In-depth mapping of the seed phosphoproteome and N-glycoproteome of Tartary buckwheat (Fagopyrum tataricum) using off-line high pH RPLC fractionation and nLC-MS/MS

The seed of Tartary buckwheat (Fagopyrum tataricum) is rich in nutrients and functional ingredients and is recommended as a healthy cereal food. The total proteins of Tartary buckwheat seed (TBS) were extracted and digested; then, the phosphopeptides and glycopeptides were separately enriched and identified by nano liquid chromatography/tandem mass spectrometry. A total of 2613 phosphorylation sites from 1670 phosphoproteins and 404 N-glycosylation sites from 285 N-glycoproteins were identified in TBS. Function and pathway analyses showed that TBS phosphoproteins were significantly enriched in transport, energy metabolism, amino acids bio-synthesis/metabolism, and signaling and TBS N-glycoproteins were significantly enriched in modification regulation. The present study reports the first profiles of the phosphoproteome and N-glycoproteome of TBS and provides important post-translational modifications information on the proteins in TBS. The results of this study will aid the understanding of the underlying mechanism of the germination of TBS during cultivation and edible quality changes during storage and processing. (C) 2019 Elsevier B.V. All rights reserved.