Characterisation of epigenetic modifications during plant development in wild and cultivated tomato species

Tomato is currently used as a model system to study fruit development and quality. Tomato fruit development can be divided in 3 distinct phases, namely cell division, cell elongation and fruit ripening. These developmental phases lead to massive changes of gene expression pattern. To analyse the potential role of epigenetic mechanisms during the development of tomato plant and fruit, genomic DNA methylation analysis were performed demonstrating global and locus specific variations of CG and CXG methylation pattern in fruits of the cultivated tomato. The comparative analysis of DNA methylation in wild and cultivated tomato species indicate contrasted situations, characterized by different pattern of DNA methylation at repetitive loci such as the 5s rDNA and various retrotransposons. In addition, the molecular analysis of genes encoding the Polycomb (PcG) proteins demonstrates a genetic variability at these loci. The functional consequences of these observations are currently investigated