Metabolomic Analysis
Reveals Patterns of Whole Wheat
and Pearling Fraction Flour Quality Response to Nitrogen in Two Wheat
Lines with Contrasting Protein Content
Nitrogen
(N) application increases wheat yield and protein content
and affects the nutritional quality of the grain. Analysis of N use
efficiency revealed that N uptake efficiency is a key factor affecting
protein content. Two wheat lines with significant differences in protein
content were used to investigate the response of differential accumulation
of metabolites to N levels and the spatial variation pattern of metabolites
related to nutritional quality in wheat grains using widely targeted
metabolomics analysis. The results showed that amino acids, nucleic
acids, and phytohormones and their derivatives and glycolytic processes
are the crucial factors affecting protein content in two wheat lines.
Amino acids and derivatives, lipids, and flavonoids are the main contributors
to metabolite spatial variation of grains, which were interactively
regulated by nitrogen and genotypes. N application significantly increased
the relative accumulation of beneficial bioactive substances in the
inner layer (P3 to P5), but excessive N application may inhibit this
effect and lead to poor nutritional quality.