terclim by ICS banner
IVES 9 IVES Conference Series 9 GiESCO 9 Water deficit impacts grape development without dramatically changing thiol precursor levels

Water deficit impacts grape development without dramatically changing thiol precursor levels


Context and purpose of the study – The use of new fungus disease-tolerant grapevine varieties is a long-term and promising solution to reduce chemical input in viticulture. However, little is known about the effects of water deficit (WD) on the thiol aromatic potential of new varieties coming up from breeding programs. Varietal thiols such as 3-sulfanylhexan-ol (3SH), 4-methyl-4-sulfanylpentan-2-one (4MSP) and their derivatives are powerful aromatic compounds present in wines coming from odorless precursors in grapes, and could contribute to the wine typicity of such varieties. This study aimed to characterize the fruit response of 6 new INRAE fungus disease-tolerant varieties and the Syrah control in (i) thiol precursor levels and (ii) main primary metabolites accumulation.

Material and methods – Field grown vines of 3 white (Floréal, 3159B and G5) and 3 red (Artaban, 3176N and G14) fungus disease-tolerant varieties and Syrah were individually monitored during the 2021 season. A gradient of WD was applied and followed by weekly measures of predawn water potentials. Grapes were sampled at the physiological ripe stage (phloem unloading arrest into berries). Primary metabolites (glucose, fructose, tartrate, malate and yeast assimilable nitrogen) were assessed by HPLC and enzymatic methods. Thiol precursors as S-conjugate to glutathione (G3SH and G4MSP), to cysteine (Cys3SH and Cys4MSP) and to dipeptides (CysGly3SH and g-GluCys3SH) were analyzed by LC-MS/MS using Stable Isotope Dilution Assay quantification approach.

Results – Despite genotypes showing low differences on primary metabolites concentrations, a great variability on thiol precursors levels was reported. Among all precursors only G3SH, Cys3SH and CysGly3SH were identified and quantified in all genotypes. For all genotypes, G3SH contents accounted for 75% – 100% of the thiol aromatic potential, while Cys3SH and CysGly3SH accounted for a maximum of 16% and 13%, respectively. Regardless of WD level, the concentrations of G3SH ranged from 31 µg/kg to 132 µg/kg in white varieties (G5 and Floréal respectively) and from 68 µg/kg to 466 µg/kg in red varieties (Syrah and 3176N respectively). Minor effects of WD were observed on soluble sugars, organic acids, YAN and thiol precursor concentrations expressed as µg/kg (average concentrations). However, severe WD strongly reduced all metabolites production per unit of fruit and per plant. The most impacted genotype by severe WD was Floréal, which showed reductions of 70% in primary metabolites and thiol precursors quantity per plant. The least impacted genotype regarding primary metabolites quantity per plant was 3176N (-20%) while Artaban showed the lowest reductions in thiol precursors per plant (-25%). These results showed that a severe WD ultimately reduce the production of metabolites per unit area of cultivation or plant without significantly improving the concentration of compounds of interest in the grape, potentially causing significant economic losses.


Publication date: July 5, 2023

Issue: GiESCO 2023

Type: Poster


Luciana Wilhelm de Almeida1, Laurent Torregrosa1,2, Gabriel Dournes3, Anne Pellegrino2, Hernan Ojeda1 and Aurelie Roland4

1Unité Expérimentale de Pech Rouge, INRAE, F-11430 Gruissan, France
2UMR LEPSE, Montpellier Uni, CIRAD, INRAE, Institut Agro Montpellier, 2 Place Viala, 34060 Montpellier, France
3UMT GenoVigne, IFV, INRAE, Institut Agro Montpellier, 2 Place Viala, 34060 Montpellier, France
4SPO, Univ Montpellier, INRAE, Institut Agro, Montpellier 34060, France

Contact the author*


water deficit, thiol precursors, resistant varieties, YAN


GiESCO | GIESCO 2023 | IVES Conference Series


Related articles…


Climate change has brought several impacts that are becoming increasingly intense during the last few years and put at risk the quality of the berries or even the plant’s sustainability. Such extreme climatic events impact the composition of the wine while modulating its quality and the consumer preferences (Tempère et al., 2019). The three most important changes that take place in the must are: 1) decrease acidity, 2) increase of the concentration of sugar, hence increase of alcohol in the wine, and 3) modification
of the sensory balance and the development for example of cooked fruit aromas.


In Italy, in the past two decades, the rate of temperature increases (0.0369 °C per year) was slightly higher compared to the world average (0.0313 °C per year). It has also been indicated that the number and intensity of heat waves have increased considerably in the last decades. (IEA, 2022). Viticultural zones can be classified with climatic indexes. Huglin’s index (HI) considers the temperature in a definite area and has been considered as reliable to evaluate the thermal suitability for winegrape production (Zhang et al., 2023).

A synthesis approach on the impact of elevated CO2 on berry physiology and yield of Vitis vinifera

Besides the increase in global mean temperature the second main challenge of a changing climate is the increase in atmospheric carbon dioxide (CO2) in relation to physiology and yield performance of grapevines. The benefits of increasing CO2 levels under greenhouse environment or open field studies have been well investigated for various annual crops. Research under free carbon dioxide enrichment on field-grown perennial plants such as grapevines is limited to a few studies. Further, chamber and greenhouse experiments have been conducted mostly on potted vines under eCO2 conditions.

Microbial ecosystems in wineries – molecular interactions between species and modelling of population dynamics

Microbial ecosystems are primary drivers of viticultural, oenological and other cellar-related processes
such as wastewater treatment. Metagenomic datasets have broadly mapped the vast microbial species
diversity of many of the relevant ecological niches within the broader wine environment, from vineyard
soils to plants and grapes to fermentation. The data highlight that species identities and diversity
significantly impact agronomic performance of vineyards as well as wine quality, but the complexity
of these systems and of microbial growth dynamics has defeated attempts to offer actionable
tools to guide or predict specific outcomes of ecosystem-based interventions.

Searching for the sweet spot: a focus on wine dealcoholization

It is well known that the vinification of grapes at full maturation can produce rich, full-bodied wines,
with intense and complex flavour profiles. However, the juice obtained from such grapes may have very
high sugar concentration, resulting in wines with an excessive concentration of ethanol. In addition, the decoupling between technological maturity and phenolic/aromatic one due to global warming, exacerbates this problem in some wine-growing regions. In parallel with the increase of the mean alcohol content of wines on the market, also the demand for reduced alcohol beverages has increased in recent years, mainly as a result of health and social concerns about the risks related to the consumption of alcohol.