Metabolome and Transcriptome Analyses Reveal Tissue-Specific Variations in Gene Expression and Metabolites of Olive

Metabolome and transcriptional correlation analyses can be used to reveal the relationship between metabolites and gene expression in different tissues. Here, targeted metabolome and Illumina RNA-Seq analyses were used for the identification of co-regulated metabolites and genes from three different tissue of Olea europaea (fruits, new leaves, and old leaves). In total, 57.49 Gb of clean data from nine samples was obtained. The clean data of each sample reached 5.25 Gb, and the Q30 base percentage exceeded 88.44%. Through sequence alignments of clean reads from each sample with the olive reference genome, 3049 newly annotated genes were identified, of which 2350 were functionally annotated. Differentially expressed genes (DEGs) and metabolite correlation analysis showed that most of the up-regulated genes in fruits were enriched in fatty acid (FA) biosynthesis metabolic pathways; the up-regulated genes in leaves were mainly related to plant hormones, biotic (abiotic) stress tolerance, signal transduction, and secondary metabolite biosynthesis pathways. The current global gene expression and metabolite content profiling exercise provides a comprehensive view of the combination of transcriptome and metabolome data, which provides valuable information for identifying DEGs in olives.