| Adelphocoris lineolatus (Hemiptera:Miridae:Adelphocoris) is one of the phytophagous pests which undergoes incomplete metamorphosis. It has a large range of plant hosts, including a variety of economic crops, like Chenopodiaceae, Fabaceae, Linaceae etc. Lately, with the widespread of Bt cotton, the population of Helicoverpa armigera Hubner and some other Lepidoptera pests have decreased dramatically while the crop damage caused by Miridae pests is increasing severely. Nowadays, based on the chemical communication mechanism, we suppress the reproduction of the pest population and reach the pest control target by regulating the chemical communication among different insects or between insect and plant. The method has become one of the research hotspots in the field of chemical ecology.The insects have gained highly specialized olfactory system in the long evolution process. Their effective perception of the information objects in the environment and timely reaction behavior in favor of survival and reproduction contributes a lot to the prosperity of insect population. The insect olfactory recognition is completed by the synergism of a series of olfactory related proteins. Those proteins include odorant binding protein (OBP), chemosensory protein (CSP), olfactory receptor (OR), sensory neuron membrane protein (SNMP) and odorant degrading enzymes (ODEs) and so on, among which, chemosensory protein is considered to be the product of the insect during the long evolution. Except the combination and transport of odorants, the chemosensory protein undertakes more physiological functions, like the regulation in the growth and development and the participation in the immunoreaction of insects. In this research, we ensured the full-length sequences of AlinCSP7-8 by screening and identifying target genes. The gene expression profiles of AlinCSP7-8 in different tissues of male and female adults A. Lineolatus was measured by the qPCR technology. We also cloned, expressed and purified the two proteins of AlinCSP7-8. Their binding properties and the location in the antennae were explored with fluorescence competitive binding assays and immunocytochemistry localization technology. The main results are as follows:1. The expression level of AlinCSP7-8 transcripts in different tissues of male and female adults A. Lineolatus were measured by qPCR.The results showed that the AlinCSP7-8 were mainly expressed in the antennae、legs and wings, while have a very low expression level in other tissues. The expression level of AlinCSP7-8 in the female adult antennae were higher than in the male adult antennae.2. AlinCSP7-8 were cloned, expressed and purified. Fluorescence Binding Assays were used to determine the binding affinities of the AlinCSP7-8 proteins to 20 candidate odorants. AlinCSP7 bound very strongly to DL-Isoborneol, Citronellol and β-ocimene, while AlinCSP8 bound very strongly to DL-Isoborneol, Citronellol and β-pinene. AlinCSP7-8 also bound to sex pheromone analogs of most plant bugs. The results suggested that AlinCSP7-8 may have functions to binding both sex pheromone and common plant volatiles.3. Immunocytochemistry were used to position AlinCSP7-8 in different antennae sensilla of male and female adult A. lineolatus. The results showed that gold particles labeled short sensilla basiconica(SSB) and long curved sensilla chaetica (LCSC), suggesting the protein expression of the CSP7-8 in these sensilla. However, sensilla trichodea(ST) and long straight sensilla chaetica (LSSC) was never labeled. The result suggested that AlinCSP7-8 may have function to perception general odorant and taste.In a word, AlinCSP7-8 play roles in the olfactory recognition. They can be the potential target to control the pest by disturbance to the location of host plants and mating of A.lineolatus. |
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