Characterisation of the cacao somatic embryogenesis receptor-like kinase (SERK) gene expressed during somatic embryogenesis

Somatic embryogenesis is a useful tool for plant propagation and consists of a good model for embryo development studies. During somatic embryogenesis, some morphological and biochemical changes occur in response to alterations in gene expression patterns. The somatic embryogenesis receptor kinase (SERK) gene is an important element related to this process. In this work we have focused on the function of SERK in Theobroma cacao. Our main questions were whether this gene exists in this plant with another arrangement; if it is functional and, in a positive case, in which tissues it acts. We have found only one copy of SERK that is functional and analyzed its expression in a series of tissues. The phylogenetic tree showed that the available sequences of SERK are highly conserved and a considerable number of species contain different sequences of SERK, confirming it as a gene family with variant repeats. (C) 2004 Elsevier Ireland Ltd. All rights reserved.