Fluorescence In Situ Location Of (E)-β-farnesene (EBF) Binding Proteins (SaveOBP3/7/9) In Sitobion Avenae

The grain aphid Sitobion avenae is the dominant wheat aphid in China.It can seriously reduce yield as well as deteriorate quality of wheat by sucking phloemsap of host plant,carrying and transmitting plant virus.Odorant binding proteins(OBPs)play a vital role in olfactory recognition.The OBPs involved in the first step of the odors perception.Odors are usually volatile small molecular compounds,including plant volatiles and insect pheromones,to help insects avoiding risks and tending benefits to avoiding risks and tending benefits.(E)-β-farnesene(EBF)is a common functional component of aphid alarm pheromone.The release of EBF generally evoke defense responses and repellent behaviors of aphid.Based on the previous studies in our team,that OBP3/7/9 showed their binding properties to EBF.In present study,the ultrastructure of sensilla antennae of S.avenae was observed using a scanning electron microscopy(SEM).And the spatial expressions of OBP3/7/9 on antennae were revealed by whole mount of fluorescence in situ hybridization.The results were as fellows:1.The antennae of winged and wingless adults at 0 h,2 h,6 h and 12 h after molting were observed by SEM.The results showed that there are mainly 5 types of antennal sensilla,namely the primary rhinaria,secondary rhinaria,type I and type Ⅱ trichoid sensillum,coeloconic pegs and campaniform sensillum.The antennal sensilla(secondary sensory rhinaria)were consistent at their distribution between winged and wingless aphids,but with different number(winged type 8-12,wingless type 1-5).The results of scanning revealed that the morthology of secondary rhinaria of both phenotype had not full developed at 0 h of molting,and all sensilla had full developed after 2hours of molting.2.EBF binding protein gene Cloning.Based on the results of previous research,Save OBP3/7/9which showed their binding property to EBF were selected as target genes.the accurate sequence were identified by gene colone.3.Detection of EBF binding protein genes expression by whole-mount in situ Hybridization.The results showed that: 1).In the winged adults,Save OBP3/7/9 were expressed on the trichoid sensilla(type I,both 3rd to 5th segment;typeП,6th segment),the placoid sensilla(the primary sensory rhinaria,5th and 6th segment;the secondary sensory rhinaria,3rd segment).2).In the wingless adults.Save OBP3/9 were expressed on the trichoid sensilla(type I,4th segment;typeП,6th segment),the placoid sensilla(the primary sensory rhinaria,5th and 6th segment;the secondary sensory rhinaria,3rd segment);Save OBP7 were expressed on the trichoid sensilla(type I,4th segment;typeП,6th segment),the placoid sensilla(the primary sensory rhinaria,5th and 6th segment).