Conference lecture and academic presentation » Poster
Effects of combined N and S fertilisation on protein composition as examined by FPLC and proteome analysis
8 th Gluten Workshop; Viterbo, Italy, 2003-09-08–2003-09-10
Uhlen, Anne Kjersti; Hollung, Kristin; Flæte, Nina Solheim; Ruud, Leif; Magnus, Ellen Merethe
To study effects of nitrogen (N) and sulphur (S) fertilisation on wheat yield and quality, a pot experiment consisting of different amounts and different timing of N- and S fertiliser was conducted. The spring wheat cultivar Bastian of strong gluten quality was used in the experiment. Natural soil of very low fertility was used, fertilised with appropriate amounts of macro- and micronutrients, except for N and S. Different combinations of N and S-fertiliseres were applied at sowing, and as split amounts between sowing and at terminal spikelet (Zadoks 31) or at heading (Zadoks 51). Wheat samples was analysed for N- and S-content, protein content and by SDS sedimentation volume. The different N/S combinations applied in fertiliser was to a large extend revealed in the N/S-ratio of the grains. The protein content, analysed by NIR, varied according to amount and timing of the N fertiliser applied, as well as to variations in yield. The SDS sedimentation volume, however, was greatly affected by S-fertilisation and the N/S- ratio in the grains. Selected samples representing extremes in N/S-ratio was analysed for rheological properties by mixograph and Kieffer Micro Extensiograph with Texture Analyzer Kieffer Rig, and for protein composition by size-exclusion fast protein liquid chromatography (SE-FPLC). To further explore the effects of N/S-fertilisation on the protein composition, two-dimentional electrophoresis and proteome analyses was carried out on the selected samples. The results focus the need to consider properly the S-fertilisation in the bread wheat production to avoid unpredictable variations in gluten quality. The results also indicate potentials of S-and N-fertilisation given as a late application in the growth periode from terminal spikelet to heading. Differences in protein profiles is discussed in relation to quality parameters.