Development of PCR markers for Tamyb10 related to R-1, red grain color gene in wheat
Development of PCR markers for Tamyb10 related to R-1, red grain color gene in wheat
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DOI：
10.1007/s00122-011-1555-2
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发表时间：
2011-05-01
影响因子：
5.4
通讯作者：
Noda, Kazuhiko
中科院分区：
文献类型：
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作者：
Himi, Eiko;Maekawa, Masahiko;Noda, Kazuhiko
小麦粒色不仅影响面粉的亮度，而且还影响小麦对穗发芽的耐性。粒色由位于六倍体小麦染色体3A、3B和3D长臂上的显性R-1基因（分别为R-A1、R-B1和R-D1）控制。谷物种皮的红色素由儿茶素和原花青素（PA）组成，它们是通过类黄酮生物合成途径合成的。我们分离了分别位于染色体3A、3B和3D上的Tamyb 10-A1、Tamyb 10-B1和Tamyb 10-D1基因。这些基因编码R2 R3型MYB结构域蛋白，类似于拟南芥的TT 2，其控制种皮中的PA合成。在隐性R-A1系中，有两种类型的Tamyb 10-A1基因：（1）MYB区R2重复序列的前半部分缺失和（2）属于hAT家族的2.2-kb转座子插入。隐性R-B1系的Tamyb 10-B1基因有19个碱基的缺失，导致开放阅读框的中部发生移码。利用小麦胚芽鞘的瞬时检测，我们发现显性R-1等位基因中的Tamyb 10基因激活了类黄酮生物合成基因。我们开发了基于PCR的标记来检测R-A1、R-B1和R-D1的显性/隐性等位基因。这些标记与33个品种的已知R-1基因型相关，只有一个单核苷酸突变体除外。此外，发现来自红粒系和白粒系之间的杂交的双单倍体（DH）系必然携带功能性Tamyb 10基因。因此，基于PCR的Tamyb 10基因标记对于检测R-1等位基因非常有用。
The grain color of wheat affects not only the brightness of flour, but also tolerance to preharvest sprouting. Grain color is controlled by dominant R-1 genes located on the long arm of hexaploid wheat chromosomes 3A, 3B, and 3D (R-A1, R-B1, and R-D1, respectively). The red pigment of the grain coat is composed of catechin and proanthocyanidin (PA), which are synthesized via the flavonoid biosynthetic pathway. We isolated the Tamyb10-A1, Tamyb10-B1, and Tamyb10-D1 genes, located on chromosomes 3A, 3B, and 3D, respectively. These genes encode R2R3-type MYB domain proteins, similar to TT2 of Arabidopsis, which controls PA synthesis in testa. In recessive R-A1 lines, two types of Tamyb10-A1 genes: (1) deletion of the first half of the R2-repeat of the MYB region and (2) insertion of a 2.2-kb transposon belonging to the hAT family. The Tamyb10-B1 genes of recessive R-B1 lines had 19-bp deletion, which caused a frame shift in the middle part of the open reading frame. With a transient assay using wheat coleoptiles, we revealed that the Tamyb10 gene in the dominant R-1 allele activated the flavonoid biosynthetic genes. We developed PCR-based markers to detect the dominant/recessive alleles of R-A1, R-B1, and R-D1. These markers proved to be correlated to known R-1 genotypes of 33 varieties except for a mutant with a single nucleotide substitution. Furthermore, double-haploid (DH) lines derived from the cross between red- and white-grained lines were found to necessarily carry functional Tamyb10 gene(s). Thus, PCR-based markers for Tamyb10 genes are very useful to detect R-1 alleles.