Expression of , the Flowering Inducer of Asiatic Hybrid Lily, in the Bulb Scales.

Asiatic hybrid lily leaves emerge from their bulbs in spring, after cold exposure in winter, and the plant then blooms in early summer. We identified four ()-like genes, , , , and , from an Asiatic hybrid lily. Floral bud differentiation initiated within bulbs before the emergence of leaves. genes were mainly expressed in bulb scales, and hardly in leaves, in which the genes of many plants are expressed in response to environmental signals. was expressed in bulb scales after vernalization and was correlated to flower bud initiation in two cultivars with different flowering behaviors. was upregulated in bulb scales after cold exposure and three alternative splicing variants with a nonsense codon were simultaneously expressed. was upregulated in bulb scales after flower initiation, whereas was expressed constantly in all organs. overexpression complemented the late-flowering phenotype of , whereas that of did so partly. and overexpression could not complement. Yeast two-hybrid and analyses showed that the LhFT1 protein interacted with the LhFD protein. LhFT6 and LhFT8 proteins also interacted with LhFD, as observed in AlphaScreen assay. Based on these results, we revealed that acts as a floral activator during floral bud initiation in Asiatic hybrid lilies. However, the biological functions of , , and remain unclear.