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Turlings, Ted

Nom
Turlings, Ted
Affiliation principale
Fonction
Professeur.e ordinaire
Email
ted.turlings@unine.ch
Identifiants
https://libra.unine.ch/handle/123456789/330
_
0000-0002-8315-785X

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  • Publication
    Métadonnées seulement
    Metabolomics reveals herbivore-induced metabolites of resistance and susceptibility in maize leaves and roots
    (2013)
    Marti, Guillaume
    ;
    Erb, Matthias 
    ;
    Boccard, J.
    ;
    Glauser, Gaëtan 
    ;
    Doyen, G. R.
    ;
    Villard, Neil 
    ;
    Robert, Christelle Aurélie Maud
    ;
    Turlings, Ted 
    ;
    Rudaz, S.
    ;
    Wolfender, Jean-Luc
    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 1,3-benzoxazin-4-ones, phospholipids, N-hydroxycinnamoyltyramines, azealic acid and tryptophan. Only few changes were found in the root metabolome, but 1,3-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.
  • Publication
    Métadonnées seulement
    Genetically engineered maize plants reveal distinct costs and benefits of constitutive volatile emissions in the field
    (2013)
    Robert, Christelle Aurélie Maud
    ;
    Erb, Matthias 
    ;
    Hiltpold, Ivan 
    ;
    Hibbard, Bruce Elliott
    ;
    Gaillard, Mickaël David Philippe
    ;
    Bilat, Julia
    ;
    Degenhardt, Jörg
    ;
    Cambet-Petit-Jean, Xavier
    ;
    Turlings, Ted 
    ;
    Zwahlen, Claudia 
    Genetic manipulation of plant volatile emissions is a promising tool to enhance plant defences against herbivores. However, the potential costs associated with the manipulation of specific volatile synthase genes are unknown. Therefore, we investigated the physiological and ecological effects of transforming a maize line with a terpene synthase gene in field and laboratory assays, both above- and below ground. The transformation, which resulted in the constitutive emission of (E)--caryophyllene and -humulene, was found to compromise seed germination, plant growth and yield. These physiological costs provide a possible explanation for the inducibility of an (E)--caryophyllene-synthase gene in wild and cultivated maize. The overexpression of the terpene synthase gene did not impair plant resistance nor volatile emission. However, constitutive terpenoid emission increased plant apparency to herbivores, including adults and larvae of the above ground pest Spodoptera frugiperda, resulting in an increase in leaf damage. Although terpenoid overproducing lines were also attractive to the specialist root herbivore Diabrotica virgifera virgifera below ground, they did not suffer more root damage in the field, possibly because of the enhanced attraction of entomopathogenic nematodes. Furthermore, fewer adults of the root herbivore Diabrotica undecimpunctata howardii were found to emerge near plants that emitted (E)--caryophyllene and -humulene. Yet, overall, under the given field conditions, the costs of constitutive volatile production overshadowed its benefits. This study highlights the need for a thorough assessment of the physiological and ecological consequences of genetically engineering plant signals in the field to determine the potential of this approach for sustainable pest management strategies.
  • Publication
    Métadonnées seulement
    Induction of root-resistance by leaf-herbivory follows a vertical gradient
    (2011)
    Erb, Matthias 
    ;
    Robert, Christelle Aurélie Maud
    ;
    Turlings, Ted 
    Leaf-herbivory can lead to systemic changes in root metabolism and resistance. As yet, it is unknown if these changes affect the whole root system, or if they are more pronounced in the upper root parts, which are closer to the actual site of attack. As this spatial aspect may be an important determinant of the interactions that can be expected to occur within the rhizosphere, we investigated if leaf-herbivore induced root resistance differs between upper and lower roots of maize. We also tested if the density of leaf-herbivores correlates with intensity of the root response. The systemic increase in resistance was found to be more pronounced in the upper than the lower roots and was independent of leaf herbivore density. The results suggest that there is a vertical gradient in the strength of the root response following leaf-herbivory, and that soil organisms living closer to the surface may be more affected by leaf-attack than the ones living in deeper soil layers.
  • Publication
    Accès libre
    Sequence of arrival determines plant-mediated interactions between herbivores
    (2011)
    Erb, Matthias 
    ;
    Robert, Christelle Aurélie Maud
    ;
    Hibbard, Bruce E.
    ;
    Turlings, Ted 

    1. Induced changes in plant quality can mediate indirect interactions between herbivores. Although the sequence of attack by different herbivores has been shown to influence plant responses, little is known about how this affects the herbivores themselves.
    2. We therefore investigated how induction by the leaf herbivore Spodoptera frugiperda influences resistance of teosinte (Zea mays mexicana) and cultivated maize (Zea mays mays) against root-feeding larvae of Diabrotica virgifera virgifera. The importance of the sequence of arrival was tested in the field and laboratory.
    3. Spodoptera frugiperda infestation had a significant negative effect on colonization by D. virgifera larvae in the field and weight gain in the laboratory, but only when S. frugiperda arrived on the plant before the root herbivore. When S. frugiperda arrived after the root herbivore had established, no negative effects on larval performance were detected. Yet, adult emergence of D. virgifera was reduced even when the root feeder had established first, indicating that the negative effects were not entirely absent in this treatment.
    4. The defoliation of the plants was not a decisive factor for the negative effects on root herbivore development, as both minor and major leaf damage resulted in an increase in root resistance and the extent of biomass removal was not correlated with root-herbivore growth. We propose that leaf-herbivore-induced increases in feeding-deterrent and/or toxic secondary metabolites may account for the sequence-specific reduction in root-herbivore performance.
    5. Synthesis. Our results demonstrate that the sequence of arrival can be an important determinant of plant-mediated interactions between insect herbivores in both wild and cultivated plants. Arriving early on a plant may be an important strategy of insects to avoid competition with other herbivores. To fully understand plant-mediated interactions between insect herbivores, the sequence of arrival should be taken into account.