甘蔗ScF-box基因cDNA全长克隆和生物信息学分析

Cloning and Bioinformatics Analysis of Full-Length c DNA Sequence of ScF-box Gene in Sugarcane

【目的】独脚金内酯是近年来发现的一种新型激素,能够有效抑制植物分枝(蘖),在其信号转导途径中MAX2/RMS4/D3基因扮演着十分关键的作用。为了研究该基因在甘蔗分蘖性状表现中的功能作用具有重要意义。【方法】本研究利用RT-PCR和RACE技术克隆出其同源基因(ScF-box)的c DNA全长,并对其序列和编码蛋白开展生物信息学分析。【结果】ScF-box基因的c DNA全长为2642 bp(KR870233),具2103 bp的开放阅读框(ORF,113~2215 bp),编码700个氨基酸;蛋白质分析表明,ScF-box为不稳定的水溶性非分泌蛋白,主要在氨基酸生物合成和中央中介代谢中发挥作用。亚细胞定位于细胞质,存在22个磷酸化位点,4个NES信号和1个NLS信号位点,不存在信号肽,二级结构以α螺旋和无规则卷曲为主,保守结构域和三级结构预测均表明该蛋白存在一个F-box结构,能特异识别与之作用的底物。【结论】推测ScF-box可能作为独脚金内酯调控甘蔗分蘖信号转导途径中一个具有特异性识别功能的组分而起作用。进化树分析表明该蛋白与高粱、玉米等单子叶植物进化关系较近。

[ Objective] As a novel hormone, strigolaetones can repress plant tillering effectively. In its signal transduction pathways, MAX2/RMS4/D3 plays a crucial role in transferring signal. The present paper aims to know the function characteristic of MAX2 homolog of sugar- cane in tillering trait regulation. [ Method] The cDNA of this gene named ScF-box was cloned from sugarcane variety by using RT-PCR and RACE technology. Then the structure and function of ScF-box were analyzed using bioinformatics technology. [ Result ] The sequence analy- sis showed that ScF-box had a length of 2642 bp containing the open reading frame （ ORF, 113 - 2215 bp）, which encoded 700 amino acid residues. The characters predicted based on the bioinformatics analysis revealed that ScF-box was an unstable soluble, non-secreted protein, which mainly played role in amino acid biosynthesis and central intermediary metabolism. And its protein was located in cytoplasmic, and had no signal peptide but contained 22 phosphorylation sites with 4 NES and 1 NLS. The secondary structure of ScF-box protein mainly enco- ded a-helix and random coil. With a conserved F-box which could specifically recognizes the interaction substrate. [ Conclusion ] The results mentioned above presumed that ScF-box might be as the composition of specific recognition in the strigolactones signal transduction pathways in regulating sugarcane tillering. Phylogenetic analysis showed that it had a closer evolutionary relationship with monocotyledon such as sor- ghum and maize.