ScFT6: A Putative Candidate for Sugarcane Floral Inducer
Abstract One of the factors that can decrease sugarcane productivity is the flowering, because it affects the quantity and quality of feedstock, due to sucrose consumption from the stem during inflorescence emission. Photoperiodicity is the main environmental factor involved in sugarcane floral induction, which occurs by the integration of gene regulatory networks in response to environmental and endogenous stimuli. One of the genes involved in those regulatory networks is the FLOWERING LOCUS T (FT), which is considered a phloem-mobile signal that stimulates floral induction in the shoot apical meristem. This work aimed to identify and characterize homologs of the FT gene in sugarcane, as well as to determine the putative function of these genes during floral induction. From this perspective, we have conducted in silico analyses of putative FT orthologs in sugarcane, as well as the expression levels in different photoperiodic conditions in a 24-hours-day-cycle of ScFT6 in different plant tissues in contrasting cultivars in terms of flowering time. Three new possible FT orthologs were found with high similarity to FT homologs in other species. Among three genes identified, we highlighted ScFT6, which has a conserved domain and amino acids at characteristic positions for the flowering inducer phosphatidylethanolamine-binding protein gene family. Additionally, its expression occurs according to coincidental model, possibly being controlled by the circadian clock. Cultivars with distinct flowering time behavior display variable expression for the ScFT6 gene, suggesting a possible genotypic relationship for its expression. Therefore, sugarcane has at least one putative orthologous gene in relation to FT that promotes floral induction.