Ensuring plant health through environmentally sustainable and innovative approaches has become a critical objective for contemporary agriculture. The intensification of abiotic constraints, with soil salinity emerging as one of the most severe, increasingly compromises agricultural productivity amid the reduction of cultivable land and ongoing population expansion. In this study, chestnut-derived wood vinegar and an extract obtained from chestnut woodchips were evaluated to investigate their effects on plant growth, physiology, and defense responses, with a special focus on the molecular mechanisms underlying their bioactivity as plant defense inducers. A multidisciplinary approach was applied through field experiments conducted during the summer season on tobacco (Nicotiana tabacum), used as a model species, and on tomato (Solanum lycopersicum), an agronomically relevant crop. Plants were grown under both standard and saline conditions to assess the efficacy of the treatments under abiotic stress.Physiological analyses, including biomass accumulation, chlorophyll content, and stomatal conductance, revealed responses that were often dose dependent in both species. Furthermore, gene expression analyses of selected defense-related markers demonstrated that both treatments induced significant modulation of key hormonal and defense-signaling pathways. In particular, the activation of pathogenesis-related proteins suggested that these products elicit defense responses resembling those triggered by pathogen attack.Overall, the results indicate that chestnut-derived wood vinegar and woodchip extract can effectively enhance plant defense mechanisms while influencing physiological performance under normal and saline conditions, highlighting their potential as eco-friendly tools for sustainable crop management.