Genome-Wide Identification and Expression Analysis of the Fructose 1,6-Bisphosphate Aldolase (FBA) Gene Family Members in Seashore Paspalum in Response to Cadmium Stress

The fructose 1,6-bisphosphate aldolase (FBA) gene family plays crucial roles in plant energy metabolism, growth, development, and abiotic stress responses, as it modulates antioxidant synthesis and soluble sugar accumulation to enhance plant cadmium tolerance. Seashore paspalum (Paspalum vaginatum Sw.), a halophytic perennial C4 turfgrass renowned for its exceptional cadmium tolerance, is ideal for phytoremediation of cadmium-contaminated soil. FBA family genes have been identified in several grass species, such as maize, rice, and wheat, but systematic investigations into FBA family genes and their functions in seashore paspalum remain scarce. In this study, seven class I FBAs (named as PvFBA1–PvFBA7) and one class II FBA (named as PvFBA8) in seashore paspalum were identified. The physicochemical properties, evolutionary relationships, gene structures, conserved domains, protein structures, cis-acting regulatory elements, chromosomal localizations, and collinearity relationships of eight PvFBAs were analyzed. These analyses suggested that PvFBA genes had highly conserved domains and belonged to ultra-conserved core genes. Expression pattern analysis indicated that the PvFBA gene family was dynamically responsive to cadmium stress. PvFBA6 and PvFBA7 were highly expressed in leaves, whereas PvFBA1 and PvFBA3 showed almost no expression. The RT-qPCR results suggested that the expression levels of PvFBA5 and PvFBA6 were highly consistent with the FPKM value trends analyzed in the transcriptomic data. Collectively, this study not only provides a theoretical foundation for the understanding of the evolution of the PvFBA gene family but also offers potential candidate genes for enhancing cadmium stress tolerance in plants.