FT-ICR/MS and GC-EI/MS metabolomics networking unravels global potato sprout's responses to Rhizoctonia solani infection

PLoS One. 2012;7(8):e42576. doi: 10.1371/journal.pone.0042576. Epub 2012 Aug 3.

Abstract

The complexity of plant-pathogen interactions makes their dissection a challenging task for metabolomics studies. Here we are reporting on an integrated metabolomics networking approach combining gas chromatography/mass spectrometry (GC/MS) with Fourier transform ion cyclotron resonance/mass spectrometry (FT-ICR/MS) and bioinformatics analyses for the study of interactions in the potato sprout-Rhizoctonia solani pathosystem and the fluctuations in the global metabolome of sprouts. The developed bioanalytical and bioinformatics protocols provided a snapshot of the sprout's global metabolic network and its perturbations as a result of pathogen invasion. Mevalonic acid and deoxy-xylulose pathways were substantially up-regulated leading to the biosynthesis of sesquiterpene alkaloids such as the phytoalexins phytuberin, rishitin, and solavetivone, and steroidal alkaloids having solasodine and solanidine as their common aglycons. Additionally, the perturbation of the sprout's metabolism was depicted in fluctuations of the content of their amino acids pool and that of carboxylic and fatty acids. Components of the systemic acquired resistance (SAR) and hypersensitive reaction (HR) such as azelaic and oxalic acids were detected in increased levels in infected sprouts and strategies of the pathogen to overcome plant defense were proposed. Our metabolic approach has not only greatly expanded the multitude of metabolites previously reported in potato in response to pathogen invasion, but also enabled the identification of bioactive plant-derived metabolites providing valuable information that could be exploited in biotechnology, biomarker-assisted plant breeding, and crop protection for the development of new crop protection agents.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkaloids / biosynthesis
  • Amides / metabolism
  • Amino Acids / metabolism
  • Biomarkers / metabolism
  • Biosynthetic Pathways
  • Carbohydrate Metabolism
  • Cell Wall / metabolism
  • Cyclotrons
  • Discriminant Analysis
  • Fatty Acids / metabolism
  • Fourier Analysis*
  • Gas Chromatography-Mass Spectrometry / methods*
  • Hydrogen Peroxide / metabolism
  • Least-Squares Analysis
  • Metabolic Networks and Pathways*
  • Metabolome
  • Metabolomics*
  • Nucleosides / metabolism
  • Phenols / metabolism
  • Phenylacetates / metabolism
  • Plant Diseases / microbiology*
  • Plant Proteins / metabolism
  • Principal Component Analysis
  • Rhizoctonia / physiology*
  • Solanum tuberosum / metabolism*
  • Solanum tuberosum / microbiology

Substances

  • Alkaloids
  • Amides
  • Amino Acids
  • Biomarkers
  • Fatty Acids
  • Nucleosides
  • Phenols
  • Phenylacetates
  • Plant Proteins
  • Hydrogen Peroxide
  • phenylacetic acid

Grants and funding

The work has been funded by a Discovery grant from the Natural Sciences and Engineering Research Council of Canada (NSERC). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.