小麦维生素E基因TaHGGT-7AL的克隆与表达分析

Cloning and expression analysis of Triticum aestivum vitamin E gene TaHGGT-7AL

从小麦( Triticum aestivum L.)品种‘科农199’籽粒中克隆出维生素E基因 TaHGGT-7AL 及其另外两个拷贝,通过生物信息学分析,对其序列结构特征及蛋白序列的系统发育关系进行了初步研究。结果显示: TaHGGT- 7AL 基因编码区长1227 bp,共编码408个氨基酸;TaHGGT-7AL与另外两个拷贝的序列一致性为95. 45%。TaHGGT-7AL蛋白序列具有9个α-螺旋,该序列与禾本科HGGT蛋白的同源性在58. 7%~ 98. 5%之间。3个 TaHGGT 基因分别位于小麦基因组的7AL、7BL和7DL染色体上,均具有与膜相关的UbiA异戊烯基转移酶家族的保守结构域和一个转运肽。系统进化分析结果表明,TaHGGT-7AL与禾本科植物的亲缘关系较近。qRT-PCR分析结果显示, TaHGGT-7AL 只在小麦颖壳和籽粒中表达,且在花后13 d籽粒的表达量最高。在ABA、4℃低温、干旱及黑暗胁迫处理下, TaHGGT-7AL 表达量上调;NaCl处理24 h后,该基因表达量升高,表明 TaHGGT-7AL 可以对非生物胁迫产生响应。

The vitamin E gene TaHGGT-7AL and two other copies were cloned from Triticum aestivum L. variety ‘Kenong 199’and the sequence structure and phylogenetic relationship of the protein sequence were analyzed by bioinformatics. Results showed that the coding region of the TaHGGT-7AL gene was 1227 bp in length, encoding a total of 408 amino acids;the sequence identity of TaHGGT-7AL with the two other copies was 95. 45%. The TaHGGT-7AL protein sequence had nine α-helices and showed the sequence homology with grass HGGT protein of between 58. 7% and 98. 5%. The three TaHGGT genes were located on the 7AL, 7BL, and 7DL chromosomes of the genome, each having a conserved domain of the UbiA prenyltransferase family associated with the membrane and a transit peptide. Phylogenetic analysis showed that TaHGGT-7AL was closely related to gramineous plants. The qRT-PCR analysis results showed that TaHGGT-7AL was only expressed in T.aestivum hulls and grains, and the highest expression was observed 13 d after flowering. Under ABA, low temperature (4℃), drought, and dark stress treatments, the expression of TaHGGT-7AL was up-regulated compared with the control;after 24 h of NaCl treatment, the expression increased, indicating that TaHGGT-7AL responds to abiotic stress.