TRANSCRIPTOMIC ANALYSIS REVEALS THE GENE REGULATORY NETWORKS INVOLVED IN LEAF AND ROOT RESPONSE TO OSMOTIC STRESS IN TOMATO

Tomato (Solanum lycopersicum L.) is a major horticultural crop that is cultivated worldwide and is characteristic of the Mediterranean agricultural system. Its cultivation in open field often experiences drought episodes, leading to severe yield losses. Water stress leads to changes in the expression of stressresponsive genes in different plant tissues, and transcriptomics can support the identification of genes and pathways regulating this response. We performed a transcriptomic analysis of two tomato genotypes in response to a PEG-mediated osmotic treatment. The analysis was conducted separately on leaves and roots to characterize the specific response of these two organs. A total of 6,267 differentially expressed transcripts related to stress response was detected. The construction of gene co-expression networks defined the molecular pathways of the common and specific responses of leaf and root.