Identification and Characterization of the FT/TFL1 Gene Family in the Biofuel Plant Jatropha curcas

The transition from vegetative to reproductive growth is one of the most important developmental steps made by flowering plants. At the molecular level, the genes in the FLOWERING LOCUS T (FT)/TERMINAL FLOWER 1 (TFL1) family, which encode proteins with high similarity to phosphatidyl ethanolamine-binding proteins, function as flowering promoters or repressors. Here, we isolated six members of the FT/TFL1 family from Jatropha curcas, a plant with considerable potential for various uses including biofuels. All members of this gene family display a common exon-intron organization. Sequence comparisons and phylogenetic analysis with homologous genes from other plant species group Jatropha FT/TFL1 genes into three major subfamilies: one into the FT-like, three into the TFL1-like, and two into the MOTHER OF FT AND TFL1 (MFT)-like subfamilies. Expression analysis indicates differences in the expression patterns of these six genes at the temporal and spatial levels. JcFT, the Jatropha FT homolog, is primarily expressed in the reproductive organs. JcTFL1a and JcTFL1c, two genes in the TFL1-like subfamily, are mainly expressed in the roots of juvenile plants, whereas JcTFL1b transcripts are abundantly accumulated in the fruits. In addition, two JcMFT genes are primarily expressed in the fruits. The differential expression of the FT/TFL1 gene family in Jatropha suggests that this gene family plays multifaceted roles in plant growth and development.