www.checkbiotech.org ; www.raupp.info ; www.czu.cz

UConn (University of Connecticut) plant biologists have developed a tool
that may help alleviate public concerns surrounding genetically-modified
plants, February 2007 by Beth Krane.

Controlling the flow of transgenic genes into the wild via pollen and
seeds has been a huge concern to the public and a major challenge for
scientists specializing in agricultural biotechnology.

The tool, called a "GM-gene-deletor," could prevent genetically-modified
gene flow into non-biotech crops or weeds.

The invention may be particularly useful to confine genetically altered
genes used in vegetatively-propagated, undomesticated bio-energy crops, such
as poplar, willow, and switchgrass.

The technology, developed in the laboratory of Yi Li, associate professor of
plant science, provides a successful method for eliminating all the
transgenic genes from pollen and seeds if needed. The research is published
in the March issue of Plant Biotechnology Journal.

UConn?s GM-gene-deletor technology also could allow farmers to produce
non-genetically modified consumer products, such as seeds, fruits, and
flowers, from transgenic plants.

?For example,? Li explains, ?herbicide-resistant genetically-modified traits
are primarily needed to protect crops during growth prior to seed or fruit
development.

The GM-gene-deletor could initiate the gene deletion process immediately
prior to seed or fruit development.

That way, farmers would get the benefit of the added crop protection during
a critical growth stage, without the unintended consequence of an
uncontrolled spread of a herbicide-resistant gene, which some believe could
create ?super weeds.??

UConn?s GM-gene-deletor also could be used in crops that are genetically
modified for the production of pharmaceuticals to block the accidental
transmission of these traits into food crops through seed or pollen.

The new technology also holds the potential to end a long-standing debate on
so-called ?terminator? gene or ?terminator? seed technology that has pitted
major agricultural biotechnology companies against poor farmers in
developing countries.

The terminator technology inserts terminator or suicidal genes into
genetically-modified seeds to ensure that no genes from genetically-modified
crops contaminate non-genetically-modified crops.

This process protects the companies? patents and could alleviate some of the
same consumer concerns Li?s technology addresses, but at the expense of poor
farmers in developing countries, who would have to buy fresh seeds every
year because the terminator gene system renders the genetically modified
plants sterile.

The terminator technology has yet to be commercialized because of the
problems it poses for farmers in developing countries.

?With our technology,? says Hui Duan, one of Li?s former doctoral students
and a co-author of the published research, ?the seeds the farmers save will
not have genetically-modified traits. The farmers would need to buy new
seeds each year if they want the crops to have genetically-modified traits
such as insect resistance or herbicide resistance. But if they did not want
to do so or could not afford to do so, they would still be left with viable
seeds to replant.?

Li?s group at UConn started this project in 2000 with funding from
Connecticut Innovation Inc., the Consortium for Plant Biotechnology Research
/ U.S. Department of Energy, and UConn.

The team, and collaborators in China and at the University of Tennessee,
reported a novel use of two site-specific DNA recombination systems to
assemble a highly efficient gene eliminator that specifically targets the
foreign genes.

By incorporating these systems into the genome of the genetically-modified
plants, the scientists found the undesirable genes were removed from the
pollen and seeds of the plant with as much as 100 percent efficiency.

Because of the exceptionally high deletion efficiency observed in the
experimental plants, Li and his collaborators anticipate enormous potential
for the technology to be used in large-scale plantings of agricultural
crops, as well as genetically improved trees and bio-energy/bio-fuel and
pulp-generating plant species.

[www.advance.uconn.edu]