Conversion of Perianth into Reproductive Organs by Ectopic Expression of the Tobacco Floral Homeotic Gene NAG1

Abstract

Mutations in the AGAMOUS (AG) gene of Arabidopsis tbaliana result in the conversion of reproductive organs, stamens and car- pels, into perianth organs, sepals and petals. We have isolated and characterized the putative AC gene from Nicotiana fabacum, NAG1, whose deduced protein product shares 73% identical amino acid residues with the Arabidopsis AG gene product. RNA tissue in situ hybridizations show that NACl RNA accumulates early in tobacco flower development in the region of the floral meristem that will later give rise to stamens and carpels. Ectopic expression of NACl in transgenic tobacco plants results in a conversion of sepals and petals into carpels and stamens, respectively, indicating that NACl is sufficient to convert perianth into reproductive floral organs.