The fca mutant belongs to a group of late flowering mutants that flower late under both long day and short day conditions but flower almost like wild type after vernalization. FCA was recently cloned and encodes a protein with two RNA-binding domains. The third intron is maintained in one FCA transcript and maybe involved in regulation of FCA expression. Several experiments are proposed to elucidate the role of FCA in floral induction FCA expression will be localized using antibodies. The role of the third intron will be studied by making transgenic plants with an FCA construct with and without the third intron. The splicing efficiency of the third intron will be analyzed using a transient tobacco protoplast assay. Epistatic relations of FCA with other genes involved in floral induction will be studied using a transgenic FCA overexpressor line. Using differential display and RNA binding experiments, transcripts will be identified that are directly regulated by FCA.