Characterization of MADS box genes from hot pepper

The cDNA clone, CanMADS1, was isolated from young flower buds of the hot pe pper (Capsicum annuum L. by screening a cDNA library using the OsMADS1 rice MADS-bos gene as a probe. We used a yeast two-hybrid screening method to i nvestigate interaction partners of the protein product of CanMADS1. A MAI)S -box gene, CanMADS6, was isolated from young flower buds using the region c ontaining the K domain and 15 amino acid residues of the C-terminal region of CanMADS1 as a bait. CanMADS1 and CanMADS6 showed high amino acid sequenc e similarities to members of the AGL2 subfamily and the SQUA subfamily, res pectively, CanMADS1 transcript was expressed in flower buds and fruits, and the transcription signal was the strongest in the stage of the fruit set ( 2 d after anthesis). CanMADS6 showed the same expression pattern as CanMADS 1. CanMADS1 and CanMADS6 were not expressed in leaves. These results sugges t that a regulatory role for flower and fruit development of the hot pepper may be accomplished through an interaction of the protein products of the two MADS-box genes, CanMADS1 and CanMADS6.