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Turlings, Ted
Nom
Turlings, Ted
Affiliation principale
Fonction
Professeur.e ordinaire
Email
ted.turlings@unine.ch
Identifiants
Résultat de la recherche
Voici les éléments 1 - 4 sur 4
- PublicationRestriction temporaireFrom cotton to odor sensors: unraveling the dynamics, specificity, and exploitability of herbivore-induced plant volatilesLes plantes émettent des odeurs constituées de divers composés volatils pour interagir avec les organismes de leur environnement. Parmi eux, les composés volatils induits par l’herbivorie jouent un rôle clé dans la défense des plantes contre les insectes phytophages. Ces composés interviennent en modulant les interactions avec les herbivores eux-mêmes, leurs ennemis naturels ou encore avec les plantes voisines. À ce titre, les composés volatils produits par les plantes cultivées représentent un levier prometteur pour le développement de stratégies de lutte durable contre les ravageurs. Cette thèse explore différents aspects de la production de composés volatils chez le cotonnier (Gossypium hirsutum) en réponse aux attaques d’insectes herbivores, et examine leur potentiel pour la détection précoce et précise des ravageurs dans les cultures, en utilisant le maïs comme plante modèle. Le premier chapitre s'intéresse à la spécificité de l’accumulation de composés stockés dans les glandes du cotonnier suite à des dommages. Les deuxième et troisième chapitres portent sur la caractérisation des réponses volatiles de cotonniers sauvages originaires du Yucatán, cousins des variétés domestiquées. Ces travaux ont été menés d'abord en conditions contrôlées en laboratoire avec de jeunes plants cultivés en serre, puis dans l’environnement naturel des cotonniers, avec des plantes matures. Le quatrième chapitre examine la réponse volatile du cotonnier à Bucculatrix thurberiella, un insecte spécialiste. Ensemble, ces chapitres fournissent un éclairage nouveau sur la dynamique et la spécificité des volatiles chez le cotonnier. Enfin, le dernier chapitre adopte une approche plus appliquée en évaluant le potentiel de technologies existantes de détection d’odeurs pour identifier la présence de ravageurs dans les champs agricoles. ABSTRACT Plants emit odors composed of diverse volatile compounds that serve as signals to interact with surrounding organisms. Among these, herbivore-induced plant volatiles (HIPVs) play a central role in plant defense by mediating interactions with herbivores, their natural enemies, and neighboring plants. As such, HIPVs produced by crop plants represent a promising avenue for sustainable pest management. This thesis investigates multiple aspects of HIPV production in cotton (Gossypium hirsutum) in response to herbivory and explores how these volatiles could be harnessed for the early and accurate detection of pests in agricultural fields, using maize as a model system. The first chapter examines the specificity of damage-induced accumulation of compounds stored in the glandular structures of cotton plants. Chapters two and three focus on characterizing the volatile responses of wild cotton populations from Yucatán, relatives of domesticated varieties. These studies were first conducted under controlled conditions in the laboratory with greenhouse-grown seedlings, and subsequently in the plants’ natural environment, with mature plants. The fourth chapter investigates the HIPV response of cotton to the specialist herbivore Bucculatrix thurberiella. Together, these chapters provide new insights into the dynamics and specificity of HIPV in cotton. The final chapter adopts a more applied perspective, assessing whether existing odor-sensing technologies may be used to detect pest presence in crops.
- PublicationAccès libreBelowground and aboveground herbivory differentially affect the transcriptome in roots and shoots of maize(2022-7-22)
; ; ; ; Plants recognize and respond to feeding by herbivorous insects by upregulating their local and systemic defenses. While defense induction by aboveground herbivores has been well studied, far less is known about local and systemic defense responses against attacks by belowground herbivores. Here, we investigated and compared the responses of the maize transcriptome to belowground and aboveground mechanical damage and infestation by two well-adapted herbivores: the soil-dwelling western corn rootworm Diabrotica virgifera virgifera (Coleoptera: Chrysomelidae) and the leaf- chewing fall armyworm Spodoptera frugiperda (Lepidoptera: Noctuidae). In responses to both herbivores, maize plants were found to alter local transcription of genes involved in phytohormone signaling, primary and secondary metabolism. Induction by real herbivore damage was considerably stronger and modified the expression of more genes than mechanical damage. Feeding by the corn rootworm had a strong impact on the shoot transcriptome, including the activation of genes involved in defense and development. By contrast, feeding by the fall armyworm induced only few transcriptional changes in the roots. In conclusion, feeding by a leaf chewer and a root feeder differentially affects the local and systemic defense of maize plants. Besides revealing clear differences in how maize plants respond to feeding by these specialized herbivores, this study reveals several novel genes that may play key roles in plant–insect interactions and thus sets the stage for in depth research into the mechanism that can be exploited for improved crop protection. - PublicationAccès libreRestoring a maize root signal that attracts insect-killing nematodes to control a major pest(2009)
; - PublicationAccès libreHerbivore-induced emissions of maize volatiles repel the corn leaf aphid, shape Rhopalosiphum maidis(1998)
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In a Y-tube olfactometer significantly more aphids chose the odour of healthy, undamaged maize seedlings when tested against clean air or plants treated with regurgitant. Clean air was chosen more often when tested next to the odour of treated plants. This apparently repellent effect of the odour of treated plants was significant for winged aphids, but not for the wingless aphids.
In field experiments aphids were released in the centre of circles of eight potted maize plants. Four plants in each circle were damaged and treated with caterpillar regurgitant while the other plants were left unharmed. At different intervals after aphid release, the number of aphids was counted on each plant. Significantly fewer winged and wingless aphids were found back on treated plants than on healthy plants.
We suggest that herbivores may be repelled by the odours because they could indicate that: 1) the plant has initiated the production of toxic compounds; 2) potential competitors are present on the plant; 3) the plant is attractive to parasitoids and predators. Aphids may be particularly sensitive to induced maize volatiles because one of the major compounds emitted by the plant is (E)-β-farnesene, which is a common alarm pheromone for aphids. Collections and analyses of the odours emitted by crushed R. maidis confirmed that it too emits (E)-β-farnesene when stressed. The results are discussed in context of plant defence strategies and their possible exploitation for the control of pest insects.