不同盐旱胁迫下青甘韭代谢差异分析

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Abstract：This study employed non-targeted metabolomics to analyze the diferential metabolic responses of the wild onion species Allium przewalskianum Regel to salt stress （ ΔNaCl ），drought stress（PEG），and combined salt-drought stress （NaCl_PEG），with the aim of elucidating its adaptation mechanisms.The experiment design included four treatments：a pure water control，240 mmol/L NaCl stress， 12% PEG-60o0 drought stress，and a combined stress of 240 mmol/L NaCl+12% PEG-6ooo. Metabolite profiling was conducted using ultraperformance liquid chromatography-massspectrometry （UPLC-MS）. Subsequent analyses including Principal Component Analysis （PCA），volcano plots，hierarchical clustering，Venn diagrams，and KEGG pathway enrichment，identified 622 differentially accumulated metabolites （DAMs）.The results showed that combined stress induced the most severe perturbation in the metabolic network ofA. przewalskianum，with a great number of DAMs （331）compared to salt stress （185）and drought stress （212）.Fatt acids and terpenoids were identified as the major metabolite classs responsive to stress Notably，52 fatty acids were upregulated under combined stress，highlighting theirrole in osmoregulation.Among the top 2O metabolites with the highest variatio，flavan-3-olsand oleanane-type triterpenoidsparticipated instressadaptation through antioxidant activity，signal transduction（e.g.，cross-pathway regulation by NAE （ ），and defense functions.KEGG enrichment analysis revealed distinct pathway responses：salt stress afected nucleotide metabolism；drought stress primarily involved glyoxylate and carbon metabolism；while combined stressactivated ABC transporters andamino acid biosynthesis.K-Means clustering identified a subset of10O metabolites exhibiting gradual upregulation specifically under combined stress，suggesting synergistic response mechanisms. This study provides the first characterization of the metabolic responses of this species to multiple abiotic stresses.The key metabolites （e.g.，fatty acids，terpenoids） and pathways （e.g.，ABC transporters）ofer newl targets for elucidating molecular resistance mechanisms.These findings provide a theoretical basis for improving cultivation practices and enhancing stress resistance breeding ofcharacteristic Allium plant resources on the Qinghai-Tibet Plateau.

KeyWords：Allium przewalskianum Regel;salt stress;drought stress;metabolomics;differentialmetabolites

青甘韭（AlliumprzewalskianumRegel）是百合科葱属多年生植物[1-2]，主要分布在青藏高原及周边地区，在海拔 2000～4800m 的高寒干旱生境中均可生长[3-4]。（剩余16959字）