While the impact of elevated CO₂ (eCO₂) on plant growth and biological activity has been widely studied, the metabolic bases of these changes, especially in medicinal and herbal plants, are not well understood. This study aims to elucidate the biochemical and physiological responses of Salvia officinalis , an important aromatic plant and a key natural food preservative, under elevated CO₂ conditions. Exposure to eCO₂ significantly improved fresh and dry biomass by 23.8% and 33.3%, respectively, along with a 34.4% increase in photosynthetic efficiency. Amino acids such as phenylalanine, which act as precursors for secondary metabolites, were notably upregulated, supporting enhanced biosynthesis of phenolic compounds and flavonoids. Flavonoid levels rose by 36.2%, and total phenolics by 22.1%, reflecting a clear shift of carbon allocation toward bioactive, defense-related metabolites. Essential oil profiles, particularly monoterpenes, were also altered under eCO₂, with borneol content increasing by 51.3%. Antioxidant capacity improved significantly, as indicated by a 40.5% increase in FRAP values. Furthermore, eCO₂-treated plants displayed significant increase of antibacterial activity against some pathogenic bacteria and anti-inflammatory properties, attributed to the enhanced phenolic compounds and essential oils. Our study highlights the role of medicinal plants in the future climate scenarios and positions S. officinalis cultivation as sustainable and effective tool for improving CO 2 vegetation flux and utilizing eCO 2 .
Alsherif et al. (Sat,) studied this question.