dc.contributor.author | Ariz, Idoia | |
dc.contributor.author | Cruz, Cristina | |
dc.contributor.author | Morán, José F. | |
dc.contributor.author | González Moro, María Begoña | |
dc.contributor.author | García Olaverri, Carmen | |
dc.contributor.author | González Murua, María del Carmen Begoña | |
dc.contributor.author | Martins-Loução, Maria A. | |
dc.contributor.author | Aparicio Tejo, Pedro M. | |
dc.date.accessioned | 2012-03-30T14:14:32Z | |
dc.date.available | 2012-03-30T14:14:32Z | |
dc.date.issued | 2011-05-16 | |
dc.identifier.citation | BMC Plant Biology 11(83) : (2011) | es |
dc.identifier.issn | 1471-2229 | |
dc.identifier.uri | http://hdl.handle.net/10810/7294 | |
dc.description.abstract | Background: In plants, nitrate (NO(3)(-)) nutrition gives rise to a natural N isotopic signature (delta(15)N), which correlates with the delta(15)N of the N source. However, little is known about the relationship between the delta(15)N of the N source and the (14)N/(15)N fractionation in plants under ammonium (NH(4)(+)) nutrition. When NH(4)(+) is the major N source, the two forms, NH(4)(+) and NH(3), are present in the nutrient solution. There is a 1.025 thermodynamic isotope effect between NH(3) (g) and NH(4)(+)(aq) which drives to a different delta(15)N. Nine plant species with different NH(4)(+)-sensitivities were cultured hydroponically with NO(3)(-) or NH(4)(+) as the sole N sources, and plant growth and delta(15)N were determined. Short-term NH(4)(+)/NH(3) uptake experiments at pH 6.0 and 9.0 (which favours NH(3) form) were carried out in order to support and substantiate our hypothesis. N source fractionation throughout the whole plant was interpreted on the basis of the relative transport of NH(4)(+) and NH(3). -- Results: Several NO(3)(-)-fed plants were consistently enriched in (15)N, whereas plants under NH(4)(+) nutrition were depleted of (15)N. It was shown that more sensitive plants to NH(4)(+) toxicity were the most depleted in (15)N. In parallel, N-deficient pea and spinach plants fed with (15)NH(4)(+) showed an increased level of NH(3) uptake at alkaline pH that was related to the (15)N depletion of the plant. Tolerant to NH(4)(+) pea plants or sensitive spinach plants showed similar trend on (15)N depletion while slight differences in the time kinetics were observed during the initial stages. The use of RbNO(3) as control discarded that the differences observed arise from pH detrimental effects. -- Conclusions: This article proposes that the negative values of delta(15)N in NH(4)(+)-fed plants are originated from NH(3) uptake by plants. Moreover, this depletion of the heavier N isotope is proportional to the NH(4)(+)/NH(3) toxicity in plants species. Therefore, we hypothesise that the low affinity transport system for NH(4)(+) may have two components: one that transports N in the molecular form and is associated with fractionation and another that transports N in the ionic form and is not associated with fractionation. | es |
dc.description.sponsorship | This work was supported by the Spanish MICIIN (grant nos. AGL2006-12792-CO2-01 and 02 and AGL2009- 13339-CO2-01 and 02 [to P.A.-T. and C. G. M.] and AGL2007-64432/AGR [to J.F.M.]), by the Portuguese FCT (PTDC/BIA- BEC/099323/2008) and by the Basque Government IT526-10. IA was supported by a postdoctoral Fellowship from the Public University of Navarre. Technical support was provided by SGIker to the UPV/EHU researchers. | es |
dc.language.iso | eng | es |
dc.publisher | BioMed Central | es |
dc.rights | info:eu-repo/semantics/openAccess | es |
dc.subject | low affinity ammonium transporters | es |
dc.subject | nitrogen isotopic signature | es |
dc.subject | ammonium/ammonia | es |
dc.subject | ammonium dissociation isotope factor | es |
dc.subject | ammonia uptake | es |
dc.title | Depletion of the heaviest stable N isotope is associated with NH4 +/NH3 toxicity in NH4 +-fed plants | es |
dc.type | info:eu-repo/semantics/article | es |
dc.rights.holder | © 2011 Ariz et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. | es |
dc.relation.publisherversion | http://www.biomedcentral.com/1471-2229/11/83 | es |
dc.identifier.doi | 10.1186/1471-2229-11-83 | |
dc.departamentoes | Biología vegetal y ecología | es_ES |
dc.departamentoeu | Landaren biologia eta ekologia | es_ES |
dc.subject.categoria | PLANT SCIENCES | |