Carbon-13 Nuclear Magnetic Resonance Analysis of Metabolism in Soybean Labeled by CO(2)

Abstract

Fourier transform (13)C nuclear magnetic resonance spectra have been obtained of intact, fresh soybean ovules (Glycine max L. cv. Dare) harvested from pods subtended by a trifoliolate exposed to (13)CO(2) 1 to 3 days earlier. The high resolution spectra are interpreted in terms of the labeled sugars and lipids in the ovule. Comparison of the spectra taken over the 3-day period permits qualitative estimates of sugar metabolism and rates of lipid synthesis. The spectra also contain information about the distribution of labels within the lipid chains. This information leads to a method of estimating the extent to which glucose degradation in the synthesizing soybean ovule is involved in the reactions of the phosphogluconate pathway.