There is an urgent need for a routine, high frequency, barley transformation system to facilitate both fundamental research and crop improvement. The barley transformation systems which are currently available, tend to be based on the biolistic method which has many shortfalls including dependence on high-cost instrumentation, low transformation frequency, and complex re-arrangement of multiple copies of transgenes in the transgenic plants which are produced. Agrobacterium-mediated DNA delivery promises to be an attractive alternative, which, when optimised, will permit facile, routine, low cost, high frequency transformation of barley. In this project, we plan to establish such a transformation system. We will concentrate upon the development of highly regenerable cultures from immature embryos and microspores as target materials for Agrobacterium and upon the optimisation of co-cultivation procedures, with special emphasis upon the assessment of the effect of wounding and vir gene induction on the transformation frequency. In close collaboration with scientists at the John Innes Centre, IACR-Rothamsted and IGER, we will define an efficient binary vector system and optimise the procedures for growth of highly potent Agrobacterium strains. The new transformation system will facilitate advances in fundamental molecular genetics and barley crop improvement and will also have relevance to corresponding research in other cereals and grasses.