The effects of nano-ZnO and nano-TiO2 on expression of Phenylalanine ammonia lyase (PAL) and Cinnamyl alcohol dehydrogenase (CAD) genes in cell culture of Linum usitatissimum L.

The flaxseed (Linum usitatissimum L) is recognized as an important crop and the rich source of useful fatty acids, protein, dietary fiber and lignans.Lignans as antioxidant compounds are an important group of secondary metabolites that have important biological activities, such as anti-cancer effects in humans. In this study, the expression of Phenylalanine ammonia lyase (PAL) and Cinnamyl alcohol dehydrogenase (CAD) genes in the lignan biosynthesis pathway were investigated under the influence of nano-ZnO and nano-TiO2 in flax cell culture. For this purpose, a factorial experiment in a completely randomized design with three replications were done to study the effects of of nano-ZnO and nano-TiO2. Nano-ZnO at 0, 30, 60 and 120 mg/L and nano-TiO2 at 0, 50, 100 and 150 mg/L were added to cell cultures and samples were collected at 0, 24, 48, and 72 h after adding nanoparticles. The gene expression analysis were studied using Real-Time PCR. The highest expression of PAL gene was observed at the concentrations of 30 and 60 mg/L, and the lowest expression was observed at the concentration of 120 mg/L of nano-ZnO. Nano-TiO2 had no significant effect on PAL gene expression, but the use of 150 mg/L nano-TiO2 led to increased expression of CAD at 48 and 72h. CAD expression increased at 60 mg/L concentration of nano ZnO at all intervals and the lowest expression of CAD was observed at 120 mg/L nano ZnO. The results of this study showed that zinc nanoparticles are effective in increasing the expression of both PAL and CAD genes, while the nano-TiO2 only affect the expression of CAD and has no effect on the expression of PAL expression.