Metabolic pathways of the wheat (Triticum aestivum) endosperm amyloplast revealed by proteomics
Frances M. Dupont
United States Department of Agriculture, Agricultural Research Service, Western Regional Research Center, 800 Buchanan Street, Albany CA 94710
510-559-5702; fmd@pw.usda.gov
Reference
BMC Plant Biology (Submitted July 2007; Revised December 2007)
Abstract
Background: By definition, amyloplasts are plastids specialized for starch production. However, a proteomic study of amyloplasts isolated from wheat (Triticum aestivum Butte 86) endosperm at 10 days after anthesis (DPA) detected enzymes from many metabolic and biosynthetic pathways [1]. To better understand the role of amyloplasts in food production, the data from [1] were evaluated in detail and an amyloplast metabolic map was outlined.
Results: Analysis of 285 proteins detected in an amyloplast preparation predicted that only 179 were amyloplast proteins. Criteria included homology with known plastid proteins, prediction of a plastid transit peptide for the wheat gene product or a close homolog, known plastid location of the pathway, or predicted plastid location for other members of the same pathway. The enzymes were arranged into pathways for carbohydrate, lipid, amino acid, nucleic acid and other biosynthetic processes.
Conclusions: It is essential to determine how metabolic pathways are distributed among cellular compartments of the endosperm in order to understand genetic and environmental effects on starch and protein production and model the interacting effects of temperature and the carbon/nitrogen/sulfur balance on yield and composition for this major food source. The pathways outlined in this paper suggest that amyloplasts play a central role in endosperm metabolism.
Instructions: FTP the XML file to your own computer and unzip the file. Access the GPM viewer at the GPM web site http://www.thegpm.org/ [94] and use the "view saved xml file" function to browse and find the XML file on your computer and open in it in GPM. The protein of interest can then be found within the XML file by searching with the sequence identifier given in the Supplementary Table to the paper.
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