Proteome changes in Garnacha Tintorera red grapes during post-harvest drying

Grapevine bZIP transcription factor bZIP45 regulates VvANN1 and confers drought tolerance in Arabidopsis

Drought is a severe environmental condition that restricts the vegetative growth and reduces the yield of grapevine (Vitis vinifera L.). However, the mechanisms underlying grapevine response and adaptation to drought stress remain unclear. In the present study, we characterized an ANNEXIN gene, VvANN1, which plays a positive role in the drought stress response. The results indicated that VvANN1 was significantly induced by osmotic stress. Expression of VvANN1 in Arabidopsis thaliana enhanced osmotic and drought tolerance through modulating the level of MDA, H₂O₂, and O₂ ^·- at the seedling stage, implying that VvANN1 might be involved in the process of ROS homeostasis under drought or osmotic stress conditions. Moreover, we used yeast one-hybridization and chromatin immunoprecipitation assays to show that VvbZIP45 could regulate VvANN1 expression by directly binding to the promoter region of VvANN1 in response to drought stress. We also generated transgenic Arabidopsis that constitutively expressed the VvbZIP45 gene (35S::VvbZIP45) and further produced VvANN1Pro::GUS/35S::VvbZIP45 Arabidopsis plants via crossing. The genetic analysis results subsequently indicated that VvbZIP45 could enhance GUS expression in vivo under drought stress. Our findings suggest that VvbZIP45 may modulate VvANN1 expression in response to drought stress and reduce the impact of drought on fruit quality and yield.

A new design for obtaining of white zein micro- and nanoparticles powder: antisolvent-dialysis method

The objective of this work was propose antisolvent-dialysis as a new, easy, one-step and reproducible method for obtaining white zein micro- and nanoparticles powder. Firstly, the study by SEM of white zein powder predicted micro- and nanoparticles with spherical morphology and average diameters of 243.2 ± 94.5 nm for nanoparticles and 0.74 ± 0.2 μm for microparticles. UV-Vis predicted lower absorbance of 250-500 nm for white zein powder compared to commercial yellow zein powder. FT-IR showed shifting of the main bands to the right, due to changes in particle-shaped microstructure that acquires white zein powder compared to yellow zein powder. In TGA white zein powder showed a decomposition range from 214 to 400 °C, while yellow zein powder from 240 to 400 °C. Therefore, antisolvent-dialysis is new method to obtain white zein micro- and nanoparticles with potential applications such as polymer matrix and white natural coloring.

Analysis of proteomic responses of freeze-dried Oenococcus oeni to access the molecular mechanism of acid acclimation on cell freeze-drying resistance

Malolactic fermentation (MLF), usually induced by Oenococcus oeni (O. oeni), is an important process to improve wine quality. Acid acclimation has been proven to be useful for enhancing the viability of lyophilized O. oeni. To explain the involved mechanisms, cell integrity, morphology and protein patterns of lyophilized O. oeni SD-2a were investigated with acid acclimation. After lyophilization, improvement of cell integrity and more extracellular polymeric substances (EPS) were observed in acid acclimated cells. Combined with GO and KEGG analysis, different abundant proteins were noticeably enriched in the carbohydrate metabolism process, especially amino sugar and nucleotide sugar metabolism. The most significant result was the over-expression of proteins participating in cell wall biosynthesis, EPS production, ATP binding and the bacterial secretion system. This result indicated the important role of acid acclimation on cell envelope properties. In addition, protein response to stress and arginine deiminase pathway were also proven to be over-expressed.

Metabolic Profiling and Post-harvest Behavior of "Dottato" Fig (Ficus carica L.) Fruit Covered With an Edible Coating From O. ficus-indica

Fig fruits are usually highly sensitive to some physiopathological disorders during post-harvest life, such as softening and skin cracking. Indeed, the use of edible coating (EC) has been evaluated in several fruit crops to reduce fruit post-harvest transpiration and to maintain fruit visual quality. The aim of this study was to determine the post-harvest metabolic response of breba figs treated with mucilage extract from O puntia ficus-indica cladodes, using an untargeted metabolomic approach. Coated and non-coated (control) fruit were sealed in plastic bags, and stored at 4°C for 7 days. The effect of the ECs on their quality fruit during cold storage and qualitative attributes were evaluated by analyzing the fruit primary metabolism and other qualitative parameters such as total soluble solids (TSS) content, titratable acidity (TA), fresh weight loss and firmness. Results underlined that EC was effective in maintaining fruit fresh weight, and fruit firmness. Stepwise discriminant analysis was able to discriminate fruit conditions. Alanine, xylulose, aspartic acid, glutamic, acid and 2,5-dihydroxypyrazine showed a significant role on discriminating edible coated fruit from untreated ones. Principal component analysis (PCA) was able to highlight clear differences in the overall metabolism changes between untreated and treated fruit. The application of EC significantly mitigated the decrease of most of the aminoacid content during cold storage. EC treatment caused the changes of several organic acids in comparison to untreated control, increasing the amount of carbohydrates and other key metabolites, such as beta-sitosterol, glycerol, and uracil. These results clearly showed the drastic effects of EC on fig metabolism during post-harvest and shed light on the beneficial mechanisms of this treatment.