TOXICITY TO CHRYSOMELA-TREMULAE (COLEOPTERA, CHRYSOMELIDAE) OF TRANSGENIC POPLARS EXPRESSING A CYSTEINE PROTEINASE-INHIBITOR

The aim of this study was to test the potential of proteinase inhibito rs to control Chrysomela tremulae, a beetle that causes severe damage in young plantations and in short-rotation intensive culture (SRIC) of poplar. As a first step, cysteine proteinases were determined to be t he major digestive proteinases of C. tremulae and oryzacystatin OCI, a cysteine proteinase inhibitor, was shown to inhibit this activity in vitro. The gene encoding OCI was introduced into poplar (Populus tremu la x P. tremuloides) and transgenic plants expressing OCI at a high le vel were selected. Feeding tests on these transgenic plants demonstrat e the toxicity of OCI-producing poplar leaves against C. tremulae larv ae.