Functional conservation and divergence of -like genes in floral development in .

is one of the most important traditional Chinese Orchids due to its unique and highly ornamental floral organs. Although the ABCDE model for flower development is well-established in model plant species, the precise roles of these genes in are not yet fully understood. In this study, four -like genes were isolated and identified from . and were grouped into the clade, while and were included in the clade. The expression pattern of genes showed that they were significantly accumulated in reproductive tissues and expressed during flower bud development but only mildly detected or even undetected in vegetative organs. Subcellular localization revealed that and were localized to the nucleus, while and were located at the nuclear membrane. Promoter sequence analysis predicted that genes contained a number of hormone response elements (HREs) and MADS-box binding sites. The early flowering phenotype observed in transgenic Arabidopsis plants expressing four genes, along with the expression profiles of endogenous genes, such as , , , , and , in both transgenic Arabidopsis and protoplasts, suggested that the genes played a regulatory role in the flowering transition by influencing downstream genes related to flowering. However, only transgenic plants overexpressing and caused abnormal phenotypes of floral organs, while and had no effect on floral organs. Protein-protein interaction assays indicated that CsSEPs formed a protein complex with B-class CsAP3-2 and CsSOC1 proteins, affecting downstream genes to regulate floral organs and flowering time. Our findings highlighted both the functional conservation and divergence of -like genes in floral development. These results provided a valuable foundation for future studies of the molecular network underlying floral development in .