Genome-wide analysis of the Alba gene family members in soybean (Glycine max L.): characterization and...

The Alba (Acetylation lowers binding affinity) protein family consists of small, conserved nucleic acid-binding proteins involved in regulating gene expression and stress responses. Although studied in several plants, their roles in legumes remain poorly understood. Characterizing Alba genes in soybean (Glycine max L.), a crop highly affected by climate stress, is essential for improving its stress resilience.

In this study, a total of 15 Glycine max Alba (GmAlba) genes were identified, unevenly distributed across 14 chromosomes with varied exon-intron structures and conserved hydrophilic domains. Phylogenetic analysis grouped them into five clades: Groups 1-2 (Rpp25-like) and Groups 3-5 (Rpp20-like), with Group 4 only containing soybean-specific members, indicating functional divergence. Promoter analysis revealed multiple cis-elements related to phytohormone and stress responses. Transcriptomic data showed broad expression across tissues, with GmAlba5/6/10 highly expressed, especially in reproductive organs. RT-qPCR confirmed differential expression under salt, heat, cold, and ABA treatments, suggesting roles in stress adaptation. Structural modelling revealed protein diversity, while subcellular localization showed nuclear, cytoplasmic, and dual localization patterns, supporting DNA/RNA-related functions. Co-expression network analysis indicated interactions with diverse proteins, highlighting involvement in multiple biological processes.

This study provides the first comprehensive analysis of the GmAlba gene family in soybeans, detailing their phylogeny, structure, and spatiotemporal expression across tissues and stress conditions. These findings lay the groundwork for future research to enhance stress resilience in soybeans.