目的 克隆铁皮石斛Dendrobium officinale类受体激酶（receptor-like kinase，RLK）基因，命名为DoRLK（GenBank注册号ANC68272.1）。方法 采用实时荧光定量PCR（qRT-PCR）和RACE技术获取基因全长；利用生物信息学软件预测蛋白的理化性质、结构域和亚细胞定位等分子特性；用软件DNASTAR 6.0和MEGA 7.0分别进行氨基酸多序列比对和进化关系分析；借助定量PCR检测基因表达模式。结果 DoRLK基因cDNA全长1 715 bp，编码1条由423个氨基酸组成的多肽，相对分子质量47 800.88，等电点为9.47。DoRLK蛋白包含RLK蛋白家族的1个蛋白激酶结构域（85~370）和一个跨膜基序（250~270）。DoRLK基因与多种植物RLK基因相似性很高（43.62%~63.35%），与小兰屿蝴蝶兰、海枣、芦笋等植物亲缘关系较近。DoRLK基因具有组织表达特异性，其转录本在石斛根中表达量较高，分别为叶和茎中的2.22、2.75倍。结论 DoRLK基因的分子鉴定为进一步揭示RLK在铁皮石斛与环境互作中的功能奠定基础。

Objective To identifiy a receptor-like kinase (RLK) encoding gene named as DoRLK (GenBank accession No. ANC68272.1) from Dendrobium officinale. Methods RT-PCR and RACE technologies were used to isolate the full length cDNA of DoRLK. Characteristics of physiochemical properties, conserved domains, and subcellular localization of the deduced DoRLK protein were determined by a series of bioinformatics tools. The analyses of multiple alignment and phylogenetic tree were performed using DNASTAR 6.0 and MEGA 7.0 softwares, respectively. Quantitative PCR was used for gene expression analysis. Results The results showed that the full length cDNA of DoRLK was 1 715 bp in length and encoded a 423 aa protein with a molecular weight of 47 800.88 and an isoelectric point (pI) of 9.47. The deduced DoRLK protein, like other RLK proteins, constituted one conserved domains (85-370) and one transmembrane motifs (250-270). Multiple sequence alignment and phylogenetic analyses demonstrated that DoRLK had high identity (43.62%-63.35%) to a number of RLK genes from various plants and was closely related to Phalaenopsis equestris, Phoenix dactylifera and Asparagus officinalis. Real time quantitative PCR (qPCR) analysis revealed that DoRLK was expressed in the three included organs. The transcripts were the most abundant in the roots with 2.22 fold over that in the leaves, followed by that in the stems with 2.75 fold. Conclusion Molecular characterization of DoRLK will be useful for further functional elucidation of the gene involving in D. officinale responses to environmental factors.

国家自然科学基金项目（31600320）；陕西省高校科协青年人才托举计划项目（20170208）；陕西省社会发展科技攻关项目（2018SF-338）；陕西省普通高校青年杰出人才计划项目；陕西中医药大学“秦药”品质评价及资源开发学科创新团队项目；陕西中医药大学“思邈青年学者”项目