Stellenbosch University's (SU's) Department of Botany and Zoology research
team has successfully established cultures from hairy rooted South African
plants that are currently exploited for their medicinal value.
Hairy roots are formed when the soil bacterium Agrobacterium rhizogenes
infects wounded plants. This particular bacterium is regarded as nature's
genetic engineer as it has the ability to transfer part of its genetic
material, its root inducing genes, to the host plant's DNA. Upon infection,
the plant becomes genetically modified to produce fine roots, which grow at
high rates.

Recent findings indicate that the hairy root cultures accumulate a complex
of compounds which have antifungal activity. These transgenic roots may be
easily established as a production platform for the agrochemicals sector.

Pelargonium sidoides is used to produce an herbal extract for the treatment
of lung infections. This plant is harvested from the Eastern Cape for its
underground tubers, which are used to produce a root extract for the
international natural products sector. As a result, populations of this
plant in the wild are dwindling at an alarming rate.

The remarkable quality of the hairy root system is that it provides an
alternative source of compounds, thus reducing the need for wild harvesting
of medicinal plants and meeting commercial demands for natural products. The
team's research aims to use bioengineering to alter metabolic pathways so
that it can increase compound yield.
South African researchers are beginning to recognise the potential of using
?hairy root' technology for producing industrially useful compounds. In the
past 25 years, successes in using this system for producing compounds are
many including the production of anticancer compounds, vincristine and
vinblastine from periwinkle.

Chinese scientists have been investigating the potential of exploiting hairy
roots of Danshen a plant that is used in Chinese traditional medicine to
treat cardiovascular diseases. Hairy roots may be regarded as biofactories
or chemical factories, which have many advantages for producing
pharmaceutics, agrochemicals, food flavourants, dyes and other chemicals,
which may be industrially useful. In Africa, use of this technology is
lagging behind even though this continent has a long established history of
medicinal plant use.

The genetically modified roots accumulates chemical compounds at higher
levels compared to non-genetically modified cultures. Sometimes novel
compounds, which are not normally found in the plant may be synthesised. In
order to harness the potential of these fine, fuzzy roots, scientists need
to determine whether the nature of the compounds and whether these hairy
roots are able to synthesise compounds on a long-term basis. Hairy roots may
then be transferred to a bioreactor, or fermenter, for commercial production
of useful chemical stability of compounds synthesis.
www.checkbiotech.org