Increasing of p-coumarate 3-hydroxylase gene expression and phenylpropanoid compounds of Scrophularia striata by chitosan

Chitosan is the main compounds of fungal species cell walls and as biotic elicitors could be used to improve secondary metabolites. In this study, we have verified the time-course of cell growth, phenylpropanoid compounds ( total phenol, flavonols, flavonoids and echinacoside) production in cells treated with chitosan. To study mechanism of chitosan action, expression of p-coumarate 3-hydroxylase (C3H) gene was investigated. The cells were treated with 10 mg/L chitosan. Cells were harvested for 3,5 and 7 days after elicitation. Echinacoside quantified by high-performance liquid chromatography (HPLC) and other phenylpropanoid compounds were measured with spectrophotometric assay. Cells samples were used to elucidate the expression level of C3H gene by Semi-quantitative RT-PCR. Following treatments with chitosan, the results showed that the cell growth and viability of cells were decreased as compared to control. In addition, chitosan increased total phenol, flavonoids and flavonols. Cells elicited with chitosan for 5 days yielded the highest amount of echinacoside wich was about 5.7-fold higher than control. The expression of gene by chitosan was increased, reaching a peak at 5 day after treatment (2-fold higher than control). Chitosan up-regulate the production of phenylpropanoid compounds and derivates such as echinacoside, by effecting on gene expression of this compounds biosynthesis pathway.