The Study of Effect of Myo-Inositol on Biomass and Secondary Metabolites value in Adventitious Roots of St. John’s wort (Hypericum perforatum L.)

St. John’s wort is a traditional herbal medicine used to treat depression and wound healing. Natural resource dependency and traditional cultivation methods often require months and years of time to reach medicinal plants. Establishing a hairy root suspension culture system can accelerate proliferation on a large scale, improve breeding and protect the species, but optimization and production on a large scale require an increase in the biomass and secondary metabolites of the root. In this study, the effect of different concentrations of myo-inositol (50, 75, 100, 125, 150, 175, 200, 225, 250, and 275 mg / l) were evaluated on biomass, phenol, flavonoid, DPPH activity and secondary metabolites in St. John's wort adventitious root in Agricultural Biotechnology Research Institute-Central Region of Iran. The results showed that 125 and 150 mg L-1 myo-inositol concentration had the highest dry weight, growth rate and growth ratio. The concentrations of 100 and 250 mg L-1 myo-inositol have been showed the highest and lowest amount of hypericin and pseudohypercin, respectively. From the viewpoint of production of hyperforin, the treatment with 100 mg L-1 myo-inositol was highest and the concentration of 125 mg L-1 had the least effect on the level of hyperforin in St. John's wort adventitious root culture. There was a significant difference between treatments in terms of phenol and flavonoid content, so the concentration of 75 and 225 mg L-1 and 75 mg L-1 myo-inositol had the highest amount of phenol and flavonoids. The DPPH activity changes were different between treatments, and the 50 mg L-1 showed the lowest amount of DPPH activity. However, the DPPH activity was highest in treatment with 75 mg L-1 myo-inositol concentration. Since the potential for stimulating secondary metabolites varies among cultures, elicitors, conditions for applying different treatments and other parameters, further research is needed to optimize better and more efficient guidelines.