Abstract
The gene TERMINAL FLOWER1 (TFL1) regulates the floral phases and the inflorescence architecture of Arabidopsis. A TFL1 homolog designated as RsTFL1 was isolated from radish (Raphanus sativus). The deduced amino acid sequence had 96% identity with TFL1—higher than the values obtained for other reported TFL1-like proteins. The genomic organization of RsTFL1 is very similar to that of TFL1 and consists of 4 exons and 3 introns. Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis revealed that RsTFL1, like TFL1, is continuously expressed in both vegetative and reproductive tissues. RsTFL1 was expressed throughout seed development until seed desiccation. RsTFL1 mRNA was detected after seed imbibition, suggesting that the gene expression is initiated during germination. In situ hybridization analysis revealed that RsTFL1 was expressed in the inflorescence meristem but not in the floral meristems. The expression was not limited to the inner cells of the inflorescence meristem, unlike the expression of TFL1 in Arabidopsis. This expression pattern of RsTFL1 may make it possible that radish maintains its indeterminate inflorescence.
