ARE THEY REALLY
C Kameswara Rao
Foundation for Biotechnology Awareness
and Education, Bangalore,
Restriction Technologies (GURTs) are a group of tools to regulate gene
expression, in different ways. The concept is not new and there have
been many conventional means to alter gene expression such as addition or
deletion of genes, induced gene mutations, induced polyploidy, experimental
hybridization and somatic hybridization. However, these are difficult
to manipulate with precision. Modern GURTs protocols, such as the
patented ‘Control of Plant Gene Expression’
(CPGE, US Patent No. 5,723,765, March 1998), RNA interference (RNAi, gene
silencing) and the now well known rDNA technology, are more precise.
The CPGE (aka
Terminator Technology) allows the crop to grow normally and set seed, but the
seed would not germinate as the development of the embryo was
arrested. The anti-tech activists have conducted such massive fear-generating campaigns against CPGE that
made Governments of many countries prohibit the use of CPGE in
agriculture. Even the Patent holders had agreed not to use CPGE in any
crop. CPGE was not targeted at the farmer to prevent him from using the
previous seasons’ seed, but this was the thrust of the anti-tech argument.
In another approach of CPGE, derogatively dubbed as
the ‘traitor technology’, the expression of a specific desirable transgenic
trait is dependent upon spraying a specific proprietary chemical, sold
separately, often by the same company.
RNA interference (RNAi, gene silencing),
which was awarded the Nobel Prize in 2006, has gained scientific acceptance
and is being deployed in several innovative products, particularly in
medicine. A variety of coffee without caffeine was developed by gene
silencing, as also a ‘tearless onion’ demonstrated in February 2008.
The technology for ‘reversible transgenic sterility’ (RTS), patented a couple of years ago, allows the farmer
or breeder to restore the seed’s fertility by applying an external chemical
CPGE gained all
its notoriety as unfortunately it was first demonstrated in the context of
arrest of the development of the embryo making the seed unusable to raise a
crop from it.
Opponents to GURTs argue that the ‘terminator and
traitor seeds’ could make farmers dependent on multinational companies
(MNCs). Profitable and sustainable agriculture depends upon quality
seed of even the non-GE crops an area already dominated by the MNCs, because
of large scale failure of the public sector in different parts of the world,
more particularly the developing countries.
technology essentially requires to be triggered by a chemical compound, such
as a tetracycline antibiotic, to arrest embryo development, which any one
should know as expensive and irrelevant to field agriculture.
CPGE can be used
safely to prevent gene flow where the commercial product is not the embryo
but the endosperm as in rice, wheat and corn. It can also be used where
the crop is vegetatively propagated such as potato or grape vine. It is
useful in producing almost seedless fruits of cucumber, melon and pumpkin or
aubergines, where the seed is wholly formed of the embryo. CPGE would
not be used when the seed formed wholly of the embryo is the commercial
product, such as chickpea, groundnut, soybean, etc.
GURTs containing crops are not designed for the
marginal and poor farmers in the developing countries who use their own or a
local seed. GURTs are meant for farmers who are technologically savvy
and can afford to buy hybrid GURTs-incorporated transgenic seed each season,
to prevent gene flow from GE crops. For decades, farmers who have been
using branded designer seed, GE or not, are fully aware that they cannot
recycle the seed as the benefits of the technology rapidly dwindle with each
On the other hand, the seed companies know that
it is not ethical and/or economical to jeopardize the interests of the small
farmer who may recycle the seed season after season and the revenue loss to
the companies from such ill advised use of seed is inconsequential.
Benefits from GURTs in Crops
Despite the very
vehement opposition emanating from reasons other than sound science, GURTs
can be used to benefit. The more important advantages are:
a) Prevent gene flow from transgenics through pollen by producing sterile
pollen or through seed by arresting embryo development.
Help in containing GE pharma crops that synthesize therapeutically active
c) Protect Organic Farming, since
sterile pollen cannot cause cross pollination that may affect Organic
Certification, though currently this is not an issue.
d) Induced male sterility is an accepted tool in plant breeding to produce
hybrids in otherwise difficult crops such as sorghum and mustards, and GURTs
make this much easier than
CPGE could be a boon, if the trigger, instead of a tetracycline antibiotic,
is a product of a seed pathogen such as that causes grain smut or a product
of the host, produced in
response to the pathogen’s entry into the developing
grain. Arresting embryo development in such seeds would control
the transmission of the seed borne pathogen to the next
f) Protect the genetic design of GE
g) Prevent the unauthorized or illegal
cultivation of transgenic crops.
h) Since GURTs would block gene flow
from transgenic crops, their incorporation into transgenics is actually in
keeping with the aims of the Cartagena Protocol on Biodiversity (Article
and GURTs do not threaten
biodiversity as alleged by activists.
GURTs and Convention on Biological Diversity
The UN body, Convention on Biological Diversity
(CBD) has slapped a de facto moratorium over six years ago on the use
of GURTs in crops. In 2006, Australia, Canada and New Zealand
backed a proposal to end the moratorium on CPGE at the meetings of 8th
Conference of the Parties (CoP) of CBD which rejected the
proposal. At the same meetings, another proposal for field
trials and a case-by-case assessment of GURTs, concerning the potential impact
on the environment, human health, and traditional agriculture and knowledge,
was rejected by a working group
of the CBD.
The issue is on the agenda of the 9th CoP of the CBD held during 20th to
30th May 2008, discussed under a) Impact of GURTs on Farmers Seed
Systems, and b) A New Generation of GURTs: the Potential Impacts on
Biodiversity and Food Sovereignty. The notes accompanying these agenda
items did not look positive in approach and predictably no decision came on
even relaxing the restriction let alone lifting the moratorium.
objective behind GURTs is biocontainment of transgenes in crops and trees, to
the advantage of the farmer, the consumer, biodiversity and the environment.