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…

Characterization of a Sémillon clonal population: exploring genetic diversity, metabolomic profiles, and phenotypic variations

Sémillon is a cultivated grape variety known for contributing to dry and sweet white wine production. However, only seven approved clones have been officially recognized in France[1]. In this study, we aimed to characterize the genetic diversity and metabolomic profiles of a Sémillon clonal population, shedding light on the potential variations within this important grape variety.

The evolution of the aromatic composition of carbonic maceration wines

The vinification by Carbonic maceration (CM) involves the process whereby the whole bunches are subjected to anaerobic conditions during several days. In this anaerobic condition, the grape endogenous enzymes begin an intracellular fermentation. This situation favors that whole grapes split open and release their juice into the tank, increasing the liquid phase that is fermented by yeasts [1]. Then, two types of wines are obtained; one from the free-run liquid in the tank (FCM) and other from the liquid after pressing the whole grape bunches (PCM). PCM wines are recognized as high quality young wines because their fruity and floral aromas[2] that although they are very intense at the end of the winemaking they gradually disappear during conservation.

Barrels ad-hoc: Spanish oak wood classification by NIRs 

The wooden barrel is a key factor in enology, since wine chemical composition and sensory properties changes significantly in contact with the barrel[1]. Today’s highly competitive market constantly demands new differentiated products and wineries search innovations continuously.
Wood selection is crucial: barrels stability to keep constant their contribution and the result on products, and additional and differentiated wood contributions to impact their new products. Oak wood selection has traditionally been carried out using parameters such as specie, location and grain, however, it goes one step further nowadays. Large cooperage work with non-destructive techniques that allow classifying oak wood quickly and easily according to their organoleptic contribution[2].

Association between dietary pattern and wine consumption and Alzheimer’s disease in a cohort from La Rioja (Spain)

Addressing modifiable risk factors is the most promising strategy to prevent/delay Alzheimer Disease (AD)[1]. The aim of the study was to establish the connections between dietetic habits, wine consumption and AD. Thus, 98 volunteers were recruited: 50 diagnosed as AD and 48 healthy/controls. The Food Frequency Questionnaire (FFQ) was used for dietary patterns assessment and, based on these data, the Mind Diet Score was calculated. (Poly)phenol metabolites (especially derived from wine consumption) were analyzed by UPLC-QqQ-MS/MS in 24-h urine samples to confirm dietary (poly)phenol consumption.

Nitrogen forms and Iron deficiency: how do Grapevine rootstocks responses change?

Grapevine rootstocks provide protection against environmental biotic and abiotic stresses. Nitrogen (N) and iron (Fe) are growth-limiting factors in many crop plants due to their effects on the chlorophyll and photosynthetic characteristics. Iron nutrition of plants can be significantly affected by different nitrogen forms through altering the uptake ratio of cations and anions, and changing rhizosphere pH. The aim of this study was to investigate the response mechanisms of grapevine rootstocks due to the interaction between different nitrogen forms and iron uptake.