Somatic embryogenesis receptor-like kinase(SERK) genes were identified in different plant species, such as Daucus carota, Arabidopsis thaliana and Oryza sativa. Studies of these genes showed that they have conserved structures and expression patterns. These genes are not only expressed in embryogenic tissues, but also in post-embryogenic development. They function in embryogenesis and reproductive development and defences in particular, related signal transduction pathways.