Linum lewisii Adventitious and Hairy-Roots Cultures as Lignan Plant Factories

Plants synthesize specific secondary metabolites for survival, reproduction, environmentalresilience, and defense. Among them, lignans are a class of polyphenols with several bioactiveproperties: chemopreventive, anti-inflammatory, antiviral, and antioxidant. These compounds areoften extracted from field-grown plants with very low yields. To overcome these constraints, in vitrotissue cultures provide a tool to optimize large-scale production. Moreover, the use of elicitationto increase secondary metabolite production is gaining importance. The aim of this work was todevelop adventitious (ARL) and hairy roots (HRL) from Linum lewisi, a species able to synthesizearylnaphthalene lignans such as justicidin B. The ARL and HRL were obtained for the first timeand characterized for their phenol content, antioxidant activity, and the production of justicidin Bafter treatments with several elicitors and precursor feeding. Through NMR spectroscopy, other fourlignans were highlighted and identified in the roots extracts. A pilot-scale bioreactor was adopted toassess the suitability of the developed root cultures for future large-scale production. The ARL andHRL cultures showed a justicidin B production higher than other Linum species cultures described upto now (75.8 mg/L and 82.2 g/L), and the production more than doubled after elicitation with MeJA.