Submitted to: International Wheat Quality Conference
Publication Type: Proceedings
Publication Acceptance Date: April 1, 2005
Publication Date: June 1, 2005
Citation: Altenbach, S.B., Dupont, F.M., Hurkman, W.J., Vensel, W.H. 2005. Biosynthesis of gliadins and glutenin subunits during grain development under different environmental conditions. In: D.K. Chung and G.L. Lockhart), editors. Proceedings of the Third International Wheat Quality Conference., May 22-26, 2005, P. 189-194. Interpretive Summary: The gluten proteins are present in large quantities in wheat grains and make it possible to produce a wide variety of high quality baked products from wheat flour. Temperature, water and fertilizer levels during wheat grain development can alter the functional properties of the resulting flour, but the precise effects of environmental factors on the synthesis of the major gluten proteins is unknown. In this paper, the complexity of the gluten proteins is demonstrated by comparing the many sequences of genes encoding these proteins in a single US wheat variety. Gene expression and protein accumulation patterns for the major classes of wheat gluten proteins are presented under several different controlled environmental regimens. The paper highlights the striking similarities of expression patterns among the different groups of proteins and discusses the difficulties in identifying the relatively small changes in specific proteins that might influence flour quality.
Technical Abstract: The a-, g- and w-gliadins and LMW- and HMW-glutenin subunits, the major storage proteins in wheat endosperm, confer elasticity and extensibility properties essential for the functionality of wheat flour. These proteins are encoded by genes with highly repetitive sequences that are members of large, complex gene families. Gluten protein transcripts begin to accumulate early in endosperm development and are present throughout the grain filling period. There is a remarkable coordination in the timing of transcript accumulation for genes encoding proteins in the different classes as well as for individual genes within the different families. Changing environmental conditions shift the timing of transcript accumulation, but do not uncouple the coordinate expression of the gluten protein genes. Proteomic analyses of storage protein fractions from developing grains also reveal striking similarities in the profiles for different gluten proteins, particularly with respect to the timing of protein accumulation. Gene expression profiles and proteomic analyses of gluten proteins during grain development under different temperature, water and fertilizer regimens are discussed.