Genome-wide evolutionary characterization and expression analysis of the AT-HOOK MOTIF CONTAINING NUCLEAR LOCALIZED gene family in Brachypodium distachyon.

Plants adapt to diverse environments through complex gene regulatory networks, with the AT-HOOK MOTIF CONTAINING NUCLEAR LOCALIZED (AHL) gene family playing a crucial role. This research identified and examined the AHL gene family within Brachypodium distachyon, a model plant for Pooideae grasses including essential cereal crops. AHL proteins are conserved across land plants, suggesting an ancient origin and fundamental importance in plant development and adaptation. B. distachyon is an efficient research model for monocot studies due to its compact genome, short life cycle, and genetic manipulation compatibility. While Arabidopsis thaliana has consistently served as a valuable model for studying the AHL gene family, understanding their function in monocots, particularly grasses, is essential for crop improvement. The conserved evolutionary history of AHL proteins makes them an excellent target for comparative genomic research across eudicots and monocots systems. Although AHL functions have been studied in A. thaliana, their roles in Pooideae grasses remain largely unknown. This research identified 22 BdAHL genes classified into 2 monophyletic clades and 3 protein types based on conserved domains. By characterizing BdAHL gene structure, phylogeny, expression, and potential protein interactions, this study lays the groundwork for future functional analyses of Pooideae grasses. BdAHL expression profiles across different tissues and global coexpression patterns were also examined. These findings provide a foundation for future research into specific AHL gene functions in B. distachyon growth, development, and stress responses, potentially enhancing our understanding of AHL function in other Pooideae grasses and aiding crop improvement strategies.