Grafting enhances water deficit tolerance in grapevines
image: Experimental design on greenhouse conditions at three different water deficit levels depending on the hydric potential of leaves (Mild: −0.6 MPa ≤ Ψstem ≤ −0.9 MPa; High: −0.9 MPa ≤ Ψstem ≤ −1.4 MPa; Extreme: Ψstem ≥ −1.4 MPa) on 2-year study (2020 and 2022).
Credit: Horticulture Research
As global climate change exacerbates water scarcity, understanding how grapevines respond to water deficit stress is vital for ensuring the sustainability of vineyards. A new study highlights how grafting practices, specifically using rootstocks like 110 Richter, can improve the resilience of grapevine cultivars to drought conditions. The research focused on two grapevine cultivars, Callet and Merlot, revealing that rootstock selection, combined with cultivar characteristics, significantly influences water stress tolerance. The study shows that the near-isohydric Callet cultivar, grafted onto 110 Richter, exhibits better water-use efficiency and oxidative stress management compared to the anisohydric Merlot cultivar. These findings offer critical insights for adapting viticulture practices to changing climatic conditions.
Water scarcity is increasingly affecting agricultural production worldwide, and viticulture is no exception. Grapevines, like many crops, exhibit varied responses to drought stress, with some cultivars being more resilient than others. This variability is partly determined by the cultivar's stomatal behavior and its ability to manage water loss. In this context, rootstocks like 110 Richter have been shown to improve drought tolerance in grafted grapevines. The study compares two grapevine cultivars, Merlot and Callet, under different levels of water deficit stress to better understand how scion-rootstock interactions influence water stress resilience. Based on these challenges, there is a need for further research into optimizing rootstock and cultivar combinations to mitigate water deficit impacts.
Researchers from various institutions, including the Centro de Biotecnología y Genómica de Plantas (CBGP-INIA) in Spain, recently published (DOI: 10.1093/hr/uhae291) their findings in Horticulture Research on 23 October 2024. Their study explores how the interaction between grapevine cultivars and rootstocks can enhance drought tolerance. By using three levels of water deficit stress, the study assessed both physiological and transcriptomic responses in two cultivars: Callet, a drought-tolerant cultivar, and Merlot, a more water-sensitive variety, grafted onto 110 Richter rootstocks. The results reveal significant differences in the stress responses of the two cultivars, with Callet displaying superior resilience.
The study's findings underscore the importance of scion-rootstock interactions in regulating grapevine responses to water deficit stress. In particular, Callet grafted onto 110 Richter exhibited a more coordinated gene expression response, activating stress-related genes in both the aerial and root systems. This response included increased production of secondary metabolites like flavonoids and polyphenols, which help mitigate oxidative stress. In contrast, Merlot grafted onto the same rootstock displayed a less specific response, particularly in the roots, suggesting a reduced ability to cope with water stress. The study also highlights the key role of abscisic acid (ABA), a hormone involved in stress signaling, in enhancing drought tolerance. These differences in gene expression and metabolic adjustments emphasize the significance of selecting the right cultivar-rootstock combinations for sustainable viticulture.
According to Dr. Alberto Rodriguez-Izquierdo, a leading author of the study, "Our research demonstrates that the resilience of grapevines to water deficit can be significantly enhanced through careful selection of scion-rootstock combinations. Callet’s enhanced ABA sensitivity and metabolic responses offer a promising strategy for improving vineyard management under drought conditions."
This research has crucial implications for grapevine breeding and vineyard management in the face of climate change. By selecting cultivars that are more responsive to ABA and grafting them onto suitable rootstocks like 110 Richter, viticulturists can optimize water use efficiency and improve crop resilience. These findings could lead to more sustainable vineyard practices, ensuring better grape production and wine quality in regions facing water scarcity. Additionally, the identification of specific genes involved in drought tolerance could aid in the development of new grapevine varieties better suited to future environmental conditions.
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References
DOI
Original Source URL
https://doi.org/10.1093/hr/uhae291
Funding information
This study was supported by the Research and Science Ministry of Spain (project RTI2018-094470-R-C21 and PID2021-1255750R-C21).
About Horticulture Research
Horticulture Research is an open access journal of Nanjing Agricultural University and ranked number one in the Horticulture category of the Journal Citation Reports ™ from Clarivate, 2023. The journal is committed to publishing original research articles, reviews, perspectives, comments, correspondence articles and letters to the editor related to all major horticultural plants and disciplines, including biotechnology, breeding, cellular and molecular biology, evolution, genetics, inter-species interactions, physiology, and the origination and domestication of crops.