Comparing the chemical and sensory consequences of grapevine smoke exposure in grapes and wine from different cultivars and different wine regions in Australia

Each grapevine variety has a specific water use regulation response under drought, and it is still unclear whether this regulation results from innate genotypic behavior (iso- and anisohydric), or is a response to environmental factors, namely recurrent water stress priming effects. In the present work, we explored the influence of the field-grown genotypes’ drought memory in the drought-response phenotype of their vegetative progenies, in Trincadeira (isohydric) and Castelão (anisohydric) varieties under a drought event followed by recovery in a glasshouse. Cuttings from both cultivars subjected to full irrigation (FI) and non-irrigation (NI) treatments for 5 consecutive years were used.

In the Champagne’s region, a complete press cycle is a series of pressure increases (squeezes) and decreases (returns). After alcoholic fermentation, the two wines (the “cuvee” and the “tailles”) obtained from grape juice fractions exhibit strong differences for numerous characteristics. Nevertheless, there is no study of the impact of the press cycle, followed after each pressure increase (22-28 steps), on wine colour, current analyses and phenolic composition. So, the aim of this study (vintage 2020) was to investigate the composition changes of Pinot noir and Pinot meunier wines, produced from 22-28 grape juices isolated for each complete pressing cycle.

In neutral grapes, it is known that most aroma compounds are present as non-volatile
precursors.

The ‘fresh mushroom off-flavour’ has been recognized by the wine industry as an emerging defect since the 2000s. For many years, this off-flavour was not specifically characterized and rather grouped under ‘earthy’ and ‘musty’ taints. However, it has become increasingly problematic due to its rising prevalence. In some vineyards, incidents of this off-flavour now occur as frequently as once every five years. This trend may be associated with climatic changes affecting regions that are more prone to warm and wet seasons.

Botrytis cinerea (Bc) is one of the main pathogens affecting the cultivated grapevine. A key role in grapevine tissue colonization is played by cell wall (CW) remodeling driven by CW Modifying Enzymes (CWMEs), expressed both by the host and the pathogen. Their action can impact CW integrity and trigger specific immune signaling, thus influencing Bc infection outcome. To further characterize the role of the CW in the grapevine response to Bc, two contrasting genotypes in their resistance to the fungus were artificially inoculated at full bloom. RNA-seq analysis and biochemical characterization of the CW and its modification in samples collected at 24 hours post-inoculation highlighted significant differences between genotypes.