PROTEINASE-INHIBITOR-II GENE IN TRANSGENIC POPLAR - CHEMICAL AND BIOLOGICAL ASSAYS

Transgenic poplar lines were developed to investigate the role of a pr oteinase inhibitor in pest resistance of woody plants. Using an Agroba cterium binary vector system, the clone 'Hansen' (Populus alba L. x P. grandidentata Michx.) was transformed with chimeric genes containing the coding region of potato proteinase inhibitor II (PIN2) linked to e ither a bacterial nopaline synthase (nos) or a cauliflower mosaic viru s (35S) promoter. All transferred DNA also contained a selectable mark er in the form of a nos promoter linked to a neomycin phosphotransfera se II (NPT II) structural gene; The presence of the transferred PIN2 a nd NPT II sequences in poplar was confirmed for nine transgenic lines using polymerase chain reaction (PCR). Expression of PIN2 in leaves of transgenic poplar was demonstrated by enzyme-linked immunosorbent ass ays (ELISAs) and western blots. Two unique polypeptides from transgeni c poplar, of ca 8 kDa and ca 12 kDa, indicate that PIN2 was translated appropriately. Resistance to the imported willow leaf beetle was test ed in Laboratory bioassays. The untransformed clone 'Hansen' and 11 tr ansgenic lines were submitted to freshly hatched larvae to determine e ffects on pupal weight, larval development time and leaf area consumed . A significant difference from the untransformed clone in leaf area c onsumed was detected in one transgenic line, Tr665. Trends were indica ted for several other transgenic lines for the other parameters. Publi shed by Elsevier Science Ltd.