In situ 13CO2 pulse labelling of field-grown eucalypt trees revealed the effects of potassium nutrition and throughfall exclusion on phloem transport of photosynthetic carbon

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Autor(es): dc.contributorUniversit de Lorraine-
Autor(es): dc.contributorCentre de Nancy-
Autor(es): dc.contributorEcologie Fonctionnelle and Biogochimie des Sols and Agro-cosystèmes-
Autor(es): dc.contributorEmpresa Brasileira de Pesquisa Agropecuária (EMBRAPA)-
Autor(es): dc.contributorUniversidade Estadual Paulista (UNESP)-
Autor(es): dc.contributorUniversidade de São Paulo (USP)-
Autor(es): dc.contributorKyoto University-
Autor(es): dc.creatorEpron, Daniel-
Autor(es): dc.creatorCabral, Osvaldo Machado Rodrigues-
Autor(es): dc.creatorLaclau, Jean-Paul [UNESP]-
Autor(es): dc.creatorDannoura, Masako-
Autor(es): dc.creatorPacker, Ana Paula-
Autor(es): dc.creatorPlain, Caroline-
Autor(es): dc.creatorBattie-Laclau, Patricia-
Autor(es): dc.creatorMoreira, Marcelo Zacharias-
Autor(es): dc.creatorTrivelin, Paulo Cesar Ocheuze-
Autor(es): dc.creatorBouillet, Jean-Pierre-
Autor(es): dc.creatorGrant, Dominique-
Autor(es): dc.creatorNouvellon, Yann-
Data de aceite: dc.date.accessioned2022-08-04T22:05:24Z-
Data de disponibilização: dc.date.available2022-08-04T22:05:24Z-
Data de envio: dc.date.issued2022-04-28-
Data de envio: dc.date.issued2022-04-28-
Data de envio: dc.date.issued2015-08-11-
Fonte completa do material: dc.identifierhttp://dx.doi.org/10.1093/treephys/tpv090-
Fonte completa do material: dc.identifierhttp://hdl.handle.net/11449/220573-
Fonte: dc.identifier.urihttp://educapes.capes.gov.br/handle/11449/220573-
Descrição: dc.descriptionPotassium (K) is an important limiting factor of tree growth, but little is known of the effects of K supply on the long-distance transport of photosynthetic carbon (C) in the phloem and of the interaction between K fertilization and drought. We pulse-labelled 2-year-old Eucalyptus grandis L. trees grown in a field trial combining K fertilization (+K and -K) and throughfall exclusion (+W and -W), and we estimated the velocity of C transfer by comparing time lags between the uptake of 13CO2 and its recovery in trunk CO2 efflux recorded at different heights. We also analysed the dynamics of the labelled photosynthates recovered in the foliage and in the phloem sap (inner bark extract). The mean residence time of labelled C in the foliage was short (21-31 h). The time series of 13C in excess in the foliage was affected by the level of fertilization, whereas the effect of throughfall exclusion was not significant. The velocity of C transfer in the trunk (0.20-0.82mh-1) was twice as high in +K trees than in -K trees, with no significant effect of throughfall exclusion except for one +K-W tree labelled in the middle of the drought season that was exposed to a more pronounced water stress (midday leaf water potential of -2.2MPa). Our results suggest that besides reductions in photosynthetic C supply and in C demand by sink organs, the lower velocity under K deficiency is due to a lower cross-sectional area of the sieve tubes, whereas an increase in phloem sap viscosity is more likely limiting phloem transport under drought. In all treatments, 10 times less 13C was recovered in inner bark extracts at the bottom of the trunk when compared with the base of the crown, suggesting that a large part of the labelled assimilates has been exported out of the phloem and replaced by unlabelled C. This supports the 'leakage-retrieval mechanism' that may play a role in maintaining the pressure gradient between source and sink organs required to sustain high velocity of phloem transport in tall trees.-
Descrição: dc.descriptionUMR 1137 Ecologie et Ecophysiologie Forestières Facult des Sciences Universit de Lorraine-
Descrição: dc.descriptionINRA UMR 1137 Ecologie et Ecophysiologie Forestières Centre de Nancy-
Descrição: dc.descriptionCIRAD UMR Ecoandsols Ecologie Fonctionnelle and Biogochimie des Sols and Agro-cosystèmes-
Descrição: dc.descriptionEmbrapa Meio Ambiente-
Descrição: dc.descriptionUniversidade Estadual de São Paulo-
Descrição: dc.descriptionDepartamento de Ciências Florestais ESALQ Universidade de São Paulo ESALQ-
Descrição: dc.descriptionLaboratory of Forest Utilization Department of Forest and Biomaterial Science Graduate School of Agriculture Kyoto University-
Descrição: dc.descriptionCentro de Energia Nuclear Na Agricultura Universidade de São Paulo-
Descrição: dc.descriptionDepartamento de Ciências Atmosfricas IAG Universidade de São Paulo ESALQ-
Descrição: dc.descriptionUniversidade Estadual de São Paulo-
Formato: dc.format6-21-
Idioma: dc.languageen-
Relação: dc.relationTree Physiology-
???dc.source???: dc.sourceScopus-
Palavras-chave: dc.subjectcarbon isotope-
Palavras-chave: dc.subjectcarbon transfer-
Palavras-chave: dc.subjectdrought-
Palavras-chave: dc.subjectEucalyptus grandis-
Palavras-chave: dc.subjectfertilization-
Título: dc.titleIn situ 13CO2 pulse labelling of field-grown eucalypt trees revealed the effects of potassium nutrition and throughfall exclusion on phloem transport of photosynthetic carbon-
Tipo de arquivo: dc.typelivro digital-
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