terclim by ICS banner
IVES 9 IVES Conference Series 9 International Congress on Grapevine and Wine Sciences 9 2ICGWS-2023 9 Energy partitioning and functionality of photosystem II in water-stressed grapevines during heatwaves revealed by continuous measurements of chlorophyll fluorescence

Energy partitioning and functionality of photosystem II in water-stressed grapevines during heatwaves revealed by continuous measurements of chlorophyll fluorescence

Abstract

The increased intensity and frequency of heatwaves, coupled with prolonged periods of drought, are a significant threat to viticulture worldwide. During these conditions the more exposed leaves can show visible symptoms of heat damage. We monitored the functionality of photosystem II (PSII) in the field to better understand the impact of heatwaves on canopy performance. A factorial experiment was established in summer 2023 using Shiraz grapevines in the Barossa valley of South Australia, involving water-stressed and well-watered vines. To monitor the impacts of irrigation and leaf position on PSII functionality, MONI/MICRO PAM heads were mounted on the south (polar facing) and north (equatorial facing) sides of the canopy of each vine. Water stress decreased midday stem water potential (SWP) to -1.4 MPa in water-stressed plants, while well-watered plants maintained SWP at -0.8 MPa. Maximum efficiency of PSII (Fv/Fm) decreased by higher exposure to heat and radiation on the northern side, especially when plants were subjected to water stress. Absorbed energy partitioning in PSII differed between northern and southern sides, and it was influenced by irrigation. At midday, leaves on the southern side showed higher photochemical (Y(II)) and lower non-photochemical yield (Y(NPQ)) than northern leaves. Water stress decreased Y(II) and increased Y(NPQ) at midday predominantly on the northern side. During a heatwave, PSII showed an increase in photoinhibition (Y(NO)) in water-stressed plants on the northern side; however, this effect was reversible and persisted only one day following the heatwave and decreased thereafter to a similar rate to that observed in the rest of the canopy. These findings suggest that, in the short-term, irrigation can be tailored to sustain the canopy during heat waves, while in the medium-term, canopy management strategies (such as shade netting) may be needed to maintain leaf function during and following heatwaves.

DOI:

Publication date: October 5, 2023

Issue: ICGWS 2023

Type: Article

Authors

Walaa Shtai1*, Paul Petrie2, Marcos Bonada3, Massimo Tagliavini1 , Georg Wohlfahrt5, Edwards Everard4

1Free University of Bolzano- Bozen, Italy
2South Australian Research and Development Institute (SARDI), Adelaide, Australia
3Treasury Wine Estates, Adelaide, Australia.
4CSIRO Agriculture and Food, Adelaide, Australia
5University of Innsbruck, Austria

Contact the author*

Keywords

chlorophyll fluorescence, heat stress, water stress, grapevines, energy partitioning, heat dissipation, photoinhibition

Tags

2ICGWS | ICGWS | ICGWS 2023 | IVES Conference Series

Citation

Related articles…

Correlative study between degradation of rosé wine under accelerated conditions and under normal conditions

Several studies have tried to develop different methods to study the photodegradation of wine in an accelerated way, trying to elucidate the effect of light on the wine compounds[1]. In a previous study, our team developed a chamber that speeds up the photodegradation of rosé wine[2]. In the present work we have tried to establish a correlation between irradiation times in accelerated conditions and the natural exposure to the cycles of light that usually exist in markets or at home.

Effect of two water deficit regimes on the agronomic response of 12 grapevine varieties cultivated in a semi-arid climate

The Mediterranean basin is one of the most vulnerable regions to Climate Change effects. According to unanimous forecasts, the vineyards of Castilla-La Mancha will be among the most adversely affected by rising temperatures and water scarcity during the vine’s vegetative period. One potential strategy to mitigate the negative impacts of these changes involves the identification of grapevine varieties with superior water use efficiency, while ensuring satisfactory yields and grape quality.

The use of plasma activated water in barrel disinfection: impact on oak wood composition

The use of barrels is a practice that improves the quality of wines. The porous structure of wood favors the accumulation of microorganisms that can deteriorate the quality of wines so that barrel cleaning and sanitizing treatments are essential. The burning of sulphur discs has been the most common practice in winemaking because ots biocide effect. Nevertheless, its effectiveness is still insufficient and it is harmful for human health.

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.

Water and nutritional savings shape non-structural carbohydrates in grapevine (Vitis vinifera L.) cuttings

Global changes and sustainability challenge researchers in saving water and nutrients. The response of woody crops, which can be forced at facing more drought events during their life, is particularly important. Vitis vinifera can be an important model for its relevance in countries subjected to climate changes and its breeding, requiring cuttings plantation and strong pruning.