Fluorescence competition assay for the assessment of green leaf volatiles and trans-β-farnesene bound to three odorant-binding proteins in the wheat aphid Sitobion avenae (Fabricius).
Odorant-binding proteins (OBPs) are important parts of insect olfactory systems, and sensitive olfaction is vital for phytophagous insects in host foraging. Electrophysiological studies are helpful in understanding olfactory sensing in Sitobion avenae (Hemiptera: Aphididae), but the functions of odorant-binding proteins in this insect are poorly understood. In this study, we used fluorescence competition assays to measure the binding specificities of SaveOBPs. The results showed that both SaveOBP2 and SaveOBP3 were superior to SaveOBP7 in binding green leaf volatiles. It was unexpected that SaveOBP7 bound trans-β-farnesene strongly, which was known as alarm pheromone of this species. Host volatiles were recognized much more easily by SaveOBP2, and the observed binding activity of SaveOBP2 equaled for tested green leaf volatiles. Our results imply that SaveOBP7 might play a more important role in aphid alarm pheromone discrimination.
State Key Laboratory for the Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China. zhongtao_069@163.com
Tao
T
Zhong
Jiao
J
Yin
Sisi
S
Deng
Kebin
K
Li
Yazhong
Y
Cao
D000595:Amino Acid Sequence; D000818:Animals; D001042:Aphids / Q000502:physiology*; D001483:Base Sequence; D015153:Blotting, Western; D003001:Cloning, Molecular; D005470:Fluorometry; D008969:Molecular Sequence Data; D010802:Phylogeny; D018515:Plant Leaves / Q000378:metabolism*; D011485:Protein Binding / Q000502:physiology; D012313:RNA / Q000737:chemistry / Q000235:genetics; D018035:Receptors, Odorant / Q000378:metabolism*; D012044:Regression Analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D012717:Sesquiterpenes / Q000378:metabolism*
D018035:Receptors, Odorant; D012717:Sesquiterpenes; C045648:odorant-binding protein; C062671:beta-farnesene; D012313:RNA