Cloning, Sequences Analysis And Localization In Tissues Of EβF-binding Proteins In Lipaphis Erysimi (Kaltenbach)

Olfactory system is one of the most important physiological systems for the sense of chemical communication. Acute olfaction allows insects to orientate food and mates, and hide from predators quite accurately by discriminating semiochemical cues in natural environment. EβF is one of the significant research objects for finally clarifying molecular mechanism of olfactory signal transmission in aphids. ApisOBP3and ApisOBP7from Acyrthosiphum pisum were known as its affinity to (E)-β-famesene (EBF). They are highly conserved among aphids, which indicates that this protein plays a very critical role in the process of ahpids’ olfaction. Study on insect EβF perception aids in deeper insight into behaviors of insect and answering why and how the aphids are repelled by EPF, and also supply theorical principle for refining ’Push and Pull’ strategy based on EPF for integrated pest management (IPM).The turnip aphid, Lipaphis erysimi, responds weakly to (E)-β-famesene, the main component of the most aphid alarm pheromone. But the response is substantially increased by incorporating plant-derived isothiocyanates. We treated the turnip aphid as the experimental subjects to test if the genes of OBP3and OBP7were expressed in it. Lipaphis erysimi is an important pest of vegetables. The specific reaction to EβF of Lipaphis erysimi caused our attention. And then we analyzed the LeryOBPs by bioinformatics, and the expression profiles of two OBPs in different tissues (antennae, head, thorax, abdomen, legs and embryo) and different stages of develepment were analyzed by real-time quantitative PCR.1. Two genes named LeryOBP3(KJ703012) and LeryOBP7(KJ703013) were identified in L. erysimi by molecular biological methods. And what we obtained here showed evidences at molecular level for that there are EβF binding proteins expresses in L. erysimi. The full length of LeryOBP3and LeryOBP7was357bp and468bp, encoding118aa and155aa, respectively. L. erysimi is insensitive to EβF indicated that they can detect EβF but not consider it as the main component of alarm pheromone anymore. This consist with previous thesis that EβF from L. erysimi is utilized to distinguish host plant and its conspecifics.2. The two gene sequences have high similarity comparing with other aphids. LeryOBP3and LeryOBP7conform to the typical characteristic of odorant binding protein and share high identities (94%and85%, respectively) with OBP3andOBP7from other aphids. This suggested that LeryOBPs have structural and functional characteristics of aphids OBPs. And also L. Erysimi has some differences in genetic relationship with other aphids.3. The expression profiles of the2OBPs in different tissues (head, antennae, thorax, abdomen, legs and embryo) of apterous adults and spatio-temporal expression pattern were analyzed by real-time quantitative PCR. The two genes were thought to be involved in olfactory recognition, because they both expressed in the antennae. LeryOBP7was predominantly expressed in the antennae while LeryOBP3was much higher in the leg tissues. The obvious expression peak of both OBPs appears at adults during the whole developmental stage suggested that they may play important roles in the host-seeking of the apterous adults.