Abstract: Insecticidal protein gene CrylA (c) from Bacillus thuringiensis (Bt toxin gene) was placed under the control of psbA5'- and 3'- regulatory regions of rice (Oryza sativa L. ) chloroplast to construct Bt expression cassette, which was ligated with selectable marker aadA cassette and homology regions of tobacco ( Nicotiana tabacum L. ) chloroplast genome to generate transformation vector pTRS8. Leaves of tobacco plant cv. NC89 were transformed with particle bombardment method, plastid transformants were selected by their resistance to 500 mg/L of spectinomycin. Some transplastomic plants were toxic to the third-instar larvae of Helicoverpa zea, and the growth of the survived insects was remarkably inhibited. Genetic and molecular analyses of T1 and T2 progenies of plants with highly efficient insect resistance showed that Bt toxin gene had been inherited in progenies, and spectinomycin resistance was inherited maternally.

Key words: Bt toxin gene, Chloroplast transformation, Insect resistance, Maternal inheritance, aadA gene