Comprehensive Analyses of Four Genes from and Impacts on Flowering Time.

Nuclear Factor Y (NF-Y) is a class of heterotrimeric transcription factors composed of three subunits: NF-A, NF-YB, and NF-YC. NF-YC family members play crucial roles in various developmental processes, particularly in the regulation of flowering time. However, their functions in petunia remain poorly understood. In this study, we isolated four genes from petunia and confirmed their subcellular localization in both the nucleus and cytoplasm. We analyzed the transcript abundance of all four genes and found that and were highly expressed in apical buds and leaves, with their transcript levels decreasing before flower bud differentiation. Silencing using VIGS resulted in a delayed flowering time and reduced chlorophyll content, while -silenced plants only exhibited a delayed flowering time. Furthermore, we detected the transcript abundance of flowering-related genes involved in different signaling pathways and found that , , , , and were regulated by both and . Additionally, the transcript abundance of , , and increased only in -silenced plants. Overall, these results provide evidence that and negatively regulate flowering time in petunia by modulating a series of flowering-related genes.