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 performance and quality. However, the potential of many wild plant species remains largely unexplored. This study characterized the biochemical composition of Silene vulgaris (syn. Silene inflata) leaves and roots and evaluated the biostimulant effects of their crude extracts, applied by irrigation at 1 and 10 mL/L, on greenhouse-grown lettuce (Lactuca sativa L. cv. Canasta). S. vulgaris leaves showed higher contents of proteins, chlorophylls, phenolic compounds, ascorbic acid and saponins than roots. The effects on lettuce varied according to the S. vulgaris organ used to prepare extracts, extract concentration and lettuce trait assessed. Leaf extract at 1 mL/L increased dry biomass, chlorophyll, protein, soluble sugar and phenolic contents, as well as antioxidant activity in lettuce, whereas at 10 mL/L it increased dry biomass and phenolic content. Fresh biomass remained unaffected. Root extract at 1 mL/L increased dry biomass, phenolic content and antioxidant activity, whereas at 10 mL/L it enhanced soluble sugar and phenolic contents. Overall, both leaf and root extracts influenced lettuce growth-related and biochemical traits in a concentration- and trait-dependent manner. These findings support further investigation of S. vulgaris as a potential source of plant-derived biostimulants for horticultural applications.