A transcriptome‐based study using PEG‐induced drought simulation in <i>Allium mongolicum</i> seeds

Abstract To explore the molecular mechanisms underlying drought‐stress response in Allium mongolicum seeds, Agramma mongolicum seeds were used as the experimental material in this study. Drought stress in the seeds was induced using 20% PEG‐6000. The germination indicators of A. mongolicum seeds were determined at the early (5d) and the later stage of stress (10d). Transcriptome sequencing was performed for four treatment groups: soak seeds in distilled water for 5 days (5d CK), soak seeds in 20% PEG for 5 days (5d 20% PEG), soak seeds in distilled water for 10 days (10d CK) and soak seeds in 20% PEG for 10 days (10d 20% PEG). The values of the germination indicators of the seeds were significantly reduced as the stress duration increased. In the early and later stages of stress, 15,759 and 18,122 genes were differentially expressed, with 5,759 and 6,461 genes being significantly upregulated, 6,264 and 5,938 genes being significantly downregulated, respectively. According to the results of the Gene Ontology (GO) enrichment analysis, differentially expressed genes (DEGs) were primarily enriched in the cytoplasmic translation process and ribosome‐related structures. KEGG enrichment analysis results showed that the DEGs were mainly enriched in ribosomes, pyruvate metabolism, glycolysis/gluconeogenesis, the TCA cycle and cysteine and methionine metabolism pathways. The DEGs were significantly enriched in C2H2, AP2/ERF‐ERF, bZIP and MYB transcription factor families. After drought‐stress treatment, nine genes belonging to the glycolysis/gluconeogenesis pathway were differentially expressed. The drought tolerance in A. mongolicum seeds is largely associated with the scale and nature of gene expression changes under stress. A. mongolicum seeds may adapt to drought stress via the glycolysis/gluconeogenesis and TCA cycle pathways. The results of this study provide a reference for further exploring the molecular regulatory mechanisms underlying the drought‐stress response of A. mongolicum seeds.