypic consequences. novel, rapid and convenient techniques or materials are very important and useful to accelerate gene identification in functional genomics research. here, over-expression of pmft (prunus mume), a novel ft orthologue, and ptft (populus tremula) lead to shortening of the tobacco life cycle. a series of novel short life cycle stable tobacco lines (30-50 days) were develope ... | 2012 | 23107371 |
| poplar gtl1 is a ca2+/calmodulin-binding transcription factor that functions in plant water use efficiency and drought tolerance. | diminishing global fresh water availability has focused research to elucidate mechanisms of water use in poplar, an economically important species. a gt-2 family trihelix transcription factor that is a determinant of water use efficiency (wue), ptagtl1 (gt-2 like 1), was identified in populus tremula × p. alba (clone 717-ib4). like other gt-2 family members, ptagtl1 contains both n- and c-terminal trihelix dna binding domains. ptagtl1 expression, driven by the arabidopsis thaliana atgtl1 promote ... | 2012 | 22396800 |
| the competitive status of trees determines their responsiveness to increasing atmospheric humidity - a climate trend predicted for northern latitudes. | the interactive effects of climate variables and tree-tree competition are still insufficiently understood drivers of forest response to global climate change. precipitation and air humidity are predicted to rise concurrently at high latitudes of the northern hemisphere. we investigated whether the growth response of deciduous trees to elevated air humidity varies with their competitive status. the study was conducted in seed-originated silver birch and monoclonal hybrid aspen stands grown at th ... | 2017 | 27779805 |
| osmolality and non-structural carbohydrate composition in the secondary phloem of trees across a latitudinal gradient in europe. | phloem osmolality and its components are involved in basic cell metabolism, cell growth, and in various physiological processes including the ability of living cells to withstand drought and frost. osmolality and sugar composition responses to environmental stresses have been extensively studied for leaves, but less for the secondary phloem of plant stems and branches. leaf osmotic concentration and the share of pinitol and raffinose among soluble sugars increase with increasing drought or cold ... | 2016 | 27313582 |
| artificially decreased vapour pressure deficit in field conditions modifies foliar metabolite profiles in birch and aspen. | relative air humidity (rh) is expected to increase in northern europe due to climate change. increasing rh reduces the difference of water vapour pressure deficit (vpd) between the leaf and the atmosphere, and affects the gas exchange of plants. little is known about the effects of decreased vpd on plant metabolism, especially under field conditions. this study was conducted to determine the effects of artificially decreased vpd on silver birch (betula pendula roth.) and hybrid aspen (populus tr ... | 2016 | 27255929 |
| the efficacy of six elite isolates of the fungus chondrostereum purpureum against the sprouting of european aspen. | the sprouting of broad-leaved trees after cutting is problematic in forest regeneration areas, along roads and railways, under electric power and above gas pipe lines. in finland, one of the most difficult species to control in these areas is the european aspen (populus tremula), which produces both stump sprouts and root suckers after saplings have been cut. in this study, we investigated whether a decay fungus of broad-leaved trees, chondrostereum purpureum, could be used as a biological contr ... | 2016 | 26899306 |
| forest floor leachate fluxes under six different tree species on a metal contaminated site. | trees play an important role in the biogeochemical cycling of metals, although the influence of different tree species on the mobilization of metals is not yet clear. this study examined effects of six tree species on fluxes of cd, zn, doc, h(+) and base cations in forest floor leachates on a metal polluted site in belgium. forest floor leachates were sampled with zero-tension lysimeters in a 12-year-old post-agricultural forest on a sandy soil. the tree species included were silver birch (betul ... | 2013 | 23376521 |
| 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 |
| rna-seq-mediated transcriptome analysis of actively growing and winter dormant shoots identifies non-deciduous habit of evergreen tree tea during winters. | tea [camellia sinensis (l.) o. kuntze] is a perennial tree which undergoes winter dormancy and unlike deciduous trees, the species does not shed its leaves during winters. the present work dissected the molecular processes operating in the leaves during the period of active growth and winter dormancy through transcriptome analysis to understand a long-standing question: why should tea be a non-deciduous species? analyses of 24,700 unigenes obtained from 57,767 primarily assembled transcripts sho ... | 2014 | 25090269 |
| modelling the mechanical behaviour of pit membranes in bordered pits with respect to cavitation resistance in angiosperms. | various correlations have been identified between anatomical features of bordered pits in angiosperm xylem and vulnerability to cavitation, suggesting that the mechanical behaviour of the pits may play a role. theoretical modelling of the membrane behaviour has been undertaken, but it requires input of parameters at the nanoscale level. however, to date, no experimental data have indicated clearly that pit membranes experience strain at high levels during cavitation events. | 2014 | 24918205 |
| hydrolase treatments help unravel the function of intervessel pits in xylem hydraulics. | intervessel pits are structures that play a key role in the efficiency and safety functions of xylem hydraulics. however, little is known about the components of the pit membrane (pm) and their role in hydraulic functions, especially in resistance to cavitation. we tested the effect of commercial chemicals including a cellulase, a hemicellulase, a pectolyase, a proteinase and dtt on xylem hydraulic properties: vulnerability to cavitation (vc) and conductance. the effects were tested on branch se ... | 2014 | 23981110 |
| light-mediated k(leaf) induction and contribution of both the pip1s and pip2s aquaporins in five tree species: walnut (juglans regia) case study. | understanding the response of leaf hydraulic conductance (k(leaf)) to light is a challenge in elucidating plant-water relationships. recent data have shown that the effect of light on k(leaf) is not systematically related to aquaporin regulation, leading to conflicting conclusions. here we investigated the relationship between light, k(leaf), and aquaporin transcript levels in five tree species (juglans regia l., fagus sylvatica l., quercus robur l., salix alba l. and populus tremula l.) grown i ... | 2012 | 22544048 |
| effect of tree species on enzyme secretion by the shiitake medicinal mushroom, lentinus edodes (agaricomycetes). | we compared cold and hot wood extracts of 3 endemic siberian trees-namely, prunus padus (bird cherry), populus tremula (aspen), and betula sp. (birch)-on biomass production and laccase and peroxidase secretion in submerged cultures by the medicinal mushroom lentinus edodes. of the conditions tested, only hot prunus extracts stimulated biomass production, whereas all extracts stimulated laccase and peroxidase secretion, albeit to different extents. a large, differential stimulation of manganese p ... | 2016 | 27649732 |