Genome-Wide Association Study Identifies Candidate Genes for Starch Content Regulation in Maize Kernels.
Genome-Wide Association Study Identifies Candidate Genes for Starch Content Regulation in Maize Kernels.
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全基因组关联研究确定了玉米籽粒淀粉含量调节的候选基因
DOI：
10.3389/fpls.2016.01046
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发表时间：
2016
影响因子：
5.6
通讯作者：
Tang J
中科院分区：
文献类型：
--
作者：
Liu N;Xue Y;Guo Z;Li W;Tang J
籽粒淀粉含量是玉米的一个重要性状。因为它占干粒重的65-75%，并且与种子产量正相关。近年来在玉米中发现了许多与淀粉合成相关的基因。然而，玉米自交系间淀粉含量变异的许多位点仍有待确定。目前的研究是一个全基因组关联研究，使用了一套263玉米自交系。在这个面板中，平均籽粒淀粉含量为66.99%，在三个研究年中的范围为60.60%至71.58%。这些近交系用SNP 50 BeadChip玉米阵列进行基因分型，该阵列由56，110个均匀间隔的随机SNP组成。种群结构由TASSEL软件包中实现的混合线性模型（MLM）控制。经统计学分析，确定了4个与淀粉含量显著相关的SNPs（P ≤ 0.0001），其中1个位于1号染色体，2个位于5号染色体。此外，77个候选基因与淀粉合成相关的100 kb的间隔内发现这四个QTL，和4个高度相关的基因在20 kb的间隔内的相关SNP。在这四个基因中，葡萄糖-1-磷酸腺苷酰转移酶（APS 1;基因ID GRMZM 2G 163437）被认为是籽粒淀粉含量的重要调节因子。这些SNP、QTL和候选基因不仅可用于分子标记辅助育种的种质改良，而且可用于阐明淀粉含量的遗传基础。对这些候选基因的进一步研究可能有助于确定玉米和其他重要谷类作物籽粒淀粉含量调控的分子机制。
Kernel starch content is an important trait in maize (Zea mays L.) as it accounts for 65–75% of the dry kernel weight and positively correlates with seed yield. A number of starch synthesis-related genes have been identified in maize in recent years. However, many loci underlying variation in starch content among maize inbred lines still remain to be identified. The current study is a genome-wide association study that used a set of 263 maize inbred lines. In this panel, the average kernel starch content was 66.99%, ranging from 60.60 to 71.58% over the three study years. These inbred lines were genotyped with the SNP50 BeadChip maize array, which is comprised of 56,110 evenly spaced, random SNPs. Population structure was controlled by a mixed linear model (MLM) as implemented in the software package TASSEL. After the statistical analyses, four SNPs were identified as significantly associated with starch content (P ≤ 0.0001), among which one each are located on chromosomes 1 and 5 and two are on chromosome 2. Furthermore, 77 candidate genes associated with starch synthesis were found within the 100-kb intervals containing these four QTLs, and four highly associated genes were within 20-kb intervals of the associated SNPs. Among the four genes, Glucose-1-phosphate adenylyltransferase (APS1; Gene ID GRMZM2G163437) is known as an important regulator of kernel starch content. The identified SNPs, QTLs, and candidate genes may not only be readily used for germplasm improvement by marker-assisted selection in breeding, but can also elucidate the genetic basis of starch content. Further studies on these identified candidate genes may help determine the molecular mechanisms regulating kernel starch content in maize and other important cereal crops.