Effect of Nitrogen Fertilization and Fungicide Application at Heading on the Gluten Protein Composition and Rheological Quality of Wheat

Abstract

Optimizing the bread-making quality properties of flour is currently one of the main aims of the bakery industry. Therefore, this study has investigated the effects of N fertilization and fungicide application at wheat heading on the protein content (GPC), gluten composition and rheological properties of wheat. Field experiments were carried out in North-West Italy over a 3 year period, on a high protein cultivar of soft winter wheat. Grain samples were collected for each agronomic treatment at four ripening timings, from the milk stage to the final combine harvesting, and the contents of the different gluten fractions were quantified. The late N fertilization increased the GPC (+1.2%) and dough strength (W) (+22%) as a result of a similar enhancement of all the gluten protein fractions, while the fungicide application slightly reduced the GPC (−0.3%) and W (−4%), mainly because of a dilution of the gliadin content, due to the significantly higher grain yield (+8.6%) and thousand kernel weight (+5.5%). These agronomic practices did not modify the gluten composition significantly, expressed as the relative ratio between the gliadins (glia) and the high (HMW) and low (LMW) molecular weight glutenins (gs), and confirmed by the accumulation trend of the different protein fractions during ripening. The year resulted to have the most marked effect on the gluten protein fraction ratios and alveographic parameters. The lowest W was observed in 2015, and although the highest GPC was recorded for the same year, the lowest gs/glia ratio was also observed. Instead, 2016 showed the highest gs/glia and HMW-gs/LMW-gs (H/L) ratios, and also the highest P/L value (2.2). In 2015, a slightly higher temperature during the ripening stage resulted in a greater increase in the γ-gliadin enriched fraction than the α/β gliadin ones, and marked differences were noted in the rheological traits. This field experiment has highlighted the interactive role of environmental and agronomic factors on the content and quality of gluten proteins and their bread-making ability, thus making a further contribution to the development of an integrated crop strategy for the cultivation of high protein wheat in humid Mediterranean areas.

Influence of Fertilization Methods and Types on Wheat Rhizosphere Microbiome Community and Functions

“…Grain yield, protein, wet gluten, and starch were increased after the application of N-fertilizer (Table ). N supply has been shown to correlate with tillers, protein concentration, gluten strength and most protein components, total glutenin, gliadin, and the content of most monomeric and polymeric proteins. − In contrast, fertilizer-K had less impact on yield . However, K improved the wheat quality by increasing the protein content, wet gluten, and starch content (Table ).…”

Wheat Quality Formation and Its Regulatory Mechanism

“…In wheat production, fertilization and watering strategies are also often considered for quality improvement ( Li et al, 2018 , 2019b ; Yu et al, 2018a , 2021 ). As nitrogen (N) is one of the most important and essential elements for wheat, N fertilizer is usually the most efficient input for simultaneously increasing grain protein content and grain yield in wheat production ( Zebarth et al, 2007 ; Malik et al, 2013 ; Zhen et al, 2018 , 2020 ; Zhong et al, 2018 , 2020 ; Ding et al, 2020 ; Xia et al, 2020 ; Hermans et al, 2021 ; Landolfi et al, 2021 ; Lyu et al, 2021 ; Dong et al, 2022 ; Liu et al, 2022 ; Ma et al, 2022 ). Kichey et al (2007) demonstrated that 50–95% of nitrogen in mature grains is derived from the remobilization of nitrogen stored in the tissues before anthesis.…”

Chemistry of wheat gluten proteins: Quantitative composition

“…The proportions of total gliadins and glutenins including all types were higher at grain maturity with the N240 level compared to N180 (Zhen et al, 2020). Landolfi, D'Auria, et al (2021) studied the effect of N fertilization rate (N80, 80 kg N/ha and N160, 160 kg N/ha, applied as top dressings split equally at tillering and stem elongation) on the gluten protein composition of one old and one modern wheat variety. Higher N supply resulted in an increase of grain protein content from 17.1% to 18.2% for the landrace and from 14.5% to 15.2% for the modern variety.…”

“…The concomitant application of fungicide at heading caused a slight reduction in grain protein content (−0.3%), but again, gluten composition remained unaffected. In contrast, the environmental conditions during each of the three years had the largest effect on gluten protein composition (Landolfi, Visioli, et al, 2021).…”