A study of the production of essential oils in chamomile hairy root cultures

The active substances in chamomile (Matricaria recutita L.) belong to chemically different structural types. The largest group of medically important compounds forming the essential oils are primarily chamazulene, (-)-alpha-bisabolol, bisabololoxides, bisabolonoxide A, trans-beta-farnesene, alpha-farnesene, spathulenol and the cis/trans-en-in-dicycloethers. Flavonoids, coumarins, mucilages, mono- and oligosaccharides also have pharmacological effects. We studied the production of essential oils in genetically transformed cultures. Sterile juvenile chamomile plants were infected with A4-Y strains of Agrobacterium rhizogenes. They are known plant pathogens and are capable of inducing so-called hairy roots. The transfer DNA segment of the Ri-virulence plasmid of A. rhizogenes becomes integrated in the genome of the plant cells. The isolated hairy roots grow rapidly on hormone-free media. In order to obtain bacteria-free media, we cultured the transformed roots on Murashige-Skoog (MS) medium supplemented with carbenicillin (800 mg/l). To study the production of essential oils, the clones were propagated on liquid and solid MS and Gamborg (B5) media, respectively. According to gas chromatography, the composition of the essential oil of hairy root cultures on different media was found to be similar, but differing in proportion. The main component of the essential oil which was identified by gas chromatography and mass spectrometry was trans-beta-farnesene, as in the intact roots.