Cell culture establishment and regulation of two phenylethanoid glycosides accumulation in cell suspension culture of desert plant Cistanche tubulosa

Cistanche tubulosa is one of the most valuable desert medicinal plants, whose cell culture investigations have been rarely reported before. Phenylethanoid glycosides (PhGs) are its major components with a wide range of pharmacological activities. In this article, callus culture and cell suspension of C. tubulosa were established. Fleshy stems were found to be the most suitable explants for callus induction, and the optimal medium for induction was B5 solid medium supplemented with 0.8 g/L casein hydrolysate, 20 g/L sucrose, 2 mg/L naphthaleneacetic acid (NAA), and 1 mg/L 6-benzyladenine (6-BA). Based on qualitative and quantitative determination of two PhGs (echinacoside and acteoside) contents, the effects of carbon source concentration, precursor feeding, and elicitor treatments on cell growth and two PhGs accumulation in cell suspension cultures were investigated. Thirty g/L was the optimal initial sucrose concentration to obtain the high yield of biomass (9.29 g dry weight, DW) per liter cell suspension culture, echinacoside (12.14%, based on DW cells) and acteoside (2.17%). Precursor feeding also had a positive effect on PhGs accumulation. Feeding of precursor tyrosine (1 g/L) to the cell cultures increased the levels of echinacoside to 18.83% and acteoside to 2.92%, which were approximate 1.5 times of the corresponding levels in the control group. Methyl jasmonate (MJ) was the ideal elicitor for PhGs accumulations in C. tubulosa, particularly for eliciting acteoside production. The maximum echinacoside and acteoside contents reached 21.18 and 5.24% after 12 h of treatment with 200 µM MJ, respectively, which were approximate twofold higher than those in wild plant.