|Here's some food for
thought: Agricultural Research Service
scientists have discovered how to use eggs to protect certain grains from
gnawing bugs--without chemicals.
Here are more details
on this "egg-citing" news: Egg whites
have a protein called avidin. ARS chemist Karl Kramer and other scientists
showed that avidin blocks insect growth by tying up a vitamin called biotin. If
the bugs can't get their biotin, they can't grow, says Dr. Kramer, at the ARS
Grain Marketing and Production Research Center in Manhattan, Kansas.
insects cause millions of dollars of damage by chewing on stored products like
corn, wheat, rice and grain sorghum. ARS scientists are working to find ways to
control these insect pests without chemicals. One way is to change the plant's
genes with "resistance traits"--so the plant can resist the insect
without help from chemicals.
two or more heads
are better than one when it comes to fighting a common enemy--pests! So Dr.
Kramer's team joined up with researchers from two private companies: Pioneer
Hi-Bred International, Inc., in Johnston, Iowa, and ProdiGene, Inc. of College
Station, Texas. Together, these scientists are able to stay one step ahead of
many different kinds of stored-grain insects. Some, like the sawtoothed grain
beetle and the confused flour beetle, get into food containers in home
cupboards through cracks and holes. Others--like the lesser grain borer,
warehouse beetle, and even one called the cigarette beetle--actually chew holes
in plastic or cardboard packages.
Scientists at the biotechnology companies found a way to give
corn plants a little "something extra"--the egg gene that helps
produce avidin. This borrowed gene helps the corn fight off attacks by insects,
even when it's stored in grain bins or kitchen cupboards for months.
| Scientists have used this idea of borrowed genes
before. They put the genes for a substance from Bacillus thuringiensis
(Bt) bacteria into corn plants. But Dr. Kramer thinks that putting
avidin into corn is even smarter, because avidin can kill more kinds of
insects. Bt mainly kills moths and only a few beetles.
In lab experiments,
scientists found that most insects stopped growing and developing when they ate
corn with 100 parts per million (ppm) of avidin. (One hundred parts per million
is equal to one dollar in a pile of $10,000.) Only about half the insects died
when they ate corn with only 30 ppm of avidin.
You can learn even more
about avidin from a longer story in the August 2000 issue of Agricultural
Click here to
read it on the World Wide Web.