Production of phenylethanoid glycosides under PEG-induced osmotic stress in Scrophularia Striata Boiss. Cell culture in bioreactor

Abstract

Scrophularia striata Boiss. (Scrophulariaceae) is a significant medicinal and economic plant endemic to Iran. In the research, the effect of osmotic stress on metabolite content during cell growth was studied in S. striata cell culture in a bioreactor system. The high-performance liquid chromatography(HPLC) metabolic profiling showed changes in levels of primary metabolites, containing some amino acids and carbohydrates, secondary metabolites, containing some phenolic acids, flavonoids (diosmin, catechin, rutin,and myricetin), a stilbenoid (resveratrol) and phenylethanoid glycosides (acteoside and echinacoside) in response to elicitation with polyethylene glycol (PEG) 6000. Content of acteoside was significantly induced and was achieved by 6.38 folds compared to the control. This approach can be used to improve mass production of acteoside from S. striata cell culture in industrial bioreactors. The two-dimensional electrophoresis (2-DE) study showed that elicitation of cell culture with PEG 6000 led to modification of proteome profile. In PEG-treated cells, 45 spots were upregulated and 47 spots were downregulated (fold>2 and p<0.05) compared to control and 4 protein spots were determined by MALDI-ToF MS. These proteins corresponded to Glyceraldehyde 3-phosphate dehydrogenase, Cinnamoyl alcohol dehydrogenase, Manganese superoxide dismutase, and Flavodoxin-like quinone reductase 1, expressions of which were associated with stress condition.