DFG Plant Metabolome Analysis

Source: EUS

The plant metabolome is composed of thousands of small molecules and represents the final metabolic chemotype (‘metabotype’) of plants which arises from gene expression, modulation of protein function(s) and the influence of environmental factors. The tremendous progress in the high-throughput analysis of genes and proteins as well as in the targeted (LC-MS and GC-MS) and untargeted (Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS)) paves the way to describe plant behaviour (genotype (G) x environment (E) interactions) in a holistic and comprehensive way.

The project ‘Linking Populus nigra metabotypes to genetic variation and plant-herbivore interactions’ is part of the DFG Research Unit FOR3000 ‘Ecology and Evolution of Intraspecific Chemodiversity of Plants’ which started in April 2020.

It is well known that trees such as the black poplar, Populus nigra, have an immense variety of specialised metabolites and a very diverse species-rich arthropod fauna. Thus, this species is ideally suited for analyzing the importance of intraspecific plant chemodiversity for the interactions between plants and herbivores. Furthermore, the available genetic resources for poplars together with modern methods of metabolomics pave the way for linking genetic variability with the expression of metabolic pathways and intraspecific chemodiversity relevant for biotic interactions. In plants, more than 70% of the metabolomic data cannot yet be used for a deeper systems biological interpretation as the knowledge of chemical structures and biochemical pathways is still insufficient. The mass difference network analysis (MDiN) is a new strategy for the evaluation of mass spectrometric metabolomics data which includes all exact mass characteristics with known sum formulas in the data evaluation and interpretation. Within FOR3000 we are investigating the differences between black poplar genotypes in the leaf emissions of volatile organic compounds (VOCs) induced by herbivores and their links to the constitutively expressed metabolome by means of mass difference enrichment analysis (MDEA). The experiments are performed under controlled conditions in climate chambers in a multi-cuvette phenotyping system which enables the recording of the entire plant gas exchange in high temporal resolution. In collaboration with FOR3000 partners we are also investigating how constitutive and herbivore-induced metabolomic networks are linked to changes in gene expression and genetic variation. Overall, our metabolic and molecular biological data will contribute to the development of virtual plants and to the improvement of chemodiversity indices as well as help to functionally analyse the importance of intraspecific plant chemodiversity. The project runs jointly with the Research Unit Biogeochemistry (BGC).

Selected Publications

Kaling et al. (2018) : Mycorrhiza-triggered transcriptomic and metabolomic networks impinge on herbivore fitness. Plant Physiology 176: 2639-2656

Moritz F, Kaling M, Schnitzler JP, Schmitt-Kopplin P (2017): Characterization of poplar metabotypes via mass difference enrichment analysis. Plant, Cell & Environment 40: 1057-1073 .

Kaling et al. (2015): UV-B mediated metabolic rearrangements in poplar revealed by non-targeted metabolomics. Plant, Cell & Environment 38: 892-904 .