The Study Of Odorant Binding Proteins Function In Oviposition Host Selection In Females And The Study Of Their Identification

Bactrocera dorsalis (Hendel) is the major insect pests of fruit and vegetables. It has a wide host range, and can be feed with more than250kinds of fruits and vegetables, causing severe economic losses to the fruit and vegetables industry. However, there is no effective and environmentally friendly control measure currently. So,it has great practical significance to study molecular mechanism of feeding, and other behavior about B.dorsalis in order to design green and sustainable pest management strategy. The olfactory perception of insect plays an important role in maintaining their feeding, ovipositing another basic biological processes. Insects select host in the process, mainly through the olfactory receptors on the host plant volatiles in odor identification particularity to discover and reach the host plant.Insects also choose suitable spawning sites to choose suitable host for future generations. Olfactory system play a role in insect relies on a wide variety of proteins in vivo, including odorant binding protein (odorant binding proteins, OBPs), odorant receptors (olfactory receptors, ORs) and odor-degrading enzyme (odor degrading enzymes, ODEs) and so on.Which, research shows that olfactory receptors is a key molecule in signal transduction system.This study selected B.dorsalis gene transcription library in OBP as the research object, its expression pattern in B.dorsalis in different tissues using real-time quantitative PCR and other molecular biology techniques, as well as OBP in Citrus reticulate Blanco, Musa paradisiacal, Luffa cylindrica Roem and balsam pear four fruits and vegetables after processing in different tissues females expression patterns, and these four fruits and vegetables of volatile substances detected. The results not only help to improve B.dorsalis oviposition our understanding of the molecular mechanisms, but also for the prevention and treatment of B. dorsalis offers new ideas and new approaches.1. Odorant binding protein gene identification and tissue expression pattern analysisWe identified12genes homologous to Drosophila OBPs from the establishment of the laboratory that are involved in feeding and oviposition, respectively named BdorOBP1-BdorOBP12. qRT-PCR was used to analyze the tissue expression pattern of BdorOBP1-BdorOBP12. qRT-PCR revealed that each of the twelve OBPs had abundant expression in antenna, except B dor OBP7. While that among these genes,three OBP genes (BdorOBP1, BdorOBP8, BdorOBP10) were expressed much more abundantly in female antenna. The expression levels of five classic OBP genes (BdorOBP2, BdorOBP3, BdorOBP4, BdorOBP5, and BdorOBP9) were much higher in male antenna than female antenna. It is noteworthy that, BdorOBP11and BdorOBP12expression was significantly higher than in other abdominal organs, while the expression levels of the female antennae are also relatively high. BdorOBP7abundantly expressed mainly on foot Bactrocera dorsalis, the expression of the other organizations no significant difference.2. Different fruit and vegetable processing odorant binding protein expression pattern analysisAccording to the last chapter findings,we choose BdorOBP1, BdorOBP2, BdorOBP2, BdorOBP2, BdorOBP3, BdorOBP4, BdorOBP5, BdorOBP6, and BdorOBP11seven OBP genes, processed fruits and vegetables be different odorant binding protein expression pattern analysis of the experiment. Except for BdorOBP4, the rest of OBP are abundantly expressed in the B.dorsalis female head of Citrus reticulate Blanco; In addition BdorOBP5abundantly expressed in B.dorsalis females head, the rest of OBP was no significant difference in the expression of the Musa nana Lour treatment group and the control group; In Loofah of Latin treatment groups, BdorOBP3expression of the B.dorsalis females head was significantly lower than the control group, no significant difference BdorOBP6with the control group, expression levels were significantly higher than the rest of OBP; OBP in the expression levels of all treatment groups Balsam pear B.dorsalis females head was significantly higher than the control group.3. Four volatiles analysis of fruit and vegetable ingredientsWe collect volatiles of four fruits and vegetables samples by solid phase micro-extraction method,and using GC-MS technique for the analysis of volatile substances species.Detected four major components of the volatiles content exceeds1% in citrus, mainly to the diene compound;detected17major components of the volatiles, the relative content exceeds1%in Musa paradisiacal,the main components attributable to the ester compound; detected11species relative content more than1%in Luff a cylindrica Roem, representing the main component of an alcohol; balsam pear volatiles content is detected is detected, have9species more than1%of the relative content,of which the major proportion is aldehyde alcohol.Insect olfactory perception system plays an important part in its host selection process. Our results show that the odorant binding protein is highly expressed in B.dorsalis antennal and other olfactory sensors, and after handling different fruits and vegetables have significantly differentially expressed, implies OBP involved in B.dorsalis females lay eggs host location process. However, OBP and host volatiles molecular mechanism of action is unclear. B.dorsalis body contains a variety of OBP proteins, and fruits and vegetables have a variety of different volatile gas composition, Which OBP involved in specific host location specific fruits and vegetables, which volatile gases and other components involved in the transport OBP, needs further study.