Columbia, Missouri
January 28, 2009
In Missouri, where soybeans reign
as the number one cash crop, soybean pathogens can cut yields
and impact the state's economy. A research effort to identify
the genes essential for a strong plant defense against three
diseases got a boost recently with a new $2.1 million grant by
the National Science Foundation
to Iowa State University
and the University of Missouri.
The project, led by Iowa State, will focus on genetic resistance
against three important soybean pathogens: soybean mosaic virus,
Asian soybean rust and soybean cyst nematode. Melissa Mitchum,
assistant professor of plant sciences at CAFNR and member of the
Interdisciplinary Plant Group, will help lead the research on
the soybean cyst nematode.
According to the National Agricultural Statistics Service, 4.6
million acres of land in Missouri were planted with soybean in
2007, yielding approximately 1.8 tons of soybean and $1.7
billion in production. Although no statistics exist on the
impact of the cyst nematode on soybean yield in Missouri, yield
losses linked to the cyst nematode have been estimated to cost
U.S. soybean producers $750 million annually.
Despite the heavy reliance on host plant resistance to manage
this nematode, scientists know little about the specific genes
responsible for defending the soybean plant against the cyst
nematode or against any diseases for that matter. Mitchum, along
with her colleagues at Iowa State University, hope to close this
knowledge gap by identifying the defense signaling pathways in
soybean.
"Currently, more than 95 percent of soybean cultivars in the
field derive their resistance from a single source of
resistance, a plant introduction called 88788," explains
Mitchum, who is also an investigator in MU's Christopher S. Bond
Life Sciences Center. "The problem with having a single source
of resistance is that we end up selecting for populations of the
nematode that can grow on that type of resistance. We can deploy
new types of resistance using natural resistant cultivars, but
the same thing is going to happen: the nematode is going to
adapt."
To overcome this cyclical problem, Mitchum and her colleagues
will use a new approach in soybean, called virus-induced gene
silencing, to identify the genes that provide the underlying
basis of resistance in the soybean plant.
"Once we understand the genetic mechanism for resistance in the
plant, we can then use that information to assist breeders in
developing soybean cyst nematode resistant cultivars as well as
design novel transgenic resistance," said Mitchum.
Additional benefits of the project include training of MU
undergraduates and K-12 teachers, which may encourage students
to consider careers in the plant and biological sciences.
Mitchum said the success of the NSF grant application was rooted
in results of earlier studies supported by Missouri Soybean
Merchandising Council. |
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