| 1. |
- Bichao, H., et al.
(author)
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Five types of olfactory receptor neurons in the strawberry blossom weevil Anthonomus rubi : Selective responses to inducible host-plant volatiles
- 2005
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In: Chemical Senses. - : Oxford University Press (OUP). - 0379-864X .- 1464-3553. ; 30:2, s. 153-170
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Journal article (peer-reviewed)abstract
- Plants release hundreds of volatiles that are important in the interaction with herbivorous animals, but which odorants are detected by which species? In this study, single receptor neurons on the antenna of the oligophagous strawberry blossom weevil Anthonomus rubi were screened for sensitivity to naturally produced plant compounds by the use of gas chromatography linked to electrophysiological recordings from single cells. The narrow tuning of the neurons was demonstrated by responses solely to a few structurally related sesquiterpenes, aromatics or monoterpene hydrocarbons out of hundreds of plant constituents tested. We present five olfactory receptor neuron types, identified according to one primary odorant i.e. the compound to which the neurons are most sensitive. These odorants, (-)-germacrene D, (-)-beta-caryophyllene, methyl salicylate, E-beta-ocimene and (3E)-4,8-dimethyl-1,3,7-nonatriene, present in the intact strawberry plant, are induced in higher amounts by weevil feeding. This suggests that these compounds can provide information about the presence of conspecifics. We used protocols especially designed to allow comparison with previously investigated species. Striking similarities, but also differences, are demonstrated between receptor neuron specificity in the strawberry weevil and moths.
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| 2. |
- Bichao, H., et al.
(author)
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Identification of plant odours activating receptor neurones in the weevil Pissodes notatus F. (Coleoptera, Curculionidae)
- 2003
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In: Journal of Comparative Physiology A. Sensory, neural, and behavioral physiology. - : Springer Science and Business Media LLC. - 0340-7594 .- 1432-1351. ; 189:3, s. 203-212
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Journal article (peer-reviewed)abstract
- Plants release complex mixtures of volatiles important in the interaction with insects and other organisms. In the search for compounds that contribute to the perception of odour quality in the weevil Pissodes notatus, single olfactory receptor neurones on the antennae were screened for sensitivity to naturally produced plant volatiles by the use of gas chromatography linked to single cell recordings. We here present 60 olfactory neurones responding to 25 of the numerous compounds released by host and non-host plants. All the neurones show high selectivity and are classified into 12 distinct types. The two most abundant types respond to alpha-pinene, beta-pinene, and 3-carene (n = 17), and to isopinocamphone and pinocamphone (n = 17), respectively. Other neurone types respond to limonene (n = 9), beta-phellandrene (n = 3), and fenchone (n = 4). Responses to beta-caryophyllene (n = 1) and to ethanol (n = 4) are also shown. Except for two pairs, the neurone types do not show overlap of the molecular receptive range. The active compounds are present in the host, Pinus pinaster, as well as in non-hosts, supporting the idea that plant odour quality is mediated by the ratio of the compounds rather than specific odorants.
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| 3. |
- Bichao, H., et al.
(author)
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Molecular receptive ranges of olfactory receptor neurones responding selectively to terpenoids, aliphatic green leaf volatiles and aromatic compounds, in the strawberry blossom weevil Anthonomus rubi
- 2005
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In: Chemoecology. - : Springer Science and Business Media LLC. - 0937-7409 .- 1423-0445. ; 15:4, s. 211-226
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Journal article (peer-reviewed)abstract
- An important question in insect-plant interactions is which of the numerous plant compounds contribute to the perception of odour qualities in herbivorous insects and are likely to be used as cues in host-searching behaviour. In order to identify which plant-produced volatiles the strawberry blossom weevil Anthonomus rubi detects, we have used electrophysiological recordings from single olfactory neurones linked to gas chromatography and mass spectrometry. We here present 15 receptor neurone types specialised for naturally produced compounds present in the host and nonhost plants and two types for two aggregation pheromone components. The active compounds were terpenoids, aromatic and aliphatic esters, alcohols and aldehydes, some of which are induced by feeding activity of the weevils. The neurones were characterised by a strong response to one or two primary odorants and weaker responses to a few others having similar chemical structure. With one exception, the molecular receptive range of each neurone type was within one chemical group. Enantiomers of linalool separated on a chiral column activated two neurone types with different enantioselectivity. Inhibition by linalool of another neurone type, excited by alpha-pinene, indicated an additional mechanism for coding the information about this compound. Altogether, detection of 54 compounds by olfactory receptor neurones is shown, of which 40 have been chemically identified in this study. Thus A. rubi has the ability to detect a large number of odorants that may be used in host selection behaviour.
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