terclim by ICS banner
IVES 9 IVES Conference Series 9 International Congress on Grapevine and Wine Sciences 9 2ICGWS-2023 9 Time vs drought: leaf age rather than drought drives osmotic adjustment in V. vinifera cv. Pinot Noir

Time vs drought: leaf age rather than drought drives osmotic adjustment in V. vinifera cv. Pinot Noir

Abstract

Global warming and increased frequency and/or severity of drought events are among the most threatening consequences of climate change for agricultural crops. In response to drought, grapevine (as many other plants) exhibits osmotic adjustment through active accumulation of osmolytes which in turn shift the leaf turgor loss point (TLP) to more negative values, allowing to maintain stomata opened at lower water potentials1. We investigated the capacity of Pinot noir leaves to modulate their osmotic potential as a function of: (i) time (seasonal osmoregulation), (ii) growing temperatures, and (iii) drought events, to enhance comprehension of the resilience of grapevines in drought conditions. We performed trails under semi-controlled field conditions, and in two different greenhouse chambers (20/15 °C vs 25/20 °C day/night). For two consecutive vegetative seasons, grafted potted grapevines (Pinot noir/SO4) were subjected to two different water regimes for at least 30 days: well-watered (WW) and water deficit (WD). Via pressure-volume (PV) curves and osmometer measurements we derived the leaf osmotic adjustment capability and TLP, while monitoring the plant gas exchange and water potential. Surprisingly, lower water potentials in WD vines throughout the season and in all situations (field and greenhouse) did not trigger osmoregulation, changes in TLP nor a modification of the modulus of elasticity. PV curves provided clear evidence that both temperature and water availability do not stimulate active osmotic adjustment in Vitis vinifera cv. Pinot Noir. Conversely, there is a clear impact of seasonal osmoregulation throughout the growing season2, decreasing the osmotic potential at full turgor by an average of 0.46 MPa in 90 days. Lack of osmotic adjustment in response to drought observed in this cultivar suggests Vitis genotypes have a broad spectrum of responses to drought and the strategy adopted to cope with it is highly dependent on the cultivar under analysis.

Acknowledgements:

The work was financially supported by the Austrian Science Fund (FWF): I 4848 “PlasticGrape”.

References:

1)  Bartlett, M. K., Scoffoni, C., & Sack, L. (2012). The determinants of leaf turgor loss point and prediction of drought tolerance of species and biomes: a global metaanalysis. Ecology letters15(5), 393-405.

2)  Herrera, J. C., Calderan, A., Gambetta, G. A., Peterlunger, E., Forneck, A., Sivilotti, P., … & Hochberg, U. (2022). Stomatal responses in grapevine become increasingly more tolerant to low water potentials throughout the growing season. The Plant Journal109(4), 804-815.

DOI:

Publication date: October 3, 2023

Issue: ICGWS 2023

Type: Article

Authors

Elena Farolfi1*, Francesco Flagiello2, Federica De Berardinis1, Soma Laszlo Tarnay1, Jan Reščič3, Astrid Forneck1, Jose Carlos Herrera1

1University of Natural Resources and Life Sciences, Vienna, Department of Crop Sciences, Institute of Viticulture and Pomology, 3430 Tulln an der Donau, Austria
2University of Natural Resources and Life Sciences, Vienna, Department of Crop Sciences, Institute of agronomy, 3430 Tulln an der Donau, Austria
3University of Nova Gorica, School for Viticulture and Enology, Dvorec Lanthieri/Lanthieri Mansion Glavni trg 8, 5271 Vipava, Slovenia

Contact the author*

Keywords

grapevine, drought, osmotic adjustment, osmoregulation, turgor loss point

Tags

2ICGWS | ICGWS | ICGWS 2023 | IVES Conference Series

Citation

Related articles…

Grapevine adaptation to drought and resistance to Neofusicoccum parvum, causal agent of Botryosphaeria dieback

The sustainability of viticulture in response to climate change has been addressed mainly considering agronomic impacts, such as water management and diseases, either separately or together.
In grapevines, there is strong evidence that different genotypes respond differently to biotic and abiotic stresses. A screening was conducted on various local cultivars in response to drought and Neofusicoum parvum infection aiming to evaluate their susceptibility to abiotic stress and resistance to fungal diseases.

Sugar accumulation disorder Berry Shrivel – from current knowledge towards novel hypothesis

In contrast to fruit and grape berry ripening, the biological processes causing ripening disorders are often much less understood, although shriveling disorders of fruits are manifold and contribute to yield losses and reduced fruit quality worldwide. Shrinking berries are a common feature for all shriveling disorders in grapevine although their timing of appearance during the berry ripening process and their underlying induction processes distinct them from each other. The sugar accumulation disorder Berry Shrivel (BS) is characterized by a suppression of sugar accumulation short after veraison resulting in berries low in sugar content and anthocyanins in berry skins, while the organic acid content is similar. Recent studies analyzed the biochemical, morphological and molecular processes affected in BS berries and linked early changes to the period of ripening onset [1,2].

Understanding the impact of rising temperatures due to climate change on aromatic compositions in Malbec wines from Mendoza, Argentina

Mendoza is one of Argentina’s most important and outstanding wine regions producing the renowned Malbec wines due to its optimal soil and weather conditions. However, the effects of 21st-century climate change would negatively impact Malbec wines quality. This study investigated the effect of temperature increase and the impact of plant hormone abscisic acid (ABA) used to mitigate the negative effect of temperature increase on Malbec wines aromatic composition through GC-MS. Four treatments were applied on vines at field condition: Control, Control + 3 ºC, ABA and ABA + 3 ºC.

Grape pomace, an active ingredient at the intestinal level: Updated evidence

Grape pomace (GP) is a winemaking by-product particularly rich in (poly)phenols and dietary fiber, which are the main active compounds responsible for its health-promoting effects. GP-derived products have been proposed to manage cardiovascular risk factors, including endothelial dysfunction, inflammation, hypertension, hyperglycemia, and obesity. Studies on the potential impact of GP on gut health are much more recent. However, it is suggested that, to some extent, this activity of GP as a cardiometabolic health-promoting ingredient would begin in the gastrointestinal tract as GP components (i.e., (poly)phenols and fiber) undergo extensive catabolism, mainly by the action of the intestinal microbiota, that gives rise to low-molecular-weight bioactive compounds that can be absorbed and utilized by the body.

Identification of several glycosidic aroma precursors in six varieties of winemaking grapes and assessment of their aroma potential by acid hydrolysis

In winemaking grapes, it is known that most aroma compounds are present as non-volatile precursors, such as glycosidic precursors. In fact, there is strong evidence supporting the connection between the content of aroma precursors and the aromatic quality of wine [1]. Acid hydrolysis is preferred to reveal the aroma potential of winemaking grapes, as it predicts more accurately the chemical rearrangements occurring during fermentation in acidic environments [2]. In this study, a method involving a fast fermentation followed by acid hydrolysis at 75ºC was used to evaluate the accumulation of aroma compounds over time in fractions obtained from six different varieties of winemaking grapes.