CLONING AND MOLECULAR ANALYSIS OF THE ARABIDOPSIS GENE TERMINAL-FLOWER-1

The Arabidopsis gene Terminal Flower 1 (TFL1) controls inflorescence m eristem identity. A terminal flower (tfl1) mutant, which develops a te rminal flower at the apex of the inflorescence, was induced by transfo rmation with T-DNA. Using a plant DNA fragment flanking the integrated T-DNA as a probe, a clone was selected from a wild-type genomic libra ry. Comparative sequence analysis of this clone with an EST clone (129 D7T7) suggested the existence of a gene encoding a protein similar to that encoded by the cen gene which controls inflorescence meristem ide ntity in Anti-rrhinum. Nucleotide sequences of the region homologous t o this putative TFL1 gene were compared between five chemically induce d tfl1 mutants and their parental wildtype ecotypes. Every mutant was found to have a nucleotide substitution which could be responsible for the tfl1 phenotype. This result confirmed that the cloned gene is TFL 1 itself. In our tfl1 mutant, no nucleotide substitution was found in the transcribed region of the gene, and the T-DNA-insertion site was l ocated at 458 bp downstream of the putative polyadenylation signal, su ggesting that an element important for expression of the TFL1 gene exi sts in this area.