A New Approach that Saves Eyesight and Lives in the
May 3, 2010
Two Agricultural Research Service (ARS)
scientists are part of an international team that has found a way to boost the
nutritional value of corn. This has the potential to reduce the number of
children in developing countries who lose their eyesight, become ill or die
each year because of vitamin A deficiencies.
Corn contains carotenoids, some of which the body can convert to vitamin A.
Beta-carotene is the best vitamin A precursor, but only a very small percentage
of corn varieties have naturally high beta-carotene levels. In Africa and other
developing regions, corn is a major staple and hundreds of thousands of
children become blind, develop weakened immune systems and die because of diets
based largely on corn that lacks sufficient beta-carotene.
Warburton, a geneticist with the
Corn Host Plant Resistance Research Unit in Starkville, Miss.;
Buckler, a geneticist in the ARS
W. Holley Center for Agriculture and Health in Ithaca, N.Y., and their
colleagues published results identifying genetic sequences linked to higher
beta-carotene levels in corn and demonstrating an inexpensive and fast way to
identify corn plants that will produce even higher levels. The report, recently
published in Nature
Genetics, is considered a breakthrough in nutritional plant breeding.
The project was funded in part by the National
Science Foundation and included major scientific contributions from Torbert
Rocheford of Purdue University and
Jianbing Yan of the International Maize and
Wheat Improvement Center in Mexico.
In their study, the researchers surveyed the genetic sequences of corn from
around the world through association mapping, a method made possible by recent
breakthroughs that accelerate the genetic profiling of crops.
The genetic survey revealed natural variations in one gene sequence linked
to higher beta-carotene levels. These variations interacted with a gene
identified previously, and the best variations of the two genes together led to
an 18-fold increase in beta-carotene, according to Warburton. The mapping
survey identified molecular markers that breeders can use to incorporate the
desired gene variants into corn for the developing world. Warburton and Yan are
now working with breeders oversees to train them on use of the new techniques.
more about this research in the May/June 2010 issue of Agricultural
ARS is the principal intramural scientific research agency of the
U.S. Department of Agriculture (USDA). This
research supports the USDA priority of promoting international food security.