Abstract
Elevated atmospheric CO2 (eCO(2)) can significantly enhance plant metabolism and improve their nutritional quality. Although several studies addressed the effect of eCO(2) on plants, to our knowledge, there are no studies that have applied eCO(2) to improve growth, chemical composition, and biological properties of ajwain (Trachyspermum ammi) during sprouting. Herein, eCO(2) (620 mu mol mol(-1)) was employed to enhance photosynthetic reactions. Improved photosynthesis induced primary and bioactive secondary metabolism, which led to improved biological activities of T. ammi sprouts in comparison with control sprouts and seeds. eCO(2)-treated sprouts showed significantly (p < 0.05) higher levels of most measured nutritional primary and secondary metabolites like soluble sugars, essential amino acids, organic acids, essential oils, phenolics, and flavonoids than control sprouts, which had significantly higher values than control seeds. eCO(2) significantly improved the antimicrobial properties of T. ammi sprouts against 11 out of 13 microbial species than control sprouts, which had more potent antimicrobial activities than seeds. The significant increase in the antioxidant potential of treated sprouts was indicated by improved levels of ferric reducing antioxidant power (FRAP), DPPH, and oxygen radical absorbance capacity (ORAC). In addition, the anticancer activity against four different human tumor cell lines was significantly (p < 0.05) boosted by both sprouting and eCO(2) exposure. Thus, the present study confirms the synergistic effect of sprouting with eCO(2) exposure as promising approaches to produce ajwain sprouts with rich nutraceuticals, effective phytochemicals, and enhanced biological activities.