Abstract: Somatic embryogenesis receptor-like kinase (SERK) is widely found in the plant community and has a variety of functions. Two SERK genes were identified from the genomic scaffold data by BLAST alignment in Dendrobium officinale Kimura et Migo, named DoSERK1 and DoSERK2. DoSERK1 has been reported, encoding 633 amino acids; but DoSERK2 is a new SERK gene. The coding sequence(CDS) length of DoSERK2 is 1877 bp, encoding 628 amino acids; DoSERK2 has the typical structure of SERK protein; it has five leucine-rich repeat(LRR) regions, one transmembrane region, one SPP motif and one intracellular kinase area. Conserved domains analysis finds that the active area of its intracellular kinase is in the depression of DoSERK2 three-dimensional structure. Quantitative analysis showed that DoSERK2 expressed in all eight stages of protocorm development, the highest expression level was in the first stage. Tissue expression analysis showed that the DoSERK2 expression was highest in flower, but in other tissues and organs it also could be detected. The gene expression profile indicated that DoSERK2 may play an important role in the early embryo development and reproductive process.

Key words: Dendrobium officinale Kimura et Migo, SERK, protocorm development, expression analysis