Optimized protocol for high-quality RNA extraction from grape tissues using sorbitol pre-wash

Malolactic fermentation (MLF) is a desired process in red and acidic white wines, after alcoholic fermentation (AF), carried out by the lactic acid bacterium (LAB) Oenococcus oeni. The advantages are an increase of pH, microbiological stabilization and organoleptic improvement of the final wine. However, the presence of stress factors such as ethanol, low pH, high total SO2, lack of nutrients and presence of inhibitors, could affect the successful completion of MLF [1]. Changes in amino acid composition and deficiencies in peptides after AF, showed that MLF can be delayed, signaling its importance for bacterial growth and L-malic acid degradation during MLF [2].

Proteins constitute one of the three main components of grape juice and white wine, phenolic compounds and polysaccharides being the others. A specific group of the total grape-derived proteins resists degradation or adsorption during the winemaking process and remains in finished wine if not removed by the commonplace commercial practice of bentonite fining. While bentonite is effective in removing the problematic proteins, it is claimed to adversely affect the quality of the treated wine under certain conditions, through the removal of colour, flavor and texture compounds. A number of studies have indicated that different protein fractions require distinct bentonite concentrations for protein removal and consequent heat stabilization.

The Columbia Gorge Wine Region (CGWR) extends for about 100km along the Columbia River and includes the Columbia Gorge American Viticultural Area (AVA) and the southwest portion of the Columbia Valley AVA.

Soil management through cover crops in the lines of the vineyards is a common practice in viticulture, since it improves the characteristics of the soil. It has been shown that the cover crops can influence the cycle of nutrients, promote infiltration, decrease erosion, and enhance the soil microbiota biodiversity improving the grapevines. However, the area under the vines tends to be left bare by applying herbicides or tillage to avoid competition with the crop in hot climates. The use of cover crops under the vines might be a plausible alternative to the use of herbicides or cultivation, improving grapevine quality and soil characteristics. The aim of this research was to study the implications of different management of the soil under the vines (herbicide, cultivation or cover crops) on grapevine growth, water and nutritional status and belowground microbial communities.

The classical pharmacological model assumes that the effect of a drug is proportional to the fraction of receptors occupied by the drug. In the simplest circumstances, the relationship between dose of a drug and response, when plotted on a logarithmic scale for drug concentration, is described by a sigmoidal curve. It presumes the existence of a threshold dose, below which no biological effect appears, and a maximal response in the form of a plateau, when a further increase in the dose of drug has no effect.