[SI_Forage] _Characterization of defense responses in forage and food barley hosts during interaction with Epichloë endophyte
Year: 2026
Type: article
Abstract: ■ Endophyte colonization was significantly higher in wild barley (54.21%) than in cultivated barley (9.91%). ■ Transcriptomics profiling revealed host metabolic reprogramming against endophyte stress. ■ Endophyte triggered a pathogen-like defense response in cultivated host, which mounted an earlier and stronger defense with elevated MAPK/ROS. Endophytes are prevalent in plants and significantly contribute to plant growth and development. In the present study, Epichloë bromicola endophyte strain WBE1 was artificially inoculated into wild barley ( Hordeum brevisubulatum , natural host) and cultivated barley ( Hordeum vulgare , novel host) to obtain endophyte - barley symbionts. Physiological traits, such as callus formation, lignin content, cell mortality, early signaling molecules, second messenger endogenous signaling molecules, and the expression patterns of differential genes at different time periods were studied. The colonization rate of E. bromicola was 54.21% in wild barley and 9.91% in cultivated barley. Artificial endophytic infection enhanced callus growth, lignin content, and cell mortality in both hosts, with cultivated barley showing stronger resistance than wild barley. The infection induced the expression of early signaling molecules, and the O 2 - production rate as well as H 2 O 2 and NO contents were increased in both hosts. During the early infection stage, mitogen-activated protein kinase (MAPK) activity in cultivated barley increased by 12.24% and 54.60% compared with wild barley at 2 and 4 days post-infection, respectively. Transcriptomic analysis revealed that cultivated barley triggered an earlier and targeted defense response than wild barley, characterized by the stage-specific upregulation of genes involved in resistance-related secondary metabolite biosynthesis and key signaling molecules. Expression patterns showed upregulation of signaling molecules alongside downregulation of genes associated to oxylipin biosynthesis, lipid oxidation, cellular responses to environmental stimuli, oxidoreductase activity, and heme binding. These findings indicated that E. bromicola infection effectively triggered an enhanced and timely defense response in cultivated barley.
Authors: Kamran Malik, Fangli Wei, Taixiang Chen, Chunjie Li
Language: English
Domain: Life Sciences
SDG: Zero hunger
Open Access status: gold
Estimated APC paid: $1,000
OpenAlex ID: W7128514696