玉米耐盐基因ZmHKT1的序列变异分析

HKT(High-affinity potassium transporter,高亲和性钾转运蛋白)基因所编码的蛋白能起到维持植物体内的Na+/K+平衡的作用。在作物中HKT蛋白主要通过排出叶片中的Na+,从而提高植物耐盐性。对54份玉米自交系材料的Zm HKT1基因及上游序列进行多态性分析。结果表明,在3 784 bp的序列中,共有194个SNP和32个In Del。大部分变异集中在基因上游序列和内含子区,编码区的变异相对较少,说明编码区在进化和人工选择中承受了更大的选择压力。根据序列变异情况可将54份玉米自交系材料划分为15个单倍型,上游序列主要存在3种单倍型,而基因序列存在9种单倍型。遗传重组和连锁不平衡分析发现,全长序列只有3次重组事件发生,上游序列存在着非常强的连锁不平衡。

Nucleotide Diversity of Drought Tolerance Related Gene ZmHKT1

HKT(high-affinity potassium transporter) genes are known to be important in the regulation of Na⁺ and K⁺ transportation in higher plants. In crops, the major contribution of the HKT in salt tolerance is the exclusion of Na⁺ from leaves. In order to illustrate the sequence polymorphism of maize gene ZmHKT1, the ZmHKT1 genes in 54 maize inbred lines were sequenced, using the sequence of B73 as the reference. One hundred and ninety-four SNPs and thirty-two InDels were identified in the 3 784 bp nucleotide sequences of ZmHKT1. Most of these polymorphic sites were found to be located in the upstream sequence and introns, forty-two SNPs and three InDels were in the coding regions, some of which may change the amino acid sequences. The SNPs and InDels of ZmHKT1 classified all the tested inbred lines into 15 haplotypes. The polymorphic sites in the upstream sequences and gene sequences clustered the lines into three and nine haplotypes, respectively. Recombination and linkage disequilibrium analysis indicated that three recombination events had occurred in ZmHKT1 locus and the linkage disequilibrium is strong in the upstream sequences.