The Effect of Chitosan and Chitin Oligomers on Gene Expression and Lignans Production in Linum album Cell Cultures

Background: Linum album, a herbaceous and medicinal plant, has been shown to accumulate anti-tumor podophyllotoxin (PTOX) and related lignans. Objective: In this study, we have verified the time-course of cell growth, lignan production in cells treated with chitosan and chitin oligomers. To study mechanism of chitosan and chitin oligomers action, expression of phenylalanine ammonio-lyase (PAL), cinnamoyl-CoA reductase (CCR), cinnamyl alcohol dehydrogenase (CAD) and pinoresinol lariciresinol reductase (PLR) genes were investigated. Methods: The cells were treated with 100 mg l-1 chitin and chitosan oligomers. Cells were harvested for 5 days after elicitation. lignans quantified by reverse-phase high-performance liquid chromatography (HPLC). Cell samples frozen with liquid N2 were used to elucidate the expression level of genes by quantitative PCR (qPCR). Results: Cells elicited with chitosan hexamer for 5 days yielded the highest amount of PTOX (73.5 µg/g dry weight) and lariciresinol (96 µg/g DW) which were about 3-fold and 2-fold higher than control, respectively. The expression of genes by oligomers was increased, reaching a peak at 3 day after treatment. Conclusion: Chitosan and chitin oligomers up-regulate the production of PTOX, by effecting on gene expression of PTOX biosynthesis pathway.