Efficient in vitro elicitation of β-carboline alkaloids in transformed root cultures of Peganum harmala

Abstract

An efficient in vitro production of biomass hairy root cultures and elicitation of β-carboline alkaloids of Peganum harmala was established from P. harmala seedlings. Hairy root culture was arised by inoculation of the excised seedling with Agrobacterium rhizogenes. Analysis of rolC and virC genes by using polymerase chain reaction (PCR) has confirmed the transformation of the root culture. Hairy root cultures were employed to study the production of harmine as the main β-carboline alkaloids. The transformed cultures were incubated with potential elicitors, such as hydrogen peroxides (H2O2), or biosynthetic precursor as tryptophane in order to stimulate the biosynthesis of β-carboline alkaloids, mainly harmine as the major one. Profile and amounts of β-carboline alkaloids were analyzed using capillary GLC–MS.The results revealed that, treatment of the cultures with H2O2 (0.01%) induced the accumulation of harmine, as the major β-carboline alkaloids in root, by approximately sixfold as compared to the untreated control. The highest stimulation resulted in a harmine level of ca. 4.5mg/g DW after 24h of incubation. Concerning the biosynthetic precursor, tryptophane (2mM) enhanced the alkaloid production approximately fivefold (0.25–0.3mg/g DW) within 24h.