Manhattan, Kansas
February 11, 2008
Scientists at
Kansas State University have
discovered that the salivary glands of a tiny insect may hold a
key
to developing pest resistance in plants.
A team of K-State researchers found that by using technology to
silence a gene in the salivary glands of pea aphids, the
insect´s lifespan was cut by more than 50 percent.
"What we found is that when we silenced the most abundant
transcript (gene), the aphids died in a few days," said K-State
professor of entomology John Reese.
The findings could lead to new ways to control insects in
plants, including such important crops as wheat, alfalfa,
soybeans, corn and sorghum, Reese said.
Finding ways to develop insect-resistant crops also brings
scientists closer to finding ways to reduce agricultural
producers´ dependence on pesticides. That helps the environment
and lowers growers´ input costs.
"If we can figure out how to get a plant to prevent the
functioning of an insect pest's gene, we can turn that plant
into a non-host for that pest," Reese said.
Reese was part of a research team that included assistant
professor of entomology Yoonseong Park and former graduate
student Navdeep Mutti, as well as molecular geneticists.
In the study, which was published in the Journal of Insect
Science, the researchers injected siRNA into the salivary glands
of adult pea aphids, a pest that can be particularly damaging to
alfalfa yields. Aphids treated in this way could not survive
more than a few days on plants.
Saliva is important in the interaction between aphids and host
plants, Reese said. Proteins, including enzymes of aphid saliva,
are thought to play several roles - some of which may overcome a
plant´s defenses and possibly stimulate plant defenses in
non-host plants.
At stake are billions of dollars worth of crops grown every year
in the United States and around the world. For example, a study
first published by Iowa State University in 2005 found that
soybean aphids alone had the potential to cause approximately 3
million acres to be sprayed - an economic toll on its own - and
to cause yield losses of more than 55 million bushels, meaning
an economic impact of more than $250 million in an outbreak
year.
Information on the Iowa State study can be found at
http://www.ipm.iastate.edu/ipm/icm/node/53.
The K-State research was supported by a U.S. Department of
Agriculture grant and by the Kansas Agricultural Experiment
Station.
K-State Research and Extension is a short name for the Kansas
State University Agricultural Experiment Station and Cooperative
Extension Service, a program designed to generate and distribute
useful knowledge for the well being of Kansans. Supported by
county, state, federal and private funds, the program has county
Extension offices, experiment fields, area Extension offices and
regional research centers statewide. Its headquarters is on the
K-State campus in Manhattan. |
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