Molecular and phylogenetic analyses of the MADS-box gene family in tomato.

MIKCc-type MADS-box genes encode key transcriptional regulators of a variety of developmental processes in Arabidopsis thaliana. However, there has been relatively little effort to systematically carry out comparative genomic or functional analyses of these genes across flowering plants. Here we describe a strategy to identify members of the MIKCc-type MADS-box gene family from any angiosperm species of interest. Using this approach, we have identified 24 MIKCc-type MADS-box genes in tomato, including 17 that have not previously been characterized. Using these sequences, we have performed phylogenetic analyses that indicate that there have been a number of gene duplication and loss events in tomato relative to Arabidopsis. We also describe the expression domains of these genes and compare these results with their cognates in Arabidopsis. These analyses demonstrate the utility of this approach for characterizing a large number of MIKCc-type MADS-box genes from any flowering plant species of interest and provide a framework for evolutionary comparisons of this important gene family across angiosperms.