Optimization of rapid and efficient hairy root induction in two Hyoscyamus reticulatus L. and Hyoscyamus pusillus L.

Hyoscyamus species such as H. reticulatus L. and H. pusillus L. are rich sources of tropane alkaloids, mainly hyoscyamine and scopolamine, which are used for their mydriatic, antispasmodic, anticholinergic, analgesic and sedative properties. In this study, in the first experiment, the effects of four strains of Agrobacterium rhizogenes (ATCC 15834, A4, A7 and A13) and three explants (leaf, hypocotyls, and cotyledon) on hairy root induction were investigated in both H. reticulatus and H. pusillus species. In the second experiment, the effects of various culture media (MS, 1/2 MS, 1/4 MS, and B5) were evaluated on some morphological and phytochemical traits of hairy roots. The results showed that in H. reticulatus, maximum hairy root induction (78%) was obtained in the cotyledon explant inoculated with A7 strain and maximum hairy roots fresh weight (6.25 g) and dry weight (0.5 g) were recorded in MS medium. In this species, the highest total phenol (3.82 mg GAE g-1 FW) and total flavonoid (7 mg QUE g-1 FW) content were observed in MS medium; however, no significant changes were observed in the activity of antioxidant enzymes of hairy roots cultured in different media. In H. pusillus, the leaf explant inoculated with A13 strain showed maximum hairy root induction (90%), and the highest hairy root fresh weight (5.25 g) and dry weight (0.43 g) were observed in MS medium and the highest total phenol (2.26 mg GAE g-1 FW) and flavonoid (9.22 mg QUE g-1 FW) content were obtained in B5 medium. This study showed that basal culture medium type and plant species had a significant impact on the biomass and phytochemical characteristics of hairy roots.