المؤلفون: Zhao, Kaifen, Villar Salvador, Pedro, Li, Guolei

المساهمون: Universidad de Alcalá. Departamento de Ciencias de la Vida. Unidad Docente Ecología

مصطلحات موضوعية: Acorn N, N allocation, 15N-labelling, Remobilization, Soil N, Ecología, Ecology

الوصف: 40 p. ; Several studies have addressed the role of soil fertility on acorn N remobilization during seedling growth, but have focused on very early development stages or have assessed remobilization at a coarse grain ontogenetic scale making it difficult to know the precise time when seedlings switch from acorn N to soil N use. We cultivated Quercus variabilis seedlings under two distinct soil N fertility and assessed their growth, acorn N remobilization, and absorption of soil N at five distinct development stages, spanning from the incipient shoot emergence to the completion of the second flush of growth. Acorn N contributed more to seedling N content than soil N at all development stages. Seedlings began to uptake substantial amounts of soil N after the completion of leaf expansion during the first shoot flush of growth, coinciding with a fine root area that reached 50% of the maximum value observed at the end of the study. Roots became less dependent on acorn N before shoots. Soil fertility, rather than seedling growth rate, determined soil N uptake after the completion of leaf expansion in the first shoot flush of growth. We conclude that the acorn is the primary N source for Q. variabilis seedlings until the completion of the first shoot flush of growth. Soil fertility does not significantly affect either the amount of N remobilized from acorns or the switch from acorn N to massive soil N use, suggesting a minimal effect of forest microhabitat fertility on acorn N utilization by Q. variabilis seedlings. ; Gobierno de España ; Comunidad de Madrid ; National Natural Science Foundation of China ; China Scholarship Council

وصف الملف: application/pdf

العلاقة: info:eu-repo/grantAgreement/MICINN/ QueVADIS/PID2022-141762OB-I00/ES//; info:eu-repo/grantAgreement/CM/REMEDINAL/S2018%EMT-4338/ES//; Trees, 2024, v. Online, n. , p. -; http://hdl.handle.net/10017/60670Test; AR/0000047077; Trees; online

الإتاحة: https://doi.org/10.1007/s00468-023-02481-7Test
http://hdl.handle.net/10017/60670Test

المؤلفون: Mengle Wang, Stefan Asam, Jianqi Chen, Matthias Ehrmann, Michael Rychlik

المصدر: Frontiers in Microbiology, Vol 12 (2021)

مصطلحات موضوعية: biosynthesis, Propionibacterium freudenreichii, chemically defined medium, vitamin B12, cobalamins, 15N-labelling, Microbiology, QR1-502

الوصف: Cobalamins (vitamin B12) are required by humans for their essential roles as enzyme cofactors in diverse metabolic processes. The four most common cobalamin vitamers are hydroxocobalamin (OHCbl), adenosylcobalamin (AdoCbl), methylcobalamin (MeCbl), and cyanocobalamin (CNCbl). Humans are not able to synthesise cobalamins de novo and thus must acquire them from external sources. Therefore, a reliable and robust analytical method to determine the cobalamins in dietary sources is highly required. For such a purpose, stable isotope dilution assays (SIDAs) with LC-MS/MS are most suited due to their superior sensitivity, specificity, and ability to compensate for matrix effects and analyte loss during sample work-up. However, a critical bottleneck for developing a SIDA method for cobalamins is the availability of stable isotope-labelled internal standards. In the present study, we harnessed the potential of Propionibacterium (P.) freudenreichii for the biosynthesis of 15N-labelled cobalamins. First, we developed a chemically defined medium (CDM) containing ammonium sulphate as a single nitrogen source except three essential vitamins that supported long-term stable growth of P. freudenreichii throughout continuous transfers. The CDM was further optimised for cobalamin production under different incubation schemes. With the optimised CDM and incubation scheme, fully 15N-labelled cobalamins were obtained in P. freudenreichii with a final yield of 312 ± 29 μg/L and 635 ± 102 μg/L, respectively, for [15N]-OHCbl and [15N]-AdoCbl. Additionally, an optimised incubation process under anaerobic conditions was successfully employed to produce specifically labelled [15N, 14N2]-cobalamins, with a yield of 96 ± 18 μg/L and 990 ± 210 μg/L, respectively, for [15N, 14N2]-OHCbl and [15N, 14N2]-AdoCbl. The labelled substances were isolated and purified by solid phase extraction and semi-preparative HPLC. Chemical modifications were carried out to produce [15N]-CNCbl and [15N]-MeCbl. Eventually, 15N-labelled compounds were obtained for the four cobalamin vitamers in high chromatographic and isotopic purity with desired 15N-enrichment and labelling patterns, which are perfectly suited for future use in SIDAs or other applications that require isotopologues.

وصف الملف: electronic resource

العلاقة: https://www.frontiersin.org/articles/10.3389/fmicb.2021.713321/fullTest; https://doaj.org/toc/1664-302XTest

الوصول الحر: https://doaj.org/article/bd6ac326778046a1bb6ce0913b5e956cTest

المؤلفون: Leiva, Blanca, Paneque Carmona, M., Rosa Arranz, José M. de la, González-Pérez, José Antonio, Leiva, María José, Knicker, Heike

المساهمون: Ministerio de Ciencia, Innovación y Universidades (España), Rosa Arranz, José M. de la, González-Pérez, José Antonio, Knicker, Heike, Paneque Carmona, M.

مصطلحات موضوعية: 13C and 15N‐labelling, Biochar, Carbon sequestration, Long‐term fertilization, Pot experiments, Soil amendments

الوصف: 14 páginas.- 4 figuras.- 8 tablas.- referencias ; Hydrothermal carbonization and dry pyrolysis transform sewage sludge (SS) into nitrogen‐ (N) and phosphorus‐ (P) rich hydrochars (Hyd) and pyrochars (Py), respectively, which may act as slow‐release fertilizers with carbon (C) sequestration potential. Whereas this has been mostly studied with short‐term experiments, this study focused on the cycling of char‐derived N, P and C after ageing during a second grass cropping cycle. Lolium perenne was grown for 3 months in pots on soil mixed with 13C and 15N‐enriched SS, Hyd or Py and allowed to age during a first cropping period of 10‐month incubation. The δ 15N of the plants confirmed that even during the second cropping, N derived from the amendments was plant accessible. Higher uptake of N from Hyd than from Py is explained by the lower biodegradability of the latter. Plant growth during the second cropping period was associated with a decrease of total P in all treatments, but only the soils with Hyd and Py evidenced an increase of Olsen P. Thus, during the second cropping, more insoluble P was mobilized from the carbonized residues than P needed for plant growth. Compared to control soils prepared with and without KNO3, higher biomass production was yielded with the amended soils. Hyd proved to have the highest longer‐term N mobilization potential. Following the change in δ 13C of the soil, we observed that during the second incubation, independently of their aromaticity, all amendments and the native soil organic matter had comparable turnover rates, although the amount of organic matter with slower turnover added with the amendment increased with aromaticity. A rough estimation of the impact of thermal treatment of SS on its C‐sequestration potential revealed no major differences between char types. The higher fertilization capacity of Hyd, however, indicates that it is a good candidate for soil amendment as long‐term fertilization is combined with a long‐term increase of the SOC pool. ; Ministerio de Ciencia ...

العلاقة: #PLACEHOLDER_PARENT_METADATA_VALUE#; info:eu-repo/grantAgreement/MINECO/Plan Estatal de Investigación Científica y Técnica y de Innovación 2013-2016/CGL2015-64811-P; info:eu-repo/grantAgreement/MINECO/Plan Estatal de Investigación Científica y Técnica y de Innovación 2013-2016/CGL2016-78937-R; Postprint; http://dx.doi.org/10.1111/ejss.13000Test; Sí; European Journal of Soil Science 72(3): 1256-1269 (2021); http://hdl.handle.net/10261/215451Test

الإتاحة: https://doi.org/10.1111/ejss.13000Test
http://hdl.handle.net/10261/215451Test

المؤلفون: Alexander, I. J., Millard, P., Proe, M. F.

المصدر: Functional Ecology, 2003 Oct 01. 17(5), 690-699.

الوصول الحر: https://www.jstor.org/stable/3599165Test

المؤلفون: Bobille, Helene, Fustec, Joelle, Robins, Richard J., Cukier, Caroline, Limami, Anis M.

المساهمون: Institut de Recherche en Horticulture et Semences (IRHS), Université d'Angers (UA)-Institut National de la Recherche Agronomique (INRA)-AGROCAMPUS OUEST, Légumineuses, Ecophysiologie Végétale, Agroécologie (LEVA), Institut National de la Recherche Agronomique (INRA)-Ecole supérieure d'Agricultures d'Angers (ESA), Chimie Et Interdisciplinarité : Synthèse, Analyse, Modélisation (CEISAM), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut de Chimie - CNRS Chimie (INC-CNRS)-Centre National de la Recherche Scientifique (CNRS), French Region Pays-de-la-Loire, project "RHIZOSFER" (2012-09695 ), French Region Pays-de-la-Loire, project "PLAISIR" Association for International Structure on "Isotopomic Research" French Regional International Strategy Grant

المصدر: Phytochemistry ; https://hal.science/hal-02140854Test ; Phytochemistry, 2019, 161, pp.75-85. ⟨10.1016/j.phytochem.2019.01.015⟩

مصطلحات موضوعية: Leguminoseae, Amino acids, Water stress, CG-MS, 15N-labelling, [CHIM]Chemical Sciences

الوصف: International audience ; Root exudation is considered to regulate the abundance of the microbial community. It may vary both qualitatively and quantitatively in response to the environment in which the plant is growing. A part of exuded N derives from amino acids (AAs). This, in turn, may help plants to cope with abiotic stresses by favouring positive interactions with the rhizosphere environment, thus playing a potential role in maintaining healthy plants. In this respect, an under-investigated area is the effect of stress due to water deficit (WD). It is proposed that the AA profile in the rhizosphere may be altered by WD, reflecting a modulation of root AA exudation linked to a physiological response of the plant to water stress. To investigate this, Pisum sativum L. plants, grown in unsterilised Rhizobium leguminosarum-enriched soil, were stem-labelled with N-15-urea for 96 h, and then subjected/not subjected to 72 h of WD. The concentrations and abundance of N-15-labelling in individual AAs were determined in both roots and the associated rhizosphere at 24,48 and 72 h after stress application. It was found that both AAs metabolism in the pea root and AAs exudation were strongly modified in WD conditions. After 24 h of WD, the concentrations of all measured AAs increased in the roots, accompanied by a dramatic stress-related increase in the N-15-labelling of some AAs. Furthermore, after 48-72 h of WD, the concentrations of Pro, Ala and Glu increased significantly within the rhizosphere, notably with a concomitant increase in N-15-enrichment in Pro, Ser, Asn, Asp, Thr and Ile. These results support the concept that, in response to WD, substantial amounts of recently assimilated N are rapidly translocated from the shoots to the roots, a portion of which is exuded as AAs. This leads to the rhizosphere being relatively augmented by specific AAs (notably HSer, Pro and Ala) in WD conditions, with a potential impact on soil water retention.

العلاقة: info:eu-repo/semantics/altIdentifier/pmid/30822623; hal-02140854; https://hal.science/hal-02140854Test; https://hal.science/hal-02140854/documentTest; https://hal.science/hal-02140854/file/S0031942218302334.pdfTest; PII: S0031-9422(18)30233-4; PRODINRA: 478073; PUBMED: 30822623; WOS: 000465062600006

الإتاحة: https://doi.org/10.1016/j.phytochem.2019.01.015Test
https://hal.science/hal-02140854Test
https://hal.science/hal-02140854/documentTest
https://hal.science/hal-02140854/file/S0031942218302334.pdfTest

المؤلفون: Thibaut Verdenal, Jorge E. Spangenberg, Vivian Zufferey, Fabrice Lorenzini, Agnes Dienes, Katia Gindro, Jean-Laurent Spring, Olivier Viret

المصدر: OENO One, Vol 50, Iss 1, Pp 23-33 (2016)

مصطلحات موضوعية: grapevine, foliar urea, 15N-labelling, yeast assimilable nitrogen, Agriculture, Botany, QK1-989

الوصف: Aims: Agroscope investigated the impact of the leaf-to-fruit ratio on nitrogen (N) partitioning in grapevine following a foliar urea application with the aim of increasing the yeast assimilable nitrogen (YAN) concentration in the must. Methods and results: Foliar urea was applied to field-grown Vitis vinifera L. cv. Chasselas grapevines as part of a split-plot trial with two variable parameters: canopy height (90 or 150 cm) and fruit load (5 or 10 clusters per vine). Foliar application of 20 kg/ha of 15N-labelled urea (10 atom% 15N) was performed at veraison. The isotope labelling method allowed to observe foliar-N partitioning in the plant at harvest. The leaf-to-fruit ratio varied between 0.4 and 1.6 m2/kg, and strongly impacted the N partitioning in the grapevines. Total N and foliar-N partitioning was mainly affected by the variation of canopy height. The YAN concentration varied from 143 to 230 mg/L (+60 %) depending on the leaf area. An oversized canopy (+31 %DW) induced a decrease in the total N concentration of all organs (-17 %), and a decrease in YAN quantity in the must in particular (-53 %). A negative correlation between the N concentration and the carbon isotope discrimination (CID) could be pointed out in a condition of no water restriction (e.g., R2 = 0.65 in the must). Conclusion: An excessive leaf area can induce YAN deficiency in the must. Thus, a balanced leaf-to-fruit ratio – between 1 and 1.2 m2/kg – should be maintained to guarantee grape maturity, YAN accumulation in the must and N recovery in the reserve organs. Significance and impact of the study: The results of this study encourage further research to understand the role of other physiological parameters that affect N partitioning in the grapevine – YAN accumulation in the must in particular – and add new perspectives for N management practices in the vineyard.

وصف الملف: electronic resource

العلاقة: https://oeno-one.eu/article/view/55Test; https://doaj.org/toc/2494-1271Test

الوصول الحر: https://doaj.org/article/5439d43268d44fd4b363cd49929fd934Test

المؤلفون: Alexander Novakovskiy, Tibisay Pérez, Christina Biasi, Tobias Rütting, Tatiana Trubnikova, Maija E. Marushchak, Dmitry Kaverin, Pertti J. Martikainen, J. Gil, Elizabeth M. Baggs

المصدر: Gil, J, Marushchak, M E, Rütting, T, Baggs, L, Pérez, T, Novakovskiy, A, Trubnikova, T, Kaverin, D, Martikainen, P J & Biasi, C 2022, ' Sources of nitrous oxide and fate of mineral nitrogen in sub-Arctic permafrost peat soils ', Biogeosciences, vol. 19, pp. 2683-2698 . https://doi.org/10.5194/bg-19-2683-2022Test

مصطلحات موضوعية: N2O emissions, Denitrification, Peat, source partitioning, Permafrost, Mineralization (biology), gross N turnover rates, chemistry.chemical_compound, Arctic, Nitrate, permafrost-climate feedbacks, sub-Arctic, mineralization, 15N-labelling, soils, denitrification, Permafrost soils, 15. Life on land, Tundra, nitrification, chemistry, 13. Climate action, Environmental chemistry, Soil water, Environmental science, Nitrification

الوصف: Nitrous oxide (N2O) emissions from permafrost-affected terrestrial ecosystems have received little attention, largely because they have been thought to be negligible. Recent studies, however, have shown that there are habitats in subarctic tundra emitting N2O at high rates, such as bare peat surfaces on permafrost peatlands. The processes behind N2O production in these high-emitting habitats are, however, poorly understood. In this study, we established an in situ 15N-labelling experiment with the main objectives to partition the microbial sources of N2O emitted from bare peat surfaces (BP) on permafrost peatlands and to study the fate of ammonium and nitrate in these soils and in adjacent vegetated peat surfaces (VP) showing low N2O emissions. Our results confirm the hypothesis that denitrification is mostly responsible for the high N2O emissions from BP surfaces. During the study period denitrification contributed with ~79 % of the total N2O emission in BP, while the contribution of ammonia oxidation was less, about 19 %. However, nitrification is a key process for the overall N2O production in these soils with negligible external nitrogen (N) load because it is responsible for nitrite/nitrate supply for denitrification, as also supported by relatively high gross nitrification rates in BP. Generally, both gross N mineralization and gross nitrification rates were much higher in BP with high N2O emissions than in VP, where the high C / N ratio together with low water content was likely limiting N mineralization and nitrification and, consequently, N2O production. Also, competition for mineral N between plants and microbes was additionally limiting N availability for N2O production in VP. Our results show that multiple factors control N2O production in permafrost peatlands, the absence of plants being a key factor together with inter-mediate to high water content and low C / N ratio, all factors which also impact on gross N turnover rates. The intermediate to high soil water content which creates anaerobic microsites in BP is a key N2O emission driver for the prevalence of denitrification to occur. This knowledge is important for evaluating future permafrost –N feedback loops from the Arctic.

وصف الملف: application/pdf

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::2cc194cbfac4e82b4bdf64d7dcbcb7e9Test
https://hdl.handle.net/20.500.11820/90f7b118-b0c0-4dae-8e6f-3b86082d396bTest

المؤلفون: Elena Gorokhova

المصدر: Royal Society Open Science, Vol 4, Iss 3 (2017)

مصطلحات موضوعية: stable isotopes, 15n-labelling, growth and life histories, longevity, isotope resonance theory, kinetic isotope effect, Science

الوصف: In ecology, stable isotope labelling is commonly used for tracing material transfer in trophic interactions, nutrient budgets and biogeochemical processes. The main assumption in this approach is that the enrichment with a heavy isotope has no effect on the organism growth and metabolism. This assumption is, however, challenged by theoretical considerations and experimental studies on kinetic isotope effects in vivo. Here, I demonstrate profound changes in life histories of the rotifer Brachionus plicatilis fed 15N-enriched algae (0.4–5.0 at%); i.e. at the enrichment levels commonly used in ecological studies. These findings support theoretically predicted effects of heavy isotope enrichment on growth, metabolism and ageing in biological systems and underline the importance of accounting for such effects when using stable isotope labelling in experimental studies.

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/2054-5703Test

الوصول الحر: https://doaj.org/article/58a33b87e69e426db51af654e526a0adTest

المؤلفون: Elena Gorokhova

مصطلحات موضوعية: Physiology, Ecology, Developmental Biology, stable isotopes, 15N-labelling, growth and life histories, longevity, isotope resonance theory, kinetic isotope effect

الوصف: In ecology, stable isotope labelling is commonly used for tracing material transfer in trophic interactions, nutrient budgets and biogeochemical processes. The main assumption in this approach is that the enrichment with a heavy isotope has no effect on the organism growth and metabolism. This assumption is, however, challenged by theoretical considerations and experimental studies on kinetic isotope effects in vivo . Here, I demonstrate profound changes in life histories of the rotifer Brachionus plicatilis fed 15 N-enriched algae (0.4–5.0 at%); i.e. at the enrichment levels commonly used in ecological studies. These findings support theoretically predicted effects of heavy isotope enrichment on growth, metabolism and ageing in biological systems and underline the importance of accounting for such effects when using stable isotope labelling in experimental studies.

العلاقة: https://figshare.com/articles/journal_contribution/Figure_S1_Food_intake_of_Brachionus_plicatilis_exposed_to_15N-enriched_algal_food_from_Shifts_in_rotifer_life_history_in_response_to_stable_isotope_enrichment_testing_theories_of_isotope_effects_on_organismal_growth/4757941Test

الإتاحة: https://doi.org/10.6084/m9.figshare.4757941.v1Test
https://figshare.com/articles/journal_contribution/Figure_S1_Food_intake_of_Brachionus_plicatilis_exposed_to_15N-enriched_algal_food_from_Shifts_in_rotifer_life_history_in_response_to_stable_isotope_enrichment_testing_theories_of_isotope_effects_on_organismal_growth/4757941Test

المؤلفون: Elena Gorokhova

مصطلحات موضوعية: Physiology, Ecology, Developmental Biology, stable isotopes, 15N-labelling, growth and life histories, longevity, isotope resonance theory, kinetic isotope effect

الوصف: In ecology, stable isotope labelling is commonly used for tracing material transfer in trophic interactions, nutrient budgets and biogeochemical processes. The main assumption in this approach is that the enrichment with a heavy isotope has no effect on the organism growth and metabolism. This assumption is, however, challenged by theoretical considerations and experimental studies on kinetic isotope effects in vivo . Here, I demonstrate profound changes in life histories of the rotifer Brachionus plicatilis fed 15 N-enriched algae (0.4–5.0 at%); i.e. at the enrichment levels commonly used in ecological studies. These findings support theoretically predicted effects of heavy isotope enrichment on growth, metabolism and ageing in biological systems and underline the importance of accounting for such effects when using stable isotope labelling in experimental studies.

العلاقة: https://figshare.com/articles/journal_contribution/Tables_S1-S5_Multiple_comparison_tests_for_life_history_traits_from_Shifts_in_rotifer_life_history_in_response_to_stable_isotope_enrichment_testing_theories_of_isotope_effects_on_organismal_growth/4757953Test

الإتاحة: https://doi.org/10.6084/m9.figshare.4757953.v1Test
https://figshare.com/articles/journal_contribution/Tables_S1-S5_Multiple_comparison_tests_for_life_history_traits_from_Shifts_in_rotifer_life_history_in_response_to_stable_isotope_enrichment_testing_theories_of_isotope_effects_on_organismal_growth/4757953Test