Genome-Wide Identification, Evolution, and Expression Patterns of the Fructose-1,6-Bisphosphatase Gene Family in Species.

Fructose-1,6-bisphosphatase (FBP) is a crucial regulatory enzyme in sucrose synthesis and photosynthetic carbon assimilation, functioning through two distinct isoforms: cytosolic FBP (cyFBP) and chloroplastic FBP (cpFBP). However, the identification and functional characterization of genes in remains limited. In this study, we conducted a systematic identification and comparative genomics analyses of in three species. We further examined their expression patterns across leaf developmental zones, spatiotemporal profiles, and responses to diurnal rhythms and hormonal treatments. Our analysis identified 95 genes, including 44 and 51 . Comparative analyses revealed significant divergence in physicochemical properties, gene structures, and motif compositions between the two isoforms. Expression profiling indicated that both and were predominantly expressed in leaves, particularly in maturing and mature zones. During diurnal cycles, their expression peaked around the night-day transition, with exhibiting earlier peaks than . in displayed greater diurnal sensitivity than those in . Hormonal treatments further revealed significant regulatory divergence in genes, both between isoforms and across species. Notably, _ and _ members consistently exhibited higher expression levels across all datasets, suggesting their pivotal roles in sugarcane physiology. These findings not only identify potential target genes for enhancing sucrose accumulation, but also highlight the breeding value of and in sugarcane breeding.