In most plants, the proportion of transcribed DNA is a small portion of the genome, and this is particularly evident for species with large genomes, e.g. hexaploid wheat (Triticum aestivum), where the 85% of the genome is composed of non-expressed repetitive DNA elements, and only about 60% of the annotated genes are expressed. Indeed, it is known that the expression of large portions of plant genomes are blocked by transcriptional gene silencing (TGS) mechanisms, controlled by epigenetic marks such as DNA methylation. In the model plant Arabidopsis thaliana, the genome wide suppression of TGS activates the expression of silenced genes and mobilises repetitive elements, generating epigenetic and genetic variation and producing new phenotypes. However, attempts to exploit this variation in crop species has been so far largely unsuccessful, mostly due to the different and more complex epigenetic regulation of larger, and often polyploid, crop genomes. Therefore, we are developing a tool to directly screen in planta for conditions able to increase epigenetic variability via the suppression of TGS. For this purpose, wheat cv. ‘Fielder’ was transformed with a reporter GUS cassette containing DNA repeats, to attract DNA methylation and establish TGS on the transgenic locus. To prove that TGS was effectively silencing the reporter gene, we exposed transgenic seedlings to Zebularine, a cytidine analog that inhibits DNA methyltransferases and suppresses TGS, resulting in an increase in GUS expression. Ongoing and future work includes the use of this reporter line to test conditions, or breeding combinations, able to affect TGS in wheat, which can generate epigenetic and genetic variation. The exploitation of such diversity in breeding programs will potentially contribute to the improvement of wheat productivity and food sustainability.