Carbon‐13 nuclear magnetic resonance measurement of oil composition in single viable soybeans

Abstract

High‐resolution, natural abundance13C NMR spectra of intact, viable soybeans have been obtained by Fourier transform techniques. The spectra are interpreted in terms of the relative concentrations of the major fatty acids present in the soybean triglycerides. This nondestructive analysis is sufficiently fast and accurate to permit the selection of individual soybeans for use in a genetic breeding program designed to reduce the undesirably high linolenic acid content of soybean oil.

13C Nuclear Magnetic Resonance Studies of Crassulacean Acid Metabolism in Intact Leaves of Kalanchoë tubiflora

“…Previous NMR studies of intact plant tissues have not utilized photosynthetic tissue, and only two reports have used '3C NMR (19,20). Also, no previous in vivo NMR studies have used 13C NMR for the determination of intracellular pH.…”

“…'H, 13C, '5N, and 31P NMR of intact tissue and cell suspensions has provided information on pH, metabolite levels and compartmentation, reaction rates, and pathway fluxes within living cells (for reviews, see 4,16,22). Studies of plant tissue by NMR have included 3P NMR of root tips (6,7,17,18) and cell suspension cultures (12) and 13C and '5N NMR of soybean ovules (19)(20)(21). In the studies of root tips, 31p was used to measure intracellular pH.…”

Carbon-13 Nuclear Magnetic Resonance Analysis of Metabolism in Soybean Labeled by 13CO2

“…The acids appear at 130 ppm, the lines between 60 and 100 ppm arise, for the most part, from the different kinds of carbons in the soluble sugars in the ovule, while the group of lines centered about 30 ppm can be attributed to the methylene and methyl carbons of the fatty acid chains (8). Immobilized materials such as rigid proteins and carbohydrates not in solution are subject to extensive carbon-proton dipolar broadening, and hence do not give rise to an observable "'C NMR signal under the conditions used in these experiments.…”

“…Analysis of the '3C NMR2 spectra of intact ovules clearly identifies the labeled lipids present, as well as those labeled sugars in solution. The spectra are well resolved, displaying widely spaced, relatively narrow lines, features common to the 22C NMR spectra of many nonrigid systems (7,8).…”

“…Analysis of the '3C NMR2 spectra of intact ovules clearly identifies the labeled lipids present, as well as those labeled sugars in solution. The spectra are well resolved, displaying widely spaced, relatively narrow lines, features common to the 22C NMR spectra of many nonrigid systems (7,8).Although the use of 1'C labels, followed by an NMR detection of the label, has been reported before, previous experiments have been, for the most part, restricted to the introduction of labeled intermediates into bacterial or mammalian systems (9). There are at least two important advantages in using '2CO2, rather than labeled intermediates, in the study of certain types of metabolism in soybeans.…”