EN
Wounding- and herbivore-inducible proteins are potential resources to enhance the resistance to insect pests in transgenic plants. In order to analyze the effects of four such highly inducible genes of Populus, two genes encoding trypsin inhibitors (PtdKTI5 from hybrid poplar, Populus trichocarpa × P. deltoides and PtKTI2 from trembling aspen, Populus tremuloides Michx.), a woundinducible gene (PtdKTI5 from hybrid poplar, Populus trichocarpa × P. deltoids) and a stress-responsive gene (PtdPOP3 from hybrid poplar, Populus trichocarpa × P. deltoids), we have produced transgenic Arabidopsis thaliana expressing these genes individually under the control of the CaMV35S promoter by Agrobacterium-mediated transformation. Stable integration and high transcriptional levels of the target cDNAs and their inheritance in transgenic Arabidopsis lines were confirmed by genomic PCR, quantitative PCR and T₃ progeny segregation analysis. In the no-choice bioassays, all the four types of transgenic Arabidopsis confer different levels of insect resistance against Plutella xylostella L. larvae at various stages and the PtdKTI5 overexpressing plants turned out to be most effective. Our data indicated that these four Populus defense-related genes under investigation could be potentially exploited for the protection against P. xylostella L. in transgenic plants.