The effect of elicitors on the biochemical properties and expression of the genes involved in sesquiterpenes biosynthesis pathway in the hairy root cultures of medicinal plant Valeriana officinalis L.

In order to induction of hairy roots, the leaf and petiole explants from seedlings grown under in vitro condition were inoculated with A4 strain of Agrobacterium rhizogenesis. Transgenic hairy roots were confirmed by PCR. Transgenic hairy roots were treated with different concentrations of iron and nickel nano-oxides and methyl jasmonate alone and in combination with L-leucine. Then hairy roots were sampled at 24 and 72 hours after treatment and the biochemical properties and expression of VoTPS1 and VoTPS6 genes were evaluated. The gene expression level was measured using real-time PCR technique and specific primers for each gene. The results showed that the combined application of 100 μM methyl jasmonat and 1 mM L-leucine was increased the activity of catalase enzymes and proline content in Valerian hairy root compared to the control. Among the different concentrations of nickel nano-oxide, the treatment containing 30 mg/l nickel nano-oxide with 1 mM L-leucine increased the activity of peroxidase enzyme and containing 60 mg/l nickel nano-oxide increased the total protein content in hairy roots. In addition, Among the different concentrations of iron nano-oxide, 30 mg/l of this nano-oxide increased the activity of peroxidase enzyme and the amount of flavonoid content, and combination of 90 mg/l of this nano-oxide with 1 mM of L-leucine amino acid was led to the an increase in proline content. The highest expression for VoTPS1 gene was observed in treatment containing 60 mg/l iron Nano-oxide at 24 hours after elicitation. The highest expression for VoTPS6 gene was observed in treatment containing methyl-jasmonate (100µM) and L-leucine (1mM) at 72 hours after elicitation.