Optimization of induction and culture conditions and tropane alkaloid production in hairy roots of Anisodus acutangulus

Abstract

In this study, an efficient transformation system for the medicinal plant Anisodus acutangulus was successfully developed and optimized using Agrobacterium rhizogenes. Three bacterial strains, A4, R1601, and modified C58C1 and three explant types, leaf blade, petiole, and stem, were examined. The highest transformation efficiency of 94.44% was achieved using strain C58C1 with stem explants. Over 20 independent hairy root lines were successfully established with strain C58C1 using stem explants, all of which contained the ro/B and ro/C genes as confirmed by polymerase chain reaction (PCR). Out of four media compositions, the liquid 1/2 MS medium was found the most suitable for hairy root growth. The maximum biomass of one hairy root line increased up to 80 times in liquid 1/2 MS medium after a 30 day culture period. Different hairy root lines displayed a varied capacity for tropane alkaloid production and the best hairy root line (T4) from the C58C1-stem combination produced up to 10.21 mg/g (dw) of hyoscyamine, which was about 1.5-fold higher than in the wild type plants. To our knowledge, this is the first report to demonstrate the production of tropane alkaloids in hairy roots of A. acutangulus.