百子莲赤霉素受体基因ApGID1全长的克隆及功能分析
Cloning and Functional Analysis of the Full-Length Gibberellin Receptor Gene ApGID1 from Agapanthus praecox ssp.orientalis

为揭示赤霉素(gibberellin,GA)对根茎类花卉百子莲(Agapanthus praecox ssp.orientalis)生长发育的调控机制,利用cDNA末端快速扩增(rapid amplification of cDNA ends,RACE)方法获得百子莲GA受体基因GIBBERELLIN INSENSITIVE DWARF1(GID1)全长cDNA,命名为ApGID1。该基因cDNA全长为1 629 bp,其中5’非编码区(untranslated region,UTR)372 bp,3’端UTR 213 bp;编码区全长为1 044 bp,共编码347个氨基酸;结构预测显示,ApGID1蛋白由8条β-折叠和7个α-螺旋组成袋状结构域,能够与GA分子结合。推导的ApGID1蛋白氨基酸序列与陆地棉(Gossypium hisutum)具有较高的同源性,可达71.8%。系统进化表明,百子莲与单子叶植物小麦(Triticum aestivum)、大麦(Hordeum vulgare)和玉米(Zea mays)聚为一类,与双子叶植物进化关系较远。ApGID1基因在根、茎和花药中表达量高。亚细胞定位显示ApGID1是核蛋白,是GA信号通路的重要组成部分。拟南芥(Arabidopsis thaliana)中过表达ApGID1可促进开花和株高建成。
To investigate the roles of gibberellin(GA)in Agapanthus praecox ssp.orientalis development,full length cDNA of gibberellin receptor GIBBERELLIN INSENSITIVE DWARF1(GID1)was isolated by rapid amplification of cDNA ends(RACE).Bioinformatics analysis indicated that the ApGID1 cDNA includes 372 bp of 5’-UTR and 172 bp of 3’-UTR,encodes a putative polypeptide of 347 amino acids which contains a GA binding domain consisted of 8 β-strands and 7 α-helices.The deduced amino acid sequence was highly homologous with Gossypium hisutum and the similarity was 71.8%.Phylogenetic analysis revealed that the ApGID1 protein was highly homologous with GID1 proteins in monocotyledons,such as Triticum aestivum,Hordeum vulgare and Zea mays.The gene expression pattern indicated that ApGID1 was critical to the organs development in plant.Subcellular localization experiment showed ApGID1was a nuclear protein.ApGID1promoted early flowering and enhanced plant height in Arabidopsis thaliana.