Exploring the Biostimulant Potential of Silene vulgaris (syn. Silene inflata): Biochemical Characterization and Evaluation of Leaf and Root Extracts in Lettuce

Plant-derived biostimulants are gaining interest as sustainable tools to improve crop per-formance and quality. However, the potential of many spontaneous plant species remains largely unexplored. This study evaluated the biochemical composition of leaf and root tissues of Silene vulgaris (syn. Silene inflata) and assessed the biostimulant activity of their extracts on lettuce (Lactuca sativa L. cv. Canasta). Leaf tissues showed substantially higher contents of proteins, phenolic compounds, ascorbic acid and saponins than roots, highlighting clear biochemical differences between the two organs. When applied as biostimu-lants, the leaf extract at lower concentration significantly increased dry biomass, chlorophyll, protein, soluble sugar and phenolic contents, as well as antioxidant activity in lettuce, whereas fresh biomass was unaffected. In contrast, root extracts induced weaker physiological responses, suggesting that additional bioactive constituents in leaves may contribute to their higher efficiency. Overall, the results indicate that S. vulgaris leaf extracts act primarily as metabolic biostimulants, enhancing plant physiological performance and nutritional quality rather than promoting biomass accumulation. These findings identify S. vulgaris as a promising source of plant-derived biostimulants with poten-tial applications in sustainable strategies aimed at improving the nutritional and func-tional quality of horticultural crops.