大豆中GmKAB1基因的克隆和信息学分析

为探讨GmKAB1在大豆处于低钾胁迫下的表达水平，以大豆钾高效品系油06-71和钾敏感型品系衡春04-11为试验材料，设置低钾胁迫试验，分别在处理后0.5h、2h、6h、12h、3d、6d、9d和12d取样提取RNA，利用Real time-PCR检测各时间段GmKAB1基因的表达量。结果显示GmKAB1基因在地下部分表达比地上部持续时间更长，地下部相对表达倍数最高为3.5，较地上部相对表达倍数更高。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，结果表明，与GmKAB1基因相似性在30%以上的同源基因有45个，GmKAB1在进化树中的位置与Glyma20g19000最近；GmKAB1编码蛋白为稳定的可溶性蛋白，具有2个保守结构域，多个磷酸化位点，表明在受到低钾胁迫后该基因编码的β亚基与α亚基结合调控电压门控钾离子通道，对大豆从根部获取钾离子可能起着关键作用。

Molecular cloning and bioinformatics analysis of GmKAB1 from soybean(Glycine max L.) Merri)

A low-K-tolerant soybean line (You06-71) and a low-K-sensitive line (Hengchun04-11) were selected as plant materials to study the expression level of GmKAB1 in low potassium stress condition. RNA was extracted at 0.5h, 2h, 6h, 12h, 3d, 6d, 9d and 12d after stress treatment, and Real-time PCR was carried out respectively. The results showed that the expression of GmKAB1 in roots were lasted longer than that in shoots, and the relative expression levels in roots were significantly higher than that in shoots, and the highest level in roots was up to 3.5 times. Homology and bioinformatics analysis after cloning the target sequencing from the two lines indicated that comparing with GmKAB1, there were 45 homologous genes with more than 30% similatity, and Glyma20g19000 was the closest to GmKAB1 in the phylogenetic tree. The protein encoded by GmKAB1 was stable and soluble, which contained two conversed structural domains, possessed multiple phosphorylation sites. These indicated that GmKABl polypeptide formed a close physical association with β subunit and α subunit to control voltage-gated K+ channel. In conclusion, GmKAB1 might have played a pivotal role in potassium absorption in soybean and had important value in research.