Expression and inheritance of Bt cry1Ia8 gene in transgenic cabbage to control Plutella xylostella

- The transgene was successfully being transmitted to self-pollinated T3 progenies.
- Transgene inheritance followed the Mendelian segregation pattern in tested lineages.
- Homozygous transgenic lines can be used as “donor” in breeding programs.

We previously transformed cabbage plants with a Bacillus thuringiensis cry1Ia8 gene. The resulting transgenic plants were able to control both susceptible and Cry1Ac-resistant Plutella xylostella larvae. For practical applications, transgenes should be inherited in a stable and predictable manner. To evaluate and characterize the stability of transgenic cabbages produced using an Agrobacterium tumefaciens-mediated transformation procedure, transgene expression and inheritance were examined in four single-copy lineages (A14-3, A14-5, A14-7, and A14-8) and their sexually derived progenies. Segregations ratios (insect-resistant:insect-sensitive) of 2.56:1, 2.75:1, 3.24:1, and 1.6:1 were observed in the T1 generation of lineages A14-3, A14-5, A14-7, and A14-8, respectively. Examinations of Cry1Ia8 activities in the T1, T2, and T3 plants indicated transgene inheritance followed the Mendelian segregation pattern in lineages A14-3, A14-5, and A14-7. Southern blot and enzyme-linked immunosorbent assay analyses of the T0, T1, T2, and T3 progenies revealed that the transgene was successfully inserted into the cabbage genome, and had been transmitted to self-pollinated T3 progenies. These results imply that the homozygous transgenic lines exhibiting stable inheritance of the transgene and can be used effectively in breeding programs.