Molecular Characterization, Gene Evolution, and Expression Analysis of the Fructose-1, 6-bisphosphate Aldolase (FBA) Gene Family in Wheat ( L.).

Fructose-1, 6-bisphosphate aldolase (FBA) is a key plant enzyme that is involved in glycolysis, gluconeogenesis, and the Calvin cycle. It plays significant roles in biotic and abiotic stress responses, as well as in regulating growth and development processes. In the present paper, 21 genes encoding TaFBA isoenzymes were identified, characterized, and categorized into three groups: class I chloroplast/plastid (CpFBA), class I cytosol (cFBA), and class II chloroplast/plastid . By using a prediction online database and genomic PCR analysis of nulli-tetrasomic lines, we have confirmed the chromosomal location of these genes in 12 chromosomes of four homologous groups. Sequence and genomic structure analysis revealed the high identity of the allelic genes and the origin of different genes. Numerous putative environment stimulus-responsive -elements have been identified in 1,500-bp regions of gene promoters, of which the most abundant are the light-regulated elements (LREs). Phylogenetic reconstruction using the deduced protein sequence of 245 genes indicated an independent evolutionary pathway for the class I and class II groups. Although, earlier studies have indicated that class II FBA only occurs in prokaryote and fungi, our results have demonstrated that a few class II CpFBAs exist in wheat and other closely related species. Class I TaFBA was predicted to be tetramers and class II to be dimers. Gene expression analysis based on microarray and transcriptome databases suggested the distinct role of TaFBAs in different tissues and developmental stages. The genes were highly expressed in leaves and might play important roles in wheat development. The differential expression patterns of the genes in light/dark and a few abiotic stress conditions were also analyzed. The results suggested that LRE cis-elements of gene promoters were not directly related to light responses. Most genes had higher expression levels in the roots than in the shoots when under various stresses. Class I cytosol genes, particularly and , and three class II genes are involved in responses to various abiotic stresses. Class I CpFBA genes in wheat are apparently sensitive to different stress conditions.