|Hurkman Ii, William|
Submitted to: European Journal of Agronomy
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 30, 2005
Publication Date: April 15, 2006
Citation: Dupont, F.M., Hurkman, W.J., Vensel, W.H., Tanaka, C., Kothari, K.M., Chung, O.K., Altenbach, S.B. 2006. Protein accumulation and composition in wheat grains: Effects of mineral nutrients and high temperature. 25(2):96-107. Interpretive Summary: Millions of tons of wheat flour are used every year by the baking and food industries. Variability in wheat flour quality is a common and serious problem for millers and bakers, and much of this variability has been attributed to environmental conditions during grain fill. Controlled environments were used to define the effects of fertilizer and high daytime and nighttime temperature on accumulation of protein by developing wheat grains. Flour contains a complex mixture of proteins called gliadins and glutenins. Two dimensional gel electrophoresis was used as a powerful tool to find changes in individual gliadins and glutenins that are likely to be related to effects of fertilizer and temperature on flour quality. The experiments are part of a broader research effort to understand the molecular basis for the effects of environment on flour quality.
Technical Abstract: Effects of fertilizer and high temperature on accumulation of total protein and individual gliadins and glutenins in wheat grains were studied under controlled environment conditions. Under a moderate temperature regimen of 24oC days, 17oC nights (24/17oC), post-anthesis fertilizer supplied by continuous drip irrigation increased the rate and duration of protein accumulation, doubled grain protein percentage and slightly increased final single kernel weight. In contrast, fertilizer had almost no effect on rate and duration of protein accumulation or final grain protein content under a high temperature regimen of 37oC days and 28oC nights (37/28oC). However, the 37/28oC regimen shortened and compressed the stages of grain fill, reduced the duration of dry matter accumulation, and reduced single kernel weight by 50%. At 37/28oC, total protein per grain was similar to that accumulated at 24/17oC in the absence of post-anthesis fertilizer, and grain protein percentage was higher than that of grain produced at 24/17oC in the presence of post-anthesis fertilizer. Transcript and protein profiling studies confirmed that the 37/28oC regimen compressed development without disrupting coordinate synthesis of gliadins and glutenin subunits. However, some specific effects of fertilizer and temperature on individual gliadins and glutenins were observed.