RESUMEN
Breeding pest-resistant plants using plant genetic engineering technique is an effective strategy in integrated pest management (IPM). Increasing the expression level of foreign insecticidal protein by using a strong promoter is a useful method. In this work, a plant expression vector, pBinMoBc, was constructed. It contained the CryIA(c) gene under the control of a chimeric OM promoter and the omega factor. As a control, another vector, pBinoBc, was also constructed in this study. pBinoBc carrying CryIA(c) gene was under the control of a CaMV 35S promoter. The vectors were transferred into tobacco plants via Agrobacterium-mediated transformation. ELISA assay showed that the average expression level of the CryIA(c) gene in pBinMoBc transgenic tobacco plants is 2.44-times that in pBinoBc transgenic tobacco plants. The expression of B.t. toxin in individual plant can be up to 0.255% of total soluble proteins. Bioassay showed that pBinMoBc transgenic tobacco plants had more notable insecticidal effects than pBinoBc transgenic tobacco plants. The above results showed that the chimeric OM promoter is a stronger promoter than the CaMV 35S promoter that was widely used in plant genetic engineering. This is very useful in pest-resistant plant genetic engineering.