Genomic and Functional Analysis of the ALOG Gene Family in Dioscorea alata

The ALOG (Arabidopsis LIGHT-DEPENDENT SHORT HYPOCOTYLS 1 (LSH1) and Oryza G1) family play crucial regulatory roles in plant growth and development, spanning both vegetative and reproductive growth. This study presents a comprehensive genomic and functional analysis of the ALOG family in greater yam (Dioscorea alata). Ten non-redundant DaALOG genes were identified and classified into two classes (I and II) based on phylogenetic analysis. These classes share a common origin, and family expansion was primarily driven by segmental duplication events. Comparative genomics across 15 plant species revealed widespread, lineage-specific divergence in ALOG gene family size and composition. Expression profiling highlighted several DaALOG genes, particularly DaALOG1, DaALOG3, and DaALOG6A, with significant upregulation in tuber and bulbil tissues, suggesting a potential role in storage organ development. Co-expression network analysis, coupled with yeast one-hybrid assays, indicated that DaALOG3 likely regulates key genes involved in starch biosynthesis. Subcellular localization confirmed the nuclear predominance of DaALOG proteins. Furthermore, functional validation in Arabidopsis demonstrated that overexpression of DaALOG1 leads to pronounced developmental alterations, including irregular leaf morphology and floral organ abnormalities (such as extra stamens and petals). Collectively, our findings establish the DaALOG gene family as an important regulator in greater yam, linking specific members to both vegetative architecture and storage organ development.