By Daniel Bardsley

It has been three decades since the earliest genetically engineered
organisms were created - the first a bacterium containing a salmonella
gene - but they continue to stir debate.
Scientists have succeeded in genetically modifying everything from fungi to
mice, but it is genetically engineered plants that perhaps create the
greatest controversy. The health impacts of eating such genetically modified
organisms (GMOs) and environmental concerns about the transfer of their
genes to wild plants are issues on which experts are sharply divided.

GMOs are commonly grown commercially in North America while Europe has been
less welcoming. Some of the fiercest opposition has come in the UK, where
last month trials of a potato engineered for resistance to nematode worms
were abandoned after protesters destroyed the crop.

EU rules state that foods containing material from GMOs be labelled as such,
and many European countries have yet to grow the plants commercially.
Similarly, such commercial growing has yet to take place in the UAE. The
emirates, however, have not enforced rules on labelling and last year the
environmental group Greenpeace revealed that out of 11 food products it
tested in the UAE, seven contained GMOs.

Among the most common GMOs grown are plants resistant to herbicides and
pests.

Clare Oxborrow, a GMO campaigner at Friends of the Earth, the environmental
group, said trials and commercial cultivation of such varieties raised many
concerns.

Herbicide-resistant plants, according to Ms Oxborrow, reduce biodiversity
because their growth is tied to the use of herbicides that kill all plant
life except the crop.

?That knocks out food for birds and insects and has potential impact up the
food chain,? she said.

Similar issues apply to pest-resistant plants, which Ms Oxborrow said could
harm ?non-target? organisms such as butterflies and moths. If wild plants
picked up genes that, for example, conferred resistance to a pesticide, then
controlling them could prove difficult. Alternatively, if pest-resistance
genes spread to wild plants, those plants could cause further harm to insect
populations.

Apart from the environmental issues, Ms Oxborrow said GMOs were ?a
corporate-led technology? that multinational companies were using ?to take
over the world?s food supply?.

?The seeds are patented so farmers cannot save them for the future. They
have to buy the seed each year. For developing countries that?s not very
suitable,? she said.

Plants that are genetically modified have had specific genes from another
organism added to them.These genes were isolated from that organism, cloned
and transferred into the plant.

Bacteria may be used as vectors or sometimes young plants are bombarded with
gold particles coated with a plasmid ? a circular piece of DNA containing
the genes of interest.

What makes genetic engineering powerful is that it allows genes to be
transferred between widely divergent organisms. For example, using
traditional techniques, plant breeders may introduce genes from a wild grass
into a variety of wheat.

In genetic engineering, because reproduction is not required for gene
transfer, even animal genes can be introduced into plants. Also, it is
possible to introduce a specified number of known genes, rather than the
hundreds that might be transferred during traditional breeding.

According to Mike May, a scientist at Broom?s Barn, a plant sciences
research site that is part of Rothamsted, the UK?s largest agricultural
research centre, many of the objections campaigners have to GM crops apply
also to varieties created using traditional techniques.

?A [conventionally bred] crop may have enhanced disease resistance. The gene
could get out into the wild. It?s not unique to GMOs and the fact it happens
isn?t necessarily a bad thing anyway,? he said.

As an example, Mr May cites the implications of developing a form of
cultivated sugar beet that contained genes which conferred resistance to a
herbicide. ?If the genes got into wild beets... they wouldn?t get an
advantage as we don?t spray them [with herbicide],? Mr May said.

On the other hand, it might cause problems if the genes were for resistance
to viruses. Another potential source of concern are pharmaceutical crops ?
plants grown to synthesise drugs.

?These would need very careful checks. It depends on what the gene is,? he
said. ?If it?s a drug that can be toxic in some forms and it gets out so
that it?s eaten by mammals or birds, there could be issues.

?If you get to the stage where there?s a risk, you don?t develop that crop.
It?s not a bad thing per se but if you don?t want it, you don?t allow it.
There has to be good regulation and a case-by-case analysis.?

In Mr May?s view, GMOs are more tightly regulated than plants produced by
other means, so the environmental or health effects will be identified
before commercial cultivation.

?If the gene is making the plant produce a toxin against insects, then these
plants are assessed for toxin levels,? he said.

?If you look at conventional breeding, we?ve created a whole host of species
that didn?t exist, often using mutagenesis ? radiation to produce a whole
range of mutants to select from. That?s pretty random, but we don?t worry
about it.?

A similar view is taken by Abdullah Ruwaida, a public health and environment
consultant to the General Secretariat of UAE Municipalities. A
biotechnologist himself, Mr Ruwaida believes it is wrong to condemn the GMOs
out of hand. ?It is good technology but it should be controlled,? he said.
?The harm that people are making about the products, it?s not reasonable.
They only stress the disadvantages that can occur.?

While the two sides disagree about the potential safety hazards of GMOs,
both camps agree that genetically modified plants have yet to fulfil early
hopes. There is little definitive evidence that genetically modified plants
produce better yields than conventionally bred equivalents. Given the
current concern over food shortages, this issue has become more critical
than ever.

?People are seeing the food crisis as a reason why we need to look at GMOs
again, but the [agricultural] companies have not produced increased yields,?
said Friends of the Earth?s Ms Oxborrow.

?[GMOs] have had some benefits, but these are the convenient effects of
growing them on a large scale.?

GM soya, for example, has yields that Ms Oxborrow said were five to 10 per
cent less than conventional varieties, but the GM version was grown because
it was herbicide-resistant and reduced growing costs. Farmers can spray the
crop and not worry about the labour-intensive process of removing weeds.

?But there are no drought or salt-tolerant crops. We?re being told these are
around the corner. GM crops haven?t delivered on their promise,? she said.

Mr May believes more time will lead to results. Genetic modification is in
his view ?another tool? that should be available to agriculture as it tries
to improve yields. Drought-tolerant plants were ?being worked on? and would
become available eventually.

?[Genetic modification] is a big advantage when it comes to making crops
that can grow in a dry area and that are more efficient in their use of
nitrogen,? he said.

www.checkbiotech.org