中文摘要：

以钾高效和钾敏感型大豆品系为试验材料，设置低钾胁迫试验，在8个时间段取样提取RNA，利用Real．timePCR检测GmKTl2基因的表达量，结果显示GmKTl2基因在不同品系地上部和地下部表达水平有显著差异，其原因来自GmKTl2基因的氨基酸序列和蛋白质结构的变异。从2个品系中分别克隆目的基因并对基因序列进行同源性及生物信息学分析表明，与GmKTl2基因相似性在30％以上的同源基因有56个，GmKTl2在进化树中的位置与Glymal8g18822最近；GmKTl2编码蛋白为可溶性跨膜蛋白，具有多个磷酸化位点，该基因与信号转导有关，对大豆获取及转运钾离子可能起着关键作用。

英文摘要：

GmKT12 predicted as a potassium transporter is of great importance in absorbing nutrients, signal transduction in plant growth. At present, there are few reports about the gene. In this paper, one low K tolerant soybean line You 06-71 and one low K intolerant line Hengchun 04-11 were used as plant materials. In order to research the expression level of GmKT12 in low potas- sium stress conditions, RNA was extracted and tested by Real-time PCR in eight periods. The results showed that there were highly significant differences between two lines due to their was diversity of amino acid sequence and protein structure. Homol- ogy and Bioinformatic analysis after cloning the target sequence from the two lines showed that comparing with GmKT12, there were 56 homologous genes with more than 30 percent similarity, GmKT12 and Glyma18g18822 were nearest in the phylogenetic tree. The protein encoded by GmKT12 was soluble transmembrane protein which contained 11-12 membrane structural domains, and possessed multiple phosphorylation sites. These indicated that the protein might take part in plant signal transduction and regulate potassium ions transportation into or out of cells. In conclusion, GmKT12 might play a pivotal role in potassium absorp- tion in soybean, on which the research is important.