title: Molecular Basis of Alarm Pheromone Detection in Aphids.
abstract: The sesquiterpene (E)-β-farnesene (EBF) is the alarm pheromone for many species of aphids [1]. When released from aphids attacked by parasitoids or predators, it alerts nearby conspecifics to escape by walking away and dropping off the host plant [2, 3]. The reception of alarm pheromone in aphids is accomplished through a highly sensitive chemosensory system. Although olfaction-related gene families including odorant receptors (ORs) and odorant-binding proteins (OBPs) have recently been identified from aphid genomes [4-6], the cellular and molecular mechanisms of EBF reception are still largely unknown. Here we demonstrate that ApisOR5, a member of the large superfamily of odorant receptors, is expressed in large placoid sensillum neurons on the sixth antennal segment and confers response to EBF when co-expressed with Orco, an obligate odorant receptor co-receptor, in parallel heterologous expression systems. In addition, the repellent behavior of Acyrthosiphon pisum to EBF disappears after knocking down ApisOR5 by RNAi as well as two A. pisum odorant-binding proteins known to bind EBF (ApisOBP3 and ApisOBP7). Furthermore, other odorants that can also activate ApisOR5, such as geranyl acetate, significantly repel A. pisum, as does EBF. Taken together, these data allow us to conclude that ApisOR5 is essential to EBF reception in A. pisum. The characterization of the EBF receptor allows high-throughput screening of aphid repellents, providing the necessary information to develop new strategies for aphid control.
authors.affiliation: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China; College of Forestry, Northeast Forestry University, Harbin 150040, China.
authors.forename: Ruibin
authors.initials: R
authors.lastname: Zhang
authors.affiliation: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
authors.forename: Bing
authors.initials: B
authors.lastname: Wang
authors.affiliation: Department of Sciences, University of Basilicata, Potenza 85100, Italy.
authors.forename: Gerarda
authors.initials: G
authors.lastname: Grossi
authors.affiliation: Department of Sciences, University of Basilicata, Potenza 85100, Italy.
authors.forename: Patrizia
authors.initials: P
authors.lastname: Falabella
authors.affiliation: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.affiliation: College of Forestry, Northeast Forestry University, Harbin 150040, China.
authors.forename: Shanchun
authors.initials: S
authors.lastname: Yan
authors.affiliation: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China; College of Plant Science, Jilin University, Changchun 130012, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Lu
authors.affiliation: College of Plant Science, Jilin University, Changchun 130012, China.
authors.forename: Jinghui
authors.initials: J
authors.lastname: Xi
authors.affiliation: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China. Electronic address: wangguirong@caas.cn.
authors.forename: Guirong
authors.initials: G
authors.lastname: Wang
mesh_terms: D000085:Acetates / Q000378:metabolism*; D000080462:Acyclic Monoterpenes; D000818:Animals; D001042:Aphids / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D005786:Gene Expression Regulation; D057166:High-Throughput Screening Assays / Q000379:methods; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism*; D007302:Insect Repellents / Q000378:metabolism; D018035:Receptors, Odorant / Q000235:genetics / Q000378:metabolism; D012717:Sesquiterpenes / Q000032:analysis* / Q000378:metabolism*; D013729:Terpenes / Q000378:metabolism*
chemical_list: D000085:Acetates; D000080462:Acyclic Monoterpenes; D019476:Insect Proteins; D007302:Insect Repellents; D018035:Receptors, Odorant; D012717:Sesquiterpenes; D013729:Terpenes; C045648:odorant-binding protein; C062671:beta-farnesene; C432872:geranyl acetate
keywords: (E)-β-farnesene; Acyrthosiphon pisum; aphid repellent; odorant receptors; odorant-binding proteins