Distribution of calcium (Ca) and magnesium (Mg) in the leaves of Brassica rapa under varying exogenous Ca and Mg supply

Background and Aims Leafy vegetable Brassica crops are an important source of dietary calcium (Ca) and magnesium (Mg) and represent potential targets for increasing leaf Ca and Mg concentrations through agronomy or breeding. Although the internal distribution of Ca and Mg within leaves affects the accumulation of these elements, such data are not available for Brassica. The aim of this study was to characterize the internal distribution of Ca and Mg in the leaves of a vegetable Brassica and to determine the effects of altered exogenous Ca and Mg supply on this distribution. Methods Brassica rapa ssp. trilocularis ‘R-o-18’ was grown at four different Ca:Mg treatments for 21 d in a controlled environment. Concentrations of Ca and Mg were determined in fully expanded leaves using inductively coupled plasma-mass spectrometry (ICP-MS). Internal distributions of Ca and Mg were determined in transverse leaf sections at the base and apex of leaves using energy-dispersive X-ray spectroscopy (EDS) with cryo-scanning electron microscopy (cryo-SEM). Key Results Leaf Ca and Mg concentrations were greatest in palisade and spongy mesophyll cells, respectively, although this was dependent on exogenous supply. Calcium accumulation in palisade mesophyll cells was enhanced slightly under high Mg supply; in contrast, Mg accumulation in spongy mesophyll cells was not affected by Ca supply. Conclusions The results are consistent with Arabidopsis thaliana and other Brassicaceae, providing phenotypic evidence that conserved mechanisms regulate leaf Ca and Mg distribution at a cellular scale. The future study of Arabidopsis gene orthologues in mutants of this reference B. rapa genotype will improve our understanding of Ca and Mg homeostasis in plants and may provide a model-to-crop translation pathway for targeted breeding.

Genetical and comparative genomics of Brassica under altered Ca supply identifies Arabidopsis Ca-transporter orthologs

Although Ca transport in plants is highly complex, the overexpression of vacuolar Ca2+ transporters in crops is a promising new technology to improve dietary Ca supplies through biofortification. Here, we sought to identify novel targets for increasing plant Ca accumulation using genetical and comparative genomics. Expression quantitative trait locus (eQTL) mapping to 1895 cis- and 8015 trans-loci were identified in shoots of an inbred mapping population of Brassica rapa (IMB211 × R500); 23 cis- and 948 trans-eQTLs responded specifically to altered Ca supply. eQTLs were screened for functional significance using a large database of shoot Ca concentration phenotypes of Arabidopsis thaliana. From 31 Arabidopsis gene identifiers tagged to robust shoot Ca concentration phenotypes, 21 mapped to 27 B. rapa eQTLs, including orthologs of the Ca2+ transporters At-CAX1 and At-ACA8. Two of three independent missense mutants of BraA.cax1a, isolated previously by targeting induced local lesions in genomes, have allele-specific shoot Ca concentration phenotypes compared with their segregating wild types. BraA.CAX1a is a promising target for altering the Ca composition of Brassica, consistent with prior knowledge from Arabidopsis. We conclude that multiple-environment eQTL analysis of complex crop genomes combined with comparative genomics is a powerful technique for novel gene identification/prioritization.

Habitação e meio-ambiente : uma abordagem crítica para o projeto sustentável

Este trabalho trata das questões ambientais vinculadas ao projeto de empreendimentos habitacionais. Inicialmente, apresentam-se as bases conceituais, discutindo, especialmente, o significado de termos como : ecologia,meio ambiente e desenvolvimento sustentável, aplicados à arquitetura. Como forma de ilustração destes conceitos, analisa-se obras relevantes. Segue-se a caracterização das várias fases de um projeto desta natureza, destacando o planejamento, a construção, a ocupação e a desativação. Por fim, aplica-se estes conceitos através da análise de um conjunto habitacional, monstrando se o mesmo é sustentável ou não. Dessa forma, colabora--se na compreensão das interdependências ecológicas e verifica-se o desempenho desse conjunto habitacional referente à sustentabilidade.

A crítica hegeliana do entendimento e a perspectiva da razão

The aim of this work is to present the critic of Hegel to the form of thinking of the Understanding (Verstand) and the perspective of a new concept of Reason (Vernunft) or rationality that then appears, and this tends as base the three moments of the logical process (the moment of the Understanding, Dialectical and the Speculative) presented by Hegel in the Encyclopedia of the Philosophical Sciences. It will be shown that this critic is done immanent to the own philosophy of Hegel, because the Understanding is so much the object of the critic, as one of the moments that constitute the own process logical-dialectic (method dialectic) that defines the rationality hegelian. Starting from that insert of the Understanding in the own Reason, we will see that the critic of Hegel won't just feel in a destructive way, in a such way that the Understanding totally goes denied, but before it will elevate this same Understanding at the level of the Reason speculative, removing like this your assumed place of absolute university of the truth and pointing it in your true place.

Garantia literária: elementos para uma revisão crítica após um século

This study contributes to a critical synthesis of the principle of literary warrant, initially formulated by Hulme in 1911. Hulme proposed that the terms of a classification system should be derived from the literature to be classified, rather than based on purely theoretical considerations. Founding literary warrant on literature which is actually documented rather than on scientific or philosophical classifications or on the supposed authority of the first classificationists implied a clear departure from the conceptions of Harris and Dewey, who had used the classifications of Bacon and Leibniz as models. The validity of this principle over the past century is studied by means of diverse documental data (entries in dictionaries, retrieval by Google, etc.), as it is recognized as a main methodological element for classification standards and systems. This study also discusses the situation with respect to the top-down or bottom-up methodologies of system design. Three traditional applications of literary warrant are described as well as three new applications are suggested, in light of its methodological potential. It is possible to conclude that this principle will find increasing applications in other contexts, within and beyond Information Science.

Os caminhos da poesia em Juan Rámon Jiménez

Pós-graduação em Letras - FCLAS

Balzac e os mitos da modernidade: Fausto e Don Juan em La peau de chagrin et L'elixir de longue vie

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

'Voluntad' de Benito Pérez Galdós : el camino hacia el texto definitivo. Edición crítica

Programa de Doctorado en Filología Española

Conocimiento y formación en cultura preventiva de riesgo en los centos de enseñanza obligatoria de la provincia de Las Palmas y su capacidad de respuesta ante una situación crítica

Programa de doctorado: Formación del Profesorado

El espacio de lo provincial en el siglo XIX : memoria descriptiva sobre el Tucumán, de Juan Bautista Alberdi

Hacia el año 1834, Juan Bautista Alberdi regresa a su Tucumán natal, luego de una larga ausencia. En ese momento, instigado por el entonces gobernador, general Alejandro Heredia, redactó su Memoria descriptiva sobre el Tucumán, considerada el primer exponente de la literatura provincial en la Argentina. En este breve texto, de menos de treinta páginas, el escritor aúna a su perspectiva de extra-ambientado, de viajero, la del romántico y la del patriota, las cuales determinan las isotopías que lo estructuran. Este trabajo intenta rescatar del olvido tan valioso texto. Para ello se analizan la estructura, procedimientos y recursos que, estando al servicio de una intención precisamente manifestada por el autor, configuran una visión idealizada del terruño natal. El procedimiento descriptivo es el principal canal de textualización. A través de él, el autor ofrece una visión subjetiva, idealizadora y humanizada del paisaje para detenerse luego en la presentación del hombre tucumano, cuyo temperamento aparece determinado por la geografía de su entorno. Finalmente, Alberdi centra su mirada en los monumentos históricos; en este caso, su discurso materializa la confrontación entre lo que ve y lo que recuerda e identifica la vida de la patria con su propia vida.