Altpeter F, Vasil V, Srivastava V, Vasil I K
Laboratory of Plant Cell and Molecular Biology, University of Florida, Gainesville 32611-0690, USA.
Nat Biotechnol. 1996 Sep;14(9):1155-9. doi: 10.1038/nbt0996-1155.
The unique bread-making characteristic of wheat flour is closely related to the elasticity and extensibility of the gluten proteins stored in the starchy endosperm, particularly the high-molecular-weight glutenin subunits (HMW-GS), which are important in determining gluten and dough elasticity. The quality of wheat cultivars depends on the number and composition of the HMW-GS present. We have introduced the HMW-GS 1Ax1 gene, known to be associated with good bread-making quality, into the Bob White cultivar of wheat (Triticum aestivum L.), in which it is not present in nature, by the biolistic bombardment of cultured immature embryos. Of the 21 independent transformed lines selected, 20 expressed the selectable bar gene, and nine the 1Ax1 gene. The amount of HMW-GS 1Ax1 protein produced in the different transgenic lines varied from 0.6% to 2.3% of the total protein, resulting in an increase of up to 71% in total HMW-GS proteins. The transgenic plants were normal, fertile, and showed Mendelian segregation of the transgenes. The accumulation of HMW-GS 1Ax1 was consistent and stable up to the R3 seed generation. These results demonstrate that it is possible to manipulate both the quantity and quality of HMW-GS, which influence the bread-making quality of wheat.
小麦粉独特的制面包特性与储存于淀粉胚乳中的面筋蛋白的弹性和延伸性密切相关，尤其是高分子量谷蛋白亚基（HMW - GS），其在决定面筋和面团弹性方面很重要。小麦品种的品质取决于所存在的HMW - GS的数量和组成。我们通过对培养的未成熟胚进行生物弹道轰击，将已知与良好制面包品质相关的HMW - GS 1Ax1基因导入在自然状态下不存在该基因的小麦（普通小麦）品种Bob White中。在所挑选的21个独立转化株系中，20个表达了选择标记bar基因，9个表达了1Ax1基因。不同转基因株系中产生的HMW - GS 1Ax1蛋白量占总蛋白的0.6%至2.3%，导致总HMW - GS蛋白增加了高达71%。转基因植株正常、可育，并且转基因呈现孟德尔分离。直至R3种子世代，HMW - GS 1Ax1的积累都是一致且稳定的。这些结果表明，有可能操控影响小麦制面包品质的HMW - GS的数量和质量。
