1. Metabolomics reveals herbivore-induced metabolites of resistance and susceptibility in maize leaves and roots
- Author
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Marti G, Erb M, Boccard J, Glauser G, Doyen GA, Villard N, Turlings TCJ, Rudaz S, and Wolfender JL
- Abstract
Plants respond to herbivory by reprogramming their metabolism. Most research in this context has focused on locally induced compounds that function as toxins or feeding deterrents. We developed an ultra high pressure liquid chromatography time of flight mass spectrometry (UHPLC TOF MS) based metabolomics approach to evaluate local and systemic herbivore induced changes in maize leaves sap roots and root exudates without any prior assumptions about their function. Thirty two differentially regulated compounds were identified from Spodoptera littoralis infested maize seedlings and isolated for structure assignment by microflow nuclear magnetic resonance (CapNMR). Nine compounds were quantified by a high throughput direct nano infusion tandem mass spectrometry/mass spectrometry (MS/MS) method. Leaf infestation led to a marked local increase of 13 benzoxazin 4 ones phospholipids N hydroxycinnamoyltyramines azealic acid and tryptophan. Only few changes were found in the root metabolome but 13 benzoxazin 4 ones increased in the vascular sap and root exudates. The role of N hydroxycinnamoyltyramines in plantherbivore interactions is unknown and we therefore tested the effect of the dominating p coumaroyltyramine on S. littoralis. Unexpectedly p coumaroyltyramine was metabolized by the larvae and increased larval growth possibly by providing additional nitrogen to the insect. Taken together this study illustrates that herbivore attack leads to the induction of metabolites that can have contrasting effects on herbivore resistance in the leaves and roots.
- Published
- 2013
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