ZmcrtRB3 Encodes a Carotenoid Hydroxylase that Affects the Accumulation of α-carotene in Maize Kernel  

作　　者：Yi Zhou Yingjia Han Zhigang Li Yang Fu Zhiyuan Fu Shutu Xu Jiansheng Li Jianbing Yan Xiaohong Yang 

机构地区：[1]National Maize Improvement Center,Key Laboratory of Crop Genomics and Genetic Improvement,China Agricultural University,100193 Beijing,China [2]Zhengzhou Sub-center of Chinese National Maize Improvement Center,Henan Agricultural University,Zhengzhou 450002,China [3]National Key Laboratory of Crop Improvement,Huazhong Agricultural University,Wuhan 430070,China

出　　处：《Journal of Integrative Plant Biology》2012年第4期260-269,共10页植物学报（英文版）

基　　金：supported by the National Hi-Tech Research and Development Program of China (863 Program,2012AA10A307);the National Natural Science Foundation of China(30821140352,31123009);the HarvestPlus Challenge Program in China

摘　　要：α-carotene is one of the important components of pro-vitamin A, which is able to be converted into vitamin A in the human body. One maize （Zea mays L.） ortholog of carotenoid hydroxylases in Arabidopsis thaliana, ZmcrtRB3, was cloned and its role in carotenoid hydrolyzations was addressed. ZmcrtRB3 was mapped in a quantitative trait locus （QTL） cluster for carotenoid-related traits on chromosome 2 （bin 2.03） in a recombinant inbred line （RIL） population derived from By804 and B73. Candidate-gene association analysis identified 18 polymorphic sites in ZmcrtRB3 significantly associated with one or more carotenoid-related traits in 126 diverse yellow maize inbred lines. These results indicate that the enzyme ZmcrtRB3 plays a role in hydrolyzing both α- andβ-carotenes, while polymorphisms in ZmcrtRB3 contributed more variation in α-carotene than that inβ-carotene. Two single nucleotide polymorphisms （SNPs）, SNP1343 in 5＇untranslated region and SNP2172 in the second intron, consistently had effects on or-carotene content and composition with explained phenotypic variations ranging from 8.7% to 34.8%. There was 1.7- to 3.7-fold change between the inferior and superior hapiotype for α-carotene content and composition. Thus, SNP1343 and SNP2172 are potential polymorphic sites to develop functional markers for applying marker-assisted selection in the improvement of pro-vitamin A carotenoids in maize kernels.α-carotene is one of the important components of pro-vitamin A, which is able to be converted into vitamin A in the human body. One maize （Zea mays L.） ortholog of carotenoid hydroxylases in Arabidopsis thaliana, ZmcrtRB3, was cloned and its role in carotenoid hydrolyzations was addressed. ZmcrtRB3 was mapped in a quantitative trait locus （QTL） cluster for carotenoid-related traits on chromosome 2 （bin 2.03） in a recombinant inbred line （RIL） population derived from By804 and B73. Candidate-gene association analysis identified 18 polymorphic sites in ZmcrtRB3 significantly associated with one or more carotenoid-related traits in 126 diverse yellow maize inbred lines. These results indicate that the enzyme ZmcrtRB3 plays a role in hydrolyzing both α- andβ-carotenes, while polymorphisms in ZmcrtRB3 contributed more variation in α-carotene than that inβ-carotene. Two single nucleotide polymorphisms （SNPs）, SNP1343 in 5＇untranslated region and SNP2172 in the second intron, consistently had effects on or-carotene content and composition with explained phenotypic variations ranging from 8.7% to 34.8%. There was 1.7- to 3.7-fold change between the inferior and superior hapiotype for α-carotene content and composition. Thus, SNP1343 and SNP2172 are potential polymorphic sites to develop functional markers for applying marker-assisted selection in the improvement of pro-vitamin A carotenoids in maize kernels.

关 键 词：α-carotene association analysis MAIZE pro-vitamin A ZmcrtRB3. 

分 类 号：S513[农业科学—作物学] Q562[生物学—生物化学]