The allelic distribution and variation analysis of the NAM-B1 gene in Chinese wheat cultivars
The allelic distribution and variation analysis of the NAM-B1 gene in Chinese wheat cultivars
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中国小麦品种NAM-B1基因等位基因分布及变异分析
DOI：
10.1016/s2095-3119(16)61459-4
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发表时间：
2017-01-01
影响因子：
4.8
通讯作者：
Ji Wan-quan
中科院分区：
文献类型：
--
作者：
Chen Xue-yan;Song Guo-qi;Ji Wan-quan
NAM-B1基因是NAC（NAM、ATAF和CUC）转录因子家族的成员，在调节小麦籽粒蛋白质含量（GPC）中起重要作用。NAM-B1等位基因在许多四倍体野生二粒小麦（Triticum turgidum ssp.）dicoccoides）和少量驯化的二粒小麦（Tturgidum ssp. dicoccum），但在六倍体面包小麦（Triticum aestivum L.）NAM-B1等位基因在中国小麦品种中的分布尚未见系统报道。本研究对218个中国栽培品种的NAM-B1等位基因进行了分析。这些品种来自5个主要麦区（12个省），覆盖了我国大部分冬小麦产区。结果表明，NAM-B1基因在53个品种（24.3%）中存在，在165个品种（75.7%）中缺失。进一步的分析表明，与野生型等位基因相比，中国小麦品种NAM-B1基因在编码区含有一个1bp的插入片段。这导致了移码突变，并在基因中间引入了一个终止密码子，使其失去功能。在53个供试品种中，有21个品种的DNA序列存在多态性。然而，cDNA序列分析表明，这些外显子区域的变异不能恢复NAM-B1基因（1-bp插入）的功能。因此，研究NAM-B1基因变异（1-bp插入和缺失）的分布规律，可为我国及其他国家冬小麦品质改良提供参考。
The NAM-B1 gene is a member of the NAC (NAM, ATAF, and CUC) transcription factor family and plays an important role in regulating wheat grain protein content (GPC). The ancestral NAM-B1 allele has been discovered in many tetraploid wild emmer (Triticum turgidum ssp. dicoccoides) accessions and few domesticated emmer accessions (T turgidum ssp. dicoccum), however, it is rarely found in hexaploid bread wheat (Triticum aestivum L.). There are no systematic reports on the distribution of NAM-B1 alleles in Chinese wheat cultivars. In this study, the NAM-B1 alleles in 218 Chinese cultivars were investigated. The cultivars were collected from five major wheat regions (12 provinces), covering most of the winter wheat growing regions in China. The results showed that the NAM-B1 gene is present in 53 (24.3%) cultivars and absent in the remaining 165 (75.7%) cultivars. Further analysis revealed that in contrast to the wild-type allele, the NAM-B1 gene in Chinese wheat cultivars contained a 1-bp insertion in the coding region. This caused a frame-shift mutation and introduced a stop codon in the middle of the gene, rendering it non-functional. Polymorphisms were detected in DNA sequences of 21 cultivars among these 53 cultivars. However, cDNA sequence analysis suggested that these variations in the exon region were not able to restore NAM-B1 gene (1-bp insertion) function. Thus, exploring the distribution of NAM-B1 gene variations (1-bp insertion and deletion) can provide some information for improving the quality of winter wheat in China and other countries.