The MADS-box genes play diverse roles in plant development. Here a MADS-box transcription factor gene, designated as FLORAL BINDING PROTEIN 20 (FBP20), was isolated, cloned and characterized from Petunia axillaris. The open reading frame of FBP20 comprised of 651bp nucleotides encoding a polypeptide of 216 amino acids. Based on sequence analysis, FPB20 is suggested to have a role in promoting flowering. Phylogenetic analysis showed that FBP20 belonged to the SOC1/TM3 clade of MADSbox proteins. Expression analysis results revealed that FBP20 was preferentially expressed 16 and 32 fold higher in flower buds in comparison to leaves and Sepals respectively. The expression of FBP20 was not detected in Petals. On the basis of sequence analysis we find that there were slight changes in nucleotide and amino acid sequence of MADS Box domain of isolated FBP20 gene from Petunia axillaris and FBP20 gene of Petunia hybrid as retrieved from genomic data sequences. Petunia axillaris FBP20 shows high homology to the SOC1 subfamily of MADS Box genes from different species. The phylogenetic findings suggested that FBP20 is closely related to TobMADS1 transcription factor of Nicotiana tobacum. | Isolation and expression analysis of floral binding protein 20 (FBP20) MADS Box Gene in Petunia axillaris
