Isolation and Functional Characterization of a SERK Gene from Soybean (Glycine max (L.) Merr.)

It is well accepted that somatic embryogenesis serves a primary role in plant regeneration. However, it is also a model system to explore the regulatory and morphogenetic events in the life of a plant. To date, a suite of genes that serve important roles in somatic embryogenesis have been isolated and identified. In the present study, a novel gene designated as GmSERK1 was isolated from soybean (Glycine max (L.) Merr). Sequence and structural analysis determined that the GmSERK1 protein, which encodes 624 amino acids, belongs to the somatic embryogenesis receptor-like kinase (SERK) gene family. GmSERK1 shared all the characteristic domains of the SERK family, including five leucine-rich repeats, one proline-rich region motif, transmembrane domain, and kinase domains. DNA gel blot analysis indicated that a single copy of the GmSERK1 gene resides in the soybean genome. The GmSERK1 tissue-specific and induced expression patterns were explored using quantitative real-time PCR. Dissimilar expression levels in various tissues under different treatments were found. In addition, transient expression experiments in onion epidermal cells indicated that the GmSERK1 protein was located on the plasma membrane. The results from this study suggested that GmSERK1, a member of the SERK gene family, exhibits a broader role in various aspects of plant development and function, in addition to its basic functions in somatic embryogenesis.