Wheat (Triticum aestivum L.) Breeding from 1891 to 2010 Contributed to Increasing Yield and Glutenin Contents but Decreasing Protein and Gliadin Contents

Abstract

Epidemiologic studies suggest an increasing prevalence of celiac disease and non-celiac gluten/wheat sensitivity. With wheat proteins being the main triggers, changes in wheat protein composition are discussed as a potential cause. The goals of breeding toward increased yield and resistance might have inadvertently contributed to a higher immunostimulatory potential of modern wheat cultivars compared to old wheat cultivars. Therefore, agronomic characteristics, protein content, and gluten composition of 60 German winter wheat cultivars first registered between 1891 and 2010 grown in 3 years were analyzed. While plant height and spike density decreased over time, yield and harvest index increased. The protein and gliadin contents showed a decreasing trend, whereas glutenin contents increased, but there were no changes in albumin/globulin and gluten contents. Overall, the harvest year had a more significant effect on protein composition than the cultivar. At the protein level, we found no evidence to support an increased immunostimulatory potential of modern winter wheat.

The Two Faces of Wheat

“…All studies report a substantial influence of the growing conditions on the content and composition of wheat proteins. Regarding protein composition, an increase in glutenins and a decrease in gliadins and gliadin/glutenin ratios, but essentially no changes for albumins/globulins and gluten, were observed in German winter wheat cultivars from 1891 to 2010, all grown at the same location in three consecutive years (189). Similar results were reported by Ozuna and Barro (190).…”

Fingerprinting of wheat protein profiles for improved distinction between wheat cultivars and species

“…PCA, principal component analysis [Colour figure can be viewed at wileyonlinelibrary.com] extractable proteins. At first glance, it becomes obvious that the harvest year had a strong influence on the cluster formation and distribution of the cultivars ( Figure S4), which is in accordance with our previous study (Pronin et al, 2020) and also evident using the traditional integration method. One reason for the stronger clustering of the wheat cultivars might be that this year had the least amount of annual mean precipitation (366 mm, as opposed to 533 mm and 557 mm in 2015 and 2017, respectively), but further investigations would be necessary to establish a clear cause-effect relation here.…”

“…The observations made for the average over three harvest years were influenced by the harvest year 2016 ( Figure S4b), since the clusters for the harvest years 2015 and 2017 were mostly overlapping and therefore difficult to distinguish. These observations are consistent with the fact the harvest year had a significant effect on the protein distribution of the 60 wheat cultivars (Pronin et al, 2020). Effectively, there is a lack of studies performing a comprehensive comparison of wheat protein patterns by means of RP-HPLC, except for the study by Daniel and Triboi (2000) that revealed significant differences between the gliadin chromatograms of a winter wheat cultivar influenced by the effects of temperature and fertilization.…”

“…Grains of 60 hexaploid German winter wheat cultivars from 1891 to 2010 were analyzed. For each decade, the five most common cultivars for the respective decade were selected (Table S1) and cultivated in a randomized field order without fertilization and harvested in 2015, 2016, and 2017 at the Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) in Gatersleben, Germany (Pronin, Börner, Weber, & Scherf, 2020). Wholemeal flours were obtained by milling the grains with a laboratory grinder (Bosch, Stuttgart, Germany) and sieving to a particle size of 0.2 mm.…”

“…In fact, we found that there seem to be differences between the profiles of old and modern cultivars. Interestingly, the profile changes were not reflected in the contents of the protein fractions and types (Pronin et al, 2020). This is why a new approach of peak integration was required to allow a better distinction of different wheat cultivars and an advanced detection of the protein fingerprints.…”