Detection of dna polymorphism of transgenic wheat plants with proline metabolism heterologous genes

Abstract

The polymorphism level of DNA regions flanked by inverted LTR-retrotransposon repeats has been analyzed by the IRAP-PCR method in genetically modified wheat plants obtained by Agrobacterium-mediated transformation in an in vitro culture. Some plants contain the Medicago truncatula ornithine--aminotransferase gene, and the other contain a double-stranded RNA suppressor of the Arabidopsis thaliana proline dehydrogenase gene. In analysis of plants with the heterologous ornithine--aminotransferase gene, the application of the primer to the Sukkula retrotransposon was the most effective, where in the nine tested plants four new amplicons were obtained in the spectrum of DNA amplification products. The findings suggest that it is the foreign DNA insertion capable of inducing transposition of retrotransposons Sukkula/Nikita and Wham/Sabrina, because in control plants derived from in vitro culture their activity has not been established. The analysis of transgenic plants with a double-stranded RNA suppressor of the proline dehydrogenase gene using highly efficient primers for the retrotransposons Sukkula, Sabrina, Wham, Nikita, and Wilma1 no DNA polymorphism was revealed. In the course of the experiment, we did not register the disappearance of amplicons in the DNA profiles of PCR and this may be index of the rearrangements absence in the primer annealing sites and in the loci studied. The emergence of new amplicons was not observed in the spectra of DNA amplification products, what indicate the absence of activation of mobile genetic elements transposon activity in transgenic plants with a double-stranded RNA suppressor of the proline dehydrogenase gene. IRAP primer pairs were selected experimentally, but the use of this method did not reveal the disappearance or emergence of polymorphic fragments. The absence of DNA polymorphism in transgenic plants with a double-stranded RNA suppressor of the proline dehydrogenase gene may be due to the phenomenon of RNA interference that suppresses retrotransposon activity.