Biology subjects

Turlings, T.

Publications and source records attributed to Turlings, T..

6 recordsLinked to original sources

bioRxiv2026

Exposure to herbivore-induced plant volatiles directly induces jasmonic acid and primes chemical defences in cotton plants

Plants can deploy alternative defensive strategies in response to airborne signals from damaged neighbours to prepare for incoming attack: a straightaway response up-regulating their defences (induction), or a primed state, leading to a faster/stronger defence response after herbivory. However, it is unclear which mechanisms are involved in each response. We used a monophagous and a polyphagous leafworm species to specifically dissect induction and priming effects of exposure to herbivore-induced plant volatiles (HIPVs). Exposure to HIPVs directly elevated jasmonate levels in undamaged receivers but did not induce defensive terpenoids or volatiles. However, HIPV-primed plants accumulated high levels of toxic terpenoids (e.g. gossypol) and emitted high quantities of volatile sesquiterpenes, when damaged by either species of caterpillars. This comprehensive study demonstrates that both defence induction and priming can be detected in cotton but occur as different, linked responses which are robust to herbivore identity, providing insights into a generalised plant communication strategy.

ecology↗

bioRxiv2024

Odor-based real-time detection and identification of pests and diseases attacking crop plants

Early detection of crop pests and diseases can enable timely, targeted interventions, and help reduce pesticide use. Plants under biotic stress are known to rapidly emit characteristic blends of volatile compounds that could potentially serve as early and attacker-specific cues for precise pest monitoring. Here, we evaluated the feasibility of this approach using two complementary, state-of-the-art sensing technologies: a handheld nanomechanical membrane-based sensor array and chemical ionization time-of-flight mass spectrometry. Under laboratory conditions, with enclosed headspace sampling, both technologies readily distinguished undamaged maize plants from plants infested by caterpillars or infected with a fungal pathogen. Under semi-controlled outdoor open-air conditions, where volatile concentrations were strongly diluted, the membrane-based sensor no longer retained discriminatory power, whereas mass spectrometry predicted herbivory status with more than 90% accuracy using one-second measurements. Finally, in an initial field trial based on simulated herbivory, a compact, field-deployable, real-time mass spectrometer distinguished damaged from undamaged maize plants with highly encouraging performance under real field conditions. Together, these results demonstrate the potential of odor-based detection of pest attacks in maize and identify real-time mass spectrometry as a promising tool for crop monitoring, while pinpointing challenges that remain to be addressed for translation to practical field applications.

plant biology↗

bioRxiv2024

Induction by caterpillars of stored and emitted volatiles among populations of wild cotton (Gossypium hirsutum)

BackgroundUpland cotton (Gossypium hirsutum) plants constitutively store volatile terpenes in their leaves, which are steadily emitted at low levels. Herbivory leads to a greater release of these stored volatiles. Additionally, damaged plants increase the accumulation of volatile terpenes in their leaves and begin to emit other terpenes and additional compounds. This has been well characterised for cultivated G. hirsutum, but little is known about volatile production in response to herbivory in wild populations. We investigated how damage by the beet armyworm (Spodoptera exigua) affects leaf-stored and emitted volatiles in wild G. hirsutum plants. These plants were grown in a greenhouse using seeds collected from populations found along the Yucatan coast, from where this cotton species originates. We assessed whether the differences in leaf terpene profiles between two known chemotypes persisted upon herbivory, in leaves and in head-space emissions, and whether these chemotypes also differed in the production and release of herbivory-induced volatiles. In addition to chemotypic variation, we further investigated intraspecific variation in the volatile response to herbivory among genotypes, populations, and four geographic regions. ResultsThe difference between the two chemotypes persisted after herbivory in the stored volatile profile of induced leaves, as well in the emissions from damaged plants. Therefore, wild cotton chemotypes may differ in their airborne interactions with their environment. The specific terpenes distinguishing these chemotypes showed a weak inducibility, raising questions about their functions. Herbivory triggered changes in stored and emitted volatiles similar to what is known for cultivated varieties of G. hirsutum. However, we report for the first time on the emission of volatile aldoximes by cotton plants, which were only detected in the headspace upon herbivory, and displayed chemotypic and interpopulation variation. Intraspecific variation was also observed in the induced emissions of nitriles and certain terpenes. Moreover, chemotypes differed in their induction of (E)-{beta}-ocimene stored in the leaves. ConclusionsThis comprehensive insight into herbivore-induced volatiles of wild cotton reveals variation in production and emission among populations. A full understanding of their ecological role may help in the development of future pest-management strategies for cotton crops.

plant biology↗

bioRxiv2024

Field evidence for the role of plant volatiles induced by caterpillar-derived elicitors in the prey location behavior of predatory social wasps

O_LIOne assumed function of herbivore-induced plant volatiles (HIPVs) is to attract natural enemies of the inducing herbivores. Field evidence for this is scarce and often indirect. Also, the assumption that elicitors in insect oral secretions that trigger the volatile emissions are essential for attraction of natural enemies has not yet been demonstrated under field conditions. C_LIO_LIAfter observing social wasps removing caterpillars from maize plants in an agricultural field, we hypothesized that these wasps use HIPVs to locate their prey. To test this, we conducted an experiment that simultaneously explored the importance of caterpillar oral secretions in the interaction. C_LIO_LIWe found that Spodoptera caterpillars placed on mechanically damaged plants treated with oral secretion were more likely to be attacked by wasps compared to caterpillars on plants that were only mechanically wounded. Both of the the latter treatments were considerably more attractive than plants that were only treated with oral secretion or left untreated. Subsequent analyses of headspace volatiles confirmed differences in emitted volatiles that likely account for the differential predation events across the treatments. C_LIO_LIThese findings highlight the importance of HIPVs in prey location by social wasps and provide evidence for the role that elicitors play in inducing attractive odor blends. C_LI

ecology↗

bioRxiv2018

Can herbivore-induced volatiles protect plants by increasing the herbivores’ susceptibility to natural pathogens?

In response to insect herbivory, plants mobilize various defenses. Defense responses include the release of herbivore-induced plant volatiles (HIPVs) that can serve as signals to alert undamaged tissues and to attract natural enemies of the herbivores. It has also been shown that some HIPVs can have a direct negative impact on herbivore survival, but it is not yet understood by what mechanism. Here we tested the hypothesis that exposure to HIPVs renders insects more susceptible to natural pathogens. Exposing caterpillars of the noctuid Spodoptera exigua to indole and linalool, but not exposure to (Z)-3-hexenyl acetate increased the susceptibility to its nucleopolyhedrovirus (SeMNPV). We also found that exposure to indole, but not exposure to linalool or (Z)-3-hexenyl acetate, increased the pathogenicity of Bacillus thuringiensis. Additional experiments revealed significant changes on gut microbiota composition after forty-eight hours of larval exposure to indole. Overall, these results provide evidences that certain HIPVs can strongly enhance the susceptibility of caterpillars to pathogens, possibly through effects on the insects gut microbiota. These findings suggest a novel mechanism by which HIPVs can protect plants from herbivorous insects.

microbiology↗

bioRxiv2017

Genotype, nitrogen and herbivory shape plant defense: the case of a vitamin-enriched maize

The cultivation of crops with novel traits could interfere with ecosystem services delivered by arthropods through bottom-up effects. Here we tested the hypothesis that a vitamin enriched maize (CarolightR) is similar in terms of plant-arthropod interactions to its wild type when compared in controlled environment and under field conditions. In order to assess the robustness of their equivalence we tested two nitrogen availability regimes. We used arthropod field abundance, the behavior and fitness of a keystone maize herbivore - the leafhopper Zyginidia scutellaris - and above ground chemistry of maize plants (volatile, hormone and metabolite profiling) as indicators of potential changes in plant-insect interactions. Nitrogen availability was the key driver of herbivore abundance and behavior, and determined direct and indirect chemical defense in maize plants. Both genotypes presented similar constitutive and inducible phytohormone profiles independently of the nitrogen regime. However, feeding by the herbivore suppressed the levels of JA-Ile and JA, without impairing the release of induced plant volatiles. CarolightR and M37W differed to some degree in the concentrations of phenolics (hydroxycinnamic acids and lignans) and in the abundance of a volatile compound. Overall the effect of maize genotype on the herbivores was smaller than the effect of nitrogen fertilization.\n\nHIGHLIGHTWe show the separate and interactive effects of nitrogen availability and genotype on the performance and behavior of a herbivore, and related these changes to constitutive and inducible maize defenses.

plant biology↗