mzGroupAnalyzer-Predicting Pathways and Novel Chemical Structures from Untargeted High-Throughput Metabolomics Data

Author(s)
Hannes Doerfler, Xiaoliang Sun, Lei Wang, Doris Engelmeier, David Lyon, Wolfram Weckwerth
Abstract

The metabolome is a highly dynamic entity and the final readout of the genotype x environment x phenotype (GxExP) relationship of an organism. Monitoring metabolite dynamics over time thus theoretically encrypts the whole range of possible chemical and biochemical transformations of small molecules involved in metabolism. The bottleneck is, however, the sheer number of unidentified structures in these samples. This represents the next challenge for metabolomics technology and is comparable with genome sequencing 30 years ago. At the same time it is impossible to handle the amount of data involved in a metabolomics analysis manually. Algorithms are therefore imperative to allow for automated m/z feature extraction and subsequent structure or pathway assignment. Here we provide an automated pathway inference strategy comprising measurements of metabolome time series using LC- MS with high resolution and high mass accuracy. An algorithm was developed, called mzGroupAnalyzer, to automatically explore the metabolome for the detection of metabolite transformations caused by biochemical or chemical modifications. Pathways are extracted directly from the data and putative novel structures can be identified. The detected m/z features can be mapped on a van Krevelen diagram according to their H/C and O/C ratios for pattern recognition and to visualize oxidative processes and biochemical transformations. This method was applied to Arabidopsis thaliana treated simultaneously with cold and high light. Due to a protective antioxidant response the plants turn from green to purple color via the accumulation of flavonoid structures. The detection of potential biochemical pathways resulted in 15 putatively new compounds involved in the flavonoid-pathway. These compounds were further validated by product ion spectra from the same data. The mzGroupAnalyzer is implemented in the graphical user interface (GUI) of the metabolomics toolbox COVAIN (Sun & Weckwerth, 2012, Metabolomics 8: 81–93). The strategy can be extended to any biological system.

Organisation(s)
External organisation(s)
Universität Wien
Journal
PLoS ONE
Volume
9
No. of pages
11
ISSN
1932-6203
DOI
https://doi.org/10.1371/journal.pone.0096188
Publication date
05-2014
Peer reviewed
Yes
Austrian Fields of Science 2012
106002 Biochemistry, 106014 Genomics, 104002 Analytical chemistry, 106044 Systems biology
Keywords
ASJC Scopus subject areas
Agricultural and Biological Sciences(all), General, Biochemistry, Genetics and Molecular Biology(all)
Portal url
https://ucris.univie.ac.at/portal/en/publications/mzgroupanalyzerpredicting-pathways-and-novel-chemical-structures-from-untargeted-highthroughput-metabolomics-data(34431e71-820e-4f9f-9b9c-3545750d7de4).html