The localisation of acids, sugars, potassium and calcium in developing grape berries

Grape berries (Vitis vinifera cv. Chardonnay) were divided into four concentric zones in order to follow the developmental changes in the concentrations of malate, tartrate, glucose, fructose, potassium and calcium within the skin and the fruit flesh. Green berries showed a definite malate gradient, increasing in concentration from the skin towards the seeds; tartaric acid, on the other hand, was highest in concentration at the periphery and lowest in the berry center. With progressing maturity, the ratio between the tartrate concentration in the skin and the corresponding values in the berry core decreased, whereas the reverse was true for malate. In the ripe berry an acid gradient could also be found in the axial direction, decreasing from the pedicel towards the stylar scar. Before the onset of ripening, the highest glucose and fructose concentrations were observed in the skin and the berry center. The accumulation of these sugars in the pulp began without any apparent lag phase at a rate of about 2 mg/ berry · d. After veraison, the highest concentrations were found in the fruit core and the tissue below the peripheral vascular bundles. Both potassium and calcium were mainly localized near the peripheral and central vascular bundles. The potassium content increased during the entire period of berry development at a constant rate of 0.04 mg/berry · d, whereas calcium accumulation stopped about 30 d after anthesis. At this time, the calcium content was approximately 0.1 mg/berry

Bounding global aerosol radiative forcing of climate change

Aerosols interact with radiation and clouds. Substantial progress made over the past 40 years in observing, understanding, and modeling these processes helped quantify the imbalance in the Earth's radiation budget caused by anthropogenic aerosols, called aerosol radiative forcing, but uncertainties remain large. This review provides a new range of aerosol radiative forcing over the industrial era based on multiple, traceable, and arguable lines of evidence, including modeling approaches, theoretical considerations, and observations. Improved understanding of aerosol absorption and the causes of trends in surface radiative fluxes constrain the forcing from aerosol-radiation interactions. A robust theoretical foundation and convincing evidence constrain the forcing caused by aerosol-driven increases in liquid cloud droplet number concentration. However, the influence of anthropogenic aerosols on cloud liquid water content and cloud fraction is less clear, and the influence on mixed-phase and ice clouds remains poorly constrained. Observed changes in surface temperature and radiative fluxes provide additional constraints. These multiple lines of evidence lead to a 68% confidence interval for the total aerosol effective radiative forcing of -1.6 to -0.6 W m−2, or -2.0 to -0.4 W m−2 with a 90% likelihood. Those intervals are of similar width to the last Intergovernmental Panel on Climate Change assessment but shifted toward more negative values. The uncertainty will narrow in the future by continuing to critically combine multiple lines of evidence, especially those addressing industrial-era changes in aerosol sources and aerosol effects on liquid cloud amount and on ice clouds

Berry Flesh and Skin Ripening Features in Vitis vinifera as Assessed by Transcriptional Profiling

Background Ripening of fleshy fruit is a complex developmental process involving the differentiation of tissues with separate functions. During grapevine berry ripening important processes contributing to table and wine grape quality take place, some of them flesh- or skin-specific. In this study, transcriptional profiles throughout flesh and skin ripening were followed during two different seasons in a table grape cultivar ‘Muscat Hamburg’ to determine tissue-specific as well as common developmental programs. Methodology/Principal Findings Using an updated GrapeGen Affymetrix GeneChip® annotation based on grapevine 12×v1 gene predictions, 2188 differentially accumulated transcripts between flesh and skin and 2839 transcripts differentially accumulated throughout ripening in the same manner in both tissues were identified. Transcriptional profiles were dominated by changes at the beginning of veraison which affect both pericarp tissues, although frequently delayed or with lower intensity in the skin than in the flesh. Functional enrichment analysis identified the decay on biosynthetic processes, photosynthesis and transport as a major part of the program delayed in the skin. In addition, a higher number of functional categories, including several related to macromolecule transport and phenylpropanoid and lipid biosynthesis, were over-represented in transcripts accumulated to higher levels in the skin. Functional enrichment also indicated auxin, gibberellins and bHLH transcription factors to take part in the regulation of pre-veraison processes in the pericarp, whereas WRKY and C2H2 family transcription factors seems to more specifically participate in the regulation of skin and flesh ripening, respectively. Conclusions/Significance A transcriptomic analysis indicates that a large part of the ripening program is shared by both pericarp tissues despite some components are delayed in the skin. In addition, important tissue differences are present from early stages prior to the ripening onset including tissue-specific regulators. Altogether, these findings provide key elements to understand berry ripening and its differential regulation in flesh and skin.This study was financially supported by GrapeGen Project funded by Genoma España within a collaborative agreement with Genome Canada. The authors also thank The Ministerio de Ciencia e Innovacion for project BIO2008-03892 and a bilateral collaborative grant with Argentina (AR2009-0021). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewe

Real-case simulations of aerosol–cloud interactions in ship tracks over the Bay of Biscay

Ship tracks provide an ideal test bed for studying aerosol–cloud interactions (ACIs) and for evaluating their representation in model parameterisations. Regional modelling can be of particular use for this task, as this approach provides sufficient resolution to resolve the structure of the produced track including their meteorological environment whilst relying on the same formulations of parameterisations as many general circulation models. In this work we simulate a particular case of ship tracks embedded in an optically thin stratus cloud sheet which was observed by a polar orbiting satellite at 12:00 UTC on 26 January 2003 around the Bay of Biscay. <br><br> The simulations, which include moving ship emissions, show that the model is indeed able to capture the structure of the track at a horizontal grid spacing of 2 km and to qualitatively capture the observed cloud response in all simulations performed. At least a doubling of the cloud optical thickness was simulated in all simulations together with an increase in cloud droplet number concentration by about 40 cm^&minus;3 (300%) and decrease in effective radius by about 5 <abbr>μm</abbr> (40%). Furthermore, the ship emissions lead to an increase in liquid water path in at least 25% of the track regions. <br><br> We are confident in the model's ability to capture key processes of ship track formation. However, it was found that realistic ship emissions lead to unrealistic aerosol perturbations near the source regions within the simulated tracks due to grid-scale dilution and homogeneity. <br><br> Combining the regional-modelling approach with comprehensive field studies could likely improve our understanding of the sensitivities and biases in ACI parameterisations, and could therefore help to constrain global ACI estimates, which strongly rely on these parameterisations

The structure of Ktr4p.

<p>Panel A shows the structure of Ktr4p in complex with GDP and Mn²⁺. α-helices are coloured in green, 3₁₀-helices in black and β-strands in orange, and all secondary structure elements are numbered. The GDP is shown in ball-and-stick representation, as are the cysteines forming disulfide-bonds. Panel B shows a cartoon representation of Ktr4p coloured by its subdomains. The two N-terminal helices (in light green) are bridging over the C-terminal subdomain (orange) and connecting to the N-terminal subdomain (dark green). Panel C shows the Ktr4p structure (green) superimposed on that of the homologous Kre2p/Mnt1p (grey).</p

Similarity in the active sites of Kre2p/Mnt1p and Ktr4p.

<p>All residues within 5Å of either GDP, Mn²⁺ or methyl-α-mannose are included in the figure and are depicted as lines in green (Ktr4p) or yellow (Mnt1p), while the ligands are depicted as sticks. Residue labels correspond to Ktr4p. Superposition was performed using all C-α atoms of the chain.</p

Data collection and refinement statistics.

<p>Values in parentheses are statistics for the highest resolution shell.</p><p></p><p></p><p></p><p></p><p><mi>R</mi><mo>=</mo></p><p></p><p></p><p></p><p><mo>∑</mo></p><p><mi>h</mi><mi>k</mi><mi>l</mi></p><p></p><p><mo>|</mo></p><p></p><p><mi>F</mi></p><p><mi>o</mi><mi>b</mi><mi>s</mi></p><p></p><p><mo>(</mo></p><p><mi>h</mi><mi>k</mi><mi>l</mi></p><mo>)</mo><p></p><mo>−</mo><p><mi>F</mi></p><p><mi>c</mi><mi>a</mi><mi>l</mi><mi>c</mi></p><p></p><p><mo>(</mo></p><p><mi>h</mi><mi>k</mi><mi>l</mi></p><mo>)</mo><p></p><p></p><mo>|</mo><p></p><p></p><p></p><p></p><p><mo>∑</mo></p><p><mi>h</mi><mi>k</mi><mi>l</mi></p><p></p><p><mi>F</mi></p><p><mi>o</mi><mi>b</mi><mi>s</mi></p><p></p><p><mo>(</mo></p><p><mi>h</mi><mi>k</mi><mi>l</mi></p><mo>)</mo><p></p><p></p><p></p><p></p><p></p><p></p><p></p><p></p><p></p><p></p><p></p><p><mi>R</mi></p><p><mi>m</mi><mi>e</mi><mi>r</mi><mi>g</mi><mi>e</mi></p><p></p><mo>=</mo><p></p><p></p><p></p><p><mo>∑</mo></p><p><mi>h</mi><mi>k</mi><mi>l</mi></p><p></p><p></p><p><mo>∑</mo></p><p><mi>i</mi><mo>=</mo><mn>1</mn></p><mi>n</mi><p></p><p><mo>|</mo></p><p></p><p><mi>I</mi><mi>i</mi></p><p><mo>(</mo></p><p><mi>h</mi><mi>k</mi><mi>l</mi></p><mo>)</mo><p></p><mo>−</mo><p><mi>I</mi><mo>¯</mo></p><p><mo>(</mo></p><p><mi>h</mi><mi>k</mi><mi>l</mi></p><mo>)</mo><p></p><p></p><mo>|</mo><p></p><p></p><p></p><p></p><p><mo>∑</mo></p><p><mi>h</mi><mi>k</mi><mi>l</mi></p><p></p><p></p><p><mo>∑</mo></p><p><mi>i</mi><mo>=</mo><mn>1</mn></p><mi>n</mi><p></p><p><mi>I</mi><mi>i</mi></p><p><mo>(</mo></p><p><mi>h</mi><mi>k</mi><mi>l</mi></p><mo>)</mo><p></p><p></p><p></p><p></p><p></p><p></p><p></p><p></p><p>Data collection and refinement statistics.</p

Activity of Ktr4p.

<p>The enzyme is active using methyl-α-mannoside (■) as acceptor substrate, and the signal observed using α-1,2-mannobiose (♦) and D-mannose (▲), respectively, is comparable to the background reading in the absence of acceptor substrate (+). The blank reading, measured in the absence of enzyme, has been deducted from all experimental readings.</p

A surface representation of Ktr4p, showing the shape and position of the substrate-binding cavity.

<p>The surface is coloured by electrostatic potential, as calculated using PyMol, and the GDP and Mn²⁺ of the complex structure are added in ball-and-stick representation to indicate the location of the active site.</p