The effect of plant growth regulators on biomass formation and lobeline production of Lobelia inflata L. hairy root cultures

We have studied the biomass and alkaloid production of genetically transformed hairy root cultures of Lobelia inflata L. The hairy root clone 8009/h7 transformed with Agrobacterium rhizogenes strain R 1601 was cultivated on B5 solid media containing different amounts of the growth regulators KIN, IAA or NAA. KIN significantly decreased growth and lobeline production and strongly inhibited biomass formation at 5 mg/l. IAA and NAA had characteristic morphological effects on growth, in increasing the number of the lateral roots. However they restricted linear growth. Addition of IAA or NAA into the culture medium increased the biomass formation and lobeline production of hairy roots. It was found that the greatest amount of lobeline was obtained at the 0.2 mg/l IAA concentration, similar to the effect of NAA.