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

Oenococcus oeni is the main lactic acid bacteria (LAB) species which conducts the malolactic fermentation (MLF) in wine. During MLF, O. oeni converts malic acid into lactic acid, which modulates wine aroma composition leading to better balanced organoleptic properties. O. oeni is a highly specialized species only detected in environments containing alcohol such as wine, cider or kombucha. Genome analysis of more than 240 strains showed that they form at least 4 main phylogenetic lineages and several sublineages, which are associated with different beverages or types of wines.

Wine acidity is a parameter of great importance that influences different quality factors of the product such as biological stability or organoleptic characteristics. In the current context of climate change, which gives rise to wines with higher levels of ethanol and lower acidity, the biological acidification with yeast species such as Lachancea thermotolerans could be a solution.
In this work, the effect of the inoculation of different L. thermotolerans on the acidity of wine was studied.

Úbeda-Aguilera, C a, b, Peña-Neira, A.b Del Barrio-Galán, R.b, c a Biomedical Sciences Institute, Science Faculty, Universidad Autónoma de Chile, Chile. b Department of Agro-Industry and Enology, Faculty of Agronomical Sciences, University of Chile, Post Office Box 1004, Santa Rosa 11315, La Pintana, Santiago, Chile c Lallemand Inc. Chile y Compañía Limitada, Rosario Norte 407, piso 6, Las Condes, Santiago, Chile The wine is a complex matrix made up of several compounds which can interact among themselves throughout the wine ageing process, thereby modifying their sensorial characteristics. It is well known that during ageing of wines on lees, polysaccharides (mainly mannoproteins) can be released and can interact with the aromatic fraction modifying its volatility.

Carbaryl is an acetylcholine esterase inhibitor-type insecticide used for pest control on grapevine. We repeatedly observed the occurrence of interveinal leaf necrosis following carbaryl spray application in a Vitis rupestris x Vitis riparia F1 hybrid progeny vineyard. Spray applications induced necrosis in this progeny under both Missouri and New York field conditions an approximate one-to-one sensitive-to-insensitive segregation ratio and with 42% concordance. Results of subsequent in vitro experiments established causality between carbaryl treatment and leaf necrosis and confirmed the pattern of segregation observed in the field. We consistently map this phenotype to a major QTL on chromosome 16 of the female parent V. rupestris ‘B38’ regardless of whether we used field or in vitro-generated phenotype data.

Trunk diseases and esca in particular, represent a major threat to the sustainability of the vineyards. The percentages of unproductive vines in a plot could vary from 4% to over 20 % depending on local conditions and vintages.