Abstract: A flowering-related MADS-box gene named PPI was cloned from pepper anthers（Gen- Bank accession No. GU812276）using rapid amplification of cDNA ends. The full length cDNA of PPI was 952 bp with an open reading frame（ORF）encoding 215 amino acids. The deduced amino acids sequence contained a typical MADS domain and a K domain. Homology analysis showed that PPI had high homology to other MADS-box proteins from different species，especially 88% similarity to tomato TPI. Phylogenetic analysis indicated that PPI belonged to the MADS-box B subfamily. RT-PCR analysis showed that the expression of PPI gene was much stronger in petals than in anthers，sepals or ovaries，and no transcription was detected in leaves.

Key words: pepper, floral organ development, MADS-box gene, PPI gene, RACE, RT-PCR