TRANSGENIC POPULUS HYBRID EXPRESS A WOUND-INDUCIBLE POTATO PROTEINASE INHIBITOR-II - CAT GENE FUSION

A hybrid poplar clone has been transformed with a previously constructed wound-inducible potato proteinase inhibitor (pin2) - chloramphenicol acetyltransferase (CAT) chimeric gene linked to a nopaline synthase (nos) - neomycin phosphotransferase II (NPT II) selectable marker gene. The Populus alba x Populus grandidentata Hansen clone was transformed by means of leaf cocultivation with Agrobacterium tumefaciens strain A281 containing a binary vector. Shoots were regenerated and rooted on selective medium containing kanamycin sulfate. Subsequently, plants were established in soil for greenhouse and field growth. NPT II activity from the nos-NPT II selectable marker gene was observed in leaf extracts, thereby confirming expression of the transferred selectable marker gene in poplar. Southern hybridization confirmed the incorporation of a single copy of the pin2-CAT construction into the genome of the transformed hybrid poplars. Northern analysis of transgenic poplar leaves demonstrated that the potato pin2-CAT gene construction also was inducible in this woody dicotyledon. Thus, the wound-inducible promoter from an herbaceous dicot functions in a distinct family of woody dicots.