Transformation And Function Characterization Of BCCodY Of Antagonistic Bacterium 2-Q-9 In Transgenic Tobacco Variety K326

Tobacco bacterial wilt, caused by Ralstonia solanacearum, is the first major bacterial disease in tobacco production in China. Every year, tobacco bacterial wilt is caused economic losses of up to 10 billion yuan. In practice, R. solanacearum could not be controlled by pesticides, rotate and other traditional measures. Currently, a gene coding an antimicrobial peptide against R. solanacearum was isolated and identified from antagonistic bacterium strain 2-Q-9. In this thesis, BCCodY was transformed to tobacco variety K326 and then identified its biological function on resistance to bacterial wilt in transgenic plants.. The paper content and the results are as follows:1. In this study, the BCCodY gene of Bacillus choshinensis strain 2-Q-9 was ligated with vector pCHF3, and then transformed the recombination vector pCHF3::BCCodY into tobacco variety K326 by Agrobacterium-mediated approach. Transgenic K326 plants were identified by polymerase chain reaction (PCR). PCR detection by NPTâ…¡and BCCodY's specific primer indicated that 95% kan resistance tobacco plants contained the BCCodY gene.2. BCCodY is successfully transcribed in the transgene K326. Trizol method was used to extract RNA of positive tobacco plant, and RT-PCR detection was carried out. Results shown that the BCCodY gene driven by the promotor CaMV 35S can be correctly transcribed into mRNA in K326, indicating that the gene can be transcribed in the transgenic plant. Normal transcription of BCCodY gene in the transgenic tobacco indicates that genes might be translated to functional protein.3. To characterize the biological function of BCCodY in transgenic K326 plants, transgenic plants were inoculated with R. solanacearum strain RS2-1 by injection. The results showed, the colony number of RS2-1 isolated from transgenic K326 plants was fewer than wild plants in 7th day after inoculation, but the difference of colony number of transgenic and wild plant was gradually disappear after 9 days. It can be deduced that the BCCodY gene maybe performed antagonistic ability against R. Solanacearum in transgenic K326 plants.