Han Caixia, Zhen Shoumin, Zhu Gengrui, Bian Yanwei, Yan Yueming
College of Life Sciences, Capital Normal University, Beijing 100048, China.
College of Life Sciences, Capital Normal University, Beijing 100048, China; Hubei Collaborative Innovation Center for Grain Industry (HCICGI), Yangtze University, 434025 Jingzhou, China.
Plant Physiol Biochem. 2017 Jun;115:320-327. doi: 10.1016/j.plaphy.2017.04.013. Epub 2017 Apr 10.
In this study, we performed the first comparative metabolomic analysis of the wheat embryo and endosperm during seed germination using GC-MS/MS. In total, 82 metabolites were identified in the embryo and endosperm. Principal component analysis (PCA), metabolite-metabolite correlation and hierarchical cluster analysis (HCA) revealed distinct dynamic changes in metabolites between the embryo and endosperm during seed germination. Generally, the metabolite changes in the embryo were much greater than those in the endosperm, suggesting that the embryo is more active than the endosperm during seed germination. Most amino acids were upregulated in both embryo and endosperm, while polysaccharides and organic acids associated with sugars were mainly downregulated in the embryo. Most of the sugars showed an upregulated trend in the endosperm, but significant changes in lipids occurred only in the embryo. Our results suggest that the embryo mobilises mainly protein and lipid metabolism, while the endosperm mobilises storage starch and minor protein metabolism during seed germination. The primary energy was generated mainly in the embryo by glycolysis during seed imbibition. The embryo containing most of the genetic information showed increased nucleotides during seed germination process, indicating more active transcription and translation metabolisms.
在本研究中，我们使用气相色谱-串联质谱法（GC-MS/MS）对种子萌发过程中的小麦胚和胚乳进行了首次比较代谢组学分析。在胚和胚乳中总共鉴定出82种代谢物。主成分分析（PCA）、代谢物-代谢物相关性分析和层次聚类分析（HCA）显示，种子萌发过程中胚和胚乳的代谢物存在明显的动态变化。一般来说，胚中的代谢物变化比胚乳中的大得多，这表明在种子萌发过程中胚比胚乳更活跃。大多数氨基酸在胚和胚乳中均上调，而与糖类相关的多糖和有机酸在胚中主要下调。大多数糖类在胚乳中呈上调趋势，但脂质的显著变化仅发生在胚中。我们的结果表明，在种子萌发过程中胚主要动员蛋白质和脂质代谢，而胚乳则动员储存淀粉和少量蛋白质代谢。种子吸胀期间主要通过糖酵解在胚中产生主要能量。含有大部分遗传信息的胚在种子萌发过程中核苷酸增加，表明转录和翻译代谢更活跃。
