Effect of different nitrate/ammonium ratios on biomass content and some biochemical characteristics of lattice henbane plant (Hyoscyamus reticulatus L.) hairy roots.

Hyoscyamus reticulatus L. is an herbaceous, biennial plant, belonging to Solanaceae family and Due to production of tropane alkaloids such as hyoscyamine and scopolamine are widely used in medicine. In the present study, in order to increase production of tropane alkaloids, cotyledon-derived hairy root cultures transformed with Agrobacterium rhizogenes strain A7, elicited by various ratio of nitrate to ammonium. The effect of different ratio of nitrate to ammonium (9.9:5.1, 19.75:10.25, 39.5:20.5 (control), 79:41 and 158:82 mM) in two exposure times (24 and 48 h) were investigated. According to the ANOVA results, the highest hyoscyamine and scopolamine production (about 1.5-fold and 1.17-fold increase over the control) was observed in treatment 9.9: 5.1 mM nitrate to ammonium at 24 hours of exposure time, respectively. Therefore, the highest catalase antioxidant enzymes activity (23/40 µmol min-1 mg-1 pro) and peroxidase (145/32 µmol min-1 mg-1 pro) and ascorbate peroxidase (24/22 µmol min-1 mg-1 pro), was obtained in nitrate to ammonium ratio (158: 82 mM) with 24 hours exposure time. According to these results, nitrate to ammonium ratio as elicitor can be used as effective strategies in plant biotechnology in order toenhance production of plant secondary metabolites such as tropane alkaloids.