---

作 者 ：张 岗,王昌利,李依民,沈 霞,刘 清

期 刊 ：西北植物学报 2013年 2期 页码：229~234

关键词：铁皮石斛；唾液酸转移酶；基因表达；分子鉴定；

Keywords:Dendrobium officinale, sialyltransferase, gene expression, molecular characterization,

摘 要 ：利用RT-PCR和RACE技术,从珍稀濒危药用植物铁皮石斛（Dendrobium officinale）中分离到一个类唾液酸转移酶（sialyltransferase-like proteins,STLP）基因,命名为DoSTLP1（GenBank注册号KC178574）。序列分析结果表明,DoSTLP1基因全长cDNA为1 340 bp,编码1条由367个氨基酸组成的肽链,分子量41.66 kD,等电点8.64；DoSTLP1蛋白具有唾液酸转移酶和糖基转移酶29家族的保守结构域（分别为1~357,87~346位氨基酸）、信号肽（1~27）和跨膜结构域（3~25,285~311）。多序列比对和系统进化结果显示,DoSTLP1与多种植物的STLPs基因有较高的相似性（44.7%~53.7%）,而且与水稻、玉米等单子叶植物STLPs基因的亲缘关系较近。实时定量PCR分析显示,DoSTLP1基因在铁皮石斛根、茎、叶器官中为组成型表达,其转录本在石斛根中的相对表达量较高,为叶中的2.857倍,茎和叶中的表达量无显著差异。该研究为进一步解析该基因在铁皮石斛生长发育过程中的生物学功能奠定基础。

Abstract:In the present study,a sialyltransferase-like proteins (STLP) gene,designated as DoSTLP1 (GenBank accession No.KC178574),was identified from a medicinally important species Dendrobium officinale,using RT-PCR and RACE methods.Sequence analyses showed that the full length cDNA of DoSTLP1 was 1 340 bp and encoded a 367 aa with a molecular weight of 41.66 kD and an isoelectric point of 8.64;The deduced DoSTLP1 protein contained the sialyltransferase and glycosyltransferase family 29 conserved domains (1~357,87~346),together with a signal peptide sequence (1~27) and two transmembrane helices (3~25,285~311).Multiple sequence alignment and phylogenetic analysis demonstrated that DoSTLP1 was highly similar (44.7%~53.7%) to STLPs genes from various plant species and was closely related to those from monocots.Real time quantitative PCR analysis revealed that DoSTLP1 was constitutively expressed in the leaf,stem and root organs.The transcription level of DoSTLP1 in roots was relatively higher than that of leaves with 2.857 fold.Molecular characterization of DoSTLP1 will be helpful for further functional elucidation of the gene involving in the development of D.officinale.

---