5 research outputs found
Tracing Hidden Herbivores: Time-Resolved Non-Invasive Analysis of Belowground Volatiles by Proton-Transfer-Reaction Mass Spectrometry (PTR-MS)
Root herbivores are notoriously difficult to study, as they feed hidden in the soil. However, root herbivores may be traced by analyzing specific volatile organic compounds (VOCs) that are produced by damaged roots. These VOCs not only support parasitoids in the localization of their host, but also may help scientists study belowground plant-herbivore interactions. Herbivore-induced VOCs are usually analyzed by gas-chromatography mass spectrometry (GC-MS), but with this off-line method, the gases of interest need to be preconcentrated, and destructive sampling is required to assess the level of damage to the roots. In contrast to this, proton-transfer-reaction mass spectrometry (PTR-MS) is a very sensitive on-line, non-invasive method. PTR-MS already has been successfully applied to analyze VOCs produced by aboveground (infested) plant parts. In this review, we provide a brief overview of PTR-MS and illustrate how this technology can be applied to detect specific root-herbivore induced VOCs from Brassica plants. We also specify the advantages and disadvantages of PTR-MS analyses and new technological developments to overcome their limitations
Identification of Volatile Markers in Potato Brown Rot and Ring Rot by Combined GC-MS and PTR-MS Techniques: Study on in Vitro and in Vivo Samples
Ralstonia solanacearum (Rs) and Clavibacter michiganensis subsp. <i>sepedonicus</i> (Cms) are the bacterial causal
agents of potato brown and ring rot,
respectively, and are included in the A2 list of quarantine pathogens
in Europe. Identification by GC-MS analysis of volatile organic compounds
from Rs or Cms cultured on different nutrient media was performed.
GC-MS and PTR-MS analysis were carried out also on unwounded potato
tubers infected with the same pathogens. Infected tubers were produced
by experimental inoculations of the plants. In in vitro experiments,
Rs or Cms emitted volatile compounds, part of which were specific
disease markers of potato (2-propanol and 3-methylbutanoic acid),
mainly originating from bacterial metabolism (i.e., amino acid degradation,
carbohydrate and fatty acid oxidation). In potato tubers, pathogen
metabolism modified the volatile compound pattern emitted from healthy
samples. Both bacteria seem to accelerate metabolic processes ongoing
in potatoes and, in the case of Rs, disease markers (1-hepten-3-ol,
3,6-dimethyl-3-octanone, 3-ethyl-3-methylpentane, 1-chloroctane, and
benzothiazole) were identified
Real-time analysis of sulfur-containing volatiles in brassica plants infested with root-feeding delia radicum larvae using proton-transfer reaction mass spectrometry
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