Washington, DC
January, 2008
HarvestPlus
collaborator Torbert Rocheford is part of an investigative team
that has identified
genetic markers associated with higher levels of Vitamin
A precursors, in maize.
This paves the way for scientists, including those in developing
countries, to easily and quickly identify varieties with
naturally higher levels of beta-carotene for breeding programs.
It’s expected that this will significantly speed up breeding for
new varieties of maize that are rich in Vitamin A.
This could be of tremendous benefit in regions such as Africa,
where Vitamin A deficiency causes tens of thousands of children
to go blind every year.
These findings were reported in
Science, on January 18.
Natural Genetic Variation in Lycopene Epsilon
Cyclase Tapped for Maize Biofortification
Carlos E. Harjes,
Torbert R.
Rocheford, Ling Bai, Thomas P. Brutnell,
Catherine Bermudez Kandianis, Stephen G. Sowinski,
Ann E. Stapleton, Ratnakar Vallabhaneni, Mark
Williams, Eleanore T. Wurtzel,7 Jianbing Yan,
Edward S. Buckler
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ABSTRACT
Dietary vitamin A deficiency causes eye disease in
40 million children each year and places 140 to 250
million at risk for health disorders. Many children
in sub-Saharan Africa subsist on maize-based diets.
Maize displays considerable natural variation for
carotenoid composition, including vitamin A
precursors -carotene, β-carotene, and
β-cryptoxanthin. Through association analysis,
linkage mapping, expression analysis, and
mutagenesis, we show that variation at the lycopene
epsilon cyclase (lcyE) locus alters flux down
-carotene versus β-carotene branches of the
carotenoid pathway. Four natural lcyE polymorphisms
explained 58% of the variation in these two branches
and a threefold difference in provitamin A
compounds. Selection of favorable lcyE alleles with
inexpensive molecular markers will now enable
developing-country breeders to more effectively
produce maize grain with higher provitamin A levels.
Source:
http://www.sciencemag.org/cgi/content/abstract/319/5861/330
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Learn more about
Vitamin A
deficiency.
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