MOLECULAR-BASIS OF THE CAULIFLOWER PHENOTYPE IN ARABIDOPSIS

Genetic studies demonstrate that two Arabidopsis genes, CAULIFLOWER an d APETALA1, encode partially redundant activities involved in the form ation of floral meristems, the first step in the development of flower s. Isolation of the CAULIFLOWER gene from Arabidopsis reveals that it is closely related in sequence to APETALA1. Like APETALA1, CAULIFLOWER is expressed in young flower primordia and encodes a MADS-domain, ind icating that it may function as a transcription factor. Analysis of th e cultivated garden variety of cauliflower (Brassica oleracea var. bot rytis) reveals that its CAULIFLOWER gene homolog is not functional, su ggesting a molecular basis for one of the oldest recognized flower abn ormalities.