Abstract: Hulless barley is an important crop with high economic and ecological value on the Tibetan Plateau. It is highly resistant to drought stress. To study the molecular mechanism of drought resistance, two hulless barley varieties with different drought resistance were subjected to simulated drought and transcriptome analysis. After 24 h of drought treatment, 85 DEGs (differentially expressed genes) were screened from the drought-sensitive variety YC85, and 186 DEGs were screened from the drought-resistant variety ZY1100. GO enrichment analysis of the DEGs revealed that water response and ion transport were mainly enriched in YC85, and acid metabolism and amino acid biosynthesis were mainly enriched in ZY1100. KEGG enrichment analysis revealed that in YC85, MAPK signaling pathway-plant, alanine, aspartate and glutamate metabolism, etc., were enriched, and in ZY1100, phytohormone signaling, amino acid biosynthesis, etc., were the main enriched pathways. By analyzing the common and specific DEGs of the two hulless barley varieties, as well as the enrichment of GO functions and KEGG pathways, 59 genes involved in the drought response were identified. The results of this study provide valuable information and resources for understanding the regulatory mechanism of gene expression and the discovery of drought resistance genes in hulless barley, as well as providing an important basis for subsequent gene function research and breeding.

Key words: hulless barley, drought, transcriptome analysis, differentially expressed genes；stress response