An expanded Web version of segments seen on CNN
Bio-engineers find a way to 'contain' super plants
Auburn University researchers are creating
bio-engineered tobacco plants that are herbicide resistant
AUBURN, Alabama (CNN) -- Researchers at Auburn University
have developed a technique that they say should wilt fears
that genetically altered plants
will spread their genes
around. Based on experiments with tobacco plants, scientists
say they can now confine certain implanted characteristics to
a single species.
The basic problem that the Auburn scientists were tackling
was this: While scientists have already been able to
genetically engineer crops that are resistant to weeds and
bugs, they want to also make sure that those "super powers"
will not be transferred to nearby weeds -- a process that
could make the weeds resistant and allow them to spread out
Coming to Terms
Chloroplast: Tiny structures inside plant cells
containing the green pigment chlorophyll. Chloroplasts are
found in the cells of leaves and in the surface cells of
stems. Within the leaf, they occur mostly in those cells near
the top of the leaf, where light intensity is greatest.
DNA: A complex two-stranded molecule that contains, in
chemical coded form, all the information needed to build,
control and maintain a living organism.
It's a fear that has been voiced by critics of bioengineering
Some critics worry that genetically altered plants
could transfer their super powers to nearby weeds
But Auburn says it may have an answer to the problem.
University researchers say they have now engineered tobacco
plants that are herbicide-resistant and can deliver a deadly
bite to bugs that usually devour the plants -- but without
passing on those characteristics to other plants.
Dr. Henry Daniell explained the
procedure to CNN: the researchers introduce specific DNA into
the part of the plant cells called the chloroplast. There, the
DNA is released and the genes get integrated into the chloroplast's
DNA. ( 102K/8 sec. AIFF or WAV sound)
The chloroplasts are the key to keeping the tough new genes
from spreading to other plants, since the altered genes stay
locked up in the chloroplasts and do not get transferred into
This means that, even if the genetically engineered plant
cross-pollinates with, say, a weed, the genes that convey bug
and herbicide resistance will not get passed on to other
In the future, scientists could use DNA-altering
processes on cotton plants, making certain cloths
Once the plant has been made resistant, it's a case of the
survival of the fittest: Those that inherit the resistant
gene thrive in the laboratory dish and grow into plants and
pass the new traits on to the next generation. Those plants
that do not accept the genetically altered state die. ( 102K/9 sec. AIFF or WAV sound)
Tobacco plants are being used because scientists can draw on
years of research that has been carried out on the plants in
years past. Another key reason is that tobacco plants can be
genetically engineered in only three months.
Similar research is already being conducted on peanuts and
Chardonnay grapes. Scientists say these techniques also could
lead to genetically altered cotton -- and to clothes that
won't fade, even after washing and sunlight exposure.
Correspondent Alesia Stanford contributed to this report.