六倍体小麦TaHKT2;2基因的克隆与多样性分析  

Cloning and Diversity Analysis of TaHKT2; 2 Gene in Hexaploid Wheat

作　　者：李孟军[1] 李亚青[1] 张士昌[1] 张楠[1] 史占良[1] 

机构地区：[1]石家庄市农林科学研究院/河北省小麦工程技术中心,河北石家庄050041

出　　处：《河南农业科学》2017年第12期1-7,共7页Journal of Henan Agricultural Sciences

基　　金：河北省现代农业科技创新工程项目(2017038997);国家重点研发计划项目(2016YFD0101802);河北省自然科学基金项目(C2014106075)

摘　　要：为深入研究小麦HKT基因家族其他成员的作用,利用同源序列克隆技术和六倍体小麦基因组BAC文库克隆了小麦TaHKT2;2基因。TaHKT2;2定位于小麦第7同源群,分别命名为TaHKT2;2-7A、TaHKT2;2-7B、TaHKT2;2-7D。TaHKT2;2与TaHKT2;1基因结构相同,均由3个外显子和2个内含子组成。在系统进化树上TaHKT2;2与TaHKT2;1聚类形成1个分支。TaHKT2;2-7A、TaHKT2;2-7B、TaHKT2;2-7D的基因编码区分别为1 602 bp、1 602 bp、1 596 bp,但利用RTPCR技术未能在8个六倍体小麦中克隆TaHKT2;2-7D c DNA。采用克隆测序技术分析了12个六倍体小麦中TaHKT2;2的自然多样性,结果表明,TaHKT2;2-7A的序列多样性高于TaHKT2;2-7B和TaHKT2;2-7D。TaHKT2;2仅见少数碱基发生改变,在TaHKT2;2 P-loop区无氨基酸变异。TaHKT2;2 5'侧翼序列保守性低于其编码区。TaHKT2;2在小麦驯化过程可能受到选择,属于驯化基因。In order to study the roles of members of HKT gene family in wheat,TaHKT2; 2 was isolated by using homologous cloning strategy and screening genomic BAC library. TaHKT2; 2 genes were mapped on chromosomes 7 A,7 B,and 7 D,named as TaHKT2; 2-7 A,TaHKT2; 2-7 B,and TaHKT2; 2-7 D. TaHKT2; 2 and TaHKT2; 1 had the same genetic structure,composed of three exons and two introns,and formed a cluster with TaHKT2; 1 on phylogenetic tree of plant HKT transporters. The coding sequences of TaHKT2; 2-7 A,TaHKT2; 2-7 B,and TaHKT2; 2-7 D were 1 602,1 602,1 596 bp long,respectively,but TaHKT2; 2-7 D c DNA sequence was not isolated by RT-PCR in eight wheat varieties. The natural diversity of TaHKT2; 2 genes was analyzed by cloning and sequencing from 12 wheat varieties. The results showed that TaHKT2; 2-7 A was found to be more diverse than TaHKT2; 2-7 B and TaHKT2; 2-7 D. Only a few bases changed in the alleles of TaHKT2; 2 genes in wheat. No amino-acid natural variation lay in the P-loops of deduced protein sequences of all alleles of TaHKT2; 2 in 12 wheat varieties. The identity of coding sequences was much higher than that of 5' flanking regions of TaHKT2; 2 genes. TaHKT2; 2 might be selected over the course of wheat domestication and belonged to domestication gene.

关 键 词：六倍体小麦 HKT基因家族 TaHKT2 2基因 BAC文库 多样性 

分 类 号：S512.1[农业科学—作物学]