Expression of two insect-resistant genes cryIA (b&c)/GNA in transgenic tobacco plants results in added protection against both cotton bollworm and aphids

The synthesized Bacillus thuringiensis insecticidal protein gene cryIA (b&c ) and the synthesized gene GNA, (the mannose specific lectin from snowdrop (Galanthus nivalis)), tumefaciens have been inserted into plant expression vector pGW4BAI. Leave stripes of Nicotiana tabacum var. K326 have been tran sformed with Agrobacterium tumefaciens strain LBA4404 harboring the plant e xpression vector. 28 kanamycin resistant tobacco plants have been obtained. PCR and Southern blot analyses show that the foreign cryIA and GNA genes h ave been inserted into the genome of transformed tobacco plants. Haemagglut ination assays show that GNA has a functional activity. Leaf disc bioassays against cotton bollworm (H. armigera) show that the transgenic tobacco pla nts have a high insecticidal activity. The inhibition of aphid population i n leaf disc bioassays against Myzus persicae shows that the fecundity of ap hid on transgenic plants is lower than that on untransformed plants; the ap hid population on the transgenic tobacco plants is 25%-70% that on untransf ormed tobacco plants. ELISA analysis of CryIA protein in tobcco leaves prov ides similar data to bioassay results. Through the two bioassays against H. armigera and M. persicae, several transgenic tobacco plants showing high i nsect-resistant activities to both pests have been obtained.