We describe the establishment of an activation tagging system in poplar based upon the maize Ac/Ds transposable element system. Transgenic poplar plants were obtained carrying either one or two of the above mentioned constructs [ Following induction of the GIP promoter only a weak transposase signal could be detected in RT- PCR experiments. Mobility of the ATDs activation construct could not be confirmed in the GIP system. [ An Activation Tagging experiment was initiated using eight different double transgenic lines. A few putative variants could be obtained revealing deficiency in...