49 research outputs found
Solar ultraviolet radiation is necessary to enhance grapevine fruit ripening transcriptional and phenolic responses
Background: Ultraviolet (UV) radiation modulates secondary metabolism in the skin of Vitis vinifera L. berries, which affects the final composition of both grapes and wines. The expression of several phenylpropanoid biosynthesis-related genes is regulated by UV radiation in grape berries. However, the complete portion of transcriptome and ripening processes influenced by solar UV radiation in grapes remains unknown.Results: Whole genome arrays were used to identify the berry skin transcriptome modulated by the UV radiation received naturally in a mid-altitude Tempranillo vineyard. UV radiation-blocking and transmitting filters were used to generate the experimental conditions. The expression of 121 genes was significantly altered by solar UV radiation. Functional enrichment analysis of altered transcripts mainly pointed out that secondary metabolism-related transcripts were induced by UV radiation including VvFLS1, VvGT5 and VvGT6 flavonol biosynthetic genes and monoterpenoid biosynthetic genes. Berry skin phenolic composition was also analysed to search for correlation with gene expression changes and UV-increased flavonols accumulation was the most evident impact. Among regulatory genes, novel UV radiation-responsive transcription factors including VvMYB24 and three bHLH, together with known grapevine UV-responsive genes such as VvMYBF1, were identified. A transcriptomic meta-analysis revealed that genes up-regulated by UV radiation in the berry skin were also enriched in homologs of Arabidopsis UVR8 UV-B photoreceptor-dependent UV-B -responsive genes. Indeed, a search of the grapevine reference genomic sequence identified UV-B signalling pathway homologs and among them, VvHY5-1, VvHY5-2 and VvRUP were up-regulated by UV radiation in the berry skin.Conclusions: Results suggest that the UV-B radiation-specific signalling pathway is activated in the skin of grapes grown at mid-altitudes. The biosynthesis and accumulation of secondary metabolites, which are appreciated in winemaking and potentially confer cross-tolerance, were almost specifically triggered. This draws attention to viticultural practices that increase solar UV radiation on vineyards as they may improve grape features. © 2014 Carbonell-Bejerano et al.; licensee BioMed Central Ltd
Propagation of Rayleighs waves in cracked media
Este trabajo está enfocado a la obtención de resultados numéricos que permitan la detección y caracterización de grietas sub-superficiales en sólidos mediante la incidencia de ondas elásticas de Rayleigh. Los resultados se obtienen a partir de ecuaciones integrales de frontera, que pertenecen al campo de la elastodinámica. Una vez que se aplican las condiciones de frontera se obtiene un sistema de ecuaciones integrales del tipo Fredholm de segunda especie y orden cero, el cual es resuelto mediante eliminación gaussiana. El método que se emplea para la discretización de dichas ecuaciones es conocido como «método indirecto de elementos frontera», el cual puede ser visto como una derivación del teorema clásico de Somigliana. A partir de los análisis realizados en el dominio de la frecuencia emergen picos de resonancia que permiten inferir la presencia de grietas mediante los cocientes espectrales. Se analizaron varios modelos de medios agrietados donde se pretende evidenciar la gran utilidad que presenta el uso de los cocientes espectrales para identificar grietas. Se estudiaron los efectos de la orientación y la localización de las grietas. Los resultados obtenidos presentan buena concordancia con los publicados previamente.This work is focused on the finding of numerical results for detection and characterization of sub-surface cracks in solids under the incidence of Rayleighs elastic waves. The results are obtained from boundary integral equations, which belong to the field of dynamics of elasticity. Once applied the boundary conditions, a system of Fredholms integral equations of second kind and zero order is obtained, which is solved using Gaussian elimination. The method that is used for the solution of such integral equations is known as the Indirect Boundary Element Method, which can be seen as a derivation of the Somiglianas classic theorem. On the basis of the analysis made in the frequency domain, resonance peaks emerge and allow us to infer the presence of cracks through the spectral ratios. Several models of cracked media were analyzed, where analyses reveal the great utility that displays the use of spectral ratios to identify cracks. We studied the effects of orientation and location of cracks. The results show good agreement with the previously published.Peer Reviewe
Biomonitoring of metal deposition in northern Spain by moss analysis
The results of the first survey carried out in northern Spain to determine atmospheric deposition of metals by
analysis of terrestrial mosses, are described. Samples of different mosses, mainly Hypnum cupressiforme and
Scleropodium purum, were collected from 134 sampling sites, between 1995 and 1996. Levels of Al, As, Cr, Cu, Fe,
Hg, Ni, Pb and Zn, were determined by flame atomic absorption or atomic fluorescence spectrophotometry. Regression
analysis was used to compare the capacity of the selected moss species to accumulate the elements, and intercalibration
of accumulation in these species was carried out where necessary. Distribution maps were prepared to allow the zones
most affected by metal deposition to be identified and to relate this to known sources of contamination: electricity
power stations and other industries (e.g. Hg and Ni), edaphic contamination (e.g. Al and Cr) and road traffic (Pb).
Background levels of metals in each species were also determined for the study area
Modelling spatial patterns of correlations between concentrations of heavy metals in mosses and atmospheric deposition in 2010 across Europe
BackgroundThis paper aims to investigate the correlations between the concentrations of nine heavy metals in moss and atmospheric deposition within ecological land classes covering Europe. Additionally, it is examined to what extent the statistical relations are affected by the land use around the moss sampling sites. Based on moss data collected in 2010/2011 throughout Europe and data on total atmospheric deposition modelled by two chemical transport models (EMEP MSC-E, LOTOS-EUROS), correlation coefficients between concentrations of heavy metals in moss and in modelled atmospheric deposition were specified for spatial subsamples defined by ecological land classes of Europe (ELCE) as a spatial reference system. Linear discriminant analysis (LDA) and logistic regression (LR) were then used to separate moss sampling sites regarding their contribution to the strength of correlation considering the areal percentage of urban, agricultural and forestry land use around the sampling location. After verification LDA models by LR, LDA models were used to transform spatial information on the land use to maps of potential correlation levels, applicable for future network planning in the European Moss Survey.ResultsCorrelations between concentrations of heavy metals in moss and in modelled atmospheric deposition were found to be specific for elements and ELCE units. Land use around the sampling sites mainly influences the correlation level. Small radiuses around the sampling sites examined (5km) are more relevant for Cd, Cu, Ni, and Zn, while the areal percentage of urban and agricultural land use within large radiuses (75-100km) is more relevant for As, Cr, Hg, Pb, and V. Most valid LDA models pattern with error rates of <40% were found for As, Cr, Cu, Hg, Pb, and V. Land use-dependent predictions of spatial patterns split up Europe into investigation areas revealing potentially high (=above-average) or low (=below-average) correlation coefficients.ConclusionsLDA is an eligible method identifying and ranking boundary conditions of correlations between atmospheric deposition and respective concentrations of heavy metals in moss and related mapping considering the influence of the land use around moss sampling sites
Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2
The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality
Moss communities in the irrigation channels of the river Iregua basin (La Rioja, northern Spain)
Nineteen bryophytes (all of them mosses), one alga and seven vascular plants were found in 26 irrigation channels of the river Iregua basin (La Rioja, northern Spain), a kind of aquatic environment not previously investigated regarding bryophytes. The species richness, the cover, and the Shannon's diversity (when calculated including bare soil - areas with no bryophyte - as an additional "species") of the communities were correlated negatively with the dryness period in the channels, and positively with the water flow and velocity. Hence, high values of those variables were found in refuge sites, such as the main control-gates through which the river water enters the irrigation channels, whereas low values were typical of frequently dry terminal channels. The diversity values were comparable to those found in the lower course of rivers (which might be systems equally adverse for bryophytes), but only half of those recorded for streams. In the canonical correspondence analysis (CCA), Cratoneuron filicinum and Rynchostegium riparioides prevailed in channels with a higher water availability, whereas Amblystegium riparium was dominant in channels with harder waters and slower currents. A wider spatial sampling, including different channel types and systems, would be needed to analyse the usefulness of bryophytes as bioindicators of the water quality in irrigation channels
Seasonal variations in UV-absorbing compounds and physiological characteristics in the aquatic liverwort Jungermannia exsertifolia subsp. cordifolia over a three-year period
Temporal physiological variations in relation to environmental factors, in particular to ultraviolet (UV) radiation, have been studied in bryophytes from circumpolar latitudes, but not in mid-latitudes with longer growing seasons. In addition, seasonal and interannual changes in individual UV-absorbing compounds (UVAC) have not been previously studied in bryophytes. To fill these gaps, samples of the aquatic liverwort Jungermannia exsertifolia subsp. cordifolia were collected on a monthly basis during 3 years from a mountain stream in northern Spain. Sclerophylly index, chlorophyll fluorescence, DNA damage, the bulk UV absorbance of methanolic extracts and the concentration of five UVAC (hydroxycinnamic acid derivatives) were measured. Interannual changes were little marked, probably because the 3 years studied were environmentally similar. In summer-autumn, with respect to seasonal variations, newly grown tender young shoots with high Fv/Fm accumulated higher amounts of several hydroxycinnamic acid derivatives than in winter-spring. DNA damage was not detected in any of the samples analyzed. p-Coumaroylmalic acid was the compound best associated with radiation changes, and the best model explaining UV-B took into consideration the concentration of this compound and the ozone level. The specific effects of UV radiation could not be separated from the effects caused by other environmental factors, such as global radiation or temperature, because all these variables were correlated. However, indirect evidence strongly suggests that seasonal changes in bulk UV absorbance and p-coumaroylmalic acid are mainly driven by UV radiation. This compound may be a promising physiological variable to be used for UV bioindication. Copyright © 2009 Physiologia Plantarum
Cell compartmentation of ultraviolet-absorbing compounds: An underexplored tool related to bryophyte ecology, phylogeny and evolution
Excessive exposure to ultraviolet (UV) radiation can be harmful to photosynthetic organisms, that most frequently respond with the accumulation of protective UV-absorbing compounds (UVACs). UVACs location in different cell compartments can influence their preferential protective role as antioxidants and/or UV screens. However, the phylogenetic, ecological and evolutionary implications of UVACs compartmentation has been little studied, particularly in bryophytes. We analysed UVACs in the methanol-soluble and -insoluble fractions (SUVACs and IUVACs respectively) in extracts of 87 bryophytes belonging to their three evolutionary lineages: 22 liverworts, 64 mosses and one hornwort. Assuming that the cell wall-bound IUVACs are more effective UV screens than the mainly vacuolar SUVACs, thus conferring a higher UV tolerance, we evaluated whether UVACs levels and compartmentation were related to: (1) the bryophyte phylogeny down to the Order level; and (2) the bryophyte ecological attributes, including sun exposure and Ellenberg indicator values (numerical system classifying species' habitat along gradients of environmental factors). A similar phylogenetic and ecological analysis was conducted on the sclerophylly index (the ratio between the dry mass and the surface area of the bryophyte shoot). Mosses showed lower SUVACs but higher IUVACs and total UVACs, together with higher IUVAC/SUVAC ratios, than liverworts. Thus, mosses would better tolerate UV radiation than liverworts, which matches well with their general ecological preferences. As bryophytes were the earliest diverging land plants, we could infer that the different UVACs compartmentation between mosses and liverworts could have influenced their ecological segregation upon plant land colonization. UVACs compartmentation also differed between the two major moss lineages (acrocarpous and pleurocarpous), while the anatomically peculiar Sphagnales were the best characterized Order. There were not solid relationships between UVACs and the ecological attributes considered. Hence, UVACs might be mainly constitutive in bryophytes, depending more on the species phylogeny than on the habitat occupied in nature. Liverworts were less sclerophyllous than mosses, and, as in tracheophytes, water restrictions and high sun exposures increased sclerophylly. In conclusion, UVACs compartmentation represents an ecophysiological trait useful to understand the bryophyte ecophylogeny, because different compartmentation modalities seem to imply different UV adaptations and tolerance. A plain language summary is available for this article. © 2018 British Ecological Society
Age-specific physiological responses to UV radiation in the aquatic liverwort Jungermannia exsertifolia subsp. cordifolia
In the UV-tolerant aquatic liverwort Jungermannia exsertifolia Steph. subsp. cordifolia (Dumort.) Váña, increased accumulation of certain hydroxycinnamoylmalic acid (HCM acid) derivatives has been observed under natural and artificial increases of UV radiation. We hypothesized that, under an artificial UV enhancement, the newly grown shoot apices would develop more physiological protection against UV radiation than the basal old parts. Both the UV increase and the tissue age affected the distribution of HCM acid derivatives after 82 days of culture. Two coumarins (5-(7, 8-dihydroxycoumaroyl)-2-caffeoylmalic acid, and its glucosyl derivative) significantly increased under the UV treatment, but their distribution between the apical and basal parts were opposite, where the former was more concentrated in the apical segments and the latter in the basal segments. p-Coumaroylmalic acid also showed a significant increase due to UV, and increased by the same proportion in both types of segments. In contrast, the main compound phaselic acid decreased in the apical parts under UV, whereas feruloylmalic acid only accumulated in the basal parts under UV. Physiological variables indicative of vitality, such as the maximum quantum yield of PSII (Fv/F m) and chlorophyll concentration, did not show any damage caused by the UV enhancement in the liverwort studied. The different distribution of the abovementioned compounds between apical and basal parts - together with the increase of carotenoids in the UV treatment - may indicate changes in metabolic pathways to increase photoprotection in young apical shoots. © 2008 Adac