FALSIFLORA, the tomato orthologue of FLORICAULA and LEAFY, controls flowering time and floral meristem identity

Characterization of the tomato falsiflora mutant shows that fa mutation mai nly alters the development of the inflorescence resulting in the replacemen t of flowers by secondary shoots, but also produces a late-flowering phenot ype with an increased number of leaves below first and successive infloresc ences. This pattern suggests that the FALSIFLORA (FA) locus regulates both floral meristem identity and flowering time in tomato in a similar way to t he floral identity genes FLORICAULA (FLO) of Antirrhinum and LEAFY (LFY) of Arabidopsis. To analyse whether the fa phenotype is the result of a mutati on in the tomato FLO/LFY gene, we have cloned and analysed the tomato FLO/L FY homologue (TOFL) in both wild-type and fa plants following a candidate g ene strategy. The wild-type gene is predicted to encode a protein sharing 9 0% identity with NFL1 and ALF, the FLO/LFY-like proteins in Nicotiana and P etunia, and about 80 and 70% identity with either FLO or LFY. In the fa mut ant, however, the gene showed a 16 bp deletion that results in a frameshift mutation and in a truncated protein. The co-segregation of this deletion w ith the fa phenotype in a total of 240 F-2 plants analysed supports the ide a that FA is the tomato orthologue to FLO and LFY. The gene is expressed in both vegetative and floral meristems, in leaf primordia and leaves, and in the four floral organs. The function of this gene in comparison with other FLO/LFY orthologues is analysed in tomato, a plant with a sympodial growth habit and a cymose inflorescence development.