title: Odorant-binding proteins display high affinities for behavioral attractants and repellents in the natural predator Chrysopa pallens.
abstract: Chrysopa pallens is an important natural predator of various pests in many different cropping systems. Understanding the sophisticated olfactory system of insect antennae is crucial for studying the physiological bases of olfaction and could also help enhance the effectiveness of C. pallens in biological control. However, functional studies of the olfactory genes in C. pallens are still lacking. In this study, we cloned five odorant-binding protein (OBP) genes from C. pallens (CpalOBPs). Quantitative RT-PCR results indicated that the five CpalOBPs had different tissue expression profiles. Ligand-binding assays showed that farnesol, farnesene, cis-3-hexenyl hexanoate, geranylacetone, beta-ionone, octyl aldehyde, decanal, nerolidol (Ki<20 μM), and especially 2-pentadecanone (Ki=1.19 μM) and 2-hexyl-1-decanol (Ki=0.37 μM) strongly bound to CpalOBP2. CpalOBP15 exhibited high binding affinities for beta-ionone, 2-tridecanone, trans-nerolidol, and dodecyl aldehyde. Behavioral trials using the 14 compounds exhibiting high binding affinities for the CpalOBPs revealed that nine were able to elicit significant behavioral responses from C. pallens. Among them, farnesene and its corresponding alcohol, farnesol, elicited remarkable repellent behavioral responses from C. pallens. Our study provides several compounds that could be selected to develop slow-release agents that attract/repel C. pallens and to improve the search for strategies to eliminate insect pests.
authors: State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Henan 455000, China; College of Plant Protection, Nanjing Agricultural University, Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing 210095, China.
authors: Zhao-Qun
authors: ZQ
authors: Li
authors: State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Henan 455000, China.
authors: Shuai
authors: S
authors: Zhang
authors: State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Henan 455000, China.
authors: Jun-Yu
authors: JY
authors: Luo
authors: College of Plant Protection, Nanjing Agricultural University, Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing 210095, China.
authors: Si-Bao
authors: SB
authors: Wang
authors: College of Plant Protection, Nanjing Agricultural University, Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing 210095, China. Electronic address: sldong@njau.edu.cn.
authors: Shuang-Lin
authors: SL
authors: Dong
authors: State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Henan 455000, China. Electronic address: cuijinjie@126.com.
authors: Jin-Jie
authors: JJ
authors: Cui
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D057506:Arthropod Antennae / Q000378:metabolism; D002630:Chemotactic Factors / Q000494:pharmacology*; D017124:Conserved Sequence; D005204:Farnesol / Q000494:pharmacology; D015870:Gene Expression; D019476:Insect Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D007302:Insect Repellents / Q000494:pharmacology*; D007313:Insecta / Q000187:drug effects / Q000235:genetics* / Q000502:physiology; D008969:Molecular Sequence Data; D009928:Organ Specificity; D010802:Phylogeny; D011485:Protein Binding; D018035:Receptors, Odorant / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D012903:Smell
chemical_list: D002630:Chemotactic Factors; D019476:Insect Proteins; D007302:Insect Repellents; D018035:Receptors, Odorant; C045648:odorant-binding protein; D005204:Farnesol
keywords: Behavioral trial; Chrysopa pallens; Fluorescence binding assay; Odorant-binding protein