Washington, DC
November 24, 2006
ARS News Service
Agricultural Research Service, USDA
Marcia Wood, (301) 504-1662,
marcia.wood@ars.usda.gov
Your favorite bread, breakfast cereal or pasta might tomorrow be
made with wheat flour that's more nutritious than ever.
Agricultural Research Service (ARS) and university scientists
have identified a gene that can increase the protein, iron and
zinc content of wheat kernels. The gene, known as Gpc-B1, does
that in bread wheats and pasta wheats alike.
Today, nearly all Americans eat enough protein for good health,
but more than 36 million of us don't get enough zinc, and more
than 15 million are short on iron. The wheat research, by
enriching the nutrients in one of the world's leading crops,
holds the potential to improve Americans' health and that of
millions of the world's malnourished.
Plant geneticist Ann E. Blechl helped prove the Gpc-B1 gene's
prowess in enhancing wheat flour's nutritional bounty. She used
a technique called "RNA interference" to lower what are known as
the gene’s expression levels in wheat plants. Blechl did the
work in her laboratory at the ARS Western Regional Research
Center in Albany, Calif.
Collaborators working under the direction of wheat breeder and
professor Jorge Dubcovsky of the University of California-Davis
found that kernels harvested from the plants with lowered Gpc-B1
levels had at least 30 percent less protein, zinc and iron.
According to Blechl, the work proved that Gpc-B1 controlled all
of these nutrients. The finding predicts that incorporating
additional copies of the functioning gene into bread and pasta
wheats will be valuable.
Blechl is an international authority on the use of RNA
interference and other biotech approaches to explore the largely
untapped capabilities of genes of grain-bearing crops.
Dubcovsky, Blechl and colleagues in Haifa, Israel, report their
findings in the current issue of the journal Science. A summary
can be viewed on the World Wide Web by going to
www.Sciencemag.org, then
clicking on "current issue."
The research was sponsored by two U.S. Department of Agriculture
agencies--ARS and the Cooperative State Research, Education and
Extension Service--and the United States-Israel Binational
Agricultural Research and Development Fund.
ARS is USDA's chief in-house scientific research agency.
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Wild gene boosts gene
nutrients |
|
Source:
University of California, Davis
Researchers at the University of
California, Davis, the U.S. Department of Agriculture and the
University of Haifa in Israel have cloned a gene from wild wheat
that increases the protein, zinc and iron content in the grain,
potentially offering a solution to nutritional deficiencies
affecting hundreds of millions of children around the world.
Results from the study were reported in the Nov. 24 issue of the
journal Science.
"Wheat is one of the world's major crops, providing
approximately one-fifth of all calories consumed by humans.
Therefore, even small increases in wheat's nutritional value may
help decrease deficiencies in protein and key micronutrients,"
said Professor Jorge Dubcovsky, a wheat breeder and lead
researcher on this paper. He noted that the World Health
Organization estimates that more than 2 billion people are
deficient in zinc and iron, and more than 160 million children
under the age of 5 lack an adequate protein supply.
The cloned gene, designated GPC-B1 for its effect on grain
protein content, accelerates grain maturity and increases grain
protein and micronutrient content by 10 to 15 percent in the
wheat varieties studied so far. To prove that all these effects
were produced by this gene, the researchers created genetically
modified wheat lines with reduced levels of the GPC gene by a
technique called RNA interference. These lines were developed by
research geneticist Ann Blechl of USDA's Agricultural Research
Service in Albany, Calif.
"The results were spectacular," Dubcovsky said. "The grains from
the genetically modified plants matured several weeks later than
the control plants and showed 30 percent less grain protein,
zinc and iron, without differences in grain size. This
experiment confirmed that this single gene was responsible for
all these changes."
Dubcovsky said the research team was surprised to find that all
cultivated pasta and bread wheat varieties analyzed so far have
a nonfunctional copy of GPC-B1, suggesting that this gene was
lost during the domestication of wheat.
"Therefore, the reintroduction of the functional gene from the
wild species into commercial wheat varieties has the potential
to increase the nutritional value of a large proportion of our
current cultivated wheat varieties," he said. "Furthermore, this
discovery provides a clear example of the value and importance
of conserving the wild germplasm -- the source of genetic
diversity -- of our crop species."
Dubcovsky leads a consortium of 20 public wheat-breeding
programs known as the Wheat Coordinated Agricultural Project,
which is rapidly introducing GPC-B1 and other valuable genes
into U.S. wheat varieties using a rapid-breeding technique
called marker assisted selection.
The resulting varieties are not genetically modified organisms,
which will likely speed their commercial adoption. More
information about the Wheat Coordinated Agricultural Project is
available online at <http://maswheat.ucdavis.edu/>.
Several breeding programs have already used the GPC-B1 gene to
develop elite breeding lines, which are close to being released
as new wheat varieties. Breeders are currently testing the new
lines in multiple environments to determine if the introduction
of GPC-B1 has any negative impacts on yield or quality. The
researchers hope that these efforts will soon translate into
food products with enhanced nutritional value.
This research was supported by the National Research Initiative
of USDA's Cooperative State Research, Education and Extension
Service, and by BARD, the United States-Israel Binational
Agricultural Research and Development Fund. |
|
Wheat gene
discovery could fight malnutrition |
Hawk Jia, SciDev.Net
Scientists have found how to boost the protein, zinc
and iron content in wheat, which could help to solve
nutritional deficiency that affects two billion
people worldwide, especially in the developing
world.
Reporting their results in the journal Science today
(24 November), the scientists identify a gene that
functions in wild wheat but not in domesticated
wheat varieties.
After inserting the gene into cultivated wheat with
conventional breeding methods, they found it makes
the grain mature more quickly and increases its
protein and nutrient content by 10-15 per cent.
According to Jorge Dubcovsky, of the University of
California in Davis, United States who led the
study, scientists have long known that several
varieties of wild wheat have higher protein content
than domesticated types.
But it is only now, using a genetic mapping
technique — which determines the relative positions
of genes on a chromosome — that they have discovered
which gene was responsible for the traits.
The work is part of a larger-scale breeding
programme for increasing wheat's nutritional
content, the seeds from which are stored in the US
National Small Grains Collection and can be provided
free of charge.
"We have already distributed seeds to India, South
America and China," Dubcovsky told SciDev.Net.
Wheat is one of the major world food crops, and
accounts for 20 per cent of human calorie intake.
Advances in basic plant sciences applied to
agriculture will be critical for successfully
eradicating malnutrition and associated childhood
mortality, says Jonathan D. Gitlin at the US-based
Washington University School of Medicine in St.
Louis, writing in a separate article in the same
issue of Science. |
Una harina de trigo
más nutritiva
Servicio Noticiero del Servicio de Investigación Agrícola (ARS
siglas en inglés)
Departamento de Agricultura (USDA siglas en inglés)
Marcia Wood, (301) 504-1662,
marcia.wood@ars.usda.gov
En el futuro, su favorito pan, cereal de desayuno o pasta podría
ser hecho con una harina de trigo más nutritiva que nunca.
Científicos del Servicio de Investigación Agrícola (ARS) y de
universidades han identificado un gen que puede aumentar los
niveles de proteína, hierro y zinc en los granos del trigo. El
gen, conocido como Gpc-B1, hace esto en ambos trigos de pan y
trigos de pasta.
Hoy en día, casi toda la gente estadounidense comen suficiente
proteína para tener una salud buena, pero más de 36 millones de
nosotros no conseguimos suficiente zinc, y a más de 15 millones
les falta hierro. La investigación de trigo, por medio del
enriquecimiento de los nutrientes en uno de los cultivos
principales del mundo, tiene el potencial para mejorar la salud
estadounidense y la salud de millones de gente desnutrida en el
mundo.
La genetista de plantas Ann E. Blechl ayudó a mejorar la
capacidad del gen Gpc-B1 para aumentar el valor nutritivo de la
harina de trigo. Ella usó una técnica llamada la interferencia
de ARN para reducir lo que se conoce como los niveles de
expresión del gen en las plantas de trigo. Blechl realizó el
trabajo en su laboratorio en el Centro de Investigación de la
Región Occidental mantenido por ARS en Albany, California.
Algunos colaboradores trabajando bajo de la dirección del
criador de trigo y profesor Jorge Dubcovsky de la Universidad de
California-Davis descubrieron que los granos cosechados de las
plantas con niveles reducidos de Gpc-B1 tuvieron por lo menos 30
por ciento menos proteína, zinc y hierro. Según Blechl, el
trabajo demostró que Gpc-B1 controló todos estos nutrientes. El
hallazgo predice que la inclusión de copias adicionales del gen
en pan y pasta será valiosa.
Blechl es una autoridad internacional sobre el uso de la
interferencia de ARN y otros métodos de biotecnología para
explorar las capacidades no explotadas de los genes de los
cultivos que rinden grano.
Dubcovsky, Blechl y colegas en Haifa, Israel, reportan sus
hallazgos en la edición actual de la revista 'Science'
(Ciencia). Se puede ver un resumen en Internet en
www.Sciencemag.org (haz
clic en 'current issue').
La investigación fue patrocinada por dos agencias del
Departamento de Agricultura de EE.UU. (USDA por sus siglas en
inglés) -- ARS y el Servicio Estatal Cooperativo de
Investigación, Educación e Instrucción -- y el Fondo Binacional
de Investigación y Desarrollo Agrícola de EE.UU. e Israel.
ARS es la agencia principal de investigaciones científicas
del USDA. |
