Transgenesis is a powerful research tool that can be adapted to investigate many aspects of gene function. It has been used widely in model plants such as Arabidopsis, tobacco and rice but until recently, bottlenecks in DNA-delivery and tissue culture meant that it could not be used routinely for wheat research. However, many aspects of grain development and composition are unique to wheat and cannot be easily investigated in model species. Over the last decade, progress in biolistic- and Agrobacterium-mediated DNA delivery, reduction in genotype-dependency in wheat tissue culture and in the development of a range of supplementary technologies has enabled its application in this traditionally recalcitrant crop. The use of genetic modification has already made a significant impact on our understanding of interactions between high molecular weight glutenin subunits and their individual contribution to dough strength. As candidate genes become available the application of genetic transformation is set to play a major part in the elucidation of their function in determining other important grain traits such as starch and lipid composition, dietary fibre composition and grain texture. (C) 2004 Elsevier Ltd. All rights reserved.