Vignette d'image

Zwahlen, Claudia

Nom
Zwahlen, Claudia
Affiliation principale
Identifiants
https://libra.unine.ch/handle/123456789/315

Résultat de la recherche

Filtres

221
11
2
Réinitialiser les filtres

Paramètres

Voici les éléments 1 - 2 sur 2
  • Publication
    Métadonnées seulement
    Herbivore-induced plant volatiles mediate host selection by a root herbivore
    (2012)
    Robert, Christelle Aurélie Maud
    ;
    Erb, Matthias 
    ;
    Duployer, M.
    ;
    Zwahlen, Claudia 
    ;
    Doyen, G. R.
    ;
    Turlings, Ted 
    In response to herbivore attack, plants mobilize chemical defenses and release distinct bouquets of volatiles. Aboveground herbivores are known to use changes in leaf volatile patterns to make foraging decisions, but it remains unclear whether belowground herbivores also use volatiles to select suitable host plants. We therefore investigated how above- and belowground infestation affects the performance of the root feeder Diabrotica virgifera virgifera, and whether the larvae of this specialized beetle are able to use volatile cues to assess from a distance whether a potential host plant is already under herbivore attack. Diabrotica virgifera larvae showed stronger growth on roots previously attacked by conspecific larvae, but performed more poorly on roots of plants whose leaves had been attacked by larvae of the moth Spodoptera littoralis. Fittingly, D similar to virgifera larvae were attracted to plants that were infested with conspecifics, whereas they avoided plants that were attacked by S similar to littoralis. We identified (E)-beta-caryophyllene, which is induced by D similar to virgifera, and ethylene, which is suppressed by S similar to littoralis, as two signals used by D similar to virgifera larvae to locate plants that are most suitable for their development. Our study demonstrates that soil-dwelling insects can use herbivore-induced changes in root volatile emissions to identify suitable host plants.
  • Publication
    Accès libre
    Synergies and trade-offs between insect and pathogen resistance in maize leaves and roots
    (2011)
    Erb, Matthias 
    ;
    Balmer, Yves
    ;
    de Lange, Elvira S.
    ;
    von Merey, Georg
    ;
    Planchamp, Chantal 
    ;
    Robert, Christelle Aurélie Maud
    ;
    Röder, Gregory 
    ;
    Sobhy, Islam
    ;
    Zwahlen, Claudia 
    ;
    Mauch-Mani, Brigitte 
    ;
    Turlings, Ted 
    Determining links between plant defence strategies is important to understand plant evolution and to optimize crop breeding strategies. Although several examples of synergies and trade-offs between defence traits are known for plants that are under attack by multiple organisms, few studies have attempted to measure correlations of defensive strategies using specific single attackers. Such links are hard to detect in natural populations because they are inherently confounded by the evolutionary history of different ecotypes. We therefore used a range of 20 maize inbred lines with considerable differences in resistance traits to determine if correlations exist between leaf and root resistance against pathogens and insects. Aboveground resistance against insects was positively correlated with the plant's capacity to produce volatiles in response to insect attack. Resistance to herbivores and resistance to a pathogen, on the other hand, were negatively correlated. Our results also give first insights into the intraspecific variability of root volatiles release in maize and its positive correlation with leaf volatile production. We show that the breeding history of the different genotypes (dent versus flint) has influenced several defensive parameters. Taken together, our study demonstrates the importance of genetically determined synergies and trade-offs for plant resistance against insects and pathogens.