一个普通小麦Trx超家族新基因TaNRX的克隆与抗旱相关标记开发

抗旱相关基因的挖掘和分子标记开发对选育抗旱小麦品种有重要意义。采用同源克隆、电子克隆、RACE技术和生物信息学分析手段,获得了普通小麦硫氧还蛋白(Trx)超家族一个新基因(TaNRX)的全长cDNA序列(GenBank登录号为KC890769),包含2015 bp,其中开放阅读框1734 bp;预测编码577个氨基酸,分子量为63.79 kD,含3个Trx活性功能区,其中2个存在典型的Cys-X1-X2-Cys结构,具有催化氧化还原反应的活性。TaNRX基因被定位在小麦的5B染色体短臂上,包含4个外显子和3个内含子。比较该基因在两组极端相对发芽率品种中的序列差异,发现第1个内含子差异明显。基于差异位点开发了4个显性互补标记,并用其检测150份小麦品种(系)。检测到TaNRX基因在普通小麦中至少存在2种与抗旱相关的等位变异,分别是TaNRX-a和TaNRX-b;TaNRX-a基因型的品种(系)平均相对发芽率显著高于TaNRX-b基因型(P0.01),说明开发的标记可被用于小麦抗旱性鉴定筛选。

Cloning a Novel Gene TaNRX of Trx Superfamily and Developing Its Molecular Markers Related to Drought Resistance in Common Wheat

Molecular markers associated with genes for drought resistance play an important role in wheat breeding aiming at improvement of drought resistance. In this study, we obtained the full-length cDNA of a novel gene of thioredoxin (Trx) superfamily, TaNRX (GenBank accession number KC890769), from common wheat (Triticum aestivumresidues with a putative molecular mass of 63.79 kD. The TaNRX is composed of three Trx-like modules arranged as direct repeats of the classic Trx domain. The first and third modules contain the amino acid sequence Cys-X1-X2-Cys, with the potential for Trx oxidoreductase activity. Gene TaNRXcomplementary dominant markers were developed. In 150 wheat varieties (lines), two genotypes on TaNRX locus, TaNRX-a and TaNRX-b, were identified to be associated with drought resistance. As revealed by the four molecular markers, the average RGer in TaNRX-a genotype was significantly higher than that in TaNRX-b genotype (P < 0.01). This result suggests that the molecular markers developed in this study are effective to be used in selection of wheat varieties with drought resistance. has four exons and three introns, and is mapped on chromosome 5BS of wheat. The variations of TaNRX sequences were mainly concentrated in the first intron according to genomic sequence variances analysis between two types of varieties with different relative germination rates (RGer). Based on the variations within the first intron of TaNRX, four L.) using the protocol of gene homology cloning, electronic cloning, RACE, and bioinformatics analysis. The open reading frame (ORF) of TaNRX is 1734 bp in length, and the 5′ and 3′ UTRs are 99 and 182 bp, respectively. The ORF encodes a protein of 577 amino acid