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Heinz Rennenberg - One of the best experts on this subject based on the ideXlab platform.
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spatial and seasonal variation in amino compounds in the xylem sap of a mistletoe viscum album and its hosts populus spp and Abies Alba
Tree Physiology, 2004Co-Authors: Peter Escher, Monika Eiblmeier, Ilka Hetzger, Heinz RennenbergAbstract:: In a field study, the composition and concentrations of amino compounds in the xylem sap of the mistletoe, Viscum album L., and in the xylem sap of two host species, an evergreen conifer (Abies Alba Mill.) and a deciduous broad-leaved tree (Populus x euramericana), were analyzed. The xylem sap of both hosts and mistletoe contained large, but similar amounts of total organic nitrogen in low molecular weight amino compounds (TONLW). Nevertheless, individual amino compounds accumulated in the xylem sap of mistletoe relative to the host xylem sap, indicating selective uptake. In the xylem sap of Populus, major amino compounds (asparagine (Asn) and glutamine (Gln)) and the bulk parameters, TONLW and proteinogenic amino acids, showed significant seasonal variation. In Abies and in mistletoe on either host, variation of amino compounds in xylem sap was largely explained by inter-annual differences, not by seasonal variation. In both hosts, TONLW in the xylem sap was dominated by Gln. There was a steady decrease in relative abundance of Gln from the host xylem sap to the mistletoe xylem sap and to the stems and leaves of mistletoe. Simultaneously, the abundance of arginine (Arg) increased. Arginine was the predominant amino compound in the stems and leaves of mistletoe, occurring at concentrations previously observed only in leaves of trees exposed to excess nitrogen. We conclude that Gln (2 mol N mol(-1)) delivered by the host xylem sap is converted, in mistletoe, to Arg (4 mol N mol(-1)) and that the organic carbon liberated from Gln contributes significantly to the parasite's heterotrophic carbon gain. Statistical analyses of the data support this conclusion. Accumulation of Arg in mistletoe is an indication of excess N supply as a result of the uptake of amino compounds from the host xylem sap and a lack of phloem uploading.
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seasonal and spatial variation of carbohydrates in mistletoes viscum album and the xylem sap of its hosts populus x euamericana and Abies Alba
Physiologia Plantarum, 2004Co-Authors: Peter Escher, Monika Eiblmeier, Ilka Hetzger, Heinz RennenbergAbstract:: In the present field study we analysed the seasonal pattern of carbohydrate composition and contents in the xylem sap of Viscum album and the xylem sap of a deciduous (Populusxeuramericana) and a coniferous (Abies Alba) host tree species. The results were compared with the soluble carbohydrate composition and contents of mistletoe tissues. On both hosts significant amounts of glucose, fructose, and sucrose were found in the xylem sap of Viscum throughout the seasons. The general seasonal pattern of sugar contents, i.e. high concentrations in spring and lower concentrations in other seasons on Populus, and intermediate concentrations throughout the year on Abies, largely reflected the xylem sap carbohydrate composition and contents of the respective host. These observations provide indirect evidence for carbohydrate flux from the xylem sap of the host into the mistletoe. However, in both hosts xylem sap seems to be deviated into the mistletoe without specific control of carbohydrate flux. Differences observed between the seasonal pattern of xylem sap carbohydrate concentrations in Viscum on Populus and Abies may originate from the different time of leaf development of these species. A clear-cut seasonal pattern of soluble carbohydrates was not observed in the leaves of Viscum on both hosts. Still soluble carbohydrates seem to be reallocated from the senescing to the newly developed leaves of Viscum indicating that the seasonal requirement of carbohydrate for growth and development can only completely be met by carbohydrate acquisition from the host and their own photosynthesis.
Thomas N Sieber - One of the best experts on this subject based on the ideXlab platform.
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impact of population dynamics of white mistletoe viscum album ssp abietis on european silver fir Abies Alba
Annals of Forest Science, 2003Co-Authors: Konrad Philipp Noetzli, Beat Muller, Thomas N SieberAbstract:Dans un peuplement de sapin pectine (Abies Alba) de 70 ans situe dans la vallee du Rhin (Canton des Grisons, Suisse), 27 arbres infestes par le gui (Viscum album ssp. abietis) ont ete abattus. La croissance de ces arbres et la dynamique de la population du parasite ont ete analysees. La courbe de croissance de ces arbres a ete comparee avec celle de 10 arbres non-infestes dans le meme peuplement afin d'etudier les correlations entre les tendances d'accroissement et l'evolution de l'infection. La population du gui a augmente de facon dramatique depuis 1983, annee avant laquelle il etait insignifiant. La croissance des arbres infestes et non-infestes etait comparable avant le debut de l'epidemie. Apres, l'accroissement moyen des arbres infestes etait en constant declin tandis que l'accroissement des arbres temoins restait regulier. La conclusion est qu'une attaque massive de gui a un effet negatif sur la croissance des arbres infestes.
Bruno Fady - One of the best experts on this subject based on the ideXlab platform.
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Signature of mid‐Pleistocene lineages in the European silver fir (Abies Alba Mill.) at its geographic distribution margin
'Wiley', 2021Co-Authors: Caroline Scotti‐saintagne, Thomas Boivin, Marie Suez, Brigitte Musch, Ivan Scotti, Bruno FadyAbstract:Abstract In a conservation and sustainable management perspective, we identify the ecological, climatic, and demographic factors responsible for the genetic diversity patterns of the European silver fir (Abies Alba Mill.) at its southwestern range margin (Pyrenees Mountains, France, Europe). We sampled 45 populations throughout the French Pyrenees and eight neighboring reference populations in the Massif Central, Alps, and Corsica. We genotyped 1,620 individuals at three chloroplast and ten nuclear microsatellite loci. We analyzed within‐ and among‐population genetic diversity using phylogeographic reconstructions, tests of isolation‐by‐distance, Bayesian population structure inference, modeling of demographic scenarios, and regression analyses of genetic variables with current and past environmental variables. Genetic diversity decreased from east to west suggesting isolation‐by‐distance from the Alps to the Pyrenees and from the Eastern to the Western Pyrenees. We identified two Pyrenean lineages that diverged from a third Alpine–Corsica–Massif Central lineage 0.8 to 1.1 M years ago and subsequently formed a secondary contact zone in the Central Pyrenees. Population sizes underwent contrasted changes, with a contraction in the west and an expansion in the east. Glacial climate affected the genetic composition of the populations, with the western genetic cluster only observed in locations corresponding to the coldest past climate and highest elevations. The eastern cluster was observed over a larger range of temperatures and elevations. All demographic events shaping the current spatial structure of genetic diversity took place during the Mid‐Pleistocene Transition, long before the onset of the Holocene. The Western Pyrenees lineage may require additional conservation efforts, whereas the eastern lineage is well protected in in situ gene conservation units. Due to past climate oscillations and the likely emergence of independent refugia, east–west oriented mountain ranges may be important reservoir of genetic diversity in a context of past and ongoing climate change in Europe
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A reference genome sequence for the European silver fir (Abies Alba Mill.): a community-generated genomic resource
'Genetics Society of America', 2020Co-Authors: Elena Mosca, Bruno Fady, Fernando Cruz, Luca Bianco, Christian Rellstab, Sabine Brodbeck, Katalin Csillery, Jèssica, Gómez Garrido, Eric Bazin, Matthias FladungAbstract:Silver fir (Abies Alba Mill.) is widespread in Central, Eastern and Southern Europe. In Southern Europe, its distribution has increased overall during the 20th century due to land-use change and recolonization from refugial, over-logged populations. During recent decades, its distribution has decreased in most of its distributional range, mainly due to extreme temperature events, forest management practices and ungulate browsing. To forecast its future distribution and survival, it is important to investigate the genetic basis of its adaptation to environmental change, notably extreme events. Here, we provide a first draft genome assembly and annotation of the silver fir genome. DNA obtained from haploid megagametophyte and diploid needle tissue was used to construct and sequence Illumina paired-end (PE) and mate-pair (MP) libraries, respectively, to high depth. The assembled A. Alba genome sequence accounted for over 37 million scaffolds corresponding to 18.16 Gb, with a scaffold N50 of 14,051 bp. Despite the fragmented nature of the assembly, a total of 50,757 full-length genes were functionally annotated in the nuclear genome. The chloroplast genome was also assembled into a single scaffold (120,908 bp) that shows a high collinearity with both the A. koreana and A. sibirica complete chloroplast genomes. This first genome assembly of silver fir is an important genomic resource that is now publicly available in support of a new generation of research. By genome-enabling this important conifer, this resource will be opening the gate for new experiments and more precise genetic monitoring of European silver fir forests
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a reference genome sequence for the european silver fir Abies Alba mill a community generated genomic resource
G3: Genes Genomes Genetics, 2019Co-Authors: Elena Mosca, Bruno Fady, Fernando Cruz, Jessica Gomezgarrido, Luca Bianco, Christian Rellstab, Sabine Brodbeck, Katalin Csillery, Matthias Fladung, Barbara FussiAbstract:Silver fir (Abies Alba Mill.) is a keystone conifer of European montane forest ecosystems that has experienced large fluctuations in population size during during the Quaternary and, more recently, due to land-use change. To forecast the species' future distribution and survival, it is important to investigate the genetic basis of adaptation to environmental change, notably to extreme events. For this purpose, we here provide a first draft genome assembly and annotation of the silver fir genome, established through a community-based initiative. DNA obtained from haploid megagametophyte and diploid needle tissue was used to construct and sequence Illumina paired-end and mate-pair libraries, respectively, to high depth. The assembled A. Alba genome sequence accounted for over 37 million scaffolds corresponding to 18.16 Gb, with a scaffold N50 of 14,051 bp. Despite the fragmented nature of the assembly, a total of 50,757 full-length genes were functionally annotated in the nuclear genome. The chloroplast genome was also assembled into a single scaffold (120,908 bp) that shows a high collinearity with both the A. koreana and A. sibirica complete chloroplast genomes. This first genome assembly of silver fir is an important genomic resource that is now publicly available in support of a new generation of research. By genome-enabling this important conifer, this resource will open the gate for new research and more precise genetic monitoring of European silver fir forests.
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linking dendroecology and association genetics stress responses archived in tree rings associate with snp genotypes in Abies Alba mill
bioRxiv, 2017Co-Authors: Katrin Heer, Sascha Liepelt, Bruno Fady, David Behringer, Alma Piermattei, Claus Bassler, Hans Jehl, Sven Lorch, Andrea Piotti, Giovanni G VendraminAbstract:Genetic association studies in forest tress would greatly benefit from information on tree response to environmental stressors over time. Dendroecology can close this gap by providing such time series measurements. Here, we jointly analyzed dendroecological and genetic data to explore the genetic basis of resistance, recovery and resilience to episodic stress in silver fir. We used individual level tree-ring data to characterize the growth patterns of surviving silver fir (Abies Alba) during the forest dieback in the 1970s and 1980s in Central Europe and associated them with SNPs in candidate genes. Most trees at our study sites in the Bavarian Forest experienced severe growth decline from 1974 until the mid-1980s, which peaked during the drought year of 1976. Using the machine learning algorithm random forest, we identified 15 candidate genes that were associated with the variance in resistance, resilience and recovery among trees in this period. With our study we show that the unique possibility of phenotypic time series archived in tree-rings are a powerful resource in genetic association studies. We call for a closer collaboration of dendroceologists and forest geneticists to focus on integrating individual tree level signals in genetic association studies in long lived trees.
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Annotation and re-sequencing of genes from de novo transcriptome assembly of Abies Alba (pinaceae)
Applications in Plant Sciences, 2013Co-Authors: Anna M. Roschanski, Bruno Fady, Birgit Ziegenhagen, Sascha LiepeltAbstract:Premise of the study: We present a protocol for the annotation of transcriptome sequence data and the identification of candidate genes therein using the example of the nonmodel conifer Abies Alba. Methods and Results: A normalized cDNA library was built from an A. Alba seedling. The sequencing on a 454 platform yielded more than 1.5 million reads that were de novo assembled into 25 149 contigs. Two complementary approaches were applied to annotate gene fragments that code for (1) well-known proteins and (2) proteins that are potentially adaptively relevant. Primer development and testing yielded 88 amplicons that could successfully be resequenced from genomic DNA. Conclusions: The annotation workflow offers an efficient way to identify potential adaptively relevant genes from the large quantity of transcriptome sequence data. The primer set presented should be prioritized for single-nucleotide polymorphism detection in adaptively relevant genes in A. Alba.
Mahdi Shahverdi - One of the best experts on this subject based on the ideXlab platform.
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effect of microwave radiation and pre steaming on the conventional drying characteristics of fir wood Abies Alba l a gymnosperm species with torus margo pit membrane
Lignocellulose Journal, 2014Co-Authors: Hadi Dashti, Mehdi Faezipour, Asghar Tarmian, Mahdi ShahverdiAbstract:In this research, effect of microwave and steaming pretreatments on drying rate and residual stresses of fir wood ( Abies Alba L.) was investigated. For this purpose, the wood samples with green dimensions 340 × 100 × 50 mm and initial moisture content of about 50% were exposed to the steam and microwave radiation before being conventionally dried. The pre-steaming was performed at temperatures of 120, 140, and 160°C for 1 hour and the microwave treatment was applied with 2450MHz frequency for 7 and 10 minutes at three different conditions. Results revealed that the pre-steaming at 140 and 160°C and the microwave radiation for 10 minutes had a greater effect on the drying rate. The residual drying stresses were reduced due to the microwave radiation; in contrast, they were increased as a result of steaming at 140 and 160°C.
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mass transfer through microwave treated fir wood Abies Alba l a gymnosperm species with torus margo pit membrane
Drying Technology, 2013Co-Authors: Hadi Dashti, Mehdi Faezipour, Asghar Tarmian, Sahab Hedjazi, Mahdi ShahverdiAbstract:In this research, the effect of microwave pretreatment on mass transfer coefficients of Abies Alba L. was investigated. For this purpose, wood specimens with dimensions of 340 × 100 × 50 mm and average moisture content of 50% were exposed to a microwave with 2450 MHz frequency for time durations of 7 and 10 minutes. After drying, the air permeability and water vapor diffusion coefficients were measured through the longitudinal and radial directions of the specimens and results were analyzed using chemical composition measurement, FT-IR (Fourier Transform Infrared) test, and SEM (Scanning Electron Microscope) studies. The FT-IR study of pretreated samples showed no specific change, although SEM photographs proved the hydrolyzation of bordered pits as a result of microwave heating. Results revealed that microwave pretreatment had no effect on the longitudinal permeability and diffusion coefficients. In contrast, the radial mass transfer rates were improved due to the microwave pretreatment. Although the mic...
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mass transfer through microwave treated fir wood Abies Alba l a gymnosperm species with torus margo pit membrane
Drying Technology, 2013Co-Authors: Hadi Dashti, Mehdi Faezipour, Asghar Tarmian, Sahab Hedjazi, Mahdi ShahverdiAbstract:In this research, the effect of microwave pretreatment on mass transfer coefficients of Abies Alba L. was investigated. For this purpose, wood specimens with dimensions of 340 × 100 × 50 mm and average moisture content of 50% were exposed to a microwave with 2450 MHz frequency for time durations of 7 and 10 minutes. After drying, the air permeability and water vapor diffusion coefficients were measured through the longitudinal and radial directions of the specimens and results were analyzed using chemical composition measurement, FT-IR (Fourier Transform Infrared) test, and SEM (Scanning Electron Microscope) studies. The FT-IR study of pretreated samples showed no specific change, although SEM photographs proved the hydrolyzation of bordered pits as a result of microwave heating. Results revealed that microwave pretreatment had no effect on the longitudinal permeability and diffusion coefficients. In contrast, the radial mass transfer rates were improved due to the microwave pretreatment. Although the mic...
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effect of pre steaming on mass transfer properties of fir wood Abies Alba l a gymnosperm species with torus margo pit membrane
Bioresources, 2012Co-Authors: Hadi Dashti, Mehdi Faezipour, Asghar Tarmian, Sahab Hedjazi, Mahdi ShahverdiAbstract:In this research, the effect of pre-steaming on mass transfer properties, including air permeability and water vapor diffusivity of fir wood (Abies Alba L.), a gymnosperm species with torus margo pit membrane, was evaluated. The pre-steaming was performed at temperatures of 120, 140, and 160°C for 1 hour under a pressure of 2-3 bars. Then, the pre-steamed specimens were conventionally dried at a constant temperature of 160°C and a relative humidity of 50% to the final moisture content of 10%. Subsequently, the mass transfer properties of the dried specimens were measured in longitudinal and radial directions. Overall, the pre-steaming was found to be an effective modification method to improve the mass transfer properties of Abies Alba L. The improvement was more remarkable for the air permeability as well as through the radial direction. The specimens steamed at the temperature of 160°C had higher mass transfer rates than those steamed at the temperatures of 120 and 140°C. Results of chemical analyses, FT-IR spectroscopy, and SEM imaging provide some explanations for the effects of pre-steaming.
Peter Escher - One of the best experts on this subject based on the ideXlab platform.
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spatial and seasonal variation in amino compounds in the xylem sap of a mistletoe viscum album and its hosts populus spp and Abies Alba
Tree Physiology, 2004Co-Authors: Peter Escher, Monika Eiblmeier, Ilka Hetzger, Heinz RennenbergAbstract:: In a field study, the composition and concentrations of amino compounds in the xylem sap of the mistletoe, Viscum album L., and in the xylem sap of two host species, an evergreen conifer (Abies Alba Mill.) and a deciduous broad-leaved tree (Populus x euramericana), were analyzed. The xylem sap of both hosts and mistletoe contained large, but similar amounts of total organic nitrogen in low molecular weight amino compounds (TONLW). Nevertheless, individual amino compounds accumulated in the xylem sap of mistletoe relative to the host xylem sap, indicating selective uptake. In the xylem sap of Populus, major amino compounds (asparagine (Asn) and glutamine (Gln)) and the bulk parameters, TONLW and proteinogenic amino acids, showed significant seasonal variation. In Abies and in mistletoe on either host, variation of amino compounds in xylem sap was largely explained by inter-annual differences, not by seasonal variation. In both hosts, TONLW in the xylem sap was dominated by Gln. There was a steady decrease in relative abundance of Gln from the host xylem sap to the mistletoe xylem sap and to the stems and leaves of mistletoe. Simultaneously, the abundance of arginine (Arg) increased. Arginine was the predominant amino compound in the stems and leaves of mistletoe, occurring at concentrations previously observed only in leaves of trees exposed to excess nitrogen. We conclude that Gln (2 mol N mol(-1)) delivered by the host xylem sap is converted, in mistletoe, to Arg (4 mol N mol(-1)) and that the organic carbon liberated from Gln contributes significantly to the parasite's heterotrophic carbon gain. Statistical analyses of the data support this conclusion. Accumulation of Arg in mistletoe is an indication of excess N supply as a result of the uptake of amino compounds from the host xylem sap and a lack of phloem uploading.
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seasonal and spatial variation of carbohydrates in mistletoes viscum album and the xylem sap of its hosts populus x euamericana and Abies Alba
Physiologia Plantarum, 2004Co-Authors: Peter Escher, Monika Eiblmeier, Ilka Hetzger, Heinz RennenbergAbstract:: In the present field study we analysed the seasonal pattern of carbohydrate composition and contents in the xylem sap of Viscum album and the xylem sap of a deciduous (Populusxeuramericana) and a coniferous (Abies Alba) host tree species. The results were compared with the soluble carbohydrate composition and contents of mistletoe tissues. On both hosts significant amounts of glucose, fructose, and sucrose were found in the xylem sap of Viscum throughout the seasons. The general seasonal pattern of sugar contents, i.e. high concentrations in spring and lower concentrations in other seasons on Populus, and intermediate concentrations throughout the year on Abies, largely reflected the xylem sap carbohydrate composition and contents of the respective host. These observations provide indirect evidence for carbohydrate flux from the xylem sap of the host into the mistletoe. However, in both hosts xylem sap seems to be deviated into the mistletoe without specific control of carbohydrate flux. Differences observed between the seasonal pattern of xylem sap carbohydrate concentrations in Viscum on Populus and Abies may originate from the different time of leaf development of these species. A clear-cut seasonal pattern of soluble carbohydrates was not observed in the leaves of Viscum on both hosts. Still soluble carbohydrates seem to be reallocated from the senescing to the newly developed leaves of Viscum indicating that the seasonal requirement of carbohydrate for growth and development can only completely be met by carbohydrate acquisition from the host and their own photosynthesis.
