Natural genetic variation in lycopene epsilon cyclase tapped for maize biofortification
Natural genetic variation in lycopene epsilon cyclase tapped for maize biofortification
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DOI：
10.1126/science.1150255
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发表时间：
2008-01-18
期刊：
影响因子：
56.9
通讯作者：
Buckler, Edward S.
中科院分区：
文献类型：
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作者：
Harjes, Carlos E.;Rocheford, Torbert R.;Buckler, Edward S.
膳食维生素A缺乏每年导致4000万儿童患眼病，并使1.4亿至2.5亿儿童面临健康障碍的风险。撒哈拉以南非洲的许多儿童以玉米为主食。玉米在类胡萝卜素组成上表现出相当大的自然变异，包括维生素A前体α -胡萝卜素、β -胡萝卜素和β -隐黄质。通过关联分析、连锁定位、表达分析和诱变，我们发现番茄红素epsilon环化酶（lcyE）位点的变异改变了类胡萝卜素途径中α -胡萝卜素和β -胡萝卜素分支的通量。四种天然赖氨酸多态性解释了这两个分支中58%的变异和维生素原a化合物的三倍差异。利用廉价的分子标记选择有利的赖氨酸等位基因，现在将使发展中国家的育种者能够更有效地生产出含有较高维生素原A水平的玉米。
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.