Comparative transcriptomic analysis of the gene expression and underlying molecular mechanism of submergence stress response in orchardgrass roots

Abstract

IntroductionSubmergence stress creates a hypoxic environment. Roots are the first plant organ to face these low-oxygen conditions, which causes damage and affects the plant growth and yield. Orchardgrass (Dactylis glomerata L.) is one of the most important cold-season forage grasses globally. However, their submergence stress-induced gene expression and the underlying molecular mechanisms of orchardgrass roots are still unknown.MethodsUsing the submergence-tolerant ‘Dianbei’ and submergence-sensitive ‘Anba’, the transcriptomic analysis of orchardgrass roots at different time points of submergence stress (0 h, 8 h, and 24 h) was performed.ResultsWe obtained 118.82Gb clean data by RNA-Seq. As compared with the control, a total of 6663 and 9857 differentially expressed genes (DEGs) were detected in Dianbei, while 7894 and 11215 DEGs were detected in Anba at 8 h and 24 h post-submergence-stress, respectively. Gene Ontology (GO) enrichment analysis obtained 986 terms, while Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis obtained 123 pathways. Among them, the DEGs in plant hormones, mitogen-activated protein kinase (MAPK) and Ca2+ signal transduction were significantly differentially expressed in Dianbei, but not in Anba.DiscussionThis study was the first to molecularly elucidate the submergence stress tolerance in the roots of two orchardgrass cultivars. These findings not only enhanced our understanding of the orchardgrass submergence tolerance, but also provided a theoretical basis 36 for the cultivation of submergence-tolerant forage varieties.

Morphological and molecular response mechanisms of the root system of different Hemarthria compressa species to submergence stress

“…This gene precisely regulates the free ABA and JA contents in seeds and germ sheaths through glycosylation of abscisic acid (ABA) and jasmonic acid (JA), thereby mediating the elongation of germ sheaths through the ABA and JA signaling pathways, which further reveals the molecular mechanism of rice flooding tolerance through the “escape strategy” ( He et al., 2023 ). Transcriptomic analysis of root tissues of flood-tolerant and flood-sensitive orchardgrass ( Dactylis glomerata ) cultivars, following submergence stress, identified DEGs of phytohormone-related genes, mitogen-activated protein kinases (MAPK), and Ca 2+ signaling genes that were significantly differentially expressed in submergence-tolerant orchardgrass ( Qu et al., 2023 ). Although the importance of research on the response mechanisms to crop flooding stress has been recognized, due to the wide range of variability between plant species and habitats, their adaptation mechanisms to flooding stress also vary significantly.…”