Multi-Omics Analysis to Visualize Ecotype-Specific Heterogeneity of the Metabolites in the Mesocarp Tissue of Three Avocado (Persea Americana Mill.) Ecotypes

The huge amount of metabolites in avocado mesocarp influences the commercial production of specific avocado fruits for consumption and for industrial applications. Additionally, the diversity in the metabolite content may be used as biomarker for differentiating among various avocado ecotypes. However, the differences in metabolites in avocado remain unclear among various avocado ecotypes. In this study, we first compared the lipid droplets, fatty acid compositions, and gene expression profiles of the mature avocado mesocarps of three ecotypes, and confirmed the differences in the mesocarp oil contents. Furthermore, the lipidomics and metabolomics based on the ultra-high-performance liquid chromatography-triple and time-of-flight mass spectrometry and ultra-high performance liquid chromatography-Q exactive-mass spectrometry were completed, respectively, which revealed considerable differences in the relative amounts of lipids from 10 classes and other metabolites from seven super-classes among the examined avocado ecotypes. The profiles of 65 lipids and 15 other metabolites could be potential candidate biomarkers useful for identifying diverse avocado ecotypes. This is the first comprehensive metabolomics-based comparative investigation of lipid and other metabolites among three avocado ecotypes.