Genetically Engineered Pesticides .
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Genetically engineered pesticides have been created with the purpose of .
killing insects that destroy crops by the use of microbial pathogens. Plants have .
also been genetically engineered to produce toxic proteins themselves, without .
needing pesticides. .
An example of this is the baculovirus which, like other genetically .
engineered pesticides, gets a gene inserted into it (by the use of restriction .
enzymes that splice DNA and allow genes to be added to the sticky ends) .
that encodes for a toxin specific to the insects it is trying to eliminate which in this .
case are bollworms and budworms. It uses a toxin found in scorpions and doesn't .
harm humans or wildlife. The sticky ends base pair with the complementary .
sticky ends of the scorpion DNA fragment. The fact that viruses and their hosts .
have such specialized relationships means that it is possible to target specific .
insects that need to be controlled, while not harming ones that may be beneficial to .
the crops.
The scientists conducted the tests on small field plots using the procedures .
of the Environmental Protection Agency. The growth of the cotton plants used .
surpassed or at least was equal to that when using different biological .
insecticides.
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A problem encountered on the way to this finding was that the virus was .
taking 5-7 days to kill the insects, and the insects exposed were eating increased .
amounts before they died. Deleting a gene in the virus solved that dilemma. .
Strains of the virus that acted faster were found, and toxin genes were inserted that .
had a toxic affect when expressed. Toxins from different organisms .
were tested for this position, and the scorpion gene proved the most effective. .
There were no effects on the innocuous insects that weren't targeted by the .
pesticide, such as spiders, honey bees, and some insects. Pesticides that are in use .
