Introduction of a 50 Kb Intact DNA Fragment in Wheat Genome Using Biolistic Technology Genetic transformation is a powerful tool for studying gene function and regulation of physiological and developmental processes in plants. Although wheat was the last of the major cereal to be transformed, the introduction and expression of transgene in this plant is now quite feasible. Nowadays another challenge in plant transformation technology is the introduction and stable integration of large intact DNA fragments in plant genome. It would make possible the study in one transformation step of multigenic traits or to study the expression of plant gene in their native genomic context. Recently, it has been shown that expression and regulation of a gene frequently require regulatory elements that could be very distant In the present study we developed a technology, based on biolistic with dephosphorylated cassettes allowing introduction of a 50 kb intact insert DNA in wheat genome. We have chosen Arabidopsis thaliana DNA as large insert fragments to make easier insert detection, and we have flanked the insert by two reporter genes in order to facilitate screening of plants containing the entire cassette. We have first demonstrated that it is possible to obtain transformed plants with a single and intact 50Kb insert, and then we have demonstrated that this insert can be transmitted intact to the T1 progeny. In our knowledge, this is the first time wheat transformation with such a fragment was demonstrated. Developing such technologies could be very useful to improve genetic engineering of wheat which is one of the major food crops in the world.