Metabolic Profiling of γ-Irradiated Barley Plants IdentifiesReallocation of Nitrogen Metabolism and Metabolic StressResponse

摘要

The favorable responses of crop species to low-dose γ irradiation can help todevelop cultivars with increased productivity and improved stress tolerance. Inthe present study, we tried to reveal the candidate metabolites involved ingrowth stimulation of barley seedlings after applying low-dose γ-radiation( Co) to seeds. Stimulating doses (5-20 Gy) provided asignificant increase in shoot length and biomass, while relatively high dose of100 Gy led to significant inhibition of growth. Gas chromatography–massspectrometry metabolomic analysis uncovered several compounds that may take partin radiation hormesis establishment in irradiated plants. This includesmolecules involved in nitrogen redistribution (arginine, glutamine, asparagine,and γ-aminobutyric acid) and stress-responsive metabolites, such as ascorbate, -inositol and its derivates, and free amino acids( -serine, β-alanine, pipecolate, and GABA). These resultscontribute to the understanding of the molecular mechanisms of hormesisphenomenon.