Characterization of proteins involved in early stage of wheat grain development by iTRAQ.

UNLABELLED: Wheat (Triticum aestivum L.) is one of the most important crops in the world due to its value as a major food source. To explore the protein synthesis, accumulation and regulation during grain development are more complex because of its large genome. In this study, grains from wheat cultivar Chinese Spring were harvested at three development stages (DAA4, DAA8 and DAA12) and were used to display variable expressed proteins during these stages. iTRAQ-based quantitative proteomic and LC-MS/MS methods were used in this study. A total of 1762 proteins showed that at least 1.5-fold differences in abundance were found during these stages; most of the differential expressed proteins (DEPs) were involved in the metabolism process, which includes carbohydrate metabolism, cell division, cytoskeleton, lipid metabolism, nitrogen metabolism, protein synthesis, signal transduction, translation and transport. The results provide insight into biochemical events taking place during the early wheat grain development and highlight the value of proteomics in characterizing complex biochemical processes. Our results also showed that the photosynthesis played an important role for implying energy during the early grain development. SIGNIFICANCE: Wheat (T. aestivum L., 2n=6X=42, AABBDD) is one of the most important crops in the world. The early phase of seed grain development mainly involved active cell enlargement, leading to a rapid increase in seed size available for further accumulation of starch of storage proteins. We applied the iTRAQ proteomic analysis to decipher the mechanism of wheat grain development during the early stage. Numerous differentially expressed proteins were identified; most of which were related to carbohydrate metabolism, cell division, cytoskeleton, lipid metabolism, nitrogen metabolism, protein synthesis, signal transduction, translation and transport. Results also showed that the photosynthesis played an important role for implying energy during the early grain development. Taken together, our results provide comprehensive proteome insights into the early wheat grain development.