|Hurkman Ii, William
|LOPEZ, ROCIO - OXNARD, CALIFORNIA
Submitted to: Journal of Cereal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/15/2006
Publication Date: 7/1/2006
Citation: Dupont, F.M., Hurkman, W.J., Vensel, W.H., Chan, R., Lopez, R., Tanaka, C.K., Altenbach, S.B. 2006. Accumulation of sulfur-rich and sulfur-poor wheat flour proteins are affected by temperature and mineral nutrition during grain development. Journal of Cereal Science. 44(1): 101-112
Technical Abstract: Post-anthesis N supplied as NPK or high temperature altered the proportions of S-rich and S-poor proteins in flour from a hard-red spring wheat (Triticum aestivum cv Butte86). Grain was produced under 24/17oC or 37/28oC day/night regimens with or without NPK. Flour proteins were analyzed and quantified by differential fractionation, RP-HPLC and two-dimensional gel electrophoresis (2-DE). The amount of most protein types per grain at 37/28oC, with or without NPK, was similar to that at 24/17oC without NPK. However, flour protein composition at 37/28oC was similar to that at 24/17oC with NPK. The ratio of S-rich to S-poor proteins decreased, from approximately 4.0 at 24/17oC without NPK to approximately 2.6 at 24/17oC with NPK and 2.7 and 2.9 at 37/28oC with or without NPK. Two-dimensional gel electrophoresis (2-DE) of gluten proteins during grain development revealed that NPK or high temperature increased the accumulation rate for S-poor proteins more than for S-rich proteins. The flours were not S-deficient and addition of post-anthesis S had no effect on protein composition. It is proposed that regulation of protein accumulation rather than supply of S was responsible for the effects of temperature and NPK. Although flour from grain produced under the 37/28oC regimen with or without NPK had protein content and loaf volumes comparable to flour produced at 24/17 with NPK, mixing tolerance was decreased by the high temperature regimen, possibly by effects on polymer size and structure rather than on subunit composition.