Transposable elements are a major constituant of genomes.
They are suspected to play a role in evolution, especially in the adaptation to stressful conditions. We are interested in the Tnt1 retrotransposon, that we isolated from tobacco, and our research focuses on the analysis of the mechanisms regulating Tnt1 transposition, the understanding of its impact on host genomes and on its potential use as a biotechnology tool. The expression of the Tnt1A element is induced by biotic and abiotic stresses and parallels early plant defense responses. Regulatory sequences have been identified in Tnt1 LTR that show homologies to regulatory motifs of plant defense genes. The high LTR variability found in Tnt1 populations suggests that these elements evolve by gaining new regulations.