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Erb, Matthias

Nom
Erb, Matthias
Affiliation principale
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https://libra.unine.ch/handle/123456789/606

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  • Publication
    Métadonnées seulement
    The maize lipoxygenase, ZmLOX10, mediates green leaf volatile, jasmonate and herbivore-induced plant volatile production for defense against insect attack
    (2013)
    Christensen, S. A.
    ;
    Nemchenko, A.
    ;
    Borrego, E.
    ;
    Murray, I.
    ;
    Sobhy, I. S.
    ;
    Bosak, L.
    ;
    DeBlasio, S.
    ;
    Erb, Matthias 
    ;
    Robert, Christelle Aurélie Maud
    ;
    Vaughn, K. A.
    ;
    Herrfurth, C.
    ;
    Tumlinson, James
    ;
    Feussner, I.
    ;
    Jackson, D.
    ;
    Turlings, Ted 
    ;
    Engelberth, J.
    ;
    Nansen, C.
    ;
    Meeley, R.
    ;
    Kolomiets, M. V.
    Fatty acid derivatives are of central importance for plant immunity against insect herbivores; however, major regulatory genes and the signals that modulate these defense metabolites are vastly understudied, especially in important agro-economic monocot species. Here we show that products and signals derived from a single Zea mays (maize) lipoxygenase (LOX), ZmLOX10, are critical for both direct and indirect defenses to herbivory. We provide genetic evidence that two 13-LOXs, ZmLOX10 and ZmLOX8, specialize in providing substrate for the green leaf volatile (GLV) and jasmonate (JA) biosynthesis pathways, respectively. Supporting the specialization of these LOX isoforms, LOX8 and LOX10 are localized to two distinct cellular compartments, indicating that the JA and GLV biosynthesis pathways are physically separated in maize. Reduced expression of JA biosynthesis genes and diminished levels of JA in lox10 mutants indicate that LOX10-derived signaling is required for LOX8-mediated JA. The possible role of GLVs in JA signaling is supported by their ability to partially restore wound-induced JA levels in lox10 mutants. The impaired ability of lox10 mutants to produce GLVs and JA led to dramatic reductions in herbivore-induced plant volatiles (HIPVs) and attractiveness to parasitoid wasps. Because LOX10 is under circadian rhythm regulation, this study provides a mechanistic link to the diurnal regulation of GLVs and HIPVs. GLV-, JA- and HIPV-deficient lox10 mutants display compromised resistance to insect feeding, both under laboratory and field conditions, which is strong evidence that LOX10-dependent metabolites confer immunity against insect attack. Hence, this comprehensive gene to agro-ecosystem study reveals the broad implications of a single LOX isoform in herbivore defense.
  • 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.