Herbivore-induced plant volatiles responses

Dicke, M., Schutte, C. and Dijkman, H. (2000). Change in behavioral response to herbivore-induced plant volatiles in a predatory mite population. Journal of Chemical Ecology 26 1497-1514. 

Maeda, T., Takabayashi, J., Yano, S. and Takafuji, A. (1999). Response of the predatory mite, Amblyseius womersleyi (Acari Phytoseiidae), toward herbivore-induced plant volatiles variation in response between two local populations. Applied Entomology and Zoology 34 449 154. 

Margolies, D. C., Sabelis, M. W. and Boyer, J. E. (1997). Response of a phytoseiid predator to herbivore-induced plant volatiles selection on attraction and effect on prey exploitation. Journal of Insect Behavior 10 695-709. 

Attracting carnivorous natural enemies by using herbivore-induced plant volatiles Mechanisms involved in the production of herbivore-induced plant volatiles Coordination of Direct and Indirect Defense Responses Antimicrobial Chemical Defense Introduction... 

Herbivore-induced plant volatiles (HIPVs) volatile compounds produced by plants in response to herbivore attacks. 

For some herbivores, the responses to herbivore-induced plant odors differ under different circumstances. For instance, the spider mite I urticae is more attracted to healthy lima bean leaves than leaves that emit volatiles induced by spider mite infestation (Dicke, 1986 Dicke and Dijkman, 1992). However, Pallini etal. (1997) found that the same mite is attracted to cucumber plants that are already infested by conspecifics. In contrast, T urticae avoids the odor of cucumber plants under attack by the western flower thrips, FranJdiniella occidentalis, which is a herbivore but also feeds on spider mites. Bark beetles can cause strong reactions in their host trees, resulting in the emission of a blend of volatile terpenoids that, in combination with aggregation pheromenes, is used in mass attacks. These same substances may attract predators (Byers, 1989) and parasitoids (Sullivan et al, 2000 Pettersson, 2001 Pettersson et al, 2001) to infested trees. 

As yet, there is no specific pattern in how induced volatiles affect the attractiveness of plants to herbivores. Obviously, the responses will be correlated with fitness consequences. Insects vulnerable to natural enemies and induced plant toxins are, therefore, expected to avoid induced plants, whereas those that are adapted to plant defenses and/or benefit from aggregating are likely to be attracted. Comparative studies could test such hypotheses. 

This rather unspecific induction of nectar secretion in cotton was surprising in light of the fact that the induction of volatile emission by this plant had been demonstrated to be specific. Herbivore-damaged plants show a higher rate of volatile emission compared with mechanically damaged plants (McCall et al, 1994), and herbivore feeding induced de novo synthesis of various terpenoids (Pare and Tumlinson, 1997), which resulted in a quantitative as well as a qualitative response to herbivory. The specificity of the plant response is not restricted to the differentiation between mechanical damage and herbivory. The composition of the induced volatile blend also varies between (even closely related) herbivore species (De Moraes etal, 1998). 

Figure 9.1. Different defense strategies of Nicotiana plants that evolved in response to herbivore attack. Besides a specialized germination-behavior that efficiently reduces the over-all number of potential herbivores, Nicotiana plants evolved the inducible nicotine synthesis as a direct defense and the inducible emission of volatiles to attract parasitoids of the herbivore as an indirect defense. A specialized defense mechanism is triggered in response to attack by the herbivore Mctduca sexta, adapted to Nicotiana plants. Attack results in an ethylene burst, which down regulates nicotine accumulation and results in a fundamental transcriptional re-organization within the plant.

JONSSON, M., ANDERS0N, P., Electrophysiological response to herbivore-induced host plant volatiles in the moth Spodoptera littoralis. Physiol. EntomoL, 1999, 24, 377-385. 

Plants respond to the mechanical or insect herbivore damage of their tissues." During herbivorous attacks, some plants emit a specific blend of volatiles, which may result in defense responses retarding development of the herbivores or attraction of herbivore enemies to feed upon them. In lima bean leaves, the spider mite-induced volatiles, as well as infestation and artificial wounding, activate the ethylene and JA signaling pathways. ... 

Plants respond to herbivory by producing volatiles that in turn attract carnivorous natural enemies of the herbivores. These volatiles are produced by the plants as a specific response to herbivore damage or mainly as a result of mechanical damage. These so-called HIPVs attract carnivores, which in turn reduce the damage caused by herbivorous arthropods. These chemical alarm calls thus represent an example of induced indirect... 

Plant defenses contain constitutive responses and inducible responses. Two functions of the induced defense response of plants are against pathogens directly and against herbivores indirectly. Once plants are damaged by herbivorous arthropods, an induced volatile blend will be emitted so that carnivores can sense it from a distance. Indirect defenses work by attracting... 

Abstract The chapter discusses the interactions of relatively low molecular weight and largely lipophilic secondary plant metabolites with insects and some other invertebrates. This includes compounds stored within plant tissues that are toxic to insects by a range of mechanisms. It covers metabolites that are both constitutively produced and those that are induced in response to defence signalling stimuli including insect attack. Also included are volatile compounds released from plants that act as signals (semiochemicals) detected by herbivorous insects and those that interact with insects at higher trophic levels. Finally, plant to plant communication is described. 

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