Grapevine (lat. Vitis vinifera) plants use two key strategies to cope with drought: maintaining water loss through the leaves or significantly reducing it. They are called isohydric and anisohydric, respectively, following a concept based on water evaporation via the stomata (the “water/air doors” in the leaves) originating from the last century. The molecular mechanisms behind these strategies are still not fully understood, but are crucial in the context of climate change and viticulture.
The vine bioinformatics team at Armenian Bioinformatics Institute (ABI) reanalyzed transcriptome data and investigated these differences using machine learning, specifically focusing on gene expression patterns over time after drought stress begins. The core method used in the lab, the Self-Organizing Maps, enabled researchers to track the response trajectories of two grapevine cultivars from Italy possessing anisohydric and isohydric characteristics, Sangiovese and Montepulciano.
The novel findings published by Konecny et al. in the Q1-journal Plants revealed a dynamic interaction between genes involved in drought stress management. Montepulciano cultivar tends to neglect the early (6 days) impacts of water deficit by opening stomatal cells until a more prolonged drought stress period (27 days) when this cultivar starts to focus on active responses like the activation of heat-shock proteins. In contrast to Montepulciano, the Sangiovese cultivar rather prioritizes water conservation through early stomatal closure with activation of the heat-shock protein response in the prolonged stress. Notably, these strategies affect not only plant survival but also aspects related to grape taste and wine quality. For example, the Montepulciano cultivar displayed a higher tendency for producing compounds such as resveratrol, which has both health benefits and contributes to wine flavor. These results indicate that drought conditions might lead to variations in wine composition related to the grapevines water management strategy.
Additionally, the ABI team identified specific genes linked to drought resilience, such as those involved in stilbenoid biosynthesis (important for antioxidant properties) and the production of chaperones that protect proteins from stress-induced damage. This molecular insight is pivotal for developing drought-resistant grapevines, which are becoming increasingly important as climate change intensifies water scarcity in wine-growing regions.
Finally, the broader significance of this study extends beyond grapevine cultivation. It illustrates how the integration of transcriptome analysis with advanced machine learning techniques like Self-Organizing Maps can uncover new layers of complexity in plant biology, with implications for crop management and climate adaptation. Ultimately, understanding how various grapevines assess the water regulation and respond to drought stress at the molecular level will help secure the future of wine production in the increasingly unpredictable weather conditions caused by climate change.
The research builds on previous findings regarding grapevine stress responses and aims to contribute to a larger body of work focused on the genomics of vine resistance to environmental stress factors. This is a part of the ongoing “Vine Bioinformatics” project, which seeks to develop bioinformatics strategies to enhance the understanding of how grapevines cope with a variety of challenges, including drought, and contribute to long-term strategies for sustainable viticulture. Studying drought management of Armenian vine accessions is planned in the wider scope of systematically characterizing genetic and phenotypic diversity of Armenian grapevines by the ABI team. The project is supported by Institute of Molecular Biology (IMB) and by Foundation of Armenian Science and Technology (FAST) in the frame of the Advanced Research Grant program.
Read the paper here.
