Genome-Wide Identification and Expression Profiling of ABA-Stress-Ripening (ASR) Gene Family in Barley (Hordeum vulgare L.)

Abscisic acid (ABA)-stress-ripening, or ABA-, stress-, and ripening-induced (ASR) proteins play an important role in responses to environmental stimuli. A total of ten barley <i>HvASRs</i> were identified in this study, which were unevenly distributed on three chromosomes. ASRs from barley, wheat, <i>Brachypodium distachyon</i>, rice, maize, foxtail millet, and tomato were classified into two distinct clusters based on phylogenetic analysis. Notably, ASRs from Poaceae were evenly distributed between these two clusters. HvASRs contained a typical ABA/WDS domain, and exhibited similar motif arrangements. Two gene pairs of tandem duplicates (<i>HvASR4/5/6/7</i> and <i>HvASR8/9</i>) were identified among <i>HvASRs</i>. <i>Cis</i>-acting elements involved in hormone and stress responses, including ABRE, MYB, ARE, and STRE, were consistently identified in the promoters of <i>HvASRs</i>. The expression of <i>HvASRs</i> was substantially influenced by salt, osmotic, and ABA treatments in the roots and leaves of barley seedlings. <i>HvASR2</i> acts as a transcriptional repressor, whereas <i>HvASR3</i> serves as a transcriptional activator. These results enhance our understanding of the <i>HvASR</i> family and provide a foundation for further functional characterization.