紫花苜蓿响应低温胁迫的蛋白组差异分析OA

To elucidate the molecular basis underlying differential cold tolerance in Medicago sativa and identify key proteins and metabolic pathways responsive to low-temperature stress,a comparative proteomic analysis was conducted.A cold-tolerant cultivar(WL343)and a cold-sensitive cultivar(GN)were subjected to 4℃for 24 h,with plants grown under normal temperature conditions serving as controls.A total of 506 differentially expressed proteins(DEPs)were identified across both cultivars under low-temperature stress.GO analysis showed that upregulated proteins in WL343 were primarily enriched in histone-related functions,pullulanase and β-amylase activities,and glucose metabolic processes,whereas upregulated DEPs in GN were mainly associated with chloroplasts,cytoplasm,and ribosomes.KEGG pathway analysis revealed that DEPs in WL343 were significantly enriched in sulfur metabolism,glycolysis/gluconeogenesis,and starch and sucrose metabolism,while DEPs in GN were mainly enriched in porphyrin metabolism,tyrosine metabolism,and starch and sucrose metabolism.Subcellular localization prediction indicated that these DEPs were predominantly distributed in the membranes,nucleus,cytoplasm,and chloroplasts.Protein-protein interaction(PPI)network analysis identified NADH-ubiquinone oxidoreductase chain 3 and 30S ribosomal protein S13 as the key hub proteins in WL343,whereas RuBisCO large subunit-binding protein and 30S ribosomal protein S1 were identified as central hub proteins in GN.In addition,several candidate functional proteins,including sucrose-phosphate phosphatase,endo-1,3-β-D-glucanase,and glutathione S-transferase,are proposed to contribute to enhanced cold tolerance by regulating carbohydrate metabolism and reactive oxygen species homeostasis.Overall,this study provides proteome-level insights into the mechanisms underlying cold tolerance in M.sativa and identifies potential protein targets for future genetic improvement.