Multi-omics data integration provides insights into the post-harvest biology of a long shelf-life tomato landrace

In this study we investigated the transcriptome and epigenome dynamics of the tomato fruit during post-harvest in a landracebelonging to a group of tomatoes (Solanum lycopersicum L.) collectively known as "Piennolo del Vesuvio", all characterized by a long shelflife. Expression of protein-coding genes and microRNAs as well as DNA methylation patterns and histone modifications were analysedin distinct post-harvest phases. Multi-omics data integration contributed to the elucidation of the molecular mechanisms underlyingprocesses leading to long shelf-life. We unveiled global changes in transcriptome and epigenome. DNA methylation increased and therepressive histone mark H3K27me3 was lost as the fruit progressed from red ripe to 150 days post-harvest. Thousands of genes weredifferentially expressed, about half of which were potentially epi-regulated as they were engaged in at least one epi-mark change inaddition to being microRNA targets in ~5% of cases. Down-regulation of the ripening regulator MADS-RIN and of genes involved inethylene response and cell wall degradation was consistent with the delayed fruit softening. Large-scale epigenome reprogrammingthat occurred in the fruit during post-harvest likely contributed to delayed fruit senescence.