PRN Biologie

2012, Hiltpold, Ivan, Turlings, Ted

In most agro-ecosystems the organisms that feed on plant roots have an important impact on crop yield and can impose tremendous costs to farmers. Similar to aboveground pests, they rely on a broad range of chemical cues to locate their host plant. In their turn, plants have co-evolved a large arsenal of direct and indirect defense to face these attacks. For instance, insect herbivory induces the synthesis and release of specific volatile compounds in plants. These volatiles have been shown to be highly attractive to natural enemies of the herbivores, such as parasitoids, predators, or entomopathogenic nematodes. So far few of the key compounds mediating these so-called tritrophic interactions have been identified and only few genes and biochemical pathways responsible for the production of the emitted volatiles have been elucidated and described. Roots also exude chemicals that directly impact belowground herbivores by altering their behavior or development. Many of these compounds remain unknown, but the identification of, for instance, a key compound that triggers nematode egg hatching to some plant parasitic nematodes has great potential for application in crop protection. These advances in understanding the chemical emissions and their role in ecological signaling open novel ways to manipulate plant exudates in order to enhance their natural defense properties. The potential of this approach is discussed, and we identify several gaps in our knowledge and steps that need to be taken to arrive at ecologically sound strategies for belowground pest management.

2004, Hansson, Christer, Aebi, Alexandre, Benrey, Betty

2012, Lippold, Felix, vom Dorp, Katharina, Abraham, Marion, Hölzl, Georg, Wewer, Vera, Yilmaz, Jenny Lindberg, Lager, Ida, Montandon, Cyrille, Besagni, Celine, Kessler, Félix

2008, Erb, Matthias, Ton, Jurriaan, Degenhardt, Joerg, Turlings, Ted

2014, Sobhy, Islam S., Erb, Matthias, Turlings, Ted

Background Herbivore-damaged plants release a blend of volatile organic compounds (VOCs) that differs from undamaged plants. These induced changes are known to attract the natural enemies of the herbivores and therefore are expected to be important determinants of the effectiveness of biological control in agriculture. One way of boosting this phenomenon is the application of plant strengtheners, which has been shown to enhance parasitoid attraction in maize. It is unclear if this is also the case for other important crops. Results We applied the plant strengtheners BTH (benzo (1,2,3) thiadiazole-7-carbothioic acid S-methyl ester) or laminarin to cotton plants and studied the effects on volatile releases and the attraction of three hymenopteran parasitoids, Cotesia marginiventris, Campoletis sonorensis and Microplitis rufiventris. After treated and untreated plants were induced by real or simulated caterpillar feeding, we found that BTH treatment increased the attraction of the parasitoids, whereas laminarin had no significant effect. BTH treatment selectively increased the release of two homoterpenes and reduced the emission of indole, the latter of which has been shown to interfere with parasitoid attraction in earlier studies. Canonical variate analyses of the data show that the parasitoid responses were dependent on the quality rather than the quantity of volatile emission in this tritrophic interaction. Conclusion Overall, these results strengthen the emerging paradigm that induction of plant defences with chemical elicitors such as BTH could provide a sustainable and environment-friendly strategy for biological control of pests by enhancing the attractiveness of cultivated plants to natural enemies of insect herbivores.

2013, Besagni, Celine, Kessler, Félix

2010, Held, Matthias, D'Alessandro, Marco, Hiltpold, Ivan, Turlings, Ted

2009, Erb, Matthias, Gordon-Weeks, Ruth, Flors, Victor, Camañes, Gemma, Turlings, Ted, Ton, Jurriaan

2013, Planchamp, Chantal, Balmer, Dirk, Hund, Andreas, Mauch-Mani, Brigitte

2014, Boachon, Benoît, Gamir, Jordi, Pastor, Victoria, Erb, Matthias, Dean, John V., Flors, Victor, Mauch-Mani, Brigitte