Innovative strategies to enhance grapevine sustainability and resilience against stresses

Feeding a growing population under climate change requires crops that are not only productive but also resilient. Grapevine, one of the world’s most valuable perennial crops, is particularly vulnerable to fungal diseases, making sustainable strategies to enhance its resistance essential. This thesis explores innovative genetic and epigenetic approaches to improve grapevine resilience while maintaining beneficial plant–microbe interactions. First, CRISPR/Cas9-mediated editing was applied to immune regulators, including MLO genes and NPR3, to assess their role in disease resistance and in shaping root symbioses. NPR3 editing enhanced tolerance to powdery and downy mildew, while also promoting arbuscular mycorrhizal accommodation, revealing that immunity and beneficial interactions can be uncoupled through precise interventions. The second part focuses on epigenetic regulation in grapevine–pathogen interactions. Through both reviews and experimental work, the role of chromatin dynamics was investigated, with particular attention to the histone variant H2A.Z and the tRNA methyltransferase DNMT2. Preliminary CRISPR-based modifications in these loci highlighted their potential in modulating immune responses and stress adaptation. Together, these studies demonstrate how genome and epigenome editing can generate disease-resilient grapevine germplasm while preserving ecological interactions. By integrating molecular biology, biotechnology, and plant–microbe ecology, this work provides novel strategies for viticulture that reconcile pathogen resistance with sustainability, offering insights relevant to other perennial crops as well.