As part of a programme to identify seed coat-specific transcripts in pea (Pisum sativum cv. Finale) using the differential display method, we identified and isolated a cDNA encoding a MADS box transcription factor. The predicted peptide contains 247 amino acids with the conserved N-terminal MADS box and is closely related to the AP1/AGL9 subfamily of the MADS box proteins. In addition to weak expression in petals, stamens and carpels, this MADS box mRNA is specifically expressed in the seed coat during seed development.