The microbiota associated with the rhizosphere is responsible for crucial processes. Understanding how the plant and its bacterial community interact is of great importance to face the upcoming agricultural and viticultural challenges. The composition of the bacterial communities associated with the rhizosphere of grapevines is the result of the interaction between many drivers: biogeography, edaphic factors, soil management and plant genotype. The experimental design of this study aimed to reduce the variability resulting from all factors except the genotype of the rootstock. This was made possible by investigating four ungrafted grapevine rootstock varieties of the same age, grown on the same soil under the same climatic conditions and managed identically. The bacterial communities associated with the rhizosphere of the rootstocks 1103 Paulsen, 140 Ruggeri, 161-49 Couderc and Kober 5BB were characterized with the amplicon based sequencing technique, targeting regions V4–V5 of 16S rRNA gene. Linear discriminant analysis effect Size (LEfSe) analysis was performed to determine differential abundant taxa. The four rootstocks showed similarities concerning the structure of the bacteria assemblage (richness and evenness). Nonetheless, differences were detected in the composition of the bacterial communities. Indeed, all investigated rootstocks recruited communities with distinguishable traits, thus confirming the role of rootstock genotype as driver of the bacteria composition.

Microorganisms are a substantial component of the rhizosphere, and the activity and composition of rhizosphere microbial populations markedly affect interactions between plants and the soil environment. In addition, the microbiota of the rhizosphere can positively influence plant development, growth and vitality. In vineyards, management practices influence both grapevine root growth directly and the rhizosphere microbiota, but the exact mode of action is largely unknown. Recently, however, two new research approaches are increasingly coming into focus to enhance grapevine growth and health: plant engineering and rhizosphere engineering. In plant engineering, knowledge about plant-microbiome interactions is used for plant breeding strategies. In rhizosphere engineering, microbial communities are modified by adding specific fertilisers, nutrients or by bio-inoculation with certain bacteria and/or fungi. Taken together, these new methods suggest a potential for reaching a more sustainable development of pesticide-reduced viticulture in the future.

Societal Impact Statement: Grape production relies signifcantly on agrochemicals, such as fertilizers and pesticides, to sustain vine health and yield. However, excessive or improper use of these inputs leads to detrimental environmental effects, including soil degradation, water contamination, and biodiversity decline. To address this, research must explore sustainable alternatives. Enhancing the symbiotic interactions between grapevine rootstocks and beneficial soil microorganisms offers a viable pathway. By fostering these natural relationships, producers and scientists can develop environmentally sustainable viticulture practices that strengthen vine resilience without compromising productivity. This approach also supports the broader transition to regenerative, ecologically balanced agricultural systems.Summary: The productivity and resilience of vineyards are influenced by complex interactions between grapevine rootstocks and the surrounding soil microbiome. Emerging research has highlighted the pivotal role of these microbe‐rootstock alliances in modulating nutrient acquisition, water‐use efficiency, and pathogen resistance. By leveraging the symbiotic potential of beneficial soil microorganisms, viticulturists can optimize vineyard management practices to enhance overall productivity, stability, and sustainability. Through the strategic selection of rootstocks with enhanced mycorrhizal associations and the targeted introduction of plant growth‐promoting rhizobacteria, growers can support the grapevine in adapting to challenging soil conditions. Aditionally, manipulating the rhizosphere microbiome, through techniques such as biofertilization and reverse microdialysis, can foster the development of robust, disease‐suppressive communities that safeguard the vines against biotic and abiotic stressors. Integrating these microbiome‐centric approaches into comprehensive vineyard management strategies, and potentially in future rootstock genetic improvement programs, holds promise for improving grape yield, quality, and the long‐term resilience of viticultural systems.

The rhizosphere is where crucial processes for the productivity of viticultural systems occur. The composition of the bacterial communities associated with the rhizosphere of grapevines is known to depend on plant genotype. However, the genotype of grafted grapevines differs between scion and rootstock; the role of each genotype is unclear. To untangle the effect of scion and rootstock, the rRNA (V4–V5 region of 16S rRNA) extracted from the rhizosphere of the grape varieties Riesling and Mueller-Thurgau ungrafted vs grafted on different rootstocks was sequenced. The bioinformatic analysis with tools designed to be robust for compositional data showed that the investigated rootstocks or scions or combinations, respectively, recruited bacterial communities with distinguishable traits. Statistical differences were revealed between ungrafted Riesling vs Mueller-Thurgau, between grafted Riesling vs ungrafted Riesling, and between ungrafted Mueller-Thurgau vs grafted Mueller-Thurgau. Thus, confirming the role of scion and rootstock genotype as a driver of the structure and composition of bacterial communities in the rhizosphere of grapevines.