135 Protein characterization and baking quality data of field grown transgenic wheats containing high molecular weight glutenin gene 1Ax1.

J. Zhao (1), S. Bean (2), P. McCluskey (2), G. Lookhart (3), H.- P. Zhou (1), W. Goure (1), F. Altpeter (4), V. Vasil (4), and I. K. VASIL (4). (1) Monsanto St. Louis, MO 63167; (2) Dept. Grain Sci. & Ind., Kansas State Univ., Manhattan, KS 66506; (3) USDA, ARS, GMPRC, Manhattan, KS 66502; (4) Lab. of Plant Cell & Mol. Biol., Univ. of Florida, Gainesville, FL 32611-0690.

Seven Bobwhite transgenic wheat lines expressing HMW-GS 1Ax1 were field grown in Arizona for milling and baking. Agronomic yields of transgenic wheats and controls were similar as were flour yields. Two transgenic lines showed slightly higher protein levels than the control cultivar. Analysis of the gross protein composition showed that two lines had slightly increased levels of 50% propanol insoluble polymeric proteins (IPP) and decreased levels of gliadins. Capillary electrophoretic (CE) analyses demonstrated that introduction of the 1Ax1 gene did not alter gliadin or low molecular weight glutenin proteins. SDS-PAGE, CE and HPLC all revealed additional proteins present in several of the transgenic lines. Line ax31, exhibited substantially different HMW-GS patterns when analyzed by CE and HPLC. Quantification of expression levels of the 1Ax1 transgene by CE showed the same levels as those reported with greenhouse grown samples. The transgenic lines showed similar loaf volumes, crumb grain, and bake absorption as the control. Six of the lines showed increased mixing times compared to the control.