Discovery of the ethylene response factors in Elymus sibiricus on a transcriptome-wide scale and the beneficial function of EsiERF285 in combating drought and heat stress

The response of plants to adverse environmental conditions is significantly influenced by Ethylene Response Factors (ERFs). Elymus sibiricus is an important native grass species that thrives in the harsh environment of the semi-arid temperate grasslands of northern Asia and exhibits remarkable tolerance to abiotic stress. However, the identification of ERF transcription factors responsible for abiotic stress in E. sibiricus remains incomplete. To identify ERF genes that respond to both drought and high temperature, and to investigate the response of these ERF genes to other exogenous hormones, the full-length transcriptome of E. sibiricus was obtained, with a total of 285 ERF genes were identified, of which 46 genes showed differential expression in response to drought stress. The rich sequence variation of EsiERF genes was observed in 175 wild E. sibiricus accessions. A total of fourteen EsiERF genes exhibited response to both drought and heat stress, and the response of these 14 EsiERF genes to exogenous Abscisic Acid, Glutathione, and Ascorbic Acid was investigated, among which EsiERF285, EsiERF264, and EsiERF283 were significantly affected. Molecular docking analysis revealed favourable binding affinities between EsiERF285/EsiERF264/EsiERF283 and these additions. The efficacy of EsiERF285, a nucleus-localized gene, was confirmed in enhancing drought and heat stress tolerance in Arabidopsis and yeast. This study provides a strong foundation for understanding the functional properties of EsiERF genes and offers opportunities for improving forages and crops through selective breeding strategies.