小麦地方品种半截芒Glu-B1位点HMW-GS基因的克隆及序列分析
Cloning and Sequence Analysis of HMW-GS Genes on Glu-B1 from Chinese Wheat (Triticum aestivum L.) Landrace Banjiemang

高分子量谷蛋白亚基（HMW-GS）与小麦的品质特性紧密相关，挖掘小麦中HMW-GS新基因，对小麦品质改良具有重要意义。以小麦地方品种半截芒为材料，利用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳（SDS-PAGE）分析其HMW-GS组成，并设计特异性引物，利用PCR技术克隆其Glu-B1位点x型和y型亚基基因。序列分析表明，2个基因具有完整编码框，长度分别为2 367 bp和2 106 bp（GenBank登录号分别为KJ579439和 KJ579440），编码789个氨基酸和702个氨基酸的蛋白，被命名为 1Bx14*和 1By15*。同源性搜索结果显示2条氨基酸序列与典型的HMW-GS有较高的同源性，且与普通小麦亚基 1Bx14和1By15的同源性均为95%。系统进化树分析表明， 1Bx14*和 1By15*分别与 1Bx14和 1By15的遗传距离较近，聚类到同一分支上。
High molecular weight glutenin subunits (HMW-GS) are closely related with bread-making qualities of common wheat flour. Exploring novel HMW-GS genes in wheat is of great significance for wheat quality improvement. The study presented in the paper analyzed the HMW-GS composition in Chinese wheat (Triticum aestivum L.) landrace Banjiemang by SDS-PAGE. The open reading frames (ORFs) of the x-type and y-type genes on Glu-B1 loci were cloned by designed specific primers. Sequence analysis showed that the ORF of x-type gene was 2 367 bp long and encoded 789 amino acid residues while the ORF of y-type gene was 2 106 bp long and encoded 702 amino acid residues. The two genes presented in the study were designated as 1Bx14* and 1By15* and deposited in GenBank with accession number KJ579439 and KJ579440, respectively. Homology search of the amino acid sequences revealed high homology between the two genes cloned here and the typical HMW-GS genes characterized previously. Both 1Bx14* and 1By15* had the identity of 95% with subunit 1Bx14 and 1By15, respectively. The phylogenetic analysis based on the amino acid sequences indicated that 1Bx14* was clustered with x-type subunits while 1By15* was clustered with y-type subunits.