title: Natural genetic variation in lycopene epsilon cyclase tapped for maize biofortification.
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 alpha-carotene, beta-carotene, and beta-cryptoxanthin. Through association analysis, linkage mapping, expression analysis, and mutagenesis, we show that variation at the lycopene epsilon cyclase (lcyE) locus alters flux down alpha-carotene versus beta-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.
authors.affiliation: Institute for Genomic Diversity, Cornell University, Ithaca, NY 14853, USA.
authors.forename: Carlos E
authors.initials: CE
authors.lastname: Harjes
authors.forename: Torbert R
authors.initials: TR
authors.lastname: Rocheford
authors.forename: Ling
authors.initials: L
authors.lastname: Bai
authors.forename: Thomas P
authors.initials: TP
authors.lastname: Brutnell
authors.forename: Catherine Bermudez
authors.initials: CB
authors.lastname: Kandianis
authors.forename: Stephen G
authors.initials: SG
authors.lastname: Sowinski
authors.forename: Ann E
authors.initials: AE
authors.lastname: Stapleton
authors.forename: Ratnakar
authors.initials: R
authors.lastname: Vallabhaneni
authors.forename: Mark
authors.initials: M
authors.lastname: Williams
authors.forename: Eleanore T
authors.initials: ET
authors.lastname: Wurtzel
authors.forename: Jianbing
authors.initials: J
authors.lastname: Yan
authors.forename: Edward S
authors.initials: ES
authors.lastname: Buckler
mesh_terms: D001483:Base Sequence; D001947:Breeding; D002338:Carotenoids / Q000032:analysis* / Q000378:metabolism; D003433:Crosses, Genetic; D065366:Cryptoxanthins; D018506:Gene Expression Regulation, Plant; D014644:Genetic Variation; D006239:Haplotypes; D019753:Intramolecular Lyases / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D016296:Mutagenesis; D009753:Nutritive Value; D011110:Polymorphism, Genetic; D040641:Quantitative Trait Loci; D024341:Xanthophylls / Q000032:analysis / Q000378:metabolism; D003313:Zea mays / Q000737:chemistry / Q000201:enzymology / Q000235:genetics*; D019207:beta Carotene / Q000032:analysis / Q000378:metabolism
chemical_list: D065366:Cryptoxanthins; D024341:Xanthophylls; D019207:beta Carotene; D002338:Carotenoids; C041635:alpha-carotene; D019753:Intramolecular Lyases; C070925:lycopene cyclase-isomerase