Growth and production of bioactive compounds are boosted in young basil plants grown under hydroponic vitamin supplementation
Background Basil is a high-value aromatic and medicinal plant widely recognized for its rich composition of bioactive compounds with applications in food, pharmaceutical, and cosmetic industries. This study aimed to evaluate the physiological responses, growth, and production of bioactive compounds in baby leaf basil cultivated in a hydroponic system supplemented with B-complex vitamins. Methods The experiment was conducted under a controlled environment using a randomized block design with four treatments: control, nicotinamide, thiamine, and pyridoxine. Plants were assessed 14 days after sowing for gas exchange parameters, biometric traits, biomass accumulation, leaf pigments, and bioactive compounds, including phenolics, flavonoids, tannins, antioxidant activity, and sun protection factor. Results Vitamin supplementation reduced intercellular CO2 concentration and significantly increased CO2 assimilation rate, water use efficiency, and carboxylation efficiency. Nicotinamide notably enhanced plant growth, increasing leaf area (78%) and plant height (34.8%), as well as shoot fresh and dry mass (49.7 and 77.9%). Bioactive compound accumulation was also stimulated, with increases of up to 129.1% in phenolics and 159.2% in antioxidant activity, with nicotinamide being superior to the other treatments in all nutraceutical characteristics. Additionally, chlorophyll and carotenoid contents were elevated, especially under nicotinamide treatment, which also reduced leaf temperature. Pyridoxine showed intermediate effects, while thiamine presented modest improvements compared to the control. Conclusion Hydroponic supplementation with B vitamins, particularly nicotinamide, enhances physiological performance, biomass production, and the accumulation of bioactive compounds in basil.