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Berlin Brandenburg

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  • 1
    In: PLoS ONE, 2014, Vol.9(12)
    Description: In the future, periods of strongly increased temperature in concert with drought (heat waves) will have potentially detrimental effects on trees and forests in Central Europe. Norway spruce might be at risk in the future climate of Central Europe. However, Douglas-fir is often discussed as an alternative for the drought and heat sensitive Norway spruce, because some provenances are considered to be well adapted to drier and warmer conditions. In this study, we identified the physiological and growth responses of seedlings from two different Douglas-fir provenances to increased temperature and atmospheric drought during a period of 92 days. We analysed (i) plant biomass, (ii) carbon stable isotope composition as an indicator for time integrated intrinsic water use efficiency, (iii) apparent respiratory carbon isotope fractionation as well as (iv) the profile of polar low molecular metabolites. Plant biomass was only slightly affected by increased temperatures and atmospheric drought but the more negative apparent respiratory fractionation indicated a temperature-dependent decrease in the commitment of substrate to the tricarboxylic acid cycle. The metabolite profile revealed that the simulated heat wave induced a switch in stress protecting compounds from proline to polyols. We conclude that metabolic acclimation successfully contributes to maintain functioning and physiological activity in seedlings of both Douglas-fir provenances under conditions that are expected during heat waves (i.e. elevated temperatures and atmospheric drought). Douglas-fir might be a potentially important tree species for forestry in Central Europe under changing climatic conditions.
    Keywords: Research Article ; Biology And Life Sciences ; Ecology And Environmental Sciences
    E-ISSN: 1932-6203
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  • 2
    Language: English
    In: Plant and Soil, 2010, Vol.332(1), pp.387-403
    Description: The root/shoot-ratio is a simple parameter to describe the systemic response of plants to alterations of their nutritional status, as indicated by the C/N-balance of leaves. The ‘functional equilibrium hypothesis’ holds that leaf growth is limited by the supply of nitrogen from the roots, whereas root growth depends on the carbon supply from leaves. The nature of the systemic control that balances root and shoot growth is not fully understood. Previous experiments have shown that root growth of transformed tobacco plants, which lack functional root nitrate reductase, was severely impeded, when plants were grown on NO 3 − as the sole N-source. In these experiments, the root/shoot-ratio was correlated with the Glutamate/Glutamine-ratio of roots. In the present study we tested the hypothesis that high internal Glu contents (in relation to Gln) inhibit root growth. Wild type and transformed tobacco plants were given access to both NH 4 and NO 3 , and were cultivated at ambient and elevated p CO 2 in order to vary carbon availability. The uptake and assimilation of NH 4 + by the root was significantly higher in transformed than in wild type tobacco, in particular at elevated p CO 2 . Consequently, the Glu/Gln-ratio in the root of transformants was significantly lower than in NO 3 − -grown plants, and was, in the present study, not different from the wild type. However, we failed to observe a correlation between plant architecture and the Glu/Gln-ratio of roots, suggesting that signals arising from the immediate products of nitrate reduction (nitrite) are involved in the systemic control of root growth. Furthermore the synthesis of root-derived signals, which affect N-turnover, starch re-mobilization and the growth of leaves, appears to be associated with root nitrate reduction. This enzymatic step seems to be indispensable for the systemic control of biomass partitioning, and plays a crucial role for the integration of carbon and nitrogen metabolism at the whole plant level.
    Keywords: Systemic control ; C/N-balance ; Root: shoot ratio ; Nitrate reduction ; Ammonium assimilation ; Glutamate signalling
    ISSN: 0032-079X
    E-ISSN: 1573-5036
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  • 3
    In: New Phytologist, April 2017, Vol.214(2), pp.597-606
    Description: The present study was performed to elucidate the fate of carbon (C) and nitrogen (N) derived from protein of prey caught by carnivorous Dionaea muscipula. For this, traps were fed 13C/15N‐glutamine (Gln). The release of 13CO2 was continuously monitored by isotope ratio infrared spectrometry. After 46 h, the allocation of C and N label into different organs was determined and tissues were subjected to metabolome, proteome and transcriptome analyses. Nitrogen of Gln fed was already separated from its C skeleton in the decomposing fluid secreted by the traps. Most of the Gln‐C and Gln‐N recovered inside plants were localized in fed traps. Among nonfed organs, traps were a stronger sink for Gln‐C compared to Gln‐N, and roots were a stronger sink for Gln‐N compared to Gln‐C. A significant amount of the Gln‐C was respired as indicated by 13C‐CO2 emission, enhanced levels of metabolites of respiratory Gln degradation and increased abundance of proteins of respiratory processes. Transcription analyses revealed constitutive expression of enzymes involved in Gln metabolism in traps. It appears that prey not only provides building blocks of cellular constituents of carnivorous Dionaea muscipula, but also is used for energy generation by respiratory amino acid degradation.
    Keywords: Amino Acid Catabolism ; Carbon Partitioning ; Dionaea Muscipula Venus Flytrap ; Glutamine ; Nitrogen N Partitioning ; Plant Carnivory ; Respiratory Degradation
    ISSN: 0028-646X
    E-ISSN: 1469-8137
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  • 4
    Language: English
    In: Environmental Pollution, June 2018, Vol.237, pp.205-217
    Description: Energy crops are an important renewable source for energy production in future. To ensure high yields of crops, N fertilization is a common practice. However, knowledge on environmental impacts of bioenergy plantations, particularly in systems involving trees, and the effects of N fertilization is scarce. We studied the emission of volatile organic compounds (VOC), which negatively affect the environment by contributing to tropospheric ozone and aerosols formation, from and willow plantations. Particularly, we aimed at quantifying the effect of N fertilization on VOC emission. For this purpose, we determined plant traits, photosynthetic gas exchange and VOC emission rates of the two systems as affected by N fertilization (0 and 80 kg ha yr ). Additionally, we used a modelling approach to simulate (i) the annual VOC emission rates as well as (ii) the OH reactivity resulting from individual VOC emitted. Total VOC emissions from was 1.5- and 2.5-fold higher compared to in non-fertilized and fertilized plantations, respectively. Isoprene was the dominating VOC in (80–130 μg g DW h ), whereas it was negligible in . We identified twenty-eight VOC compounds, which were released by with the green leaf volatile hexanal as well as dimethyl benzene, dihydrofuranone, phenol, and decanal as the dominant volatiles. The pattern of VOC released from this species clearly differed to the pattern emitted by . OH reactivity from VOC released by was ca. 8-times higher than that of . N fertilization enhanced stand level VOC emissions, mainly by promoting the leaf area index and only marginally by enhancing the basal emission capacity of leaves. Considering the higher productivity of fertilized compared to together with the considerably lower OH reactivity per weight unit of biomass produced, qualified the C -perennial grass as a superior source of future bioenergy production. N fertilization strongly increased VOC emission of but not of at the plantation level, making the latter a superior source of future bioenergy production.
    Keywords: Biogenic VOC Emissions ; Greenhouse Gas ; Plant Growth ; N Availability ; Bioenergy Crops ; Salix ; Miscanthus ; Engineering ; Environmental Sciences ; Anatomy & Physiology
    ISSN: 0269-7491
    E-ISSN: 1873-6424
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  • 5
    In: Journal Of Experimental Botany, 2013, Vol. 64(5), pp.1317-1332
    Description: Symbiotic nitrogen fixation (SNF) involves global changes in gene expression and metabolite accumulation in both rhizobia and the host plant. In order to study the metabolic changes mediated by leaf–root interaction, photosynthesis was limited in leaves by exposure of plants to darkness, and subsequently gene expression was profiled by real-time reverse transcription–PCR (RT–PCR) and metabolite levels by gas chromatography–mass spectrometry in the nodules of the model legume Lotus japonicus . Photosynthetic carbon deficiency caused by prolonged darkness affected many metabolic processes in L. japonicus nodules. Most of the metabolic genes analysed were down-regulated during the extended dark period. In addition to that, the levels of most metabolites decreased or remained unaltered, although accumulation of amino acids was observed. Reduced glycolysis and carbon fixation resulted in lower organic acid levels, especially of malate, the primary source of carbon for bacteroid metabolism and SNF. The high amino acid concentrations together with a reduction in total protein concentration indicate possible protein degradation in nodules under these conditions. Interestingly, comparisons between amino acid and protein content in various organs indicated systemic changes in response to prolonged darkness between nodulated and non-nodulated plants, rendering the nodule a source organ for both C and N under these conditions.
    Keywords: Carbon Starvation ; 〈Kwd〉〈Italic〉Lotus Japonicus〈/Italic〉〈/Kwd〉 ; Metabolomic Analysis ; Nodule ; Symbiosis ; Transcript Profile.
    ISSN: 0022-0957
    E-ISSN: 1460-2431
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  • 6
    Language: English
    In: Journal of experimental botany, 2013, Vol.64(5), pp.1317-1332
    Description: Symbiotic nitrogen fixation (SNF) involves global changes in gene expression and metabolite accumulation in both rhizobia and the host plant. In order to study the metabolic changes mediated by leaf–root interaction, photosynthesis was limited in leaves by exposure of plants to darkness, and subsequently gene expression was profiled by real-time reverse transcription–PCR (RT–PCR) and metabolite levels by gas chromatography–mass spectrometry in the nodules of the model legume Lotus japonicus. Photosynthetic carbon deficiency caused by prolonged darkness affected many metabolic processes in L. japonicus nodules. Most of the metabolic genes analysed were down-regulated during the extended dark period. In addition to that, the levels of most metabolites decreased or remained unaltered, although accumulation of amino acids was observed. Reduced glycolysis and carbon fixation resulted in lower organic acid levels, especially of malate, the primary source of carbon for bacteroid metabolism and SNF. The high amino acid concentrations together with a reduction in total protein concentration indicate possible protein degradation in nodules under these conditions. Interestingly, comparisons between amino acid and protein content in various organs indicated systemic changes in response to prolonged darkness between nodulated and non-nodulated plants, rendering the nodule a source organ for both C and N under these conditions. ; p. 1317-1332.
    Keywords: Metabolites ; Photosynthesis ; Glycolysis ; Protein Degradation ; Amino Acid Composition ; Genes ; Host Plants ; Malates ; Leaves ; Protein Content ; Nitrogen Fixation ; Gene Expression Regulation ; Reverse Transcriptase Polymerase Chain Reaction ; Scotophase ; Lotus Corniculatus Var. Japonicus ; Metabolic Studies ; Amino Acids ; Carbon ; Gene Expression ; Legumes ; Spectroscopy
    ISSN: 0022-0957
    Source: AGRIS (Food and Agriculture Organization of the United Nations)
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  • 7
    Description: Sulphate assimilation is an essential pathway being a source of reduced sulphur for various cellular processes and for the synthesis of glutathione, a major factor in plant stress defence. Many reports have shown that sulphate assimilation is well co-ordinated with the assimilation of nitrate and carbon. It has long been known that, during nitrate deficiency, sulphate assimilation is reduced and that the capacity to reduce nitrate is diminished in plants starved for sulphate. Only recently, however, was it shown that adenosine 5′ phosphosulphate reductase (APR), the key enzyme of sulphate assimilation, is regulated by carbohydrates. In plants treated with sucrose or glucose APR was induced, whereas the activity was strongly reduced in plants grown in CO 2 -free air. The availability of cysteine is a crucial factor in glutathione synthesis, but an adequate supply of glutamate and glycine are also important. The molecular mechanisms for the co-ordination of S, N, and C assimilation are not known. O -acetylserine, a precursor of cysteine, was proposed to be the signal regulating sulphate assimilation, but most probably is not the outgoing signal to N and C metabolism. cDNA arrays revealed the induction of genes involved in auxin synthesis upon S-starvation, pointing to a possible role of phytohormones. Clearly, despite significant progress in understanding the regulation of sulphate assimilation and glutathione synthesis, their co-ordination with N and C metabolism achieved, and several potential signal molecules identified, present knowledge is still far from being sufficient.
    Keywords: Glutathione Synthesis; Nitrate Deficiency; Nitrate Reduction; Sulphate Assimilation; Regulation
    ISSN: 0022-0957
    E-ISSN: 14602431
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  • 8
    Language: English
    In: Plant physiology, September 2015, Vol.169(1), pp.560-75
    Description: Isoprene emissions from poplar (Populus spp.) plantations can influence atmospheric chemistry and regional climate. These emissions respond strongly to temperature, [CO2], and drought, but the superimposed effect of these three climate change factors are, for the most part, unknown. Performing predicted climate change scenario simulations (periodic and chronic heat and drought spells [HDSs] applied under elevated [CO2]), we analyzed volatile organic compound emissions, photosynthetic performance, leaf growth, and overall carbon (C) gain of poplar genotypes emitting (IE) and nonemitting (NE) isoprene. We aimed (1) to evaluate the proposed beneficial effect of isoprene emission on plant stress mitigation and recovery capacity and (2) to estimate the cumulative net C gain under the projected future climate. During HDSs, the chloroplastidic electron transport rate of NE plants became impaired, while IE plants maintained high values similar to unstressed controls. During recovery from HDS episodes, IE plants reached higher daily net CO2 assimilation rates compared with NE genotypes. Irrespective of the genotype, plants undergoing chronic HDSs showed the lowest cumulative C gain. Under control conditions simulating ambient [CO2], the C gain was lower in the IE plants than in the NE plants. In summary, the data on the overall C gain and plant growth suggest that the beneficial function of isoprene emission in poplar might be of minor importance to mitigate predicted short-term climate extremes under elevated [CO2]. Moreover, we demonstrate that an analysis of the canopy-scale dynamics of isoprene emission and photosynthetic performance under multiple stresses is essential to understand the overall performance under proposed future conditions.
    Keywords: Climate Change ; Butadienes -- Analysis ; Hemiterpenes -- Analysis ; Pentanes -- Analysis ; Populus -- Chemistry
    ISSN: 00320889
    E-ISSN: 1532-2548
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  • 9
    In: New Phytologist, February 2015, Vol.205(3), pp.1320-1329
    Description: Carnivorous Dionaea muscipula operates active snap traps for nutrient acquisition from prey; so what is the role of D. muscipula's reduced root system? We studied the capacity for nitrogen (N) acquisition via traps, and its effect on plant allometry; the capacity of roots to absorb NO3−, NH4+ and glutamine from the soil solution; and the fate and interaction of foliar‐ and root‐acquired N. Feeding D. muscipula snap traps with insects had little effect on the root : shoot ratio, but promoted petiole relative to trap growth. Large amounts of NH4+ and glutamine were absorbed upon root feeding. The high capacity for root N uptake was maintained upon feeding traps with glutamine. High root acquisition of NH4+ was mediated by 2.5‐fold higher expression of the NH4+ transporter DmAMT1 in the roots compared with the traps. Electrophysiological studies confirmed a high constitutive capacity for NH4+ uptake by roots. Glutamine feeding of traps inhibited the influx of 15N from root‐absorbed 15N/13C‐glutamine into these traps, but not that of 13C. Apparently, fed traps turned into carbon sinks that even acquired organic carbon from roots. N acquisition at the whole‐plant level is fundamentally different in D. muscipula compared with noncarnivorous species, where foliar N influx down‐regulates N uptake by roots.
    Keywords: Ammonium ; Glutamine ; Nitrogen N Nutrition ; Plant Carnivory ; Root : shoot Integration
    ISSN: 0028-646X
    E-ISSN: 1469-8137
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  • 10
    In: Applied and Environmental Microbiology, 2010, Vol. 76(6), p.1831
    Description: The relationships between plant carbon resources, soil carbon and nitrogen content, and ectomycorrhizal fungal (EMF) diversity in a monospecific, old-growth beech (Fagus sylvatica) forest were investigated by manipulating carbon flux by girdling. We hypothesized that disruption of the carbon supply would not affect diversity and EMF species numbers if EM fungi can be supplied by plant internal carbohydrate resources or would result in selective disappearance of EMF taxa because of differences in carbon demand of different fungi. Tree carbohydrate status, root demography, EMF colonization, and EMF taxon abundance were measured repeatedly during 1 year after girdling. Girdling did not affect root colonization but decreased EMF species richness of an estimated 79 to 90 taxa to about 40 taxa. Cenococcum geophilum, Lactarius blennius, and Tomentella lapida were dominant, colonizing about 70% of the root tips, and remained unaffected by girdling. Mainly cryptic EMF species disappeared. Therefore, the Shannon-Wiener index (H') decreased but evenness was unaffected. H' was positively correlated with glucose, fructose, and starch concentrations of fine roots and also with the ratio of dissolved organic carbon to dissolved organic nitrogen (DOC/DON), suggesting that both H' and DOC/DON were governed by changes in belowground carbon allocation. Our results suggest that beech maintains numerous rare EMF species by recent photosynthate. These EM fungi may constitute biological insurance for adaptation to changing environmental conditions. The preservation of taxa previously not known to colonize beech may, thus, form an important reservoir for future forest development.
    Keywords: Engineering ; Biology ; Economics;
    ISSN: 0099-2240
    ISSN: 00992240
    E-ISSN: 10985336
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