Studies on Insect Resistance of Bt Transplastomic Plants and the Phenotype of Their Progenies
ZHANG Zhong_Lin 1CHEN Xi 2QIAN Kai_Xian 1SHEN Gui_Fang 1(Biotechnology Research Center, Chinese Academy of Agricultural Sciences, Beijing 100081) 2(Department of Bioscience and Technology, Zhejiang University, Hangzhou
Insecticidal protein gene CryIA(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 aad A 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 T 1 and T 2 progenies of plants with highly efficient insect resistance showed that Bt toxin gene had been inherited in progenies, and spectinomycin resistance was inherited maternally.