'In Germany, 57 pharmaceutical products based on Devil's Claw, marketed by 46 different companies, have cumulative sales volumes alone worth more than $40 million,' Georgiev noted.

Currently, more than 25 percent of all prescribed medicines used in the industrialised countries are derived either directly or indirectly from plants, many of which are rare and sometimes endangered.

Hairy root, an infectious plant disease caused by the soil bacteria Agrobacterium rhizogenes, is at the core of a promising new technique that could one day lead to 'biofactories' that produce medicines derived from rare plants in huge quantities at a low cost.

Georgiev notes that hairy roots are a big improvement over traditional, greenhouse-based plant culturing. Georgiev and team are the first to induce hairy root cultures of Devil's Claw.

They took the plant's roots and infected them with the A. rhizogenes soil bacteria -- a natural genetic engineer -- to create a system of hairy roots to produce the plant's key medicinal chemicals, says a release of the American Chemical Society (ACS).

These findings were reported at the 238th national meeting of the ACS.