Inhibition of Heliothis virescens larvae growth in transgenic tobacco plants expressing cowpea trypsin inhibitor

Fall armyworm (Spodoptera frugiperda) is an important pest for corn and rice in Cuba. Here, we describe the obtainment of transgenic tobacco plants expressing the cowpea trypsin inhibitor (cpti) gene as a model to explore the efficiency of this protein for fall armyworm control. Tobacco plants were transformed with Agrobacterium tumefaciens containing a plasmid conferring kanamycin resistance and carrying the cpti gene fused to the 35S promoter and the enhancer of the Ω fragment from the TMV. From the regenerated tobacco clones, lines 19 and 26 showed higher trypsin inhibitory activity and were chosen for molecular characterization and bioassays against insects. Tobacco budworm larvae feeding on leaf discs from clone 19 showed marked inhibition growth as a consequence of cpti in the plants. This demonstrates the usefulness of the cpti protein in the control of insects with trypsin-like protease activity and supports its potential to be combined with insecticidal Bacillus thuringiensis Cry proteins in transgenic plants as an alternative against the development of insect resistance.