A cDNA clone, NsMADS1, was isolated from Nicotiana sylvestris. Sequence homology analysis indicated that the gene is a member of the SQUA subfamily. Its transcript was detectable primarily in reproductive organs, especially in sepals and carpels. When the gene was expressed ectopically in tobacco plants, no phenotypic alteration was observed. Thus, NsMADS1 appears to be a new member of the MADS gene family.