巴戟天MoDXS基因及其启动子的克隆与分析

从药用植物巴戟天根部组织中克隆了3个1–脱氧–D–木酮糖5–磷酸合成酶基因MoDXS1、MoDXS2-1和MoDXS2-2,其全长cDNA分别为2 676、2 667和2 610 bp,编码区序列长度为2 154、2 121和2 190 bp,编码717、706和729个氨基酸。BlastP序列比对分析表明MoDXS蛋白与其他植物的DXS蛋白高度同源;系统进化发育树分析显示,MoDXS蛋白与中粒咖啡和小粒咖啡DXS蛋白亲缘关系最近。MoDXS1、MoDXS2-1和MoDXS2-2蛋白被分别归为clade 1、clade 3和clade 2。MoDXS1在巴戟天根中表达量最高;MoDXS2-1在巴戟天根、茎、叶中的相对表达量差异显著,叶中最高;MoDXS2-2在根中表达量最高,而在茎和叶中最低。MoDXS1、MoDXS2-1和MoDXS2-2基因的5′端上游启动子序列长度分别为2 538、732和1 744 bp。亚细胞定位预测3个MoDXS均在叶绿体上。

Cloning and Analysis of MoDXS Gene and Its Promoter in Morinda officinalis

In the root tissue of Morinda officinalis,three full-length cDNA sequences of 1-deoxy-D-xylulose 5-phosphate synthase genes(MoDXS1,MoDXS2-1 and MoDXS2-2)were successfully cloned and their length were 2676,2667,and 2610 bp,respectively.The coding sequence(CDS)of the three cDNAs were 2154,2121,and 2190 bp,encoding 717,706,and 729 amino acid residues,respectively.Sequence comparison by BlastP in NCBI database revealed that MoDXS proteins had high homology with DXS proteins from other species.The result of the phylogenetic tree displayed that MoDXS proteins had the closest relationship with DXS proteins from Coffea canephora and Coffea arabica.Furthermore,MoDXS1,MoDXS2-1,and MoDXS2-2 proteins were grouped into clade 1,clade 3,and clade 2,respectively.MoDXS1 gene had the highest expression level in roots.The expression level of MoDXS2-1 gene had significant differences in three tissues,and the expression level was the highest in leaves.However,the expression level of MoDXS2-2 gene was the highest in roots but lower in stems and leaves.The plantCARE analysis indicated that the upstream regulation sequences of MoDXS1,MoDXS2-1,and MoDXS2-2 were 2538,732,and 1744 bp,respectively.The subcellular localization exhibited that the three MoDXS proteins were located on chloroplast.