Molecular characterization, expression patterns, and ligand-binding properties of two odorant-binding protein genes from Orthaga achatina (Butler) (Lepidoptera: Pyralidae).
It is postulated that insect pheromone-binding proteins (PBPs) are involved in sex pheromone reception, while the general odorant-binding proteins (GOBPs) are involved in reception of the general odorants including plant volatiles. However, this functional specificity is not completely conclusive. In the present study, full-length sequences of two new OBP genes were molecularly identified as OachPBP1 and OachGOBP2 from Orthaga achatina, an important pest of the camphor tree Cinnamomum camphora. Quantification of transcript levels by qRT-PCR showed that the two genes highly expressed in antennae, with OachPBP1 male-biased and OachGOBP2 similar between sexes. These expression patterns are consistent with the generally proposed functions of PBPs and GOBPs. With the recombinant proteins obtained by a bacterial expression system, the binding specificity of these proteins was further investigated and compared using the competitive binding assay. OachPBP1 exhibited high binding affinities with all three putative sex pheromones and 10 pheromone analogs, supporting its role in pheromone reception. On the other hand, in addition to binding with some plant volatiles, OachGOBP2 surprisingly displayed similar or even higher binding affinities with the sex pheromones than OachPBP1. Therefore, we propose that OachGOBP2 might play roles in reception of sex pheromone. Additionally, plant volatiles farnesol and farnesene showed high binding with both OachGOBP2 and OachPBP1, suggesting that these volatile chemicals have regulatory functions in the behavior of O. achatina.
Education Ministry, Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing, China.
Shi-Jing
SJ
Liu
Nai-Yong
NY
Liu
Peng
P
He
Zhao-Qun
ZQ
Li
Shuang-Lin
SL
Dong
Lan-Fang
LF
Mu
D000818:Animals; D002352:Carrier Proteins / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D003001:Cloning, Molecular; D004926:Escherichia coli; D005260:Female; D005786:Gene Expression Regulation; D019476:Insect Proteins / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D008297:Male; D008969:Molecular Sequence Data; D009036:Moths / Q000378:metabolism*; D010675:Pheromones / Q000378:metabolism; D010944:Plants / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D018035:Receptors, Odorant / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D011994:Recombinant Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D017422:Sequence Analysis, DNA; D012724:Sex Attractants / Q000378:metabolism; D017678:Sex Distribution; D055549:Volatile Organic Compounds / Q000378:metabolism
D002352:Carrier Proteins; D019476:Insect Proteins; D010675:Pheromones; D018035:Receptors, Odorant; D011994:Recombinant Proteins; D012724:Sex Attractants; D055549:Volatile Organic Compounds; C010411:insect attractants; C045648:odorant-binding protein; C403713:pheromone binding protein, insect