Advances and challenges in the identification of volatiles that mediate interactions among plants and arthropods

Abstract

The relatively new research field of Chemical Ecology has, over the last two decades, revealed an important role of plant-produced volatile organic compounds (VOCs) in mediating interactions between plants and other organisms. Of particular interest are the volatile blends that plants actively emit in response to herbivore damage. Various efforts are underway to pinpoint the bioactive compounds in these complex blends, but this has proven to be exceedingly difficult. Here we give a short overview on the role of herbivore-induced plant volatiles in interactions between plants and other organisms and we review methods that are currently employed to collect and identify key volatile compounds mediating these interactions. Our perspective on future directions of this fascinating research field places special emphasis on the need for an interdisciplinary approach. Joint efforts by chemists and biologists should not only facilitate the elucidation of crucial compounds, but can also be expected to lead to an exploitation of this knowledge, whereby ecological interactions may be chemically manipulated in order to protect crops and the environment.

Fall Armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), Female Moths Respond to Herbivore-Induced Corn Volatiles

“…Fall armyworm moths were attracted to undamaged maize and mechanically damaged plants 5-6 and 24-25 h. However, no preference was exhibited between mechanically damaged plants 5-6 h and 24-25 h over undamaged plants (Fig 1). Undamaged corn plants release linalool, which is likely the compound responsible for female moth attraction (Jönsson & Anderson 1999, D'Alessandro & Turlings 2006. Mechanical damage generally does not elicit differential volatile plant blend later than 2 h unless mechanical Fig 1 Olfactory preference of Spodoptera frugiperda gravid females to volatiles emitted by undamaged corn plant (UP) and mechanically damaged corn plants (MDP) at 0-1, 5-6, and 24-25 h. All plant treatments that differed against blank (B) were compared to volatiles from undamaged plant (UP).…”

Exploiting scents of distress: the prospect of manipulating herbivore-induced plant odours to enhance the control of agricultural pests

“…For most natural enemies, the key attractants remain to be identified. In some cases, this could prove exceedingly difficult, but progress in volatile trapping, analytical methods and data processing, as well as interdisciplinary collaborations are likely to yield the desired results soon [50].…”

GC-MS Analysis of Volatile Plant Secondary Metabolites

“…In combination with conventional detectors (TCD, FID, MSD), they permit to go beyond quantification and identification of an aromatic mixture, to perform the organoleptic evaluation of all substances emerging from the chromatographic column (Sasamoto & Ochiai, 2010). The study of semiochemicals, for example, pheromones, involves the use of live detectors, in which the antenna of an insect is part of an electronic circuit which provides a highly specific signal to the pheromones relevant to that insect species (D'Alessandro & Turlings, 2006). Unsaturated and aromatic molecules may be differentiated from other mixture components when the photoionization (PI) detector is used (Lewis et al, 2010).…”