Forskolin production in untransformed root culture of Coleus forskohlii

Abstract

Untransformed cultures of Coleus forskohlii Briq. were initiated from in vitro micropropagated shoots derived from shoot tip culture. Effects of IAA, IBA and two IAA derivatives, 4-CI-IAA and 5,6-Cl 2-IAA were compared for growth and forskolin production in cultured roots grown on different basal media under different culture regimes. The roots grew well in the presence of all dosages of 4-CI-IAA and 5,6-Cl 2-IAA with 25% MS plus 1% sucrose and produced more forskolin as compared with IAA or IBA. The optimum concentrations needed for forskolin production were 1 μg 1 −1 for 5,6-Cl 2-IAA and 50,μg1 −1 for 4-CI-IAA. The highest amount of forskolin (0.09%) was raised at 50,μg1−1 4-CI-IAA after 60 days of culture. This enhanced level of forskolin was almost equal to the content in the wild plant. However, under similar conditions and with 500,μg 1 −1 IAA or IBA, the amount of forskolin produced was much smaller. IAA derivative-induced production of forskolin indicates the possibility for scaling up of the production of this compound in untransformed root cultur