ARS | Publication request: Distribution of the Pyruvate Dehydrogenase Complex in Developing Soybean Cotyledons

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: May 26, 2010
Publication Date: N/A

Technical Abstract: The somewhat surprising report that storage proteins and oil are non-uniformly distributed in the cotyledons of developing soybeans prompted us to determine the spatial distribution of the mitochondrial and plastidial forms of the pyruvate dehydrogenase complex (PDC). It has been proposed that plastidial PDC preferentially supplies acetyl-CoA and NADH necessary for triacylglycerol biosynthesis while mitochondrial PDC is more involved in cellular respiration. Polyclonal antibodies specific for the E1a subunit of plastidial PDC were labeled with the fluorescein, and monoclonal antibodies specific for the Ela subunit of mitochondrial PDC were labeled with Cy5. Soybean (Glycine max (L.) Merrill, cv. Jack) seeds at defined developmental stages were frozen at -80 degrees. Twenty five micron sections were cut using a cryostat, then printed on to nitrocellulose membranes. After incubating the tissue prints with the antibodies, images were captured using an epi-fluorescent binocular microscope. Overlaying the images revealed that at all stages of seed development distribution of both forms of the PDC was uniform and coincident. The signal for plastidial PDC persisted through the latter stages of seed development, while at the same time the mitochondrial PDC was phosphorylated and less abundant.