Article

Real-time monitoring of herbivore induced volatile emissions in the field

Ionicon Analytik GmbH, Technikerstrasse 21a, 6020 Innsbruck, Austria.
Physiologia Plantarum (Impact Factor: 3.14). 11/2009; 138(2):123-33. DOI: 10.1111/j.1399-3054.2009.01322.x
Source: PubMed

ABSTRACT

When plants are damaged by herbivorous insects they emit a blend of volatile organic compounds (VOCs) which include a range or terpenoids and green leaf volatiles (GLVs) formed via different metabolic pathways. The precise timing of these emissions upon the onset of herbivore feeding has not been fully elucidated, and the information that is available has been mainly obtained through laboratory based studies. We investigated emissions of VOCs from Populus tremula L. xP. tremuloides Michx. during the first 20 h of feeding by Epirrita autumnata (autumnal moth) larvae in a field site. The study was conducted using Proton Transfer Reaction-Mass Spectrometry (PTR-MS) to measure emissions online, with samples collected for subsequent analysis by complementary gas chromatography-mass spectrometry for purposes of compound identification. GLV emission peaks occurred sporadically from the outset, indicating herbivore activity, while terpene emissions were induced within 16 h. We present data detailing the patterns of monoterpene (MT), GLV and sesquiterpene (SQT) emissions during the early stages of herbivore feeding showing diurnal MT and SQT emission that is correlated more with temperature than light. Peculiarities in the timing of SQT emissions prompted us to conduct a thorough characterization of the equipment used to collect VOCs and thus corroborate the accuracy of results. A laboratory based analysis of the throughput of known GLV, MT and SQT standards at different temperatures was made with PTR-MS. Enclosure temperatures of 12, 20 and 25 degrees C had little influence on the response time for dynamic measurements of a GLV or MT. However, there was a clear effect on SQT measurements. Elucidation of emission patterns in real-time is dependent upon the dynamics of cuvettes at different temperatures.

Download full-text

Full-text

Available from: Jarmo K Holopainen, Feb 18, 2014
  • Source
    • "(2) Do different leaf wounding methods change the composition of emitted BVOCs? We used a proton­transfer­reaction time­of­flight mass spectrometer (PTR­ TOF­MS), making it possible to track the entire suite of BVOCs emitted in real­time (Brilli et al. 2011 ; Schaub et al. 2010 ), which is especially relevant for tracing plant responses to rapidly occurring stresses such as wounding. This particular instrument goes one step beyond its quadrupole­based predecessor because it instantaneously samples all the emitted masses, and can identify different compounds within a given nominal mass, sorting out the signal of single compounds in multi peaked­shaped spectra (Brilli et al. 2011 ; Portillo­Estrada 2013 ). "
    [Show abstract] [Hide abstract]
    ABSTRACT: Plant-feeding herbivores can generate complex patterns of foliar wounding, but it is unclear how wounding-elicited volatile emissions scale with the severity of different wounding types, and there is no common protocol for wounding experiments. We investigated the rapid initial response to wounding damage generated by different numbers of straight cuts and punctures through leaf lamina as well as varying area of lamina squeezing in the temperate deciduous tree Populus tremula. Wounding-induced volatile emission time-courses were continuously recorded by a proton-transfer-reaction time-of-flight mass-spectrometer. After the mechanical wounding, an emission cascade was rapidly elicited resulting in sequential emissions of key stress volatiles methanol, acetaldehyde, and volatiles of the lipoxygenase pathway, collectively constituting more than 97% of the total emission. The maximum emission rates, reached after one to three minutes after wounding, and integrated emissions during the burst were strongly correlated with the severity in all damage treatments. For straight cuts and punch hole treatments, the emissions per cut edge length were constant, indicating a direct proportionality. Our results are useful for screening wounding-dependent emission capacities.
    Full-text · Article · Oct 2015 · Journal of Chemical Ecology
  • Source
    • "Furthermore, the type of mechanical damage (cut, punctured or scraped) had relatively little effect on the VOC profiles, albeit cut leaves generally emitted fewer VOCs than punctured or scraped leaves. There are few studies regarding the duration of the change in VOC emissions of damaged plants (Turlings et al., 1998; Schaub et al., 2010). VOC emission is thought to occur during one of three time scales, depending on the synthetic pathway utilized and whether the compounds are stored in plant structures (Baldwin, 1994). "

    Full-text · Dataset · Sep 2015
  • Source
    • "Furthermore, the type of mechanical damage (cut, punctured or scraped) had relatively little effect on the VOC profiles, albeit cut leaves generally emitted fewer VOCs than punctured or scraped leaves. There are few studies regarding the duration of the change in VOC emissions of damaged plants (Turlings et al., 1998; Schaub et al., 2010). VOC emission is thought to occur during one of three time scales, depending on the synthetic pathway utilized and whether the compounds are stored in plant structures (Baldwin, 1994). "
    [Show abstract] [Hide abstract]
    ABSTRACT: Classical biological control of invasive alien weeds depends on the use of arthropod herbivores that are sufficiently host specific to avoid risk of injuring nontarget plants. Host plant specificity is usually evaluated by using a combination of behavioral and developmental experiments under choice, no-choice and field conditions. Secondary plant compounds are likely to have an important influence on host plant specificity. However, relatively little is known about the volatile organic compounds (VOCs) that are emitted by target and nontarget plants, and how environmental conditions may affect their emission. Previous studies have shown that mechanical damage of leaves increases the composition and content of VOCs emitted. In this study we measured the VOC emissions of five species of plants in the subtribe Centaureinae (Asteraceae) – Carthamus tinctorius, Centaurea cineraria, Centaurea melitensis, Centaurea rothrockii, and Centaurea solstitialis – that have previously been used in host specificity experiments for a prospective biological control agent of yellow starthistle (C. solstitialis). Leaves of each plant were punctured with a needle and the VOCs were collected by solid-phase microextraction (SPME) periodically over 48 h and analyzed by GC–MS. A total of 49 compounds were detected. Damage caused an immediate increase of 200–600% in the composition of VOCs emitted from each plant species, and the amounts generally remained high for at least 48 h. The results indicate that a very unspecific mechanical damage can cause a prolonged change in the VOC profile of plants.
    Full-text · Article · Aug 2015 · Journal of Plant Physiology
Show more