Proteomics of Seed Development in Oilseed Crops

Despite limited genome resources, recent proteomics research on select oilseed crops has shown that global analyses of proteins is currently possible. This review summarizes recent proteomic research efforts on seed development in oilseed crops, most notably soybean and oilseed rape. In-depth, systematic analyses of protein expression during the reserve deposition phase of seed development in soybean and oilseed rape have recently provided the first proteomic perspective of carbon assimilation into storage reserves for any oilseed crop (Hajduch et al. 2005, 2006). This is perhaps the first use of plant proteomics data to predict metabolic pathways with high confidence. In this review we present an updated comparison of intermediary metabolic pathways operating during pod filling in both soybean and oilseed rape. This review also discusses recent systematic analysis of phosphorylated proteins expressed during seed filling in oilseed rape using Pro-Q Diamond phosphoprotein stain in conjunction with high resolution two-dimensional gel electrophoresis. Identification of 103 of these proteins by tandem mass spectrometry revealed approximately 80 novel phosphoproteins, of which 45% were involved in metabolism or energy production. These data suggest that more metabolic enzymes could be regulated by protein phosphorylation than previously thought. Recent large-scale identification of soybean and rapeseed proteins and phosphoproteins by mass spectrometry demonstrates that proteomics research on oilseed crops is an exciting new area of research with tremendous possibilities.