Transformation of wheat with the HMW-GS 1Bx14 gene without markers

High molecular weight (HMW) glutenin polypeptides are critical contributors to the visco/elastic properties responsible for the processing characteristics and utilizations of wheat flour. In order to improve bread making quality of flour and produce transgenic plants free of selectable markers, a linear DNA construct consisting of a minimal expression cassette with the HMW-GS 1Bx14 gene was transformed into wheat cultivar Mianyang 19 by microprojectile bombardment. The transformants were selected by PCR instead of herbicidal markers. Seven transgenic plants were identified from a total of 1219 transformants, yielding a transformation frequency of 0.28%. An SDS-PAGE analysis confirmed that the 1Bx14 gene was expressed in three T1 seeds of the transgenic plants. Our results demonstrated that it is feasible to obtain marker-free transformants using the linear-expression-cassette-transformation approach coupled with PCR selection.