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

CLC Number: 

• Q78

• S512.03