Defining genetic and chemical diversity in wheat grain by 1H-NMR spectroscopy of polar metabolites

Abstract

Scope: The application of high-throughput 1H nuclear magnetic resonance (1H-NMR) of unpurified extracts to determine genetic diversity and the contents of polar components in grain of wheat.

Methods and results: Milled whole wheat grain was extracted with 80:20 D₂ O:CD₃ OD containing 0.05% d₄ -trimethylsilylpropionate. 1H-NMR spectra were acquired under automation at 300°K using an Avance Spectrometer operating at 600.0528 MHz. Regions for individual metabolites were identified by comparison to a library of known standards run under identical conditions. The individual 1H-NMR peaks or levels of known metabolites were then compared by Principal Component Analysis using SIMCA-P software.

Conclusions: High-throughput 1H-NMR is an excellent tool to compare the extent of genetic diversity within and between wheat species, and to quantify specific components (including glycine betaine, choline, and asparagine) in individual genotypes. It can also be used to monitor changes in composition related to environmental factors and to support comparisons of the substantial equivalence of transgenic lines.

Keywords: Grain Composition; Metabolomics; NMR Spectroscopy; Transgenic; Wheat.