A GENE TRIGGERING FLOWER FORMATION IN ARABIDOPSIS

IN Arabidopsis, the apical shoot meristem produces lateral meristems t hat develop into either shoots or flowers. The decision to form flower s instead of shoots is mediated by the action of floral-meristem-ident ity genes, such as APETALA1 (API) and LEAFY (LFY), which specify meris tem fate(1-7). Here we show that transgenic plants which constitutivel y express the AP1 gene show transformations of apical and lateral shoo ts into flowers, and that these plants flower much earlier than wild-t ype plants. These results indicate that AP1 alone can convert inflores ence shoot meristems into floral meristems, and that ectopic AP1 expre ssion can dramatically reduce the time to flowering.