Project description:<p>Grape juice is a major source of potential health-promoting bioactive polyphenols, especially for children and those who do not consume wine. Since the subtropical climate may negatively affect the concentrations of grape polyphenols, especially anthocyanins, elicitors such as methyl jasmonate (MeJa) could be used to promote polyphenol biosynthesis. This work aimed at investigating the impact of MeJa treatment on grape juice produced <em>via</em> a traditional low-cost process from two <em>Vitis labrusca</em> cultivars and in two Brazilian regions. The untargeted LC-MS analytical protocol demonstrated that Isabel Precoce juices strongly benefited from MeJa treatment, especially regarding their anthocyanic profile, regardless of the cultivation region. Known MeJa markers in wine and <em>V. vinifera</em> grapes (flavanols, flavonols and stilbenes) in this experiment had mixed behaviours depending on the region/variety/cultivation. Moreover, it was found that all the detected hydroxycinnamates were influenced by the treatment, especially the concentration of their glucosides, which was increased. Glutathione, 2-S-glutathionyl caftaric acid and indole lactic acid glucoside were identified for the first time as MeJa treatment biomarkers in grape products, indicating a possible positive effect on juice antioxidant properties.</p>
Project description:Drought represents a significant stress to microorganisms and is known to reduce microbial activity and organic matter decomposition in Mediterranean ecosystems. However, we lack a detailed understanding of the drought stress response of microbial decomposers. Here we present metatranscriptomic data on the physiological response of in situ microbial communities on plant litter to long-term drought in Californian grass and shrub ecosystems.
Project description:By an evolutionary approach based on long-term culture on gluconate as the sole carbon source, a Saccharomyces cerevisiae wine strains with enhanced flux through the pentose phosphate (PP) pathway were obtained. One of these evolved strains, ECA5, exhibited several novel properties with great potential for wine making, including a higher than wild-type fermentation rate and altered production of acetate and aroma compounds. To describe the mechanisms underlying this complex phenotype, we performed a comparative analysis of transcriptomic profiles between ECA5 and its ancestral strain, EC1118, under low nitrogen, wine fermentation conditions.
Project description:iTRAQ proteomics analysis in roots of wine grape (Beida) during overwintering have been revealed that low temperature induced differentially proteins accumulated.
Project description:iTRAQ proteomics analysis in roots of wine grape (Beida) during overwintering have been revealed that low temperature induced differentially proteins accumulated.
Project description:Grapevine (Vitis vinifera L.) is importantly cultivated worldwide for table grape and wine production. Its cultivation requires irrigation supply, especially in arid and semiarid areas. Water deficiency can affect berry and wine quality mostly depending on the extent of plant perceived stress, which is a cultivar-specific trait. We tested the physiological and molecular responses to water deficiency of two table grape cultivars, Italia and Autumn royal, and we highlighted their different adaptation. Microarray analyses revealed that Autumn royal reacts involving only 29 genes, related to plant stress response and ABA/hormone signal transduction, to modulate the response to water deficit. Instead, cultivar Italia orchestrates a very broad response (we found 1037 genes differentially expressed) that modifies the cell wall organization, carbohydrate metabolism, response to reactive oxygen species, hormones and osmotic stress. For the first time we integrated transcriptomic data with cultivar-specific genomics and found that ABA-perception and –signalling are key factors mediating the varietal-specific behaviour of the early response to drought. We were thus able to isolate candidate genes for the genotype-dependent response to drought. These insights will allow the identification of reliable plant stress indicators and the definition of sustainable cultivar-specific protocols for water management.
Project description:Microbial decomposition of soil organic carbon (SOC) in Arctic permafrost is one of the most important, but poorly understood, factors in determining the greenhouse gas feedback of tundra ecosystems to climate. Here, we examine changes in the structure of microbial communities in an anoxic incubation experiment at either –2 or 8 °C for up to 122 days using both an organic and a mineral soil collected from the Barrow Environmental Observatory in northern Alaska, USA. Soils were characterized for SOC and geochemistry, and GeoChips 5.0 were used to determine microbial community structure and functional genes associated with C availability and Fe(III) reduction.
Project description:Grape berries undergo considerable physical and biochemical changes during the ripening process. Ripening is characterized by a number of changes, including the degradation of chlorophyll, an increase in berry deformability, a rapid increase in the level of hexoses in the berry vacuole, an increase in berry volume, the catabolism of organic acids, the development of skin colour, and the formation of compounds that influence flavour, aroma, and therefore, wine quality. The aim of this work is to identify differentially expressed genes during grape ripening by microarray and real-time PCR techniques. Using a custom array of new generation, we analysed the expression of 6000 grape genes from pre-veraison to full maturity, in Vitis vinifera cultivar Muscat of Hamburg, in two different years (2006 and 2007). Five time points per year and two biological replicates per stadium were considered. To reduced intra-plant and inter-plant biological variability, for each ripening stadium we collected around hundred berries from several bunch grapes of five plants of V. vinifera cv Muscat of Hamburg. We will use the real-time PCR technique to validate microarray data.Muscat of Hamburg. We will use the real-time PCR technique to validate microarray data.
Project description:Many trees form ectomycorrhizal symbiosis with fungi. During symbiosis, the tree roots supply sugar to the fungi in exchange for nitrogen, and this process is critical for the nitrogen and carbon cycles in forest ecosystems. However, the extents to which ectomycorrhizal fungi can liberate nitrogen and modify the soil organic matter and the mechanisms by which they do so remain unclear since they have lost many enzymes for litter decomposition that were present in their free-living, saprotrophic ancestors. Using time-series spectroscopy and transcriptomics, we examined the ability of two ectomycorrhizal fungi from two independently evolved ectomycorrhizal lineages to mobilize soil organic nitrogen. Both species oxidized the organic matter and accessed the organic nitrogen. The expression of those events was controlled by the availability of glucose and inorganic nitrogen. Despite those similarities, the decomposition mechanisms, including the type of genes involved as well as the patterns of their expression, differed markedly between the two species. Our results suggest that in agreement with their diverse evolutionary origins, ectomycorrhizal fungi use different decomposition mechanisms to access organic nitrogen entrapped in soil organic matter. The timing and magnitude of the expression of the decomposition activity can be controlled by the below-ground nitrogen quality and the above-ground carbon supply.
Project description:Noble rot results from atypical infections of ripe grape berries by Botrytis cinerea. Unlike bunch rot, noble rot promotes favorable changes in grape berries and accumulation of secondary metabolites that enhance wine grape quality. Noble rot-infected berries of Sémillon, a white-skinned variety, were collected over three years from a commercial vineyard at the same time fruit were harvested for botrytized wine production. Transcriptomic and metabolomic data were integrated to identify pathways associated with distinct stages of noble rot. Botrytis induced the expression of known key regulators of pathways in secondary metabolism associated with berry ripening. The activation by Botrytis during noble rot of metabolic pathways associated with berry ripening was further supported by comparisons with transcriptomes of red-skinned varieties at véraison. A prominent and common outcome of noble rot and berry ripening was the enhancement of the phenylpropanoid metabolism. Induced synthesis of stilbenes, flavonoids, and anthocyanins was supported by both transcriptional and metabolite analyses. Enzyme assays and targeted gene expression analyses of samples from the three distinct years confirmed that the activation of central and peripheral phenylpropanoid pathways is a consistent hallmark of noble rot. Finally, we show that the impact of noble rot on grape metabolism is still detectable in botrytized wines. These results demonstrate that despite the late stage of terminal senescence of a plant organ, a biotic stress can cause a major reprogramming of plant metabolism leading, in case of noble rot, to the synthesis of important metabolites for grape berry flavor and aroma.