title: Tetranychus urticae-triggered responses promote genotype-dependent conspecific repellence or attractiveness in citrus.
abstract: The citrus rootstocks sour orange and Cleopatra mandarin display differential resistance against Tetranychus urticae. Sour orange plants support reduced oviposition, growth rates and damage compared with Cleopatra mandarin plants. Jasmonic acid signalling and flavonoid accumulation have been revealed as key mechanisms for the enhanced resistance of sour orange plants. In this study, we observed that the release of T. urticae herbivore-induced plant volatiles (HIPVs) from sour orange plants has a marked repellent effect on conspecific mites associated with the production of the terpenes α-ocimene, α-farnesene, pinene and d-limonene, and the green leaf volatile 4-hydroxy-4-methyl-2-pentanone. By contrast, T. urticae HIPVs from Cleopatra mandarin plants promote conspecific mite attraction associated with an increase in (2-butoxyethoxy) ethanol, benzaldehyde and methyl salicylate levels. HIPVs released from sour orange plants following T. urticae infestation induce resistance in Cleopatra mandarin plants, thereby reducing oviposition rates and stimulating the oxylipin biosynthetic gene lipoxygenase2 (LOX2). Cleopatra HIPVs do not affect the response to T. urticae of these rootstocks. We conclude that sour orange plants promote herbivore-induced resistance in Cleopatra mandarin plants and, despite the weak basal resistance of these rootstocks, herbivore resistance can be induced through the combination of HIPVs, such as α-ocimene and d-limonene.
authors.affiliation: Departament de Ciències Agràries i del Medi Natural, Unitat Associada d'Entomologia IVIA-UJI, Universitat Jaume I (UJI), Campus del Riu Sec, E-12071, Castelló de la Plana, Spain.|Departament de Ciències Agràries i del Medi Natural, Metabolic Integration and Cell Signalling Group, Universitat Jaume I (UJI), Campus del Riu Sec, E-12071, Castelló de la Plana, Spain.
authors.forename: Blas
authors.initials: B
authors.lastname: Agut
authors.affiliation: Departament de Ciències Agràries i del Medi Natural, Metabolic Integration and Cell Signalling Group, Universitat Jaume I (UJI), Campus del Riu Sec, E-12071, Castelló de la Plana, Spain.
authors.forename: Jordi
authors.initials: J
authors.lastname: Gamir
authors.affiliation: Departament de Ciències Agràries i del Medi Natural, Unitat Associada d'Entomologia IVIA-UJI, Universitat Jaume I (UJI), Campus del Riu Sec, E-12071, Castelló de la Plana, Spain.
authors.forename: Josep A
authors.initials: JA
authors.lastname: Jaques
authors.affiliation: Departament de Ciències Agràries i del Medi Natural, Metabolic Integration and Cell Signalling Group, Universitat Jaume I (UJI), Campus del Riu Sec, E-12071, Castelló de la Plana, Spain.
authors.forename: Victor
authors.initials: V
authors.lastname: Flors
mesh_terms: D000818:Animals; D002851:Chromatography, High Pressure Liquid; D002957:Citrus / Q000187:drug effects / Q000235:genetics* / Q000469:parasitology*; D003517:Cyclopentanes / Q000494:pharmacology; D060467:Disease Resistance; D005231:Fatty Acids, Unsaturated / Q000494:pharmacology; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D005838:Genotype; D060434:Herbivory / Q000187:drug effects; D007302:Insect Repellents / Q000494:pharmacology*; D055432:Metabolomics; D054883:Oxylipins / Q000494:pharmacology; D010935:Plant Diseases / Q000469:parasitology; D010940:Plant Proteins / Q000378:metabolism; D020156:Salicylic Acid / Q000494:pharmacology; D012903:Smell / Q000187:drug effects / Q000502:physiology; D040102:Tetranychidae / Q000502:physiology*; D014835:Volatilization
chemical_list: D003517:Cyclopentanes; D005231:Fatty Acids, Unsaturated; D007302:Insect Repellents; D054883:Oxylipins; D010940:Plant Proteins; C025999:12-oxophytodienoic acid; C011006:jasmonic acid; D020156:Salicylic Acid
keywords: Tetranychus urticae; citrus; herbivore-induced plant volatiles (HIPVs); induced resistance; metabolomics; volatile organic compounds (VOCs)