Expression profile of two storage-protein gene families in hexaploid wheat revealed by large-scale analysis of expressed sequence tags
Expression profile of two storage-protein gene families in hexaploid wheat revealed by large-scale analysis of expressed sequence tags
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DOI：
10.1104/pp.105.070722
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发表时间：
2005-12-01
期刊：
影响因子：
7.4
通讯作者：
Ogihara, Y
中科院分区：
文献类型：
--
作者：
Kawaura, K;Mochida, K;Ogihara, Y
为了辨别六倍体小麦（Triticum aestivum cv Chinese Spring）中各个储存蛋白基因的表达模式，我们使用生物信息学技术分析了普通小麦的综合表达序列标签（EST）。 α/β-麦醇溶蛋白和低分子量麦谷蛋白亚基的基因家族选自 EST 数据库。这些基因的比对使我们能够追踪两个基因之间的单核苷酸多态性位点。单核苷酸多态性的组合使我们能够通过等位基因特异性 PCR 将单倍型分配到其同源染色体中。这些基因的系统发育分析表明，两个储存蛋白基因家族在三个基因组（A、B 和 D）分化后迅速分化。根据 EST 的频率估计这些基因的表达模式。储存蛋白基因仅在种子发育阶段表达。 α/β-麦醇溶蛋白基因在种子成熟过程中表现出两种不同的表达模式：早期表达和晚期表达。尽管α/β-麦醇溶蛋白和低分子量麦谷蛋白亚基基因中的早期表达基因表现出相似的表达模式，并且来自D基因组的两个基因比来自A或B基因组的基因优先表达，但观察到来自A基因组的两个早期表达基因的大量表达。基因的系统发育关系与其表达模式不相关。这些证据表明，两个储存蛋白基因的表达是独立调节的，并且除了谷醇溶蛋白盒之外，α/β-麦醇溶蛋白基因还具有新的调节系统。
To discern expression patterns of individual storage-protein genes in hexaploid wheat (Triticum aestivum cv Chinese Spring), we analyzed comprehensive expressed sequence tags (ESTs) of common wheat using a bioinformatics technique. The gene families for alpha/beta-gliadins and low molecular-weight glutenin subunit were selected from the EST database. The alignment of these genes enabled us to trace the single nucleotide polymorphism sites among both genes. The combinations of single nucleotide polymorphisms allowed us to assign haplotypes into their homoeologous chromosomes by allele-specific PCR. Phylogenetic analysis of these genes showed that both storage-protein gene families rapidly diverged after differentiation of the three genomes (A, B, and D). Expression patterns of these genes were estimated based on the frequencies of ESTs. The storage-protein genes were expressed only during seed development stages. The alpha/beta-gliadin genes exhibited two distinct expression patterns during the course of seed maturation: early expression and late expression. Although the early expression genes among the alpha/beta-gliadin and low molecular-weight glutenin subunit genes showed similar expression patterns, and both genes from the D genome were preferentially expressed rather than those from the A or B genome, substantial expression of two early expression genes from the A genome was observed. The phylogenetic relationships of the genes and their expression patterns were not correlated. These lines of evidence suggest that expression of the two storage-protein genes is independently regulated, and that the alpha/beta-gliadin genes possess novel regulation systems in addition to the prolamin box.