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Free keywords:
, secondary metabolism, natural diversity, wild accessions, pathway elucidation, gene discovery
Abstract:
Whilst the structures of plant primary metabolic pathways are generally well defined and highly conserved across species, those defining specialized metabolism are less well characterized and more highly variable across species. Here, we investigate polyphenolic metabolism in the lycopersicum complex by characterizing the underlying biosynthetic and decorative reactions which comprise the metabolic network of polyphenols across eight different species of tomato. For this purpose, GC- and LC-MS based metabolomics were carried out, in concert with the evaluation of cross-hybridized-microarray for MapMan based-transcriptomic analysis, and publically available RNA sequencing data for annotation of biosynthetic genes respectively, in different tissues of Solanum lycopersicum and wild tomato species. The combined data was used to compile species-specific metabolic networks of polyphenolic metabolism allowing the proposal of an entire pan-species biosynthetic framework as well as to annotate functions of decoration enzymes involved in the creation of metabolic diversity of the flavonoid pathway. The combined results are discussed both in the context of current understanding of tomato flavonol biosynthesis as well as a global view of metabolic shift during fruit ripening. Our results are providing an example as to how large-scale biology approaches can be used for the definition and refinement of large pathways of specialized metabolism.
