Targeted and Untargeted Metabolomic Analyses Reveal Organ Specificity of Specialized Metabolites in the Model Grass Brachypodium distachyon

Abstract

Brachypodium distachyon, because of its fully sequenced genome, is frequently used as a model grass species. However, its metabolome, which constitutes an indispensable element of complex biological systems, remains poorly characterized. In this study, we conducted comprehensive, liquid chromatography-mass spectrometry (LC-MS)-based metabolomic examination of roots, leaves and spikes of Brachypodium Bd21 and Bd3-1 lines. Our pathway enrichment analysis emphasised the accumulation of specialized metabolites representing the flavonoid biosynthetic pathway in parallel with processes related to nucleotide, sugar and amino acid metabolism. Similarities in metabolite profiles between both lines were relatively high in roots and leaves while spikes showed higher metabolic variance within both accessions. In roots, differences between Bd21 and Bd3-1 lines were manifested primarily in diterpenoid metabolism, while differences within spikes and leaves concerned nucleotide metabolism and nitrogen management. Additionally, sulphate-containing metabolites differentiated Bd21 and Bd3-1 lines in spikes. Structural analysis based on MS fragmentation spectra enabled identification of 93 specialized metabolites. Among them phenylpropanoids and flavonoids derivatives were mainly determined. As compared with closely related barley and wheat species, metabolic profile of Brachypodium is characterized with presence of threonate derivatives of hydroxycinnamic acids.

Silicon’s Influence on Polyphenol and Flavonoid Profiles in Pea (Pisum sativum L.) under Cadmium Exposure in Hydroponics: A Study of Metabolomics, Extraction Efficacy, and Antimicrobial Properties of Extracts

“…These differences primarily stem from secondary metabolism processes, carbon accumulation during photosynthesis, phenylalanine metabolism, and amino acid metabolism. On the other hand, the observed metabolomic differences in the roots, both with and without Si supplementation, are a result of purine metabolism, amino acid metabolism, and the biosynthesis of secondary metabolites . In practical terms, this means that different plant parts respond differently to Si supplementation, affecting the types and quantities of biologically active compounds present in these parts.…”

“…On the other hand, the observed metabolomic differences in the roots, both with and without Si supplementation, are a result of purine metabolism, amino acid metabolism, and the biosynthesis of secondary metabolites. 58 In practical terms, this means that different plant parts respond differently to Si supplementation, affecting the types and quantities of biologically active compounds present in these parts. These compounds play a significant role in the plant’s functioning, its ability to adapt to changing environmental conditions, and its interactions with other organisms.…”