Zhang Hongying, Mao Xinguo, Zhang Jianan, Chang Xiaoping, Wang Chengshe, Jing Ruilian
The National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
Genetica. 2011 Jun;139(6):743-53. doi: 10.1007/s10709-011-9579-8. Epub 2011 Jun 3.
Sucrose non-fermenting1-related protein kinase 2 (SnRK2) plays a key role in plant stress signaling transduction pathways. In this study, one copy of TaSnRK2.7, a SnRK2 member of common wheat, was isolated and characterized for nucleotide diversity among 45 wheat accessions with different stress-response features. Most of the accessions were elite wheat cultivars, which had been subject to population bottlenecks and intensive selection during breeding. Nucleotide and haplotype diversity across the entire TaSnRK2.7-A region was 0.00076 and 0.590, respectively, and diversity in non-coding regions was higher than that in coding regions. Sliding-window analysis showed variable levels of nucleotide variation along the entire TaSnRK2.7-A region; the sixth intron and ninth exon represented variation-enriched regions. As predicted, neutrality tests revealed that population bottlenecks or purifying selection had acted on the TaSnRK2.7-A gene, a relatively conserved gene. Furthermore, strong linkage disequilibrium between SNP loci extends across the entire TaSnRK2.7-A region. These findings demonstrate that the TaSnRK2.7-A genomic region has evolved under extensive selection pressure during crop breeding.
蔗糖非发酵1相关蛋白激酶2（SnRK2）在植物胁迫信号转导途径中起关键作用。在本研究中，从小麦中分离出普通小麦SnRK2成员TaSnRK2.7的一个拷贝，并对45份具有不同胁迫响应特征的小麦材料进行了核苷酸多样性分析。大多数材料是优良小麦品种，在育种过程中经历了群体瓶颈和高强度选择。整个TaSnRK2.7-A区域的核苷酸多样性和单倍型多样性分别为0.00076和0.590，非编码区的多样性高于编码区。滑动窗口分析表明，整个TaSnRK2.7-A区域的核苷酸变异水平不同；第六内含子和第九外显子代表变异富集区。正如预测的那样，中性检验表明群体瓶颈或纯化选择作用于TaSnRK2.7-A基因，这是一个相对保守的基因。此外，SNP位点之间的强连锁不平衡延伸到整个TaSnRK2.7-A区域。这些发现表明，TaSnRK2.7-A基因组区域在作物育种过程中受到广泛的选择压力而进化。
