低磷胁迫下高羊茅蛋白组学分析

Proteomic Analysis of Festuca arundinacea under Low Phosphorus Stress

对低磷胁迫下高羊茅叶片中蛋白差异化表达和生理指标进行研究,可为高羊茅低磷胁迫响应的关键基因和重要蛋白挖掘奠定基础。采用TMT标记、基于质谱的定量蛋白质组学技术、高效液相色谱分级技术分析低磷胁迫下高羊茅叶片蛋白组学,结果共筛选到差异表达蛋白432个(上调表达127个,下调表达305个);其中,氧化还原反应以及磷代谢、胁迫相关代谢等多个途径的基因上调表达。对差异蛋白的蛋白结构域进行富集,共富集到106个结构域,包括丙酮酸盐/磷酸烯醇式丙酮酸激酶样结构域、谷胱甘肽S-转移酶C-末端样、谷胱甘肽S-转移酶N-末端、天冬氨酸肽酶结构域。差异表达蛋白亚细胞结构定位显示,其主要定位于叶绿体和细胞质。差异蛋白总共富集到了99个通路,其中只有核糖体通路上调,其余都下调,下调通路集中在糖酵解/糖异生、丙酮酸代谢、谷胱甘肽代谢中。低磷胁迫处理后,高羊茅叶绿素总量下降,可溶性蛋白含量显著下降,谷胱甘肽还原酶、过氧化氢酶、超氧化物歧化酶和过氧化物酶活性均较对照显著下降。

The study on differential expression and physiological indexes of protein in leaves of tall fescue(Festuca arundinacea)under low phosphorus stress can provide a foundation for exploring key genes and important proteins involved in low phosphorus stress in tall fescue.The TMT labeling,quantitative proteomics based on mass spectrometry and high performance liquid chromatography was employed to analyze the leaf proteome of tall fescue under low phosphorus stress.A total of 432 differentially expressed proteins were identified,including 127 upregulated proteins and 305 downregulated proteins.Among them,genes related to redox reactions,phosphorus metabolism,and stress-related metabolism pathways showed upregulated expression.Enrichment analysis of protein domains revealed 106 enriched domains,including the pyruvate/phosphoenolpyruvate kinase-like domain,the glutathione S-transferase,C-terminal-like,the glutathione S-transferase,N-terminal,and the aspartic peptidase domain.The subcellular localization of differentially expressed proteins showed that they were mainly located in chloroplasts and cytoplasm.Differential proteins were enriched in a total of 99 pathways,of which only the ribosomal pathway was up-regulated,and the rest were down-regulated.The down regulation pathway is mainly enriched in glycolysis/gluconeogenesis,pyruvate metabolism,and glutathione metabolism.After low phosphorus stress treatment,total chlorophyll content decreased,soluble protein content significantly decreased,and the activities of catalase,glutathione peroxidase,peroxidase and superoxide dismutase all decreased significantly compared to the control.