Genome-wide characterization, evolutionary and expression pattern analysis of the sHSP family genes in orchardgrass and functional characterization under abiotic stress

Orchardgrass is a vital forage crop worldwide, yet its growth and yield are highly susceptible to environmental stress. Small Heat Shock Proteins (sHSPs) family is a wide protein family crucial for enhancing plant stress tolerance. Nevertheless, a comprehensive understanding of the sHSP family in orchardgrass is lacking, particularly concerning its response to abiotic challenges. In the present study, we identified 47 sHSP family members in orchardgrass and provided a comprehensive analysis of their characteristics. Syntenic analysis revealed that the expansion of DgsHSP is primarily driven by tandem duplication events. Multiple abiotic challenges were shown to stimulate certain DgsHSP genes, suggesting they play a key regulatory role in how orchardgrass responds to these stresses. Heterologous expression in yeast demonstrated that DgsHSP30 and DgsHSP31 improve tolerance to drought and salt stress. Additionally, physiological indicators and phenotypes under stress in Arabidopsis mutants also support this viewpoint. These findings lay the groundwork for understanding the functional role of the DgsHSP family in orchardgrass under environmental stress, offering potential applications for enhancing forages and crops through breeding programs.