Investigating biotic and abiotic stress responses in grafted grapevine cultivars: A comparative study of Cabernet-Sauvignon and Cabernet Volos on M4 rootstock

Abstract

When grapevine plants are transplanted into already established vineyards, they face multiple challenges, including adverse climate, heavy metal accumulation from agronomic practices [1], and pressure from highly adapted pathogens [2]. For this reason, understanding the interactions between soil biota, scion, and rootstock [3] under environmental stressors is essential for improving grapevine resilience. This study investigates the combined effects of water stress, copper-induced toxicity, and Plasmopara viticola infection on the performance of grafted grapevines. Rootstock M4 was grafted with Cabernet Sauvignon and Cabernet Volos and subjected to copper application at the soil level, drought stress followed by heavy rainfall, and pathogen inoculation. Physiological and biochemical data were collected using both traditional methods and smart phenotyping to assess plant responses [4]. Results showed that while both cultivars experienced similar levels of water stress, they successfully restored water balance post-recovery, indicating preserved root functionality. However, photosynthetic rate and transpiration rate declined under drought conditions, with a slower recovery in inoculated plants, suggesting potential impairment of above-ground structures. The severity of Plasmopara infection was largely cultivar-dependent, with a noticeable increase in downy mildew incidence in the resistant Cabernet Volos, particularly under combined stress conditions. In both cultivars, all stressors led to a minor accumulation of molybdenum in both roots and leaves, while the two cultivars exhibited different behaviours regarding iron content at the root level. These findings highlight the complex interplay between abiotic and biotic stressors and provide insights into the adaptive responses of grapevines, which can inform future vineyard management strategies to enhance plant resilience. The next phase of this research will involve conducting open-field trials to evaluate how the observed stress responses influence grape and wine quality. This approach will support the development of viticultural practices aimed at enhancing plant resilience while preserving key fruit and wine traits.

References

[1] La Torre, A., Righi, L., Iovino, V., & Battaglia, V. (2019). Evaluation of copper alternative products to control grape downy mildew in organic farming. Journal of Plant Pathology, 101, 1005-1012.

[2] Koledenkova, K., Esmaeel, Q., Jacquard, C., Nowak, J., Clément, C., & Ait Barka, E. (2022). Plasmopara viticola the causal agent of downy mildew of grapevine: from its taxonomy to disease management. Frontiers in Microbiology, 13, 889472.

[3] Harris, Z. N., Pratt, J. E., Kovacs, L. G., Klein, L. L., Kwasniewski, M. T., Londo, J. P., … & Miller, A. J. (2023). Grapevine scion gene expression is driven by rootstock and environment interaction. BMC plant biology, 23(1), 211.

[4] Pii, Y., Orzes, G., Mazzetto, F., Sambo, P., & Cesco, S. (2024). Advances in viticulture via smart phenotyping: current progress and future directions in tackling soil copper accumulation. Frontiers in Plant Science, 15, 1459670.