Poster: Intercellular Signaling
Abs #
805: Arabidopsis TFL1 has signal peptide for intercellular trafficking.
Arabidopsis TERMINAL FLOWER 1 (TFL1) gene is required for the establishment and maintenance of inflorescence meristem (IM), since tfl1 mutants show early flowering and terminal flower phenotype. We have shown that TFL1 protein moves from inner region of L3 layer to outer layers of shoot apical meristem (SAM) in accordance with the vegetative to reproductive phase transition. TFL1 protein does not move in the vegetative meristem (VM), but start to move when the SAM is switched to IM by floral induction. This protein movement is essential for TFL1 function since immobilised TFL1 protein does not complement tfl1 mutant.
Molecular dissection of TFL1 protein revealed that 20 amino acids region is sufficient for TFL1 protein trafficking. This region is highly conserved among TFL1/FT family proteins. GFP coupled this peptide shows the same manner of protein movement as TFL1 and TFL1 does not move when this region was removed or substituted. A mutant TFL1 protein, which has single amino acid substitution in this region, did not rescue tfl1 mutation when expressed by either genomic context or CaMV 35S promoter. We are now making a series of mutant proteins to reveal whether the TFL1 function and its protein trafficking can be separated or not.
