Molecular cloning and characterization of a novel DoRLK gene from Dendrobium officinale / 中草药

ABSTRACT

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.