Molecular cloning and characterization of two tobacco MADS-box genes

We isolated and characterized two MADS-box genes, TOBM1 and TOBM2, from Nicotiana tabacum. The complete cDNA sequences of TOBM1 and TOBM2 encode a 245 and a 242 amino acid protein, respectively. Amino acid sequence alignment and phylogenetic analyses have shown that TOBM1 and TOBM2 are highly related to the MADS-box-containing PFG, SQUA, and AP1 genes. However, expression patterns of TOBM1 and TOBM2 are significantly different from those of previously published MADS-box genes. TOBM1 and TOBM2 are expressed in the inflorescence meristem and all four floral organs. Within the stamen and carpel, TOBM1 and TOBM2 transcripts are present in immature pollen, ovary wall and ovule. TOBM1 is also active in stem tissues.