Olfactory Genes Expression And OBPs Function In Dendroctonus Valens LeConte

As one of the largest groups of animals on the earth,Insects have developed a set of sophisticated olfactory system in the long process of natural selection.Dependent on the sensitivity,specificity and other characteristics of the olfactory system,insects can finish various physiological behaviors,such as finding hosts,mates,foraging and ovipositing sites and phobotaxis by sensing and recognizing pathognostic odorants from external environment.Therefore,the olfactory system plays an important role in the survival and reproduction of insects.The red turpentine beetle(RTB),Dendroctonus valens LeConte(Coleoptera: Curculionidae: Scolytinae),is a secondary pest of pines in its native range in North of America and Canada.It is a kind of stem borers of pine needles in china.D.valens' host is Chinese pine,it is an important trunk borer and the spread rate is extremely rapid.D.valens was introduced into China in the early 1980 s,where it aggressively kills pine species native to China and has brought significant ecological and economic losses to our country.D.valens is known to use host odors and aggregation pheromones,as well as non-host volatiles,in host location and mass-attack modulation,and thus antennal olfaction is of the utmost importance for the beetles' survival and fitness.It has been proved that olfactory related genes,such as odorant binding protein gene and chemosensory protein gene,play a very important role for insects to identify and screen the external odorant.Therefore,this experiment attempts to analyze and study the olfactory system from the molecular level,so as to provide a reference for the prevention and control of the D.valens in the future.The results are as follows: 1.The expression of odorant binding proteins(OBPs)in D.valens Quantitative Real-time PCR(RT-qPCR)results showed that some DvalOBPs displayed highly antennae biased expression,expressed.Except DvalOBP6 and DvalOBP9,the other DvalOBPs displayed highly female antennae biased expression in D.valens.2.The expression of chemosensory protein(CSP)in D.valens Quantitative Real-time PCR(RT-qPCR)results showed that DvalCSPs displayed a wide range of expression distribution.DvalCSP5 were highly expressed in legs and wings,DvalCSP 4,DvalCSP5 and DvalCSP6 displayed a low expression level in antennae of D.valens.3.Functional study of odorant binding proteins(OBPs)from D.valens Through the competitive fluorescence binding assay,we researched the the ability of the two proteins,DvalOBP3 and DvalOBP16,to bind 8 odors related D.valens' substances.Experimental results show that,in the 4 the Pheromones related D.valens,the ability of DvalOBP3 to bind myrtenal is the strongest.What deserves our attention is that DvalOBP3 has not a binding reaction with myrtenol;in the 4 Host plant volatiles,the binding ability of the two proteins is similar.4.Identification and analysis of odor/xenobiotic degradation genes in D.valens There are 49 cytochrome P450s(CYP450s)and 12 Glutathione S-transferases(GSTs)were identified by analyzing the antennae transcriptome.We try to analysis the genes through an evolutionary perspective,the results showed that the conservation of cytochrome P450 gene is lower than glutathione S-transferase gene.