CONVERSION OF PERIANTH INTO REPRODUCTIVE-ORGANS BY ECTOPIC EXPRESSIONOF THE TOBACCO FLORAL HOMEOTIC GENE NAG1

Mutations in the AGAMOUS (AG) gene of Arabidopsis thaliana result in t he conversion of reproductive organs, stamens and carpels, into perian th organs, sepals and petals. We have isolated and characterized the p utative AG gene from Nicotiana tabacum, NAG1, whose deduced protein pr oduct shares 73% identical amino acid residues with the Arabidopsis AG gene product. RNA tissue in situ hybridizations show that NAG1 RNA ac cumulates early in tobacco flower development in the region of the flo ral meristem that will later give rise to stamens and carpels. Ectopic expression of NAG1 in transgenic tobacco plants results in a conversi on of sepals and petals into carpels and stamens, respectively, indica ting that NAG1 is sufficient to convert perianth into reproductive flo ral organs.