Production Of Transgenic Tobacoo With Arabidopsis Thaliana Systemic Acquired Resistance Regulatory Gene (NPRl) And Genetic Analysis Of The Transgene

In order to know if the expression of heterologous Arabidopsis thaliana systemic acquired resistance(SAR) regulatory gene (NPRl) in tobacco can enable tobacco plants to be more resistant to a wide spectrums of tobacco pathogens, leave disks of Nicotiana tabacum var. K326 and Zunyan No.l were successfully transformed with Arabidopsis thaliana NPR1 gene by Agrobacterium tumefaciens mediated transformation. The transformation efficiencies for K326 and Zunyan NO.l were 27.3% and 29.8%, respectively. PCR and PCR-Southern hybridization analysis confirmed that 44 and 9 transgenic plants were generated from tobacco K326 Zunyan No.l, respectively.TO seeds had been harvested from 16 self-fertilized transgenic tobacco K326 plants. These seeds were screened on medium containing kanamycin and segregation ratio for kanamycin resistance for each transgenic line were calculated. It turned out that T0 seeds of 9 lines gave 3:1 segregation ratio for kanamycin resistance. Three plants of each transgenic lines in TI were analysed by PCR using the primers designed according to the NPRl gene. The results showed that all TI plants could give a specific PCR product except that six plants did not. The PCR products from 5 randomly selected lines were sequenced. Sequence analysis showed that the sequence of each PCR product was identical to the corresponding sequence of NPRl gene. All these results demonstrated that the NPRl gene had integrated into the genome of tobacco K326 and could be stably inherited. The test for the resistance of these transgenic tobacoo plants to tobacco pathogens is in progress. This work provides a solid basis for further studying the signal transduction pathway of SAR in plants and the use of heterologous positive regulatory gene of SAR for engineering plants to be more disease resistant.