Granger causality in integrated GC-MS and LC-MS metabolomics data reveals the interface of primary and secondary metabolism

Author(s)
Hannes Doerfler, David Lyon, Thomas Nägele, Xiaoliang Sun, Lena Fragner, Franz Hadacek, Volker Egelhofer, Wolfram Weckwerth
Abstract

Metabolomics has emerged as a key technique of modern life sciences in recent years. Two major techniques for metabolomics in the last 10 years are gas chromatography coupled to mass spectrometry (GC-MS) and liquid chromatography coupled to mass spectrometry (LC-MS). Each platform has a specific performance detecting subsets of metabolites. GC-MS in combination with derivatisation has a preference for small polar metabolites covering primary metabolism. In contrast, reversed phase LC-MS covers large hydrophobic metabolites predominant in secondary metabolism. Here, we present an integrative metabolomics platform providing a mean to reveal the interaction of primary and secondary metabolism in plants and other organisms. The strategy combines GC-MS and LC-MS analysis of the same sample, a novel alignment tool MetMAX and a statistical toolbox COVAIN for data integration and linkage of Granger Causality with metabolic modelling. For metabolic modelling we have implemented the combined GC-LC-MS metabolomics data covariance matrix and a stoichiometric matrix of the underlying biochemical reaction network. The changes in biochemical regulation are expressed as differential Jacobian matrices. Applying the Granger causality, a subset of secondary metabolites was detected with significant correlations to primary metabolites such as sugars and amino acids. These metabolic subsets were compiled into a stoichiometric matrix N. Using N the inverse calculation of a differential Jacobian J from metabolomics data was possible. Key points of regulation at the interface of primary and secondary metabolism were identified.

Organisation(s)
Journal
Metabolomics
Volume
9
Pages
564-574
No. of pages
11
ISSN
1573-3882
DOI
https://doi.org/10.1007/s11306-012-0470-0
Publication date
06-2013
Peer reviewed
Yes
Austrian Fields of Science 2012
106002 Biochemistry, 106007 Biostatistics, 106031 Plant physiology, 1040 Chemistry
Portal url
https://ucris.univie.ac.at/portal/en/publications/granger-causality-in-integrated-gcms-and-lcms-metabolomics-data-reveals-the-interface-of-primary-and-secondary-metabolism(0787d72a-ebf6-40ec-a70a-1d5a653d4a0f).html