Effect of Changes in Genome Ploidy on the Mosaic Character of nptII Gene Expression in Epialleles of the Transgenic Tobacco Line Nu21

Abstract

The influence of changes in the genome ploidy and the gene dose on the mosaic pattern of expression of the nptII gene in epialleles of the Nu21 transgenic tobacco line was evaluated. The general preservation of the expression profile of the marker gene nptII is shown (high in the Nu5 epiallele and low in the Nu6 epiallele) in heteroploid crosses of diploid transgenic plants (2n = 48) with polyploid nontransgenic plants (3n = 72, 4n = 96), as well as in self-pollination of experimentally obtained tetraploid transgenic plants of the Nu21 line (4n = 96) and in their hybrids from crossing with nontransgenic diploid plants. It has been established that the stability of expression of the nptII marker gene is influenced by the initial epigenetic status of epialleles and the direction of crossing in hybridization of tetraploid nontransgenic tobacco plants with diploid transgenic plants of the Nu21 line.