Ames, Iowa
July 31, 2007
Six new research projects at Iowa
State University are tackling scientific challenges facing Iowa
agriculture. The innovative projects recently received start-up
funding from Iowa State
University’s Plant Sciences Institute.
The grants were awarded to faculty researchers in eight
university departments through a competitive program designed to
stimulate excellence in plant science research. Grant amounts
range between $30,000 and $60,000 for two years.
The projects selected relate to the institute’s research
initiatives in biopharmaceuticals, biorenewables, crop
protection, genomics and nutrition. These initiatives target
specific issues —such as protecting against emerging crop
diseases or creating new products from plants — faced by the
state’s crop-based agriculture and plant bioscience industry,
Plant Sciences Institute Director Stephen Howell said.
“These research projects bring additional firepower to our
research initiatives,” Howell said. “They are excellent projects
that promise to advance the scientific foundation for future
developments in crop technology.”
Howell also noted that several of the projects will be conducted
in partnership with other campus units, such as the U.S.
Department of Energy’s Ames Laboratory and ISU’s Department of
Materials Science and Engineering and Department of Biophysics,
Biochemistry and Molecular Biology.
Research began in July on the projects described below.
Crop protection
Growing engineered crops that express Bt genes has become a
major strategy for caterpillar pest control. Aphids, which are
not sensitive to any known Bt proteins, have replaced
caterpillars as the primary pests on many crops. Aphids cause
major economic losses on almost all crops, and current
management relies primarily on potentially harmful chemical
insecticides. Bt proteins are not effective against aphids
because Bt proteins lack a domain that binds to the aphid
midgut, a critical step in the sequence of events that results
in Bt toxicity. Huarong Li, a researcher in entomology, will
construct a Bt toxin active against aphids. He will provide a
site in the Bt protein molecule that specifically binds to aphid
midgut membrane. If successful, the potential impact of this
technology would be considerable. For example, a soybean aphid
invasion in Iowa could require spraying about three million
acres and cause losses of more than 55 million bushels,
resulting in an economic impact of more $250 million in an
outbreak year, according to an article in the June 2005
Integrated Pest Management by ISU entomologists Carol Pilcher
and Marlin Rice, and extension specialist Todd Vagts.
Genomics
High-throughput techniques for gene discovery and expression
analysis, such as whole genome sequencing and microarrays, have
uncovered thousands of new genes with no known function. The
findings demand large-scale and efficient procedures to assign
genes their biological function. Reverse genetics is the process
used to study gene function in which researchers examine the
consequence of inactivating a specific gene. Bing Yang,
assistant professor of genetics, development and cell biology,
will develop a reverse genetics approach called virus-induced
gene silencing. The studies will be conducted in rice to develop
the genetic tools for application to other crops, including corn
and sorghum.
Biorenewables
Dedicated bioenergy crops offer new opportunities as feedstocks
for biofuel production. Emily Smith, assistant professor of
chemistry, will develop a new way to evaluate various crop
plants for their capacity for ethanol production. She will use
Raman imaging to probe plant cell wall structure, assessing
lignin, hemicellulose and cellulose content of potential biofuel
plant stocks such as switchgrass, Miscanthus, poplar, corn and
willow. Raman imaging technology uses an optical microscope with
laser beams illuminating specimens, while scattering some of the
light. By analyzing the scattered light with a spectrometer, she
can quickly acquire information used to determine the chemical
makeup of the plant material. Her goal is to improve ethanol
yields per acre of biomass by correlating plant composition and
cell wall degradation with ethanol conversion efficiency. The
U.S. Department of Energy’s Ames Laboratory also has provided
funding for this research.
Automobile tires are made from a synthetic rubber that uses
petroleum-based fillers to improve mechanical integrity and
durability. Not only does their composition rely on a
diminishing fossil fuel, but their disposal also has a negative
impact on the environment. Biobased polymers are becoming
practical alternatives to petroleum-based plastics and are
biodegradable, as well. Michael Kessler, assistant professor of
materials science and engineering, will lead a research team to
develop new biocomposites from soybean, corn and linseed oils
reinforced with inexpensive and abundant ethanol co-products.
These include distillers dried grains and solubles (from the dry
mill process) and spent germ (from the wet mill process), corn
stover, carbon black and/or clay nanoplatelets. These biobased
rubber composites are expected to be an economical and
environmentally friendly alternative to the rubber used in
tires. The Department of Materials Science and Engineering also
is contributing funding to this project.
Nutrition
The production in plants of so-called resistant starches is one
method to counter the increased incidence of obesity and related
diseases such as cancer and diabetes. These starches release
sugar more slowly in the bloodstream and act more like dietary
fiber. A research team led by Suzanne Hendrich, professor of
food science and human nutrition, will identify and compare
human intestinal bacteria in their ability to metabolize
resistant starches. The microbes may convert some of the
starches into beneficial products. These include butyrate, which
may help prevent colon cancer, and propionate, which may help
lower cholesterol. The researchers will identify key intestinal
microbes that cause butyrate and propionate formation and see
which starches are best for producing these substances.
Biopharmaceuticals
Many plant scientists aspire to produce in valued-added products
in plants, such as biopharmaceuticals. Most examples of
biopharmaceutical production in plants involve the expression of
novel proteins or therapeutic compounds in seeds or fruit. For
these organs to produce sufficient amounts of
biopharmaceuticals, they have to remain attached to the plant.
Robert Thornburg, professor of biophysics, biochemistry and
molecular biology, will look at ways plants maintain seeds and
fruit on the stem. Thornburg will identify and characterize
genes expressed during the natural process of shedding. The
biophysics, biochemistry and molecular biology department is
contributing to the funding of this project. |
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