Physiologic responses of suspension-cultured Linum album Kotschy ex Boiss. cell to fungal elicitors

Elicitors are compound with biotic or abiotic origin which induce defence responses including secondary metabolite production. Elicitors may activate new genes which induce enzymes and finally produce different biosynthesis pathways and secondary metabolites. Linum album is one of endemic species in Iran and has lignans like podophyllotoxin (PTOX). In this study، we investigated the effect of fungal extracts of Fusarium graminearum، Rhizoctonia solani، Rhizopus stolonifer، Trichoderma viride and Sclerontinia sclerotiarum on cell growth and lignans production and phenylpropanoid compounds in cell suspension cultures of L. album. Various fungal extracts uniquely induced lignan production، so that F. graminearum extract induced the highest increase of PTOX [141 μg g-1 dry weight (DW)] which was 6-fold greater than the untreated control، while R. stolonifer extract enhanced the accumulation of lariciresinol up to 365 μg g-1DW، which was 7-fold greater than the control. In addition، fungal elicitors increased the total phenol، flavonoid، flavonol and lignin. To study the mechanism of fungal elicitors action، phenylalanine ammonio-lyase (PAL) and cinnamyl alcohol dehydrogenase (CAD) activity were investigated. The activity of PAL and CAD enzymes involved in the first steps of the phenylpropanoids biosynthesis was activated by fungal elicioes، reaching a peak at 3 days after treatment.