Production of Phenolic Compounds in Iberis amara L. Cell Suspension Culture under Chitosan Treatment

Iberis amara L. medicinal herb is well-known for having pharmacological values although its use has been challenged by the low levels of secondary metabolites. For their bulk production, the present work aimed to investigate the effects of explants, different plant growth regulators, and photoperiod condition on the callus induction and cell suspension in I. amara, followed by investigating the chitosan effect on some secondary metabolites. A factorial experiment method based on completely randomized design with four replications was carried out. The optimum condition for induced callus achieved from the leaf explants in Murashige and Skoog (MS) media supplemented with 3 mg/l 6benzylaminopurine (BAP) and 1 mg/l 1-naphthalene acetic acid (NAA) under 16-h light/8-h dark photoperiod. The MS enhanced with 3 mg/L BAP, 1 mg/L NAA, and 2% (w/v) sucrose appeared to be the optimum conditions for suspension establishment. Thus, the cells were exposed to different concentrations of chitosan (200, 100, 50, and 0 mg/l) in their exponential growth stage from day 8 to 12 and day 12 to 16 following sub-cultures (T1) and sub-cultures (T2), respectively. The contents of phenolics and malondialdehyde (MDA) were then examined by UV-Vis spectrophotometer. The results showed that 50 mg/Lchitosan significantly improved the total phenol, flavonoid, flavonol, and anthocyanin content in the I. amara in a dose-dependent manner. The highest malondialdehyde (MDA) amount, as a result of lipid peroxidation, was observed under the 200 ppm chitosan elicitation. Overall, these novel findings demonstrated the possibility of applying the cell suspension of I. amara treated with chitosan as a helpful approach for improving synthesizing phenolic compounds under controlled and sterile conditions.