91av

BIOTECH companies could do a lot more to ensure the safety of genetically
modified crops, says a committee of experts advising the British government. New
technologies, it says, could be used to prevent the nightmare scenarios dreaded
by consumers and campaigners: genes resistant to herbicides crossing into other
plants creating an unstoppable superweed; plants with genes for toxic substances
pollinating crops and producing poisonous food; or modified plants containing
novel proteins provoking allergic reactions.

The Advisory Committee on Releases to the Environment (ACRE) has issued a set
of guidelines telling companies how to use the latest advances in biotechnology
to minimise any risks of gene flow鈥攖he first time a regulatory body has
offered such advice. 鈥淲e鈥檙e not saying that they are unsafe,鈥� says Brian Johnson
of the government conservation body English Nature, a member of ACRE. 鈥淲e鈥檙e
saying, yes, you could reduce the risks even further, especially the risks to
产颈辞诲颈惫别谤蝉颈迟测.鈥�

Johnson says there will be no changes in the law to force companies to make
such improvements. But if they don鈥檛, he adds, they will find it much more
difficult to get their products approved.

The ACRE report, which was released for consultation this week, details the
tools biotech companies could use to enhance safety. But some of the
technologies are still being developed, and patenting might restrict their use.
鈥淧atenting technologies such as these has serious implications for biosafety,鈥�
Johnson says. 鈥淢y personal view is that the technology should be made widely
补惫补颈濒补产濒别.鈥�

While the report puts pressure on the biotech industry to change its ways,
for anti-GM campaigners it poses something of a dilemma. The new technologies
eliminate some of the dangers they are concerned about, but the crops will still
be genetically modified. 鈥淚 think it is really encouraging that [ACRE] has
started to think about these sort of issues,鈥� says Sue Mayer of GeneWatch
UK.

The report, entitled 鈥淕uidance on Best Practice in the Design of Genetically
Modified Crops鈥�, sets out three main guidelines. First, plants should be
engineered in a way that minimises the risk of gene flow to other crops or wild
relatives via cross-pollination. There have already been several examples of
such gene flow, including the case of the sugar beet that was accidentally
endowed with resistance to two different herbicides
(91av, 21 October, p 6).

At the moment, the only way to prevent gene flow is to set up buffer zones
between closely related species. This is not 100 per cent effective. But the
report outlines numerous ways of preventing gene flow altogether, such as
engineering plants so they鈥檙e incompatible with other strains, don鈥檛 produce
viable pollen, don鈥檛 flower or reproduce asexually
(see 鈥淭he next revolution鈥�).

Controversially, this list includes 鈥渢erminator鈥� technology, a method for
making crops produce sterile seeds which campaigners say would enslave farmers
by making them buy new seed each year. But the ACRE report points out that there
are practical as well as ethical problems with using terminator crops.

The second recommendation says that as little DNA as possible should be added
to plants. In particular, companies should avoid using antibiotic resistance
genes as markers. Researchers use these genes as labels for other implanted
genes. While the overuse of antibiotics is the main cause of antibiotic
resistance, 鈥渨e must not add to the risks鈥�, Johnson says.

Lastly, the report recommends that genes added to plants should be expressed
only when and where they are needed. For example, if foreign proteins are not
expressed in the parts of plants used for food, there would be little chance of
them provoking an allergic reaction.

Such an approach could also stop foreign proteins being expressed in the
pollen of modified plants. There was an outcry last year when studies suggested
that pollen from maize engineered to make the bacterial Bt insecticide could
kill monarch butterflies (91av, 22 May 1999, p 4).

The report also suggests that GM traits in plants could be activated only
when a specific chemical is applied to a field. Anti-GM activists have attacked
such technology because they think companies will use it to force farmers to buy
expensive activation chemicals. But the report says that it could have benefits
if used in the right way.

Mayer welcomes the report because she says regulators underestimate the risks
posed by the current generation of modified crops. They assume that farmers will
follow rules about, say, maintaining buffer zones between crops. 鈥淭hat is very
耻苍濒颈办别濒测.鈥�

Biotech companies have cautiously welcomed the report. Monsanto described it
as well-considered and comprehensive. 鈥淎s a leading player, we are looking at
the feasibility and potential benefits of the technologies mentioned,鈥� says its
spokesman Tony Combes.

Mark Bailey, chair of the ACRE subgroup that compiled the report, says he
very much hopes that other countries will adopt this new approach. 鈥淣othing like
this exists elsewhere,鈥� he says.