Impact and mechanism of sulphur-deficiency on modern wheat farming nitrogen-related sustainability and gliadin content

Zitong Yu,Maoyun She,Wujun Ma,Yun Zhao,Ting Zheng,Guixiang Tang,Jingjuan Zhang,Christopher L Blanchard,Dean Diepeveen,Yujuan Zhang,Shahidul Islam,Yingquan Zhang

doi:10.1038/s42003-021-02458-7

Abstract

Two challenges that the global wheat industry is facing are a lowering nitrogen-use efficiency (NUE) and an increase in the reporting of wheat-protein related health issues. Sulphur deficiencies in soil has also been reported as a global issue. The current study used large-scale field and glasshouse experiments to investigate the sulphur fertilization impacts on sulphur deficient soil. Here we show that sulphur addition increased NUE by more than 20% through regulating glutamine synthetase. Alleviating the soil sulphur deficiency highly significantly reduced the amount of gliadin proteins indicating that soil sulphur levels may be related to the biosynthesis of proteins involved in wheat-induced human pathologies. The sulphur-dependent wheat gluten biosynthesis network was studied using transcriptome analysis and amino acid metabolomic pathway studies. The study concluded that sulphur deficiency in modern farming systems is not only having a profound negative impact on productivity but is also impacting on population health.

Highlights

Two challenges that the global wheat industry is facing are a lowering nitrogen-use efficiency (NUE) and an increase in the reporting of wheat-protein related health issues
While sulfur has been identified as a key element in regulating plant growth and grain-filling, there are still unanswered questions regarding the impact of soil sulfur deficiency including: (1) Is the soil sulfur deficiency related to the reported lowering NUE? (2) Is the biosynthesis of gluten components affected by sulfur deficiency? (3) How does sulfur regulate the N metabolism and gluten component biosynthesis? The current study addresses these questions and has confirmed that appropriate application of sulfur fertiliser in sulfur deficient farmland has a multi-faceted positive impact on wheat NUE and wheat protein biosynthesis
Under a fixed N application rate of 25 kg ha−1 in the 2014 field trial, protein yield (PY), grain yield (GY) and their corresponding NUE (NUE-PY and NUE-GY) in the sulfur deficient Western Australia Wheat Belt farming land were significantly affected by supplementation treatments of 30 kg ha−1 (S30) and 50 kg ha−1 (S50), compared to the no sulfur control (S0) (P < 0.01 at S30, P < 0.001 at S50, T-test, Supplementary Data 1; Table 1, UNIANOVA)

Summary

Introduction

Two challenges that the global wheat industry is facing are a lowering nitrogen-use efficiency (NUE) and an increase in the reporting of wheat-protein related health issues. Increasing GY and GPC is challenging due to the negative relationship between the two parameters[2] To obtain both high GY and GPC, wheat growers tend to use high amounts of nitrogen (N) fertiliser, which reduce N-use efficiency (NUE)[3]. Gliadins are the dominant carriers of toxic epitopes, which are responsible for human illness related to wheat gluten consumption including coeliac disease and gluten allergy[15]. Such conditions are induced by oral intake of wheat gluten components rich in proline (Pro), resulting in a reduced susceptibility to protease activity in the gastrointestinal tract. Removing toxic epitopes but maintaining viscoelasticity of wheat flour through genetic modification has been challenging[27,28,29,30,31,32]

Methods

Results

Conclusion