Elicitation of furanocoumarins in poison hemlock (Conium maculatum L.) cell culture

Furanocoumarins, such as psoralen, xanthotoxin and bergapten, serve as protectants against phytopathogens and are used in pharmaceutical applications e.g. as DNA-crosslinking agents against non-melanoma skin cancers. Poison hemlock plants (Conium maculatum L.) are a known source of furanocoumarins and toxic alkaloids, but systematic research on callus and suspension cultures with the aim of eliciting secondary metabolites is lacking. Therefore callus cultures of poison hemlock were induced with 0.186 mg L-1 6-benzylaminopurine and 2 or 4 mg L-1 naphthalene acetic acid on McCown's Woody plant medium. A broad variety of elicitors (alginic acid, cellulase, chitosan, ethylene, methyl jasmonate, salicylic acid, copper(II) sulphate and silver nitrate) were tested with an established cell suspension culture for their capacity to trigger differential metabolite accumulation. Samples were extracted and analysed by gas chromatography-mass spectrometry. Elicitation with alginic acid, cellulase, chitosan, silver nitrate and copper(II) sulphate induced furanocoumarins. Plant hormones (ethylene, methyl jasmonate and salicylic acid) were not able to induce furanocoumarins. Extracts contained bergapten, columbianetin, isopimpinellin, marmesin, oroselone, psoralen and xanthotoxin but not piperidine alkaloids. The relative amount of furanocoumarins was generally higher in the medium than in the cells. The report describes the angular furanocoumarins oroselone and columbianetin together with the linear furanocoumarin marmesin, elicited for the first time in poison hemlock.