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

Grapevine leaves are known to contain different polyphenols such as flavonols, catechins and stilbenes, which are known to act as main contributors for plant defense against pathogens (1). While the composition for some major cultivars has been studied, there is lack of systematic comparison about the content of these compounds in the wide ecodiversity of Vitis vinifera cv. Recent advances in Mass Spectrometry-based Metabolomics allow a wider and more sensitive description of these polyphenols, as instance of those present in leaves (2). Such information could help to better explain leaf traits regarding the development of the leaf or to the plant tolerance to a pathogen. Moreover, these compounds offer appealing applications for human health due to their antioxidant activities.

One of the limitations of vineyards in warm areas is the loss of wine quality due to higher temperatures during the grape ripening period. In order to adapt the vineyards to these new climatic conditions, a possible solution is to delay the ripening process of the grapes towards periods with milder temperatures, by means of management practices and thus improve the quality of the fruit and the wine produced. The technique of severe shoot pruning (SSP) has proven useful in achieving this objective.

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.

Climate change is resulting in more dry and hot summers, accelerating grape ripening and increasing berry sugars concentration. This results in wines with a higher alcohol content, which has a negative impact on wine quality, as well as, on consumer health. Agronomic practices that minimize these effects on berry composition and, consequently, on wine quality must be defined. In this work, different management practices have been assessed on rainfed ‘Monastrell’ grapevines in Jumilla (Murcia, Spain) from 2021 to 2023 vintages. Mulching, shading, application of kaolin and different types of pruning were evaluated, among others field adaptation practices.

In the context of global change, the environmental conditions are expected to be more stressful for viticulture. The choice of the rootstock may play a crucial role to improve the adaptation of viticulture to new biotic and abiotic threats (Ollat et al., 2016). However, the selection of interesting traits in rootstock breeding programs is complex because of the combination of multiple targets in a same ideotype. In this sense, the integration of studies about the genetic architecture for desired biotic and abiotic response traits allow us to identify genomic regions to combine and those with interesting pleiotropic effects.