Abstract:

The stable yield and income of wheat （Triticum aestivum L.） were greatly limited by salt stress. Elucidating the metabolic mechanism of wheat under salt stress will help to further optimize breeding and cultivation， thereby increasing wheat yields in saline-alkali soils. In this study， ultra performance liquid chromatography-tandem mass spectrometer（UPLC-MS/MS） was used to analyze metabolic profiling of wheat roots and leaves treated with salt stress， and to analyze their response mechanism. A total of 759 metabolites differentially accumulated in roots and leaves were identified under normal growth and 24 h salt treatment conditions. In response to salt stress， 207 and 147 metabolites were changed in roots and leaves， respectively， among which 56 were the same differentially accumulated metabolites. Amino acids and their derivatives， flavonoids， organic acids and their derivatives， nucleotides and their derivatives accounted for about 50% of the total differentially accumulated metabolites of wheat roots and leaves in response to salt stress. In addition， lipids accounted for about 20% of the differentially accumulated metabolites of wheat leaves. These differentially accumulated metabolites were mainly involved in metabolic pathways， photosynthesis， carbon fixation and glucose metabolism etc in leaves， and secondary metabolism and amino acid synthesis etc in roots. They were interrelated and constitute a regulatory network of salt stress response， which may improve the adaptability to salt stress in wheat by alleviating osmotic and oxidative stress caused by salt stress.

Key words: wheat, salt stress, metabolomics, regulation network, UPLC-MS/MS

摘要：

盐胁迫极大地限制了小麦的稳产、增收，解析小麦应答盐胁迫的代谢机制，有助于优化小麦育种和栽培措施，提高盐碱地小麦产量。运用超高效液相色谱-串联质谱（UPLC-MS/MS）技术分析小麦根和叶在NaCl处理24 h后代谢谱的变化，解析其盐胁迫响应机制。正常生长和盐胁迫处理24 h的根、叶比较共检测到759种差异积累代谢物。根和叶响应盐胁迫处理的过程中，分别有207和147个代谢物质发生变化，其中有56个相同的差异积累代谢物。氨基酸及其衍生物、黄酮类化合物、有机酸及其衍生物、核苷酸及其衍生物这几类代谢物在小麦根和叶响应盐胁迫差异积累代谢物中占比共约50%，除此之外，脂类物质在叶的差异积累代谢物中占比约20%。这些物质在叶中主要参与代谢途径、光合作用、碳固定作用、糖代谢等通路，在根中主要参与次生代谢、氨基酸合成等通路。多种代谢物质间相互关联，组成小麦盐胁迫应答的调控网络，可能通过缓解盐胁迫带来的渗透胁迫和氧化胁迫等，提高小麦对盐胁迫的适应性。

关键词: 小麦, 盐胁迫, 代谢组学, 调控网络, 超高效液相色谱-串联质谱