The influence of amino acids on the lobeline production of Lobelia inflata L. hairy root cultures

The herb Lobelia inflata L. (Lobeliaceae) contains piperidine alkaloids. The main alkaloid is the pharmacologically-active lobeline. We have studied the effects of alkaloid precursor amino acids (lysine and phenylalanine) on the growth and alkaloid production of 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 medium containing lysine (Lys) and phenylalanine (Phe) both in the presence and absence of the growth regulators IAA and kinetin. On the medium containing hormones growth was delayed until day 14. The application of growth regulators to the B5 media containing amino acids either singly or in combination increased the biomass in all cases. The maximum dry weight was achieved in a medium containing Phe + Lys and growth regulators. The highest lobeline level (36 mug/g) was detected in tissues cultivated on hormone-free medium containing Phe. In hormone-free media, lobeline production increased in the presence of either Phe or Lys compared with the control, but the addition of both greatly decreased synthesis. In contrast, the addition of both amino acids to media supplemented with IAA and kinetin increased lobeline production.