Abstract
Arabidopsis fd mutants exhibit a weak late-flowering phenotype. FD encodes a bZIP transcription factor and acts with the flowering-time gene FT to activate the transcription of the floral meristem identity gene AP1. FD contains a possible site for phosphorylation by calcium-dependent protein kinase (CDPK) in the C-terminal region. In yeast cells, mutant forms of FD which lack the potential phosphorylation site cannot interact with FT. Transgenic plants overexpressing FD which cannot interact with FT failed to complement fd late-flowering phenotype. These results suggest that the importance of the C-terminal region of FD (possibly via phosphorylation) in the interaction with FT and promotion of flowering. Its importance of this region in intercellular localization of FD is currently being examined using EYFP fusions. Results of these analysis will be presented.
