Decline of rootstock-mediated physiological responses in Tempranillo grapevines by prolonged extreme conditions

Vineyard exposure to smoke can lead to grapes and wine which exhibit objectionable smoky and ashy aromas and flavours, more commonly known as ‘smoke taint’ [1, 2]. In the last decade, significant bushfires have occurred around the world, including near wine regions in Australia, Canada, South Africa and the USA, as a consequence of the warmer, drier conditions associated with climate change. Considerable research has subsequently been undertaken to determine the chemical, sensory and physiological consequences of grapevine exposure to smoke. The sensory attributes associated with smoke-tainted wine have been linked to the presence of several smoke-derived volatile phenols, such as guaiacols, syringols and cresols [2].

The acıkara grape variety, a nearly forgotten native black variety in Anatolia/Turkey, has recently gained interest in its potential for producing high-quality wine from producers and consumers. The potential of producing high-quality red wine from the Acıkara grape variety (vitis vinifera), which is cultivated on the elmalı/antalya in the highland (1100 m altitude) of western mediterranean region, was investigated, and the suitability of the wine’s characteristics associated with high-quality red wine was determined.

Climate change is leading to a rise in average temperature and in the frequency and severity of heatwaves, and is already significantly disturbing grapevine phenology and berry composition. With the evolution of the weather of Australian grape growing regions that are already warm and hot, flavonoids, for which biosynthesis depends on bunch microclimate, are expected to be impacted. These compounds include anthocyanins and tannins which contribute substantially to grape and wine quality. The goals of this project were to determine if berry tannin accumulation is sensitive to high temperature and to enhance knowledge on upper temperature limits for viable wine production, in turn informing critical timing for mitigation strategies.

Phenolic compounds are very important in crop plants and have been the subject of a large number of studies. Three main reasons can be cited for optimizing the level of phenolic compounds in crop plants: their physiological role in plants, their technological significance for food processing, and their nutritional characteristics1 Indeed, an enormous diversity of phenolic antioxidants is found in fruits and vegetables, and their presence and roles can be affected or modified by several pre- and postharvest cultural practices and/or food processing technologies (Ruiz-García et al. 2012, Goldman et al. 1999, Tudela et al. 2002). In winegrapes, the technological importance of phenolic compounds, mainly flavonoids, is well-known.

The pioneering work of Mandelbrot in the 70’s for building the fractal theory lead rapidly to many interesting applications in different fields such as earth sciences and economy.