Proteomics Changes in Filling Seeds of Vegetable Soybean

Abstract

Vegetable soybean is an important economic and nutritious crop. In this study, 48 differentially expressed proteins were identified from filling seeds of soybean (Glycine max) cv. Mindou 6 by using two-dimensional electrophoresis (2-DE) combined with liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS). Among them, 25% were related to protein destination and storage, 42% to energy and metabolism, 15% to disease/defense, 6% to transporters, 4% to secondary metabolism, 4% to transcription, 2% to protein synthesis, and 2% to cell growth/division. Along with the maturity of seeds, the number of unchanged abundance proteins decreased, while that of both upregulated and downregulated proteins increased. Both downregulated expression of caffeic acid O-methyltransferase (COMT) and upregulated expression of sucrose-binding protein (SBP) 2 precursor may contribute to increase in digestibility, nutritional value, and eating quality of vegetative seeds at suitable picking period. The pattern of unchanged proteins during the whole seed-filling stage may be also beneficial to the quality of vegetable soybean.