摘要： 为了进一步研究冬小麦的根系建成，并为今后高寒地区的冬小麦育种奠定基础。以东农冬麦2号为材料，利用PCR技术得到TaEXPB12-A/B/D 3个同源基因的CDS全长。其核酸序列长度均为846 bp，编码281个氨基酸，同源性达到98.46%，分别定位在2AL、2BL、2DL染色体上，蛋白均具备膨胀素基因序列特有的结构域DPBB_1，分别位于142-810 bp，142-834 bp，142-834 bp。启动子分析结果显示，这3段序列中均含有多个与根特异表达相关的作用元件，以及多个激素响应元件和非生物胁迫响应元件。qRT-PCR分析发现TaEXPB12-A/B/D基因在根中特异性表达，低温会抑制TaEXPB12-A/B/D 3个同源基因的表达，而干旱、脱落酸、茉莉酸甲酯及水杨酸等处理会促进它们的表达。洋葱表皮亚细胞定位结果显示，3个基因均定位于细胞壁。TaEXPB12-A/B/D蛋白质在冬小麦根的细胞壁中特异性分布，并参与冬小麦抵御外界多种非生物胁迫的过程，在3个基因响应外界胁迫的过程中，TaEXPB12-A占据表达优势。结果说明，TaEXPB12-A/B/D在冬小麦根系建成和抵御多种非生物胁迫过程中具有重要作用。

关键词: 寒地冬小麦, 膨胀素, TaEXPB12-A/B/D, 同源基因, 表达特性分析

Abstract: In order to further study the establishment of the root system of winter wheat, and lay the foundation for winter wheat breeding in alpine regions in the future. Dongnongdongmai 2 was used as the material, and the full-length CDS of three homologous genes of TaEXPB12-A/B/D was obtained by PCR technology. The nucleic acid sequence length was 846 bp, encoding 281 amino acids, homology reached 98.46%, the three genes located on the 2AL, 2BL, 2DL chromosomes respectively, their protein had the unique domain DPBB_1 of the expand in gene sequence, locating at 142-810 bp, 142-834 bp, 142-834 bp, respectively. Promoter analysis results showed that all three sequences contained multiple action elements related to root-specific expression, as well as multiple hormone response elements and abiotic stress response elements. qRT-PCR analysis found that TaEXPB12-A/B/D genes were specifically expressed in roots. Low temperature would inhibit the expression of three homologous genes of TaEXPB12-A/B/D, while drought, abscisic acid, methyl jasmonate and salicylic acid would promote their expression. Onion epidermal subcellular localization results showed that all three genes were localized on the cell wall. TaEXPB12-A/B/D protein was specifically distributed in the cell wall of winter wheat roots, and participated in the process of winter wheat resisting a variety of abiotic stresses. In the process of three genes responding to external stress, TaEXPB12-A had an expression advantage. These results indicated that TaEXPB12-A/B/D played an important role in the establishment of winter wheat roots and resistance to various abiotic stresses.

Key words: Winter wheat in cold region, Expansin, TaEXPB12-A/B/D, Homologous gene, Expression characteristic analysis

中图分类号: 

• Q78

• S512.03