Effects of Organic and Conventional Crop Nutrition on Profiles of Polar Metabolites in Grain of Wheat

Abstract

The profiles of polar metabolites were determined in wholemeal flours of grain from the Broadbalk wheat experiment and from plants grown under organic and low-input systems to study the effects of nutrition on composition. The Broadbalk samples showed increased amino acids, acetate, and choline and decreased fructose and succinate with increasing nitrogen fertilization. Samples receiving farm yard manure had similar grain nitrogen to those receiving 96 kg of N/ha but had higher contents of amino acids, sugars, and organic acids. A comparison of the profiles of grain from organic and low-input systems showed only partial separation, with clear effects of climate and agronomy. However, supervised multivariate analysis showed that the low-input samples had higher contents of many amino acids, raffinose, glucose, organic acids, and choline and lower sucrose, fructose, and glycine. Consequently, although differences between organic and conventional grain occur, these cannot be used to confirm sample identity.

1H NMR-Based Chemometrics to Gain Insights Into the Bran of Radiation-Induced Colored Wheat Mutant

“…The 13 C NMR signals attributable to C-2 and NCH 3 were observed as triplets [δ C 56.08 (t, J = 3.75 Hz, N(CH 3 ) 3 of betaine), 56.59 (t, J = 3.75 Hz, N(CH 3 ) 3 of choline), 56.65 (t, J = 3.75 Hz, N(CH 3 ) 3 of the unidentified component), 67.50 (t, J = 3.00 Hz, C-2 of the unidentified component), 68.89 (t, J = 3.00 Hz, C-2 of betaine), 70.13 (t, J = 3.00 Hz, C-2 of choline)]. This phenomenon has been reported for choline derivatives as a consequence of the onebond 13 C- 14 N coupling ( 1 J CN ) (37)(38)(39). The highly symmetric chemical environment of the choline nitrogen nucleus induces considerably slower relaxation, resulting in the observation of substantial 13 C-14 N coupling.…”

“…The highly symmetric chemical environment of the choline nitrogen nucleus induces considerably slower relaxation, resulting in the observation of substantial 13 C-14 N coupling. The nucleus 14 N has a spin quantum number of 1 as same as 2 H (deuterium), which allows the occurrence of triplets with a spin state number of 3. The observation of distinct 13 C-14 N coupling triplets further supported the presence of another choline derivative.…”

“…Graham et al performed NMR-based metabolomics on European wheat by identifying 13 polar metabolites, and the integral data were obtained from manual binning for statistical analysis (11). Shewry et al also performed bucketing of 1 H NMR spectra for peak integration and reported quantitative data of 26 polar metabolites, which were used in sequential studies to assess genetic variations in wheat samples (12,13) and to evaluate the impacts of different farming systems (organic and conventional) on wheat growth (14). The present study adopted peak shape-based quantification using the Chenomx software by considering peak splitting patterns (singlet, doublet, triplet, and so on) with coupling constants (J) and the number of protons according to compound information from embedded or custom compound libraries.…”

Comprehensive profiling of semi‐polar phytochemicals in whole wheat grains (Triticum aestivum) using liquid chromatography coupled with electrospray ionization quadrupole time‐of‐flight mass spectrometry

“…Also metabolite profiling approaches in combination with targeted and non-targeted data analysis strategies have been applied to study wheat grain composition in dependence on genetic and environmental factors on metabolome level. For this purpose techniques based on 1 H NMR spectroscopy (Shewry et al 2017(Shewry et al , 2018 and GC/EI-MS (Bonte et al 2014;Francki et al 2016;Zhen et al 2016;Zorb et al 2006) were applied targeting polar metabolites including free amino acids, organic acids and sugars. For profiling of apolar wheat grain metabolites such as free fatty acids, oxylipins, glycerolipids, phospholipids, glycolipids, sphingolipids, alk(en)ylresorcinols and phytosterol conjugates direct infusion ESI-QqQ-MS (Gonzalez-Thuillier et al 2015) and UHPLC/API-high resolution accurate mass tandem-MS (Geng et al 2015;Riewe et al 2017) were used as analytical platforms.…”

Promoting Human Nutrition and Health through Plant Metabolomics: Current Status and Challenges

“…Plant metabolomics has been widely used to investigate metabolomes of mature and developing seeds in several major food crops, particularly in rice [60][61][62][63][64], allowing us to understand what we eat, how they are formed, and how they are changed in the process of food crop development and food processing. Plant metabolomics studies have been also employed to identify common and/or specific macro-and micro-nutrients and quality associated components in food crops [32,[64][65][66][67][68][69][70][71], their availability after cooking [70,72,73], and to discover biomarkers for future crop quality improvement. Comparative metabolomics strategies have revealed the convergent or divergent evolution of metabolism within or across plant species [47,56,63,74,75] and its mechanisms [76], which lays a solid base for crop improvement in the contest of nutrition and quality.…”