Grapevine vigour is correlated with N-mineralization potential of soil from selected cool climate vineyards in Victoria, Australia

Viticulture in Greece is the oldest, but in recent years there has been a reduction of areas intended for the production of wine products. The article contains data on viticulture in Greece. Over time, the land of Greek vineyards is fluctuating. There is a trend towards a decrease in areas in connection with the quota of products from the EU.

Wine growing regions have recently faced intense and frequent droughts that have led to substantial economical losses, and the maintenance of grapevine productivity under warmer and drier climate will rely notably on planting drought-resistant cultivars. Given that plant growth and yield depend on water transport efficiency and maintenance of photosynthesis, thus on the preservation of the vascular system integrity during drought, a better understanding of drought-related hydraulic traits that have a significant impact on physiological processes is urgently needed. We have worked towards this end by assessing vulnerability to xylem embolism in 30 grapevine commercial varieties encompassing red and white Vitis vinifera varieties, hybrid varieties characterized by a polygenic resistance for powdery and downy mildew, and commonly used rootstocks. These analyses further allowed a global assessment of wine regions with respect to their varietal diversity and resulting vulnerability to stem embolism. Hybrid cultivars displayed the highest vulnerability to embolism, while rootstocks showed the greatest resistance. Significant variability also arose among Vitis vinifera varieties, with Ψ12 and Ψ50 values ranging from -0.4 to -2.7 MPa and from -1.8 to -3.4 MPa, respectively. Cabernet franc, Chardonnay and Ugni blanc featured among the most vulnerable varieties while Pinot noir, Merlot and Cabernet Sauvignon ranked among the most resistant. In consequence, wine regions bearing a significant proportion of vulnerable varieties, such as Poitou-Charentes, France and Marlborough, New Zealand, turned out to be at greater risk under drought. These results highlight that grapevine varieties may not respond equally to warmer and drier conditions, outlining the importance to consider hydraulic traits associated with plant drought tolerance into breeding programmes and modeling simulations of grapevine yield maintenance under severe drought. They finally represent a step forward to advise the wine industry about which varieties and regions would have the lowest risk of drought-induced mortality under climate change.

Weather uncertainty is forcing Mediterranean winegrowers to adopt new irrigation strategies to cope with water scarcity while ensuring a sustainable yield and improved berry and wine quality standards. Therefore, more accurate and high-resolution monitoring of soil water content and vine water status is a major concern. Leaf water potential measured at pre-dawn (PD) is considered to be in equilibrium with soil water potential and is highly correlated with soil water content at the soil depth where roots extract water.

Bacterial malolactic fermentation (MLF) has a considerable impact on wine quality. The yeast strain used for primary fermentation can consistently stimulate (MLF+ phenotype) or inhibit (MLF- phenotype) malolactic bacteria and the MLF process as a function of numerous winemaking practices, but the molecular evidence behind still remains a mystery. In this study, such evidence was elucidated by the direct comparison of extracellular metabolic profiles of MLF+ and MLF- yeast phenotypes. Untargeted metabolomics combining ultrahigh-resolution FT-ICR-MS analysis, powerful machine learning methods and a comprehensive wine metabolite database, discovered around 800 putative biomarkers and 2500 unknown masses involved in phenotypic distinction.

Ectopic RNA application for plant defense faces challenges in tree crops, including size, diffusion, and stability of active compounds such as ribonucleoproteins and nucleic acids. While existing strategies involve expressing dsRNA in transgenic plants targeting pathogens, our research strives to develop a transient RNAi system based on Spray-Induced Gene Silencing (SIGS). This approach aims to circumvent legal barriers and public concerns associated with genetically modified organisms (GMOs). Our strategy integrates SIGS with branched polyethyleneimine-functionalized Carbon Dots (bPEI-CDs) as nanocarriers, effectively addressing unique delivery challenges in plant defense as RNA stability and uptake enhancement