2,294 research outputs found
Nitrogen metabolism and gene expression landscape in maritime pine
This work was supported by the ProCoGen grant (FP7-KBBE-2011-5) and by the MicroNUpE grant (BIO2015-73512-JIN).Maritime pine (Pinus pinaster Aiton) is one the most important conifer species in the southwestern Mediterranean region because of its economic and environmental potential. For this reason, a work program in functional genomics has been developed in the frame of the ProCoGen project. One objective was to complete the knowledge about P. pinaster transcriptome with the tissue-specific localization of the gene expression of the low accumulated transcripts in sharper regions (Cañas et al. 2017).
In order to reach these objectives total RNA was obtained from isolated tissues through laser capture microdissection (LCM). Due to the limiting amount from these extracts, the RNA samples were reverse-transcribed and the resultant cDNA amplified using our CRA+ protocol (Cañas et al. 2014). The obtained reads were assembled to improve the previous reference transcriptome. Reads were mapped against this transcriptome and the read accounts analyzed in order to found gene co-expression networks using the WGCNA software.
These results have allowed us the characterization of nitrogen metabolism in maritime pine during the seedling stage stablishing relationships between the different components. This include the identification of new genes with low or very localized expression as occurred for the PpGS1c gene encoding a new cytosolic glutamine synthetase. From this starting point, we are developing a new project, MicroNUpE, to identify and study the genes involved in ammonium uptake and regulation in different root tissues that will be isolated through LCM.
Cañas et al. (2017). Plant J, doi:10.1111/tpj.13617.
Cañas et al. (2014). Tree Physiol, 34:1278-1288.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Magnetocaloric Effect Caused by Paramagnetic Austenite–Ferromagnetic Martensite Phase Transformation
In the present work, the magnetization of Ni50Mn17.5Ga25Cu7.5 alloy undergoing the first-order phase transition from paramagnetic austenite to ferromagnetic martensite was measured to evaluate the magnetic-field-induced entropy change (MFIEC) and refrigerant capacity (RC) of the alloy. A standard method (SM) of evaluation of MFIEC is based on thermodynamic Maxwell relation. In view of the criticism of SM expressed by some scientists, the alternative method (AM), which is based on thermodynamic relationships for free energy, was proposed recently for the determination of MFIEC. We developed this method and computed MFIEC in two ways—by AM and SM. The values of MFIEC obtained for Ni50Mn17.5Ga25Cu7.5 alloy by these methods appeared to be large but very different from each other. Moreover, AM reveals the possibility of both normal and inverse magnetocaloric effects in the adjoining temperature ranges, while SM results only in the normal magnetocaloric effect.This research was funded by AEI/FEDER, UE (projects MAT2014-56116-C04-01-R and MAT2012-
37923-C02-01), NASU (project 0117U000433), MESU (project 0117U004340) and SFFR (President’s of Ukraine grant
F75/156-2018)
Analysis of NPF and NRT transporter families regarding the nitrate nutrition in maritime pine (Pinus pinaster)
Nitrogen is an essential element for life and the main limiting nutrient for plant growth and development1. The main forms of inorganic nitrogen in soils are nitrate and ammonium, which relative abundances depend on environmental conditions such as temperature. In agricultural soils the most abundant nitrogen form is nitrate because the use of chemical fertilizers however in natural ecosystems nitrogen soil composition can be more complex. Conifers are tree gymnosperms with a wide distribution although their large forests dominate the boreal ecosystems where nitrification is limited and ammonium is the main nitrogen soil source2. In this context, conifers have an appreciable tolerance to ammonium.
Maritime pine (Pinus pinaster Aiton) is a conifer from the western Mediterranean region of high economic and ecological interest in Spain, France and Portugal. This pine is also a research model tree with different genomic resources such as a reference transcriptome and a gene expression atlas3. Taking advantage of these resources the members of the NPF and NRT transporter families involved in nitrate uptake and transport have been identified and analyzed in maritime pine4. Among the transporter families, the NRT3 one is expanded and composed by six members. The capacity of maritime pine to use nitrate or ammonium has been analyzed in seedlings. The development and growth responses to nitrate nutrition are comparable to ammonium supply. At molecular level, there are strong gene expressions for genes involved in nitrate uptake and assimilation such as Nitrate Reductase, Nitrite Reductase, Glutamine Synthetase 1a, three NRT3 genes and different NPF family members in the different organs. Since the NPF proteins can transport different metabolites, peptides and hormones, the NPF transporters involved in nitrate transport are being identified.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech.
This project was supported by the grant MicroNUpE, BIO2015-73512-JIN; MINECO/AEI/FEDER, UE. JMVM was supported by a grant from the Spanish Ministerio de Educación y Formación Profesional (FPU17/03517) and FO by a grant from the Universidad de Málaga (Programa Operativo de Empleo Juvenil vía SNJG, UMAJI11, FEDER, FSE, Junta de Andalucía)
Transcriptional regulation os phenylalaline biosynthesis and utilization
Conifer trees divert large quantities of carbon into the biosynthesis of phenylpropanoids, particularly to generate lignin, an important constituent of wood. Since phenylalanine is the precursor for phenylpropanoid biosynthesis, the precise regulation of phenylalanine synthesis and utilization should occur simultaneously. This crucial pathway is finely regulated primarily at the transcriptional level. Transcriptome analyses indicate that the transcription factors (TFs) preferentially expressed during wood formation in plants belong to the MYB and NAC families. Craven-Bartle et al. (2013) have shown in conifers that Myb8 is a candidate regulator of key genes in phenylalanine biosynthesis involved in the supply of the phenylpropane carbon skeleton necessary for lignin biosynthesis. This TF is able to bind AC elements present in the promoter regions of these genes to activate transcription. Constitutive overexpression of Myb8 in white spruce increased secondary-wall thickening and led to ectopic lignin deposition (Bomal et al. 2008). In Arabidopsis, the transcriptional network controlling secondary cell wall involves NAC-domain regulators operating upstream Myb transcription factors. Functional orthologues of members of this network described have been identified in poplar and eucalyptus, but in conifers functional evidence had only been obtained for MYBs. We have identified in the P. pinaster genome 37 genes encoding NAC proteins, which 3 NAC proteins could be potential candidates to be involved in vascular development (Pascual et al. 2015). The understanding of the transcriptional regulatory network associated to phenylpropanoids and lignin biosynthesis in conifers is crucial for future applications in tree improvement and sustainable forest management.
This work is supported by the projects BIO2012-33797, BIO2015-69285-R and BIO-474
References:
Bomal C, et al. (2008) Involvement of Pinus taeda MYB1 and MYB8 in phenylpropanoid metabolism and secondary cell wall biogenesis: a comparative in planta analysis. J Exp Bot. 59: 3925-3939.
Craven-Bartle B, et al. (2013) A Myb transcription factor regulates genes of the phenylalanine pathway in maritime pine. Plant J, 74: 755-766.
Pascual MB, et al. (2015) The NAC transcription factor family in maritime pine (Pinus pinaster): molecular regulation of two genes involved in stress responses. BMC Plant Biol, 15: 254.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
An unexpected actor in ammonium assimilation in conifer trees
Conifers are tree species with enormous environmental and economic interests but with several characteristics that complicate their investigation (big size, secondary compounds, large long-life cycles, megagenomes…). However, they are well adapted to ammonium-rich soils being a good model to study ammonium assimilation in plants. Although they have a special feature, only two glutamine synthetase (GS, EC 6.3.1.2) genes, GS1a and GS1b, coding for cytosolic proteins, have been identified. In angiosperms and in the gymnosperm Ginkgo biloba there are two types of this enzyme responsible of the ammonium assimilation: GS1 expressed in the cytosol and GS2 in the plastids. Until the date, the searches of new GS1 and GS2 genes in conifers have been made with classical biochemical and molecular biology techniques without satisfactory results.
In the present context, the emergence of the next generation sequencing (NGS) techniques has open new opportunities in the resolution of old problems. They have allowed the whole sequencing of the massive conifer genomes and the analysis of their transcriptomes. Thus, in the framework of the European project ProCoGen, a gene expression atlas of the tissues of one-month seedlings was carried out using laser capture microdissection (LCM) and massive sequencing in maritime pine (Pinus pinaster), which is a conifer tree from the Southwestern Mediterranean region1. From the analysis of this work, a new gene coding for a new putative cytosolic GS has been identified, PpGS1c.
1Cañas, RA et al. (2017). Plant J, 91. 1064-1087Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech.
Project funding by Ministerio de Economía y Competitividad BIO2015-69285-R and MicroNUpE (BIO2015-73512-JIN; MINECO/AEI/FEDER, UE
Heat fluxes between the Guadalquivir river and the Gulf of Cádiz Continental Shelf
An 18-year time series of daily sea surface temperature of Gulf of Cadiz and an 18-month time series of temperature collected in the vicinity of the Guadalquivir estuary mouth have been analyzed to investigate the heat exchange between the estuary and the adjacent continental shelf. The first time identifies a continental shelf area where seasonal thermal oscillation signal (amplitudes and phase) changes abruptly.
In order to explain this anomaly, the second data set allows a description of thermal fluctuations in a wide range of frequencies and an estimation of the upstream heat budget of the Guadalquivir estuary. Results show that high frequency thermal signal, diurnal and semidiurnal, and water flux signal through Guadalquivir mouth, mainly semidiurnal, apparently interact randomly to give a small exchange of thermal energy at high frequency. There is no trace, at the estuary's mouth, of daily heat exchanges with intertidal mudflats probably because it tends to cancel on daily time scales. Results also show that fluctuations of estimated air-sea fluxes force fluctuations of temperature in a quite homogeneous estuarine, with a delay of 20 days. The along-channel thermal energy gradient reaches magnitudes of 300-400 J m-4 near the mouth during the summer and winter and drives the estuary-shelf exchange of thermal energy at seasonal scale. Particularly, the thermal heat imported by the estuary from the shelf area during late fall-winter-early spring of 2008/2009 is balanced by the thermal heat that the estuary exports to the shelf area during late spring-summer of 2008. In summary, Guadalquivir river removes/imports excess of thermal energy towards/from the continental shelf seasonally, as a mechanism to accommodate excess of heat from one side respect to the other side.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Autoridad Portuaria de Sevilla (APS
Evaluación formativa y nuevas tecnologías
La evaluación formativa, en tanto que proceso continuo de detección de dificultades en el aprendizaje del alumno, es uno de los elementos fundamentales de la individualización. Las posibilidades de gestión de la información convierten a los nuevas tecnologías en medios muy apropiados para facilitar a los alumnos una evaluación, todo lo frecuente que se quiera, de su aprendizaje. Presentamos en este trabajo un proyecto de desarrollo de una herramienta para la generación de pruebas objetivas en Internet, desarrollado por el Departamento de Educación y el Centro de Tecnología Informática de la Universidad de Navarra. El objetivo del proyecto es implementar un procedimiento de examen y autoevaluación a través del ordenador, que permita a los profesores disponer de un método de valoración inmediata de los conocimientos de los alumnos, y a éstos disponer de un sistema de autoevaluación fiable y de fácil acceso
Quality of table olives
6 páginas, 4 tablas.-- Articulo de revisión.[ES] El trabajo comenta las diferentes normas, tanto nacionales como
intemacionales, que regulan los aspectos de la calidad de las aceitunas
de mesa. Se comentan especialmente la Norma Cualitativa Unificada
Aplicable a Aceitunas de Mesa en el Comercio Intemacional y las
correspondientes COI/CODEX (Consejo Oleícola Intemacional, COI,
y COI/Codex Alimentarius, respectivamente), la Reglamentación Técnico
Sanitaria para la elaboración, circulación, y venta de aceitunas de
mesa (española), las Normas de calidad para la exportación de Aceitunas
de Mesa (española), y las «United States Standards for Grades
of Green and Canned Ripe Olives» (USA). Asimismo se analizan las
implicaciones de las nuevas reglamentaciones sobre etiquetado nutricional
(principalmente en el comercio con USA), la aplicación del Análisis
de Riesgos y Control de Puntos Críticos (ARCPC), y la necesidad
de adaptar el Sector al cumplimiento de las diversas normas de la serie
ISO 9000 o su equivalente EN 29000.[EN] The paper comments the different regulations related to table
olives at national or international scales. The Unified Qualitative
standard Applying to Table Olives in International Trade and
COI/Codex (International Olive Oil Council, IOC, and IOC/Codex
Alimentarius), «Reglamentación Técnico Sanitaria para la
elaboración, circulación y venta de aceitunas de mesa» (Spanish),
«Normas de calidad para la exportación de aceitunas de mesa»
(Spanish), and the United States Standards for Grades of Green
and Canned Ripe Olives (USA) are especially considered. The
effects of the new regulations on Nutritional Labelling (mainly in
USA), applications of the Analysis and Control of Critical Points
(ACCP), and the problems derived from the application of the ISO
9000, or EN 29000, to this Sector are also discussed.Peer reviewe
Variations in caffeine and chlorogenic acid contents of coffees: what are we drinking?
The effect of roasting of coffee beans and the extraction of ground coffee with different volumes of hot pressurised water on the caffeine and the total caffeoylquinic acids (CQAs) content of the resultant beverages was investigated. While caffeine was stable higher roasting temperatures resulted in a loss of CQAs so that the caffeine/CQA ratio was a good marker of the degree of roasting. The caffeine and CQA content and volume was determined for 104 espresso coffees obtained from coffee shops in Scotland, Italy and Spain, limited numbers of cappuccino coffees from commercial outlets and several instant coffees. The caffeine content ranged from 48–317 mg per serving and CQAs from 6–188 mg. It is evident that the ingestion of 200 mg of caffeine per day can be readily and unwittingly exceeded by regular coffee drinkers. This is the upper limit of caffeine intake from all sources recommended by US and UK health agencies for pregnant women. In view of the variable volume of serving sizes, it is also clear that the term “one cup of coffee” is not a reproducible measurement for consumption, yet it is the prevailing unit used in epidemiology to assess coffee consumption and to link the potential effects of the beverage and its components on the outcome of diseases. More accurate measurement of the intake of coffee and its potentially bioactive components are required if epidemiological studies are to produce more reliable information
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