Recent advances in wheat transformation

Since the first report of wheat transformation in the early 1990s, genetic engineering of wheat has evolved rapidly. Several laboratories worldwide have reported the production of fertile transgenic wheat plants using a variety of methods. While there are several innovative and promising approaches for wheat transformation using different explants as targets for transformation, different methods of transformation, and different selection schemes, the most common approach to wheat transformation is the bombardment of tissue derived from immature embryos followed by selection based on resistance to the bar gene. Even with all these successful reports, hurdles still exist for this recalcitrant crop. Of these hurdles, low transformation rates, tools for transgene expression, and transgene silencing in subsequent generations are probably the most critical. This review will provide an overview of wheat transformation in the past decade, addressing both positive and negative factors that effect transformation while highlighting the successes of the past and prospects for the future.