Effect of Functionalized-Carbon Nanotube on Growth Indices in Ocimum basilicum L. Grown in vitro

In order to study the effect of phenylalanine-functionalized carbon nanotubes (f-MWCNT) on the parameters of callus induction and variations in antioxidant enzymes activity as well as secondary metabolites biosynthesis of basil (Ocimum basilicum L.), optimum concentrations of functionalized and pristine carbon nanotubes were applied in optimized hormonal culture. Basil hypocotyl fragments were cultured in completely sterile conditions in culture medium with 0, 50, 100 and 200 mg/L concentrations of functionalized and pristine carbon nanotubes. The callus induction frequency Cif and dry matter content (DMC), catalase, polyphenol oxidase (PPO), peroxidase (POD), and L-phenylalanine ammonia-lyase activity were also measured in the present study. Additionally, the content of total phenolics and flavonoids, as well as individual phenolic acids, was quantified. Functionalized MWCNTs exhibited the highest callus induction as well as fresh and dry weight in the concentration, 100 mg/L of f-MWCNT. No significant differences in dry matter content between the levels was observed in this study. Catalase activity was also increased with increasing functionalized and non-functionalized carbon nanotube concentration. The highest activity of PPO, POD, and individual phenolic compounds were observed at 200 mg/L of f-MWCNT, 50 mg/L of pristine MWCNT and 100 mg/L of MWCNT, respectively.