Genome-wide analysis and characterization of the rice OsFBA family provides insights into its responses to ABA and cold stress

Fructose-1,6-bphosphate aldolases (FBAs) are key enzymes in glycolysis, gluconeogenesis, and the Calvin cycle, which are fundamental metabolic pathways in plants and they are crucial plant growth and development. While isfor FBA genes have been characterized in several plants, a thorough and comprehensive analysis of rice (Oryza sativa), has not yet been conducted. In this study, the genome-wide identification, characterization and expression analysis of FBAs were performed in Oryza sativa, and a total number of eight OsFBA genes were identified. Based on the analysis of functional domains, phylogenetic relationships, and gene structures, all OsFBAs were classified as Class I. Notably, OsFBA2, OsFBA3, OsFBA5, and OsFBA6 belonged to the same subclass and were predicted to be localized in the cytoplasm, suggesting that they might have similar functions. Furthermore, gene duplication analysis indicated that segmental duplication events promoted the expansion of the OsFBA gene family. Additionally, promoter predictions revealed the existence of various cis-acting elements related to abiotic stress and phytohormones in the 2000 bp upstream region of OsFBAs, which might influence gene expression under different environmental conditions. The expression profiles of selected OsFBA genes were differentially and markedly induced by abscisic acid (ABA) and cold stress treatments, indicating that these genes play important roles in abiotic stress. In addition, a potential interaction between OsFBA1 and OsGSK2, a protein related to seed size, was identified using the yeast two-hybrid system, suggesting that OsFBA1 might be involved in regulating seed size, an important agronomic trait. These results provide valuable foundations for further exploring the stress resistance mechanism of rice and functional characterizations of OsFBAs, and numerous OsFBAs may function as the key regulators to enhance plant tolerance to abiotic stress and in plant development.